Suggest using go-toml v2

Refs #450

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,9 +1,18 @@
 ---
 name: Bug report
 about: Create a report to help us improve
-
 ---
 
+<!--
+‼️ Main development focus is on the upcoming go-toml v2 ⚠️
+
+As a result, v1.x bugs will likely not see a fix on a v1.x version.
+However, reporting the bug is the best way to ensure that it will be fixed in v2.
+
+See https://github.com/pelletier/go-toml/discussions/506.
+-->
+
+
 **Describe the bug**
 A clear and concise description of what the bug is.
 
@@ -14,7 +23,7 @@ Steps to reproduce the behavior. Including TOML files.
 A clear and concise description of what you expected to happen, if other than "should work".
 
 **Versions**
- - go-toml: version (git sha)
+ - go-toml: version (or git sha)
  - go: version
  - operating system: e.g. macOS, Windows, Linux
 

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,17 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for this project
-
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+- package-ecosystem: gomod
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "13:00"
+  open-pull-requests-limit: 10

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,67 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '26 19 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

CONTRIBUTING.md

@@ -28,7 +28,7 @@ improve the documentation. Fix a typo, clarify an interface, add an
 example, anything goes!
 
 The documentation is present in the [README][readme] and thorough the
-source code. On release, it gets updated on [GoDoc][godoc]. To make a
+source code. On release, it gets updated on [pkg.go.dev][pkg.go.dev]. To make a
 change to the documentation, create a pull request with your proposed
 changes. For simple changes like that, the easiest way to go is probably
 the "Fork this project and edit the file" button on Github, displayed at
@@ -123,7 +123,7 @@ Checklist:
 
 [issues-tracker]: https://github.com/pelletier/go-toml/issues
 [bug-report]: https://github.com/pelletier/go-toml/issues/new?template=bug_report.md
-[godoc]: https://godoc.org/github.com/pelletier/go-toml
+[pkg.go.dev]: https://pkg.go.dev/github.com/pelletier/go-toml
 [readme]: ./README.md
 [fork]: https://help.github.com/articles/fork-a-repo
 [pull-request]: https://help.github.com/en/articles/creating-a-pull-request

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2013 - 2017 Thomas Pelletier, Eric Anderton
+Copyright (c) 2013 - 2021 Thomas Pelletier, Eric Anderton
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,17 +1,42 @@
 # go-toml
 
-Go library for the [TOML](https://github.com/mojombo/toml) format.
+Go library for the [TOML](https://toml.io/) format.
 
 This library supports TOML version
-[v1.0.0-rc.1](https://github.com/toml-lang/toml/blob/master/versions/en/toml-v1.0.0-rc.1.md)
+[v1.0.0-rc.3](https://toml.io/en/v1.0.0-rc.3)
 
-[![GoDoc](https://godoc.org/github.com/pelletier/go-toml?status.svg)](http://godoc.org/github.com/pelletier/go-toml)
+[![Go Reference](https://pkg.go.dev/badge/github.com/pelletier/go-toml.svg)](https://pkg.go.dev/github.com/pelletier/go-toml)
 [![license](https://img.shields.io/github/license/pelletier/go-toml.svg)](https://github.com/pelletier/go-toml/blob/master/LICENSE)
 [![Build Status](https://dev.azure.com/pelletierthomas/go-toml-ci/_apis/build/status/pelletier.go-toml?branchName=master)](https://dev.azure.com/pelletierthomas/go-toml-ci/_build/latest?definitionId=1&branchName=master)
 [![codecov](https://codecov.io/gh/pelletier/go-toml/branch/master/graph/badge.svg)](https://codecov.io/gh/pelletier/go-toml)
 [![Go Report Card](https://goreportcard.com/badge/github.com/pelletier/go-toml)](https://goreportcard.com/report/github.com/pelletier/go-toml)
 [![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fpelletier%2Fgo-toml.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fpelletier%2Fgo-toml?ref=badge_shield)
 
+
+## Development status
+
+**ℹ️ Consider go-toml v2!**
+
+The next version of go-toml is in [active development][v2-dev], and
+[nearing completion][v2-map].
+
+Though technically in beta, v2 is already more tested, [fixes bugs][v1-bugs],
+and [much faster][v2-bench]. If you only need reading and writing TOML documents
+(majority of cases), those features are implemented and the API unlikely to
+change.
+
+The remaining features (Document structure editing and tooling) will be added
+shortly. While pull-requests are welcome on v1, no active development is
+expected on it. When v2.0.0 is released, v1 will be deprecated.
+
+👉 [go-toml v2][v2]
+
+[v2]: https://github.com/pelletier/go-toml/tree/v2
+[v2-map]: https://github.com/pelletier/go-toml/discussions/506
+[v2-dev]: https://github.com/pelletier/go-toml/tree/v2
+[v1-bugs]: https://github.com/pelletier/go-toml/issues?q=is%3Aissue+is%3Aopen+label%3Av2-fixed
+[v2-bench]: https://github.com/pelletier/go-toml/tree/v2#benchmarks
+
 ## Features
 
 Go-toml provides the following features for using data parsed from TOML documents:
@@ -81,11 +106,11 @@ for ii, item := range results.Values() {
 ## Documentation
 
 The documentation and additional examples are available at
-[godoc.org](http://godoc.org/github.com/pelletier/go-toml).
+[pkg.go.dev](https://pkg.go.dev/github.com/pelletier/go-toml).
 
 ## Tools
 
-Go-toml provides two handy command line tools:
+Go-toml provides three handy command line tools:
 
 * `tomll`: Reads TOML files and lints them.
 
@@ -109,7 +134,7 @@ Go-toml provides two handy command line tools:
 
 ### Docker image
 
-Those tools are also availble as a Docker image from
+Those tools are also available as a Docker image from
 [dockerhub](https://hub.docker.com/r/pelletier/go-toml). For example, to
 use `tomljson`:
 

azure-pipelines.yml

@@ -2,30 +2,6 @@ trigger:
 - master
 
 stages:
-- stage: fuzzit
-  displayName: "Run Fuzzit"
-  dependsOn: []
-  condition: and(succeeded(), eq(variables['Build.SourceBranchName'], 'master'))
-  jobs:
-  - job: submit
-    displayName: "Submit"
-    pool:
-      vmImage: ubuntu-latest
-    steps:
-    - task: GoTool@0
-      displayName: "Install Go 1.14"
-      inputs:
-        version: "1.14"
-    - script: echo "##vso[task.setvariable variable=PATH]${PATH}:/home/vsts/go/bin/"
-    - script: mkdir -p ${HOME}/go/src/github.com/pelletier/go-toml
-    - script: cp -R . ${HOME}/go/src/github.com/pelletier/go-toml
-    - task: Bash@3
-      inputs:
-        filePath: './fuzzit.sh'
-      env:
-        TYPE: fuzzing
-        FUZZIT_API_KEY: $(FUZZIT_API_KEY)
-
 - stage: run_checks
   displayName: "Check"
   dependsOn: []
@@ -36,9 +12,9 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.14"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.14"
+        version: "1.16"
     - task: Go@0
       displayName: "go fmt ./..."
       inputs:
@@ -51,9 +27,9 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.14"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.14"
+        version: "1.16"
     - task: Go@0
       displayName: "Generate coverage"
       inputs:
@@ -71,54 +47,36 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.14"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.14"
+        version: "1.16"
     - script: echo "##vso[task.setvariable variable=PATH]${PATH}:/home/vsts/go/bin/"
     - task: Bash@3
       inputs:
         filePath: './benchmark.sh'
         arguments: "master $(Build.Repository.Uri)"
 
-  - job: fuzzing
-    displayName: "fuzzing"
-    pool:
-      vmImage: ubuntu-latest
-    steps:
-    - task: GoTool@0
-      displayName: "Install Go 1.14"
-      inputs:
-        version: "1.14"
-    - script: echo "##vso[task.setvariable variable=PATH]${PATH}:/home/vsts/go/bin/"
-    - script: mkdir -p ${HOME}/go/src/github.com/pelletier/go-toml
-    - script: cp -R . ${HOME}/go/src/github.com/pelletier/go-toml
-    - task: Bash@3
-      inputs:
-        filePath: './fuzzit.sh'
-      env:
-        TYPE: local-regression
-
   - job: go_unit_tests
     displayName: "unit tests"
     strategy:
       matrix:
-        linux 1.14:
+        linux 1.16:
-          goVersion: '1.14'
+          goVersion: '1.16'
           imageName: 'ubuntu-latest'
-        mac 1.14:
+        mac 1.16:
-          goVersion: '1.14'
+          goVersion: '1.16'
           imageName: 'macOS-latest'
-        windows 1.14:
+        windows 1.16:
-          goVersion: '1.14'
+          goVersion: '1.16'
           imageName: 'windows-latest'
-        linux 1.13:
+        linux 1.15:
-          goVersion: '1.13'
+          goVersion: '1.15'
           imageName: 'ubuntu-latest'
-        mac 1.13:
+        mac 1.15:
-          goVersion: '1.13'
+          goVersion: '1.15'
           imageName: 'macOS-latest'
-        windows 1.13:
+        windows 1.15:
-          goVersion: '1.13'
+          goVersion: '1.15'
           imageName: 'windows-latest'
     pool:
       vmImage: $(imageName)
@@ -155,7 +113,7 @@ stages:
     - task: GoTool@0
       displayName: "Install Go"
       inputs:
-        version: 1.14
+        version: 1.16
     - task: Bash@3
       inputs:
         targetType: inline

benchmark.sh

@@ -20,11 +20,15 @@ git clone ${reference_git} ${ref_tempdir} >/dev/null 2>/dev/null
 pushd ${ref_tempdir} >/dev/null
 git checkout ${reference_ref} >/dev/null 2>/dev/null
 go test -bench=. -benchmem | tee ${ref_benchmark}
+cd benchmark
+go test -bench=. -benchmem | tee -a ${ref_benchmark}
 popd >/dev/null
 
 echo ""
 echo "=== local"
 go test -bench=. -benchmem  | tee ${local_benchmark}
+cd benchmark
+go test -bench=. -benchmem | tee -a ${local_benchmark}
 
 echo ""
 echo "=== diff"

benchmark/benchmark_test.go

@@ -1,4 +1,4 @@
-package toml
+package benchmark
 
 import (
 	"bytes"
@@ -8,7 +8,8 @@ import (
 	"time"
 
 	burntsushi "github.com/BurntSushi/toml"
-	yaml "gopkg.in/yaml.v2"
+	"github.com/pelletier/go-toml"
+	"gopkg.in/yaml.v2"
 )
 
 type benchmarkDoc struct {
@@ -124,7 +125,7 @@ func BenchmarkParseToml(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_, err := LoadReader(bytes.NewReader(fileBytes))
+		_, err := toml.LoadReader(bytes.NewReader(fileBytes))
 		if err != nil {
 			b.Fatal(err)
 		}
@@ -136,10 +137,11 @@ func BenchmarkUnmarshalToml(b *testing.B) {
 	if err != nil {
 		b.Fatal(err)
 	}
+	b.ReportAllocs()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		target := benchmarkDoc{}
-		err := Unmarshal(bytes, &target)
+		err := toml.Unmarshal(bytes, &target)
 		if err != nil {
 			b.Fatal(err)
 		}

benchmark/go.mod

@@ -0,0 +1,11 @@
+module github.com/pelletier/go-toml/benchmark
+
+go 1.12
+
+require (
+	github.com/BurntSushi/toml v0.3.1
+	github.com/pelletier/go-toml v0.0.0
+	gopkg.in/yaml.v2 v2.3.0
+)
+
+replace github.com/pelletier/go-toml => ../

benchmark/go.sum

@@ -0,0 +1,6 @@
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

fuzzit.sh

@@ -1,26 +0,0 @@
-#!/bin/bash
-set -xe
-
-# go-fuzz doesn't support modules yet, so ensure we do everything
-# in the old style GOPATH way
-export GO111MODULE="off"
-
-# install go-fuzz
-go get -u github.com/dvyukov/go-fuzz/go-fuzz github.com/dvyukov/go-fuzz/go-fuzz-build
-
-# target name can only contain lower-case letters (a-z), digits (0-9) and a dash (-)
-# to add another target, make sure to create it with `fuzzit create target`
-# before using `fuzzit create job`
-TARGET=toml-fuzzer
-
-go-fuzz-build -libfuzzer -o ${TARGET}.a github.com/pelletier/go-toml
-clang -fsanitize=fuzzer ${TARGET}.a -o ${TARGET}
-
-# install fuzzit for talking to fuzzit.dev service
-# or latest version:
-# https://github.com/fuzzitdev/fuzzit/releases/latest/download/fuzzit_Linux_x86_64
-wget -q -O fuzzit https://github.com/fuzzitdev/fuzzit/releases/download/v2.4.52/fuzzit_Linux_x86_64
-chmod a+x fuzzit
-
-# TODO: change kkowalczyk to go-toml and create toml-fuzzer target there
-./fuzzit create job --type $TYPE go-toml/${TARGET} ${TARGET}

go.mod

@@ -1,9 +1,3 @@
 module github.com/pelletier/go-toml
 
 go 1.12
-
-require (
-	github.com/BurntSushi/toml v0.3.1
-	github.com/davecgh/go-spew v1.1.1
-	gopkg.in/yaml.v2 v2.3.0
-)

go.sum

@@ -1,19 +0,0 @@
-github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
-github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.3 h1:fvjTMHxHEw/mxHbtzPi3JCcKXQRAnQTBRo6YCJSVHKI=
-gopkg.in/yaml.v2 v2.2.3/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
-gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.5 h1:ymVxjfMaHvXD8RqPRmzHHsB3VvucivSkIAvJFDI5O3c=
-gopkg.in/yaml.v2 v2.2.5/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.7 h1:VUgggvou5XRW9mHwD/yXxIYSMtY0zoKQf/v226p2nyo=
-gopkg.in/yaml.v2 v2.2.7/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
-gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

lexer.go

@@ -9,13 +9,10 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"regexp"
 	"strconv"
 	"strings"
 )
 
-var dateRegexp *regexp.Regexp
-
 // Define state functions
 type tomlLexStateFn func() tomlLexStateFn
 
@@ -216,18 +213,12 @@ func (l *tomlLexer) lexRvalue() tomlLexStateFn {
 			break
 		}
 
-		possibleDate := l.peekString(35)
+		if next == '+' || next == '-' {
-		dateSubmatches := dateRegexp.FindStringSubmatch(possibleDate)
+			return l.lexNumber
-		if dateSubmatches != nil && dateSubmatches[0] != "" {
-			l.fastForward(len(dateSubmatches[0]))
-			if dateSubmatches[2] == "" { // no timezone information => local date
-				return l.lexLocalDate
-			}
-			return l.lexDate
 		}
 
-		if next == '+' || next == '-' || isDigit(next) {
+		if isDigit(next) {
-			return l.lexNumber
+			return l.lexDateTimeOrNumber
 		}
 
 		return l.errorf("no value can start with %c", next)
@@ -237,6 +228,32 @@ func (l *tomlLexer) lexRvalue() tomlLexStateFn {
 	return nil
 }
 
+func (l *tomlLexer) lexDateTimeOrNumber() tomlLexStateFn {
+	// Could be either a date/time, or a digit.
+	// The options for date/times are:
+	//   YYYY-... => date or date-time
+	//   HH:... => time
+	// Anything else should be a number.
+
+	lookAhead := l.peekString(5)
+	if len(lookAhead) < 3 {
+		return l.lexNumber()
+	}
+
+	for idx, r := range lookAhead {
+		if !isDigit(r) {
+			if idx == 2 && r == ':' {
+				return l.lexDateTimeOrTime()
+			}
+			if idx == 4 && r == '-' {
+				return l.lexDateTimeOrTime()
+			}
+			return l.lexNumber()
+		}
+	}
+	return l.lexNumber()
+}
+
 func (l *tomlLexer) lexLeftCurlyBrace() tomlLexStateFn {
 	l.next()
 	l.emit(tokenLeftCurlyBrace)
@@ -254,14 +271,245 @@ func (l *tomlLexer) lexRightCurlyBrace() tomlLexStateFn {
 	return l.lexRvalue
 }
 
-func (l *tomlLexer) lexDate() tomlLexStateFn {
+func (l *tomlLexer) lexDateTimeOrTime() tomlLexStateFn {
-	l.emit(tokenDate)
+	// Example matches:
+	// 1979-05-27T07:32:00Z
+	// 1979-05-27T00:32:00-07:00
+	// 1979-05-27T00:32:00.999999-07:00
+	// 1979-05-27 07:32:00Z
+	// 1979-05-27 00:32:00-07:00
+	// 1979-05-27 00:32:00.999999-07:00
+	// 1979-05-27T07:32:00
+	// 1979-05-27T00:32:00.999999
+	// 1979-05-27 07:32:00
+	// 1979-05-27 00:32:00.999999
+	// 1979-05-27
+	// 07:32:00
+	// 00:32:00.999999
+
+	// we already know those two are digits
+	l.next()
+	l.next()
+
+	// Got 2 digits. At that point it could be either a time or a date(-time).
+
+	r := l.next()
+	if r == ':' {
+		return l.lexTime()
+	}
+
+	return l.lexDateTime()
+}
+
+func (l *tomlLexer) lexDateTime() tomlLexStateFn {
+	// This state accepts an offset date-time, a local date-time, or a local date.
+	//
+	//   v--- cursor
+	// 1979-05-27T07:32:00Z
+	// 1979-05-27T00:32:00-07:00
+	// 1979-05-27T00:32:00.999999-07:00
+	// 1979-05-27 07:32:00Z
+	// 1979-05-27 00:32:00-07:00
+	// 1979-05-27 00:32:00.999999-07:00
+	// 1979-05-27T07:32:00
+	// 1979-05-27T00:32:00.999999
+	// 1979-05-27 07:32:00
+	// 1979-05-27 00:32:00.999999
+	// 1979-05-27
+
+	// date
+
+	// already checked by lexRvalue
+	l.next() // digit
+	l.next() // -
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid month digit in date: %c", r)
+		}
+	}
+
+	r := l.next()
+	if r != '-' {
+		return l.errorf("expected - to separate month of a date, not %c", r)
+	}
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid day digit in date: %c", r)
+		}
+	}
+
+	l.emit(tokenLocalDate)
+
+	r = l.peek()
+
+	if r == eof {
+
+		return l.lexRvalue
+	}
+
+	if r != ' ' && r != 'T' {
+		return l.errorf("incorrect date/time separation character: %c", r)
+	}
+
+	if r == ' ' {
+		lookAhead := l.peekString(3)[1:]
+		if len(lookAhead) < 2 {
+			return l.lexRvalue
+		}
+		for _, r := range lookAhead {
+			if !isDigit(r) {
+				return l.lexRvalue
+			}
+		}
+	}
+
+	l.skip() // skip the T or ' '
+
+	// time
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid hour digit in time: %c", r)
+		}
+	}
+
+	r = l.next()
+	if r != ':' {
+		return l.errorf("time hour/minute separator should be :, not %c", r)
+	}
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid minute digit in time: %c", r)
+		}
+	}
+
+	r = l.next()
+	if r != ':' {
+		return l.errorf("time minute/second separator should be :, not %c", r)
+	}
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid second digit in time: %c", r)
+		}
+	}
+
+	r = l.peek()
+	if r == '.' {
+		l.next()
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("expected at least one digit in time's fraction, not %c", r)
+		}
+
+		for {
+			r := l.peek()
+			if !isDigit(r) {
+				break
+			}
+			l.next()
+		}
+	}
+
+	l.emit(tokenLocalTime)
+
+	return l.lexTimeOffset
+
+}
+
+func (l *tomlLexer) lexTimeOffset() tomlLexStateFn {
+	// potential offset
+
+	// Z
+	// -07:00
+	// +07:00
+	// nothing
+
+	r := l.peek()
+
+	if r == 'Z' {
+		l.next()
+		l.emit(tokenTimeOffset)
+	} else if r == '+' || r == '-' {
+		l.next()
+
+		for i := 0; i < 2; i++ {
+			r := l.next()
+			if !isDigit(r) {
+				return l.errorf("invalid hour digit in time offset: %c", r)
+			}
+		}
+
+		r = l.next()
+		if r != ':' {
+			return l.errorf("time offset hour/minute separator should be :, not %c", r)
+		}
+
+		for i := 0; i < 2; i++ {
+			r := l.next()
+			if !isDigit(r) {
+				return l.errorf("invalid minute digit in time offset: %c", r)
+			}
+		}
+
+		l.emit(tokenTimeOffset)
+	}
+
 	return l.lexRvalue
 }
 
-func (l *tomlLexer) lexLocalDate() tomlLexStateFn {
+func (l *tomlLexer) lexTime() tomlLexStateFn {
-	l.emit(tokenLocalDate)
+	//   v--- cursor
+	// 07:32:00
+	// 00:32:00.999999
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid minute digit in time: %c", r)
+		}
+	}
+
+	r := l.next()
+	if r != ':' {
+		return l.errorf("time minute/second separator should be :, not %c", r)
+	}
+
+	for i := 0; i < 2; i++ {
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("invalid second digit in time: %c", r)
+		}
+	}
+
+	r = l.peek()
+	if r == '.' {
+		l.next()
+		r := l.next()
+		if !isDigit(r) {
+			return l.errorf("expected at least one digit in time's fraction, not %c", r)
+		}
+
+		for {
+			r := l.peek()
+			if !isDigit(r) {
+				break
+			}
+			l.next()
+		}
+	}
+
+	l.emit(tokenLocalTime)
 	return l.lexRvalue
+
 }
 
 func (l *tomlLexer) lexTrue() tomlLexStateFn {
@@ -306,7 +554,7 @@ func (l *tomlLexer) lexComma() tomlLexStateFn {
 // Parse the key and emits its value without escape sequences.
 // bare keys, basic string keys and literal string keys are supported.
 func (l *tomlLexer) lexKey() tomlLexStateFn {
-	growingString := ""
+	var sb strings.Builder
 
 	for r := l.peek(); isKeyChar(r) || r == '\n' || r == '\r'; r = l.peek() {
 		if r == '"' {
@@ -315,7 +563,9 @@ func (l *tomlLexer) lexKey() tomlLexStateFn {
 			if err != nil {
 				return l.errorf(err.Error())
 			}
-			growingString += "\"" + str + "\""
+			sb.WriteString("\"")
+			sb.WriteString(str)
+			sb.WriteString("\"")
 			l.next()
 			continue
 		} else if r == '\'' {
@@ -324,41 +574,45 @@ func (l *tomlLexer) lexKey() tomlLexStateFn {
 			if err != nil {
 				return l.errorf(err.Error())
 			}
-			growingString += "'" + str + "'"
+			sb.WriteString("'")
+			sb.WriteString(str)
+			sb.WriteString("'")
 			l.next()
 			continue
 		} else if r == '\n' {
 			return l.errorf("keys cannot contain new lines")
 		} else if isSpace(r) {
-			str := " "
+			var str strings.Builder
+			str.WriteString(" ")
+
 			// skip trailing whitespace
 			l.next()
 			for r = l.peek(); isSpace(r); r = l.peek() {
-				str += string(r)
+				str.WriteRune(r)
 				l.next()
 			}
 			// break loop if not a dot
 			if r != '.' {
 				break
 			}
-			str += "."
+			str.WriteString(".")
 			// skip trailing whitespace after dot
 			l.next()
 			for r = l.peek(); isSpace(r); r = l.peek() {
-				str += string(r)
+				str.WriteRune(r)
 				l.next()
 			}
-			growingString += str
+			sb.WriteString(str.String())
 			continue
 		} else if r == '.' {
 			// skip
 		} else if !isValidBareChar(r) {
 			return l.errorf("keys cannot contain %c character", r)
 		}
-		growingString += string(r)
+		sb.WriteRune(r)
 		l.next()
 	}
-	l.emitWithValue(tokenKey, growingString)
+	l.emitWithValue(tokenKey, sb.String())
 	return l.lexVoid
 }
 
@@ -383,7 +637,7 @@ func (l *tomlLexer) lexLeftBracket() tomlLexStateFn {
 }
 
 func (l *tomlLexer) lexLiteralStringAsString(terminator string, discardLeadingNewLine bool) (string, error) {
-	growingString := ""
+	var sb strings.Builder
 
 	if discardLeadingNewLine {
 		if l.follow("\r\n") {
@@ -397,14 +651,14 @@ func (l *tomlLexer) lexLiteralStringAsString(terminator string, discardLeadingNe
 	// find end of string
 	for {
 		if l.follow(terminator) {
-			return growingString, nil
+			return sb.String(), nil
 		}
 
 		next := l.peek()
 		if next == eof {
 			break
 		}
-		growingString += string(l.next())
+		sb.WriteRune(l.next())
 	}
 
 	return "", errors.New("unclosed string")
@@ -438,7 +692,7 @@ func (l *tomlLexer) lexLiteralString() tomlLexStateFn {
 // Terminator is the substring indicating the end of the token.
 // The resulting string does not include the terminator.
 func (l *tomlLexer) lexStringAsString(terminator string, discardLeadingNewLine, acceptNewLines bool) (string, error) {
-	growingString := ""
+	var sb strings.Builder
 
 	if discardLeadingNewLine {
 		if l.follow("\r\n") {
@@ -451,7 +705,7 @@ func (l *tomlLexer) lexStringAsString(terminator string, discardLeadingNewLine,
 
 	for {
 		if l.follow(terminator) {
-			return growingString, nil
+			return sb.String(), nil
 		}
 
 		if l.follow("\\") {
@@ -469,61 +723,61 @@ func (l *tomlLexer) lexStringAsString(terminator string, discardLeadingNewLine,
 					l.next()
 				}
 			case '"':
-				growingString += "\""
+				sb.WriteString("\"")
 				l.next()
 			case 'n':
-				growingString += "\n"
+				sb.WriteString("\n")
 				l.next()
 			case 'b':
-				growingString += "\b"
+				sb.WriteString("\b")
 				l.next()
 			case 'f':
-				growingString += "\f"
+				sb.WriteString("\f")
 				l.next()
 			case '/':
-				growingString += "/"
+				sb.WriteString("/")
 				l.next()
 			case 't':
-				growingString += "\t"
+				sb.WriteString("\t")
 				l.next()
 			case 'r':
-				growingString += "\r"
+				sb.WriteString("\r")
 				l.next()
 			case '\\':
-				growingString += "\\"
+				sb.WriteString("\\")
 				l.next()
 			case 'u':
 				l.next()
-				code := ""
+				var code strings.Builder
 				for i := 0; i < 4; i++ {
 					c := l.peek()
 					if !isHexDigit(c) {
 						return "", errors.New("unfinished unicode escape")
 					}
 					l.next()
-					code = code + string(c)
+					code.WriteRune(c)
 				}
-				intcode, err := strconv.ParseInt(code, 16, 32)
+				intcode, err := strconv.ParseInt(code.String(), 16, 32)
 				if err != nil {
-					return "", errors.New("invalid unicode escape: \\u" + code)
+					return "", errors.New("invalid unicode escape: \\u" + code.String())
 				}
-				growingString += string(rune(intcode))
+				sb.WriteRune(rune(intcode))
 			case 'U':
 				l.next()
-				code := ""
+				var code strings.Builder
 				for i := 0; i < 8; i++ {
 					c := l.peek()
 					if !isHexDigit(c) {
 						return "", errors.New("unfinished unicode escape")
 					}
 					l.next()
-					code = code + string(c)
+					code.WriteRune(c)
 				}
-				intcode, err := strconv.ParseInt(code, 16, 64)
+				intcode, err := strconv.ParseInt(code.String(), 16, 64)
 				if err != nil {
-					return "", errors.New("invalid unicode escape: \\U" + code)
+					return "", errors.New("invalid unicode escape: \\U" + code.String())
 				}
-				growingString += string(rune(intcode))
+				sb.WriteRune(rune(intcode))
 			default:
 				return "", errors.New("invalid escape sequence: \\" + string(l.peek()))
 			}
@@ -534,7 +788,7 @@ func (l *tomlLexer) lexStringAsString(terminator string, discardLeadingNewLine,
 				return "", fmt.Errorf("unescaped control character %U", r)
 			}
 			l.next()
-			growingString += string(r)
+			sb.WriteRune(r)
 		}
 
 		if l.peek() == eof {
@@ -761,30 +1015,6 @@ func (l *tomlLexer) run() {
 	}
 }
 
-func init() {
-	// Regexp for all date/time formats supported by TOML.
-	// Group 1: nano precision
-	// Group 2: timezone
-	//
-	// /!\ also matches the empty string
-	//
-	// Example matches:
-	//1979-05-27T07:32:00Z
-	//1979-05-27T00:32:00-07:00
-	//1979-05-27T00:32:00.999999-07:00
-	//1979-05-27 07:32:00Z
-	//1979-05-27 00:32:00-07:00
-	//1979-05-27 00:32:00.999999-07:00
-	//1979-05-27T07:32:00
-	//1979-05-27T00:32:00.999999
-	//1979-05-27 07:32:00
-	//1979-05-27 00:32:00.999999
-	//1979-05-27
-	//07:32:00
-	//00:32:00.999999
-	dateRegexp = regexp.MustCompile(`^(?:\d{1,4}-\d{2}-\d{2})?(?:[T ]?\d{2}:\d{2}:\d{2}(\.\d{1,9})?(Z|[+-]\d{2}:\d{2})?)?`)
-}
-
 // Entry point
 func lexToml(inputBytes []byte) []token {
 	runes := bytes.Runes(inputBytes)

lexer_test.go

@@ -1,17 +1,63 @@
 package toml
 
 import (
+	"bytes"
+	"fmt"
 	"reflect"
 	"testing"
+	"text/tabwriter"
 )
 
 func testFlow(t *testing.T, input string, expectedFlow []token) {
 	tokens := lexToml([]byte(input))
+
 	if !reflect.DeepEqual(tokens, expectedFlow) {
-		t.Fatalf("Different flows.\nExpected:\n%v\nGot:\n%v", expectedFlow, tokens)
+		diffFlowsColumnsFatal(t, expectedFlow, tokens)
 	}
 }
 
+func diffFlowsColumnsFatal(t *testing.T, expectedFlow []token, actualFlow []token) {
+	max := len(expectedFlow)
+	if len(actualFlow) > max {
+		max = len(actualFlow)
+	}
+
+	b := &bytes.Buffer{}
+	w := tabwriter.NewWriter(b, 0, 0, 1, ' ', tabwriter.Debug)
+
+	fmt.Fprintln(w, "expected\tT\tP\tactual\tT\tP\tdiff")
+
+	for i := 0; i < max; i++ {
+		expected := ""
+		expectedType := ""
+		expectedPos := ""
+		if i < len(expectedFlow) {
+			expected = fmt.Sprintf("%s", expectedFlow[i])
+			expectedType = fmt.Sprintf("%s", expectedFlow[i].typ)
+			expectedPos = expectedFlow[i].Position.String()
+		}
+		actual := ""
+		actualType := ""
+		actualPos := ""
+		if i < len(actualFlow) {
+			actual = fmt.Sprintf("%s", actualFlow[i])
+			actualType = fmt.Sprintf("%s", actualFlow[i].typ)
+			actualPos = actualFlow[i].Position.String()
+		}
+		different := ""
+		if i >= len(expectedFlow) {
+			different = "+"
+		} else if i >= len(actualFlow) {
+			different = "-"
+		} else if !reflect.DeepEqual(expectedFlow[i], actualFlow[i]) {
+			different = "x"
+		}
+		fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\t%s\t%s\n", expected, expectedType, expectedPos, actual, actualType, actualPos, different)
+	}
+	w.Flush()
+	t.Errorf("Different flows:\n%s", b.String())
+}
+
 func TestValidKeyGroup(t *testing.T) {
 	testFlow(t, "[hello world]", []token{
 		{Position{1, 1}, tokenLeftBracket, "["},
@@ -298,57 +344,280 @@ func TestKeyEqualArrayBoolsWithComments(t *testing.T) {
 	})
 }
 
-func TestDateRegexp(t *testing.T) {
-	cases := map[string]string{
-		"basic":               "1979-05-27T07:32:00Z",
-		"offset":              "1979-05-27T00:32:00-07:00",
-		"nano precision":      "1979-05-27T00:32:00.999999-07:00",
-		"basic-no-T":          "1979-05-27 07:32:00Z",
-		"offset-no-T":         "1979-05-27 00:32:00-07:00",
-		"nano precision-no-T": "1979-05-27 00:32:00.999999-07:00",
-		"no-tz":               "1979-05-27T07:32:00",
-		"no-tz-nano":          "1979-05-27T00:32:00.999999",
-		"no-tz-no-t":          "1979-05-27 07:32:00",
-		"no-tz-no-t-nano":     "1979-05-27 00:32:00.999999",
-		"date-no-tz":          "1979-05-27",
-		"time-no-tz":          "07:32:00",
-		"time-no-tz-nano":     "00:32:00.999999",
-	}
-
-	for name, value := range cases {
-		if dateRegexp.FindString(value) == "" {
-			t.Error("failed date regexp test", name)
-		}
-	}
-	if dateRegexp.FindString("1979-05-27 07:32:00Z") == "" {
-		t.Error("space delimiter lexing")
-	}
-}
-
 func TestKeyEqualDate(t *testing.T) {
-	testFlow(t, "foo = 1979-05-27T07:32:00Z", []token{
+	t.Run("local date time", func(t *testing.T) {
-		{Position{1, 1}, tokenKey, "foo"},
+		testFlow(t, "foo = 1979-05-27T07:32:00", []token{
-		{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 1}, tokenKey, "foo"},
-		{Position{1, 7}, tokenDate, "1979-05-27T07:32:00Z"},
+			{Position{1, 5}, tokenEqual, "="},
-		{Position{1, 27}, tokenEOF, ""},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "07:32:00"},
+			{Position{1, 26}, tokenEOF, ""},
+		})
 	})
-	testFlow(t, "foo = 1979-05-27T00:32:00-07:00", []token{
+
-		{Position{1, 1}, tokenKey, "foo"},
+	t.Run("local date time space", func(t *testing.T) {
-		{Position{1, 5}, tokenEqual, "="},
+		testFlow(t, "foo = 1979-05-27 07:32:00", []token{
-		{Position{1, 7}, tokenDate, "1979-05-27T00:32:00-07:00"},
+			{Position{1, 1}, tokenKey, "foo"},
-		{Position{1, 32}, tokenEOF, ""},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "07:32:00"},
+			{Position{1, 26}, tokenEOF, ""},
+		})
 	})
-	testFlow(t, "foo = 1979-05-27T00:32:00.999999-07:00", []token{
+
-		{Position{1, 1}, tokenKey, "foo"},
+	t.Run("local date time fraction", func(t *testing.T) {
-		{Position{1, 5}, tokenEqual, "="},
+		testFlow(t, "foo = 1979-05-27T00:32:00.999999", []token{
-		{Position{1, 7}, tokenDate, "1979-05-27T00:32:00.999999-07:00"},
+			{Position{1, 1}, tokenKey, "foo"},
-		{Position{1, 39}, tokenEOF, ""},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00.999999"},
+			{Position{1, 33}, tokenEOF, ""},
+		})
 	})
-	testFlow(t, "foo = 1979-05-27 07:32:00Z", []token{
+
-		{Position{1, 1}, tokenKey, "foo"},
+	t.Run("local date time fraction space", func(t *testing.T) {
-		{Position{1, 5}, tokenEqual, "="},
+		testFlow(t, "foo = 1979-05-27 00:32:00.999999", []token{
-		{Position{1, 7}, tokenDate, "1979-05-27 07:32:00Z"},
+			{Position{1, 1}, tokenKey, "foo"},
-		{Position{1, 27}, tokenEOF, ""},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00.999999"},
+			{Position{1, 33}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time utc", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27T07:32:00Z", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "07:32:00"},
+			{Position{1, 26}, tokenTimeOffset, "Z"},
+			{Position{1, 27}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time -07:00", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27T00:32:00-07:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00"},
+			{Position{1, 26}, tokenTimeOffset, "-07:00"},
+			{Position{1, 32}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time fractions -07:00", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27T00:32:00.999999-07:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00.999999"},
+			{Position{1, 33}, tokenTimeOffset, "-07:00"},
+			{Position{1, 39}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time space separated utc", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 07:32:00Z", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "07:32:00"},
+			{Position{1, 26}, tokenTimeOffset, "Z"},
+			{Position{1, 27}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time space separated offset", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:32:00-07:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00"},
+			{Position{1, 26}, tokenTimeOffset, "-07:00"},
+			{Position{1, 32}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time space separated fraction offset", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:32:00.999999-07:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00.999999"},
+			{Position{1, 33}, tokenTimeOffset, "-07:00"},
+			{Position{1, 39}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("local date", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 17}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("local time", func(t *testing.T) {
+		testFlow(t, "foo = 07:32:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalTime, "07:32:00"},
+			{Position{1, 15}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("local time fraction", func(t *testing.T) {
+		testFlow(t, "foo = 00:32:00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalTime, "00:32:00.999999"},
+			{Position{1, 22}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("local time invalid minute digit", func(t *testing.T) {
+		testFlow(t, "foo = 00:3x:00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenError, "invalid minute digit in time: x"},
+		})
+	})
+
+	t.Run("local time invalid minute/second digit", func(t *testing.T) {
+		testFlow(t, "foo = 00:30x00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenError, "time minute/second separator should be :, not x"},
+		})
+	})
+
+	t.Run("local time invalid second digit", func(t *testing.T) {
+		testFlow(t, "foo = 00:30:x0.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenError, "invalid second digit in time: x"},
+		})
+	})
+
+	t.Run("local time invalid second digit", func(t *testing.T) {
+		testFlow(t, "foo = 00:30:00.F", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenError, "expected at least one digit in time's fraction, not F"},
+		})
+	})
+
+	t.Run("local date-time invalid minute digit", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:3x:00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "invalid minute digit in time: x"},
+		})
+	})
+
+	t.Run("local date-time invalid hour digit", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27T0x:30:00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "invalid hour digit in time: x"},
+		})
+	})
+
+	t.Run("local date-time invalid hour digit", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27T00x30:00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "time hour/minute separator should be :, not x"},
+		})
+	})
+
+	t.Run("local date-time invalid minute/second digit", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:30x00.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "time minute/second separator should be :, not x"},
+		})
+	})
+
+	t.Run("local date-time invalid second digit", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:30:x0.999999", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "invalid second digit in time: x"},
+		})
+	})
+
+	t.Run("local date-time invalid fraction", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:30:00.F", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenError, "expected at least one digit in time's fraction, not F"},
+		})
+	})
+
+	t.Run("local date-time invalid month-date separator", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05X27 00:30:00.F", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenError, "expected - to separate month of a date, not X"},
+		})
+	})
+
+	t.Run("local date-time extra whitespace", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27  ", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 19}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("local date-time extra whitespace", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27     ", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 22}, tokenEOF, ""},
+		})
+	})
+
+	t.Run("offset date-time space separated offset", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:32:00-0x:00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00"},
+			{Position{1, 26}, tokenError, "invalid hour digit in time offset: x"},
+		})
+	})
+
+	t.Run("offset date-time space separated offset", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:32:00-07x00", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00"},
+			{Position{1, 26}, tokenError, "time offset hour/minute separator should be :, not x"},
+		})
+	})
+
+	t.Run("offset date-time space separated offset", func(t *testing.T) {
+		testFlow(t, "foo = 1979-05-27 00:32:00-07:x0", []token{
+			{Position{1, 1}, tokenKey, "foo"},
+			{Position{1, 5}, tokenEqual, "="},
+			{Position{1, 7}, tokenLocalDate, "1979-05-27"},
+			{Position{1, 18}, tokenLocalTime, "00:32:00"},
+			{Position{1, 26}, tokenError, "invalid minute digit in time offset: x"},
+		})
 	})
 }
 

marshal.go

@@ -18,6 +18,7 @@ const (
 	tagFieldComment = "comment"
 	tagCommented    = "commented"
 	tagMultiline    = "multiline"
+	tagLiteral      = "literal"
 	tagDefault      = "default"
 )
 
@@ -27,6 +28,7 @@ type tomlOpts struct {
 	comment      string
 	commented    bool
 	multiline    bool
+	literal      bool
 	include      bool
 	omitempty    bool
 	defaultValue string
@@ -46,6 +48,7 @@ type annotation struct {
 	comment      string
 	commented    string
 	multiline    string
+	literal      string
 	defaultValue string
 }
 
@@ -54,15 +57,16 @@ var annotationDefault = annotation{
 	comment:      tagFieldComment,
 	commented:    tagCommented,
 	multiline:    tagMultiline,
+	literal:      tagLiteral,
 	defaultValue: tagDefault,
 }
 
-type marshalOrder int
+type MarshalOrder int
 
 // Orders the Encoder can write the fields to the output stream.
 const (
 	// Sort fields alphabetically.
-	OrderAlphabetical marshalOrder = iota + 1
+	OrderAlphabetical MarshalOrder = iota + 1
 	// Preserve the order the fields are encountered. For example, the order of fields in
 	// a struct.
 	OrderPreserve
@@ -76,6 +80,7 @@ var textUnmarshalerType = reflect.TypeOf(new(encoding.TextUnmarshaler)).Elem()
 var localDateType = reflect.TypeOf(LocalDate{})
 var localTimeType = reflect.TypeOf(LocalTime{})
 var localDateTimeType = reflect.TypeOf(LocalDateTime{})
+var mapStringInterfaceType = reflect.TypeOf(map[string]interface{}{})
 
 // Check if the given marshal type maps to a Tree primitive
 func isPrimitive(mtype reflect.Type) bool {
@@ -253,11 +258,12 @@ type Encoder struct {
 	w io.Writer
 	encOpts
 	annotation
-	line        int
+	line            int
-	col         int
+	col             int
-	order       marshalOrder
+	order           MarshalOrder
-	promoteAnon bool
+	promoteAnon     bool
-	indentation string
+	compactComments bool
+	indentation     string
 }
 
 // NewEncoder returns a new encoder that writes to w.
@@ -316,7 +322,7 @@ func (e *Encoder) ArraysWithOneElementPerLine(v bool) *Encoder {
 }
 
 // Order allows to change in which order fields will be written to the output stream.
-func (e *Encoder) Order(ord marshalOrder) *Encoder {
+func (e *Encoder) Order(ord MarshalOrder) *Encoder {
 	e.order = ord
 	return e
 }
@@ -364,6 +370,12 @@ func (e *Encoder) PromoteAnonymous(promote bool) *Encoder {
 	return e
 }
 
+// CompactComments removes the new line before each comment in the tree.
+func (e *Encoder) CompactComments(cc bool) *Encoder {
+	e.compactComments = cc
+	return e
+}
+
 func (e *Encoder) marshal(v interface{}) ([]byte, error) {
 	// Check if indentation is valid
 	for _, char := range e.indentation {
@@ -403,7 +415,7 @@ func (e *Encoder) marshal(v interface{}) ([]byte, error) {
 	}
 
 	var buf bytes.Buffer
-	_, err = t.writeToOrdered(&buf, "", "", 0, e.arraysOneElementPerLine, e.order, e.indentation, false)
+	_, err = t.writeToOrdered(&buf, "", "", 0, e.arraysOneElementPerLine, e.order, e.indentation, e.compactComments, false)
 
 	return buf.Bytes(), err
 }
@@ -436,10 +448,12 @@ func (e *Encoder) valueToTree(mtype reflect.Type, mval reflect.Value) (*Tree, er
 					if tree, ok := val.(*Tree); ok && mtypef.Anonymous && !opts.nameFromTag && !e.promoteAnon {
 						e.appendTree(tval, tree)
 					} else {
+						val = e.wrapTomlValue(val, tval)
 						tval.SetPathWithOptions([]string{opts.name}, SetOptions{
 							Comment:   opts.comment,
 							Commented: opts.commented,
 							Multiline: opts.multiline,
+							Literal:   opts.literal,
 						}, val)
 					}
 				}
@@ -474,6 +488,7 @@ func (e *Encoder) valueToTree(mtype reflect.Type, mval reflect.Value) (*Tree, er
 			if err != nil {
 				return nil, err
 			}
+			val = e.wrapTomlValue(val, tval)
 			if e.quoteMapKeys {
 				keyStr, err := tomlValueStringRepresentation(key.String(), "", "", e.order, e.arraysOneElementPerLine)
 				if err != nil {
@@ -516,13 +531,13 @@ func (e *Encoder) valueToOtherSlice(mtype reflect.Type, mval reflect.Value) (int
 
 // Convert given marshal value to toml value
 func (e *Encoder) valueToToml(mtype reflect.Type, mval reflect.Value) (interface{}, error) {
-	e.line++
 	if mtype.Kind() == reflect.Ptr {
 		switch {
 		case isCustomMarshaler(mtype):
 			return callCustomMarshaler(mval)
 		case isTextMarshaler(mtype):
-			return callTextMarshaler(mval)
+			b, err := callTextMarshaler(mval)
+			return string(b), err
 		default:
 			return e.valueToToml(mtype.Elem(), mval.Elem())
 		}
@@ -534,7 +549,8 @@ func (e *Encoder) valueToToml(mtype reflect.Type, mval reflect.Value) (interface
 	case isCustomMarshaler(mtype):
 		return callCustomMarshaler(mval)
 	case isTextMarshaler(mtype):
-		return callTextMarshaler(mval)
+		b, err := callTextMarshaler(mval)
+		return string(b), err
 	case isTree(mtype):
 		return e.valueToTree(mtype, mval)
 	case isOtherSequence(mtype), isCustomMarshalerSequence(mtype), isTextMarshalerSequence(mtype):
@@ -577,6 +593,26 @@ func (e *Encoder) appendTree(t, o *Tree) error {
 	return nil
 }
 
+// Create a toml value with the current line number as the position line
+func (e *Encoder) wrapTomlValue(val interface{}, parent *Tree) interface{} {
+	_, isTree := val.(*Tree)
+	_, isTreeS := val.([]*Tree)
+	if isTree || isTreeS {
+		e.line++
+		return val
+	}
+
+	ret := &tomlValue{
+		value: val,
+		position: Position{
+			e.line,
+			parent.position.Col,
+		},
+	}
+	e.line++
+	return ret
+}
+
 // Unmarshal attempts to unmarshal the Tree into a Go struct pointed by v.
 // Neither Unmarshaler interfaces nor UnmarshalTOML functions are supported for
 // sub-structs, and only definite types can be unmarshaled.
@@ -681,6 +717,8 @@ func (d *Decoder) unmarshal(v interface{}) error {
 
 	switch elem.Kind() {
 	case reflect.Struct, reflect.Map:
+	case reflect.Interface:
+		elem = mapStringInterfaceType
 	default:
 		return errors.New("only a pointer to struct or map can be unmarshaled from TOML")
 	}
@@ -717,6 +755,10 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree, mval1 *reflect.V
 	if mvalPtr := reflect.New(mtype); isCustomUnmarshaler(mvalPtr.Type()) {
 		d.visitor.visitAll()
 
+		if tval == nil {
+			return mvalPtr.Elem(), nil
+		}
+
 		if err := callCustomUnmarshaler(mvalPtr, tval.ToMap()); err != nil {
 			return reflect.ValueOf(nil), fmt.Errorf("unmarshal toml: %v", err)
 		}
@@ -801,7 +843,21 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree, mval1 *reflect.V
 					case reflect.Int32:
 						val, err = strconv.ParseInt(opts.defaultValue, 10, 32)
 					case reflect.Int64:
-						val, err = strconv.ParseInt(opts.defaultValue, 10, 64)
+						// Check if the provided number has a non-numeric extension.
+						var hasExtension bool
+						if len(opts.defaultValue) > 0 {
+							lastChar := opts.defaultValue[len(opts.defaultValue)-1]
+							if lastChar < '0' || lastChar > '9' {
+								hasExtension = true
+							}
+						}
+						// If the value is a time.Duration with extension, parse as duration.
+						// If the value is an int64 or a time.Duration without extension, parse as number.
+						if hasExtension && mvalf.Type().String() == "time.Duration" {
+							val, err = time.ParseDuration(opts.defaultValue)
+						} else {
+							val, err = strconv.ParseInt(opts.defaultValue, 10, 64)
+						}
 					case reflect.Float32:
 						val, err = strconv.ParseFloat(opts.defaultValue, 32)
 					case reflect.Float64:
@@ -975,8 +1031,18 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}, mval1 *ref
 		return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to a slice", tval, tval)
 	default:
 		d.visitor.visit()
+		mvalPtr := reflect.New(mtype)
+
+		// Check if pointer to value implements the Unmarshaler interface.
+		if isCustomUnmarshaler(mvalPtr.Type()) {
+			if err := callCustomUnmarshaler(mvalPtr, tval); err != nil {
+				return reflect.ValueOf(nil), fmt.Errorf("unmarshal toml: %v", err)
+			}
+			return mvalPtr.Elem(), nil
+		}
+
 		// Check if pointer to value implements the encoding.TextUnmarshaler.
-		if mvalPtr := reflect.New(mtype); isTextUnmarshaler(mvalPtr.Type()) && !isTimeType(mtype) {
+		if isTextUnmarshaler(mvalPtr.Type()) && !isTimeType(mtype) {
 			if err := d.unmarshalText(tval, mvalPtr); err != nil {
 				return reflect.ValueOf(nil), fmt.Errorf("unmarshal text: %v", err)
 			}
@@ -1115,6 +1181,7 @@ func tomlOptions(vf reflect.StructField, an annotation) tomlOpts {
 	}
 	commented, _ := strconv.ParseBool(vf.Tag.Get(an.commented))
 	multiline, _ := strconv.ParseBool(vf.Tag.Get(an.multiline))
+	literal, _ := strconv.ParseBool(vf.Tag.Get(an.literal))
 	defaultValue := vf.Tag.Get(tagDefault)
 	result := tomlOpts{
 		name:         vf.Name,
@@ -1122,6 +1189,7 @@ func tomlOptions(vf reflect.StructField, an annotation) tomlOpts {
 		comment:      comment,
 		commented:    commented,
 		multiline:    multiline,
+		literal:      literal,
 		include:      true,
 		omitempty:    false,
 		defaultValue: defaultValue,

marshal_test.go

@@ -3,6 +3,7 @@ package toml
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -14,60 +15,69 @@ import (
 )
 
 type basicMarshalTestStruct struct {
-	String     string                      `toml:"Zstring"`
+	String     string   `toml:"Zstring"`
-	StringList []string                    `toml:"Ystrlist"`
+	StringList []string `toml:"Ystrlist"`
-	Sub        basicMarshalTestSubStruct   `toml:"Xsubdoc"`
+	BasicMarshalTestSubAnonymousStruct
-	SubList    []basicMarshalTestSubStruct `toml:"Wsublist"`
+	Sub     basicMarshalTestSubStruct   `toml:"Xsubdoc"`
+	SubList []basicMarshalTestSubStruct `toml:"Wsublist"`
 }
 
 type basicMarshalTestSubStruct struct {
 	String2 string
 }
 
-var basicTestData = basicMarshalTestStruct{
+type BasicMarshalTestSubAnonymousStruct struct {
-	String:     "Hello",
+	String3 string
-	StringList: []string{"Howdy", "Hey There"},
-	Sub:        basicMarshalTestSubStruct{"One"},
-	SubList:    []basicMarshalTestSubStruct{{"Two"}, {"Three"}},
 }
 
-var basicTestToml = []byte(`Ystrlist = ["Howdy", "Hey There"]
+var basicTestData = basicMarshalTestStruct{
-Zstring = "Hello"
+	String:                             "Hello",
+	StringList:                         []string{"Howdy", "Hey There"},
+	BasicMarshalTestSubAnonymousStruct: BasicMarshalTestSubAnonymousStruct{"One"},
+	Sub:                                basicMarshalTestSubStruct{"Two"},
+	SubList:                            []basicMarshalTestSubStruct{{"Three"}, {"Four"}},
+}
 
-[[Wsublist]]
+var basicTestToml = []byte(`String3 = "One"
-  String2 = "Two"
+Ystrlist = ["Howdy", "Hey There"]
+Zstring = "Hello"
 
 [[Wsublist]]
   String2 = "Three"
 
+[[Wsublist]]
+  String2 = "Four"
+
 [Xsubdoc]
-  String2 = "One"
+  String2 = "Two"
 `)
 
-var basicTestTomlCustomIndentation = []byte(`Ystrlist = ["Howdy", "Hey There"]
+var basicTestTomlCustomIndentation = []byte(`String3 = "One"
+Ystrlist = ["Howdy", "Hey There"]
 Zstring = "Hello"
 
-[[Wsublist]]
-	String2 = "Two"
-
 [[Wsublist]]
 	String2 = "Three"
 
+[[Wsublist]]
+	String2 = "Four"
+
 [Xsubdoc]
-	String2 = "One"
+	String2 = "Two"
 `)
 
 var basicTestTomlOrdered = []byte(`Zstring = "Hello"
 Ystrlist = ["Howdy", "Hey There"]
+String3 = "One"
 
 [Xsubdoc]
-  String2 = "One"
-
-[[Wsublist]]
   String2 = "Two"
 
 [[Wsublist]]
   String2 = "Three"
+
+[[Wsublist]]
+  String2 = "Four"
 `)
 
 var marshalTestToml = []byte(`title = "TOML Marshal Testing"
@@ -979,6 +989,40 @@ func TestCustomMarshaler(t *testing.T) {
 	}
 }
 
+type IntOrString string
+
+func (x *IntOrString) MarshalTOML() ([]byte, error) {
+	s := *(*string)(x)
+	_, err := strconv.Atoi(s)
+	if err != nil {
+		return []byte(fmt.Sprintf(`"%s"`, s)), nil
+	}
+	return []byte(s), nil
+}
+
+func TestNestedCustomMarshaler(t *testing.T) {
+	num := IntOrString("100")
+	str := IntOrString("hello")
+	var parent = struct {
+		IntField    *IntOrString `toml:"int"`
+		StringField *IntOrString `toml:"string"`
+	}{
+		&num,
+		&str,
+	}
+
+	result, err := Marshal(parent)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := `int = 100
+string = "hello"
+`
+	if !bytes.Equal(result, []byte(expected)) {
+		t.Errorf("Bad nested text marshaler: expected\n-----\n%s\n-----\ngot\n-----\n%s\n-----\n", expected, result)
+	}
+}
+
 type textMarshaler struct {
 	FirstName string
 	LastName  string
@@ -1079,7 +1123,7 @@ type customPointerMarshaler struct {
 }
 
 func (m *customPointerMarshaler) MarshalTOML() ([]byte, error) {
-	return []byte("hidden"), nil
+	return []byte(`"hidden"`), nil
 }
 
 type textPointerMarshaler struct {
@@ -1250,6 +1294,32 @@ NonCommented = "Not commented line"
 	}
 }
 
+func TestMarshalMultilineLiteral(t *testing.T) {
+	type Doc struct {
+		Value string `multiline:"true" literal:"true"`
+	}
+
+	d := Doc{
+		Value: "hello\nworld\ttest\nend",
+	}
+
+	expected := []byte(`Value = '''
+hello
+world	test
+end
+'''
+`)
+
+	b, err := Marshal(d)
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+
+	if !bytes.Equal(b, expected) {
+		t.Errorf("Bad marshal: expected\n-----\n%s\n-----\ngot\n-----\n%s\n-----\n", expected, b)
+	}
+}
+
 func TestMarshalNonPrimitiveTypeCommented(t *testing.T) {
 	expectedToml := []byte(`
 # [CommentedMapField]
@@ -1406,6 +1476,47 @@ commented out"""
 	}
 }
 
+func TestCompactComments(t *testing.T) {
+	expected := []byte(`
+[first-section]
+  # comment for first-key
+  first-key = 1
+  # comment for second-key
+  second-key = "value"
+  # comment for commented third-key
+  # third-key = []
+
+[second-section]
+  # comment for first-key
+  first-key = 2
+  # comment for second-key
+  second-key = "another value"
+  # comment for commented third-key
+  # third-key = ["value1", "value2"]
+`)
+	type Settings struct {
+		FirstKey  int      `toml:"first-key" comment:"comment for first-key"`
+		SecondKey string   `toml:"second-key" comment:"comment for second-key"`
+		ThirdKey  []string `toml:"third-key" comment:"comment for commented third-key" commented:"true"`
+	}
+	type Config struct {
+		FirstSection  Settings `toml:"first-section"`
+		SecondSection Settings `toml:"second-section"`
+	}
+	data := Config{
+		FirstSection:  Settings{1, "value", []string{}},
+		SecondSection: Settings{2, "another value", []string{"value1", "value2"}},
+	}
+	buf := new(bytes.Buffer)
+	if err := NewEncoder(buf).CompactComments(true).Encode(data); err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(expected, buf.Bytes()) {
+		t.Errorf("Bad marshal: expected\n-----\n%s\n-----\ngot\n-----\n%s\n-----\n", expected, buf.Bytes())
+	}
+}
+
 type mapsTestStruct struct {
 	Simple map[string]string
 	Paths  map[string]string
@@ -2151,10 +2262,7 @@ func TestUnmarshalBadDuration(t *testing.T) {
 	result := testBadDuration{}
 	err := NewDecoder(buf).Decode(&result)
 	if err == nil {
-		t.Fatal()
+		t.Fatal("expected bad duration error")
-	}
-	if err.Error() != "(1, 1): Can't convert 1z(string) to time.Duration. time: unknown unit z in duration 1z" {
-		t.Fatalf("unexpected error: %s", err)
 	}
 }
 
@@ -2245,20 +2353,22 @@ func TestUnmarshalDefault(t *testing.T) {
 	type aliasUint uint
 
 	var doc struct {
-		StringField       string  `default:"a"`
+		StringField       string        `default:"a"`
-		BoolField         bool    `default:"true"`
+		BoolField         bool          `default:"true"`
-		UintField         uint    `default:"1"`
+		UintField         uint          `default:"1"`
-		Uint8Field        uint8   `default:"8"`
+		Uint8Field        uint8         `default:"8"`
-		Uint16Field       uint16  `default:"16"`
+		Uint16Field       uint16        `default:"16"`
-		Uint32Field       uint32  `default:"32"`
+		Uint32Field       uint32        `default:"32"`
-		Uint64Field       uint64  `default:"64"`
+		Uint64Field       uint64        `default:"64"`
-		IntField          int     `default:"-1"`
+		IntField          int           `default:"-1"`
-		Int8Field         int8    `default:"-8"`
+		Int8Field         int8          `default:"-8"`
-		Int16Field        int16   `default:"-16"`
+		Int16Field        int16         `default:"-16"`
-		Int32Field        int32   `default:"-32"`
+		Int32Field        int32         `default:"-32"`
-		Int64Field        int64   `default:"-64"`
+		Int64Field        int64         `default:"-64"`
-		Float32Field      float32 `default:"32.1"`
+		Float32Field      float32       `default:"32.1"`
-		Float64Field      float64 `default:"64.1"`
+		Float64Field      float64       `default:"64.1"`
+		DurationField     time.Duration `default:"120ms"`
+		DurationField2    time.Duration `default:"120000000"`
 		NonEmbeddedStruct struct {
 			StringField string `default:"b"`
 		}
@@ -2312,6 +2422,12 @@ func TestUnmarshalDefault(t *testing.T) {
 	if doc.Float64Field != 64.1 {
 		t.Errorf("Float64Field should be 64.1, not %f", doc.Float64Field)
 	}
+	if doc.DurationField != 120*time.Millisecond {
+		t.Errorf("DurationField should be 120ms, not %s", doc.DurationField.String())
+	}
+	if doc.DurationField2 != 120*time.Millisecond {
+		t.Errorf("DurationField2 should be 120000000, not %d", doc.DurationField2)
+	}
 	if doc.NonEmbeddedStruct.StringField != "b" {
 		t.Errorf("StringField should be \"b\", not %s", doc.NonEmbeddedStruct.StringField)
 	}
@@ -2367,6 +2483,17 @@ func TestUnmarshalDefaultFailureFloat64(t *testing.T) {
 	}
 }
 
+func TestUnmarshalDefaultFailureDuration(t *testing.T) {
+	var doc struct {
+		Field time.Duration `default:"blah"`
+	}
+
+	err := Unmarshal([]byte(``), &doc)
+	if err == nil {
+		t.Fatal("should error")
+	}
+}
+
 func TestUnmarshalDefaultFailureUnsupported(t *testing.T) {
 	var doc struct {
 		Field struct{} `default:"blah"`
@@ -3848,3 +3975,147 @@ func TestPreserveNotEmptyField(t *testing.T) {
 		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
 	}
 }
+
+// github issue 432
+func TestUnmarshalEmptyInterface(t *testing.T) {
+	doc := []byte(`User = "pelletier"`)
+
+	var v interface{}
+
+	err := Unmarshal(doc, &v)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	x, ok := v.(map[string]interface{})
+	if !ok {
+		t.Fatal(err)
+	}
+
+	if x["User"] != "pelletier" {
+		t.Fatalf("expected User=pelletier, but got %v", x)
+	}
+}
+
+func TestUnmarshalEmptyInterfaceDeep(t *testing.T) {
+	doc := []byte(`
+User = "pelletier"
+Age = 99
+
+[foo]
+bar = 42
+`)
+
+	var v interface{}
+
+	err := Unmarshal(doc, &v)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	x, ok := v.(map[string]interface{})
+	if !ok {
+		t.Fatal(err)
+	}
+
+	expected := map[string]interface{}{
+		"User": "pelletier",
+		"Age":  99,
+		"foo": map[string]interface{}{
+			"bar": 42,
+		},
+	}
+
+	reflect.DeepEqual(x, expected)
+}
+
+type Config struct {
+	Key string `toml:"key"`
+	Obj Custom `toml:"obj"`
+}
+
+type Custom struct {
+	v string
+}
+
+func (c *Custom) UnmarshalTOML(v interface{}) error {
+	c.v = "called"
+	return nil
+}
+
+func TestGithubIssue431(t *testing.T) {
+	doc := `key = "value"`
+	tree, err := LoadBytes([]byte(doc))
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	var c Config
+	if err := tree.Unmarshal(&c); err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	if c.Key != "value" {
+		t.Errorf("expected c.Key='value', not '%s'", c.Key)
+	}
+
+	if c.Obj.v == "called" {
+		t.Errorf("UnmarshalTOML should not have been called")
+	}
+}
+
+type durationString struct {
+	time.Duration
+}
+
+func (d *durationString) UnmarshalTOML(v interface{}) error {
+	d.Duration = 10 * time.Second
+	return nil
+}
+
+type config437Error struct {
+}
+
+func (e *config437Error) UnmarshalTOML(v interface{}) error {
+	return errors.New("expected")
+}
+
+type config437 struct {
+	HTTP struct {
+		PingTimeout durationString `toml:"PingTimeout"`
+		ErrorField  config437Error
+	} `toml:"HTTP"`
+}
+
+func TestGithubIssue437(t *testing.T) {
+	src := `
+[HTTP]
+PingTimeout = "32m"
+`
+	cfg := &config437{}
+	cfg.HTTP.PingTimeout = durationString{time.Second}
+
+	r := strings.NewReader(src)
+	err := NewDecoder(r).Decode(cfg)
+	if err != nil {
+		t.Fatalf("unexpected errors %s", err)
+	}
+	expected := durationString{10 * time.Second}
+	if cfg.HTTP.PingTimeout != expected {
+		t.Fatalf("expected '%s', got '%s'", expected, cfg.HTTP.PingTimeout)
+	}
+}
+
+func TestLeafUnmarshalerError(t *testing.T) {
+	src := `
+[HTTP]
+ErrorField = "foo"
+`
+	cfg := &config437{}
+
+	r := strings.NewReader(src)
+	err := NewDecoder(r).Decode(cfg)
+	if err == nil {
+		t.Fatalf("error was expected")
+	}
+}

parser.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"math"
 	"reflect"
-	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -231,19 +230,38 @@ func (p *tomlParser) parseAssign() tomlParserStateFn {
 	return p.parseStart
 }
 
-var numberUnderscoreInvalidRegexp *regexp.Regexp
+var errInvalidUnderscore = errors.New("invalid use of _ in number")
-var hexNumberUnderscoreInvalidRegexp *regexp.Regexp
 
 func numberContainsInvalidUnderscore(value string) error {
-	if numberUnderscoreInvalidRegexp.MatchString(value) {
+	// For large numbers, you may use underscores between digits to enhance
-		return errors.New("invalid use of _ in number")
+	// readability. Each underscore must be surrounded by at least one digit on
+	// each side.
+
+	hasBefore := false
+	for idx, r := range value {
+		if r == '_' {
+			if !hasBefore || idx+1 >= len(value) {
+				// can't end with an underscore
+				return errInvalidUnderscore
+			}
+		}
+		hasBefore = isDigit(r)
 	}
 	return nil
 }
 
+var errInvalidUnderscoreHex = errors.New("invalid use of _ in hex number")
+
 func hexNumberContainsInvalidUnderscore(value string) error {
-	if hexNumberUnderscoreInvalidRegexp.MatchString(value) {
+	hasBefore := false
-		return errors.New("invalid use of _ in hex number")
+	for idx, r := range value {
+		if r == '_' {
+			if !hasBefore || idx+1 >= len(value) {
+				// can't end with an underscore
+				return errInvalidUnderscoreHex
+			}
+		}
+		hasBefore = isHexDigit(r)
 	}
 	return nil
 }
@@ -322,42 +340,44 @@ func (p *tomlParser) parseRvalue() interface{} {
 			p.raiseError(tok, "%s", err)
 		}
 		return val
-	case tokenDate:
+	case tokenLocalTime:
-		layout := time.RFC3339Nano
+		val, err := ParseLocalTime(tok.val)
-		if !strings.Contains(tok.val, "T") {
-			layout = strings.Replace(layout, "T", " ", 1)
-		}
-		val, err := time.ParseInLocation(layout, tok.val, time.UTC)
 		if err != nil {
 			p.raiseError(tok, "%s", err)
 		}
 		return val
 	case tokenLocalDate:
-		v := strings.Replace(tok.val, " ", "T", -1)
+		// a local date may be followed by:
-		isDateTime := false
+		// * nothing: this is a local date
-		isTime := false
+		// * a local time: this is a local date-time
-		for _, c := range v {
+
-			if c == 'T' || c == 't' {
+		next := p.peek()
-				isDateTime = true
+		if next == nil || next.typ != tokenLocalTime {
-				break
+			val, err := ParseLocalDate(tok.val)
-			}
+			if err != nil {
-			if c == ':' {
+				p.raiseError(tok, "%s", err)
-				isTime = true
-				break
 			}
+			return val
 		}
 
-		var val interface{}
+		localDate := tok
-		var err error
+		localTime := p.getToken()
 
-		if isDateTime {
+		next = p.peek()
-			val, err = ParseLocalDateTime(v)
+		if next == nil || next.typ != tokenTimeOffset {
-		} else if isTime {
+			v := localDate.val + "T" + localTime.val
-			val, err = ParseLocalTime(v)
+			val, err := ParseLocalDateTime(v)
-		} else {
+			if err != nil {
-			val, err = ParseLocalDate(v)
+				p.raiseError(tok, "%s", err)
+			}
+			return val
 		}
 
+		offset := p.getToken()
+
+		layout := time.RFC3339Nano
+		v := localDate.val + "T" + localTime.val + offset.val
+		val, err := time.ParseInLocation(layout, v, time.UTC)
 		if err != nil {
 			p.raiseError(tok, "%s", err)
 		}
@@ -370,10 +390,10 @@ func (p *tomlParser) parseRvalue() interface{} {
 		p.raiseError(tok, "cannot have multiple equals for the same key")
 	case tokenError:
 		p.raiseError(tok, "%s", tok)
+	default:
+		panic(fmt.Errorf("unhandled token: %v", tok))
 	}
 
-	p.raiseError(tok, "never reached")
-
 	return nil
 }
 
@@ -486,8 +506,3 @@ func parseToml(flow []token) *Tree {
 	parser.run()
 	return result
 }
-
-func init() {
-	numberUnderscoreInvalidRegexp = regexp.MustCompile(`([^\d]_|_[^\d])|_$|^_`)
-	hexNumberUnderscoreInvalidRegexp = regexp.MustCompile(`(^0x_)|([^\da-f]_|_[^\da-f])|_$|^_`)
-}

parser_test.go

@@ -6,8 +6,6 @@ import (
 	"reflect"
 	"testing"
 	"time"
-
-	"github.com/davecgh/go-spew/spew"
 )
 
 func assertSubTree(t *testing.T, path []string, tree *Tree, err error, ref map[string]interface{}) {
@@ -39,7 +37,7 @@ func assertSubTree(t *testing.T, path []string, tree *Tree, err error, ref map[s
 }
 
 func assertTree(t *testing.T, tree *Tree, err error, ref map[string]interface{}) {
-	t.Log("Asserting tree:\n", spew.Sdump(tree))
+	t.Logf("Asserting tree:\n (%T)(%p)(%+v)", tree, tree, tree)
 	assertSubTree(t, []string{}, tree, err, ref)
 	t.Log("Finished tree assertion.")
 }
@@ -274,6 +272,34 @@ func TestLocalDate(t *testing.T) {
 	})
 }
 
+func TestLocalDateError(t *testing.T) {
+	_, err := Load("a = 2020-09-31")
+	if err == nil {
+		t.Fatalf("should error")
+	}
+}
+
+func TestLocalTimeError(t *testing.T) {
+	_, err := Load("a = 07:99:00")
+	if err == nil {
+		t.Fatalf("should error")
+	}
+}
+
+func TestLocalDateTimeError(t *testing.T) {
+	_, err := Load("a = 2020-09-31T07:99:00")
+	if err == nil {
+		t.Fatalf("should error")
+	}
+}
+
+func TestDateTimeOffsetError(t *testing.T) {
+	_, err := Load("a = 2020-09-31T07:99:00Z")
+	if err == nil {
+		t.Fatalf("should error")
+	}
+}
+
 func TestLocalTime(t *testing.T) {
 	tree, err := Load("a = 07:32:00")
 	assertTree(t, tree, err, map[string]interface{}{

token.go

@@ -30,8 +30,9 @@ const (
 	tokenRightParen
 	tokenDoubleLeftBracket
 	tokenDoubleRightBracket
-	tokenDate
 	tokenLocalDate
+	tokenLocalTime
+	tokenTimeOffset
 	tokenKeyGroup
 	tokenKeyGroupArray
 	tokenComma
@@ -66,7 +67,8 @@ var tokenTypeNames = []string{
 	"]]",
 	"[[",
 	"LocalDate",
-	"LocalDate",
+	"LocalTime",
+	"TimeOffset",
 	"KeyGroup",
 	"KeyGroupArray",
 	",",

token_test.go

@@ -25,8 +25,9 @@ func TestTokenStringer(t *testing.T) {
 		{tokenRightParen, ")"},
 		{tokenDoubleLeftBracket, "]]"},
 		{tokenDoubleRightBracket, "[["},
-		{tokenDate, "LocalDate"},
 		{tokenLocalDate, "LocalDate"},
+		{tokenLocalTime, "LocalTime"},
+		{tokenTimeOffset, "TimeOffset"},
 		{tokenKeyGroup, "KeyGroup"},
 		{tokenKeyGroupArray, "KeyGroupArray"},
 		{tokenComma, ","},

toml.go

@@ -15,6 +15,7 @@ type tomlValue struct {
 	comment   string
 	commented bool
 	multiline bool
+	literal   bool
 	position  Position
 }
 
@@ -122,6 +123,89 @@ func (t *Tree) GetPath(keys []string) interface{} {
 	}
 }
 
+// GetArray returns the value at key in the Tree.
+// It returns []string, []int64, etc type if key has homogeneous lists
+// Key is a dot-separated path (e.g. a.b.c) without single/double quoted strings.
+// Returns nil if the path does not exist in the tree.
+// If keys is of length zero, the current tree is returned.
+func (t *Tree) GetArray(key string) interface{} {
+	if key == "" {
+		return t
+	}
+	return t.GetArrayPath(strings.Split(key, "."))
+}
+
+// GetArrayPath returns the element in the tree indicated by 'keys'.
+// If keys is of length zero, the current tree is returned.
+func (t *Tree) GetArrayPath(keys []string) interface{} {
+	if len(keys) == 0 {
+		return t
+	}
+	subtree := t
+	for _, intermediateKey := range keys[:len(keys)-1] {
+		value, exists := subtree.values[intermediateKey]
+		if !exists {
+			return nil
+		}
+		switch node := value.(type) {
+		case *Tree:
+			subtree = node
+		case []*Tree:
+			// go to most recent element
+			if len(node) == 0 {
+				return nil
+			}
+			subtree = node[len(node)-1]
+		default:
+			return nil // cannot navigate through other node types
+		}
+	}
+	// branch based on final node type
+	switch node := subtree.values[keys[len(keys)-1]].(type) {
+	case *tomlValue:
+		switch n := node.value.(type) {
+		case []interface{}:
+			return getArray(n)
+		default:
+			return node.value
+		}
+	default:
+		return node
+	}
+}
+
+// if homogeneous array, then return slice type object over []interface{}
+func getArray(n []interface{}) interface{} {
+	var s []string
+	var i64 []int64
+	var f64 []float64
+	var bl []bool
+	for _, value := range n {
+		switch v := value.(type) {
+		case string:
+			s = append(s, v)
+		case int64:
+			i64 = append(i64, v)
+		case float64:
+			f64 = append(f64, v)
+		case bool:
+			bl = append(bl, v)
+		default:
+			return n
+		}
+	}
+	if len(s) == len(n) {
+		return s
+	} else if len(i64) == len(n) {
+		return i64
+	} else if len(f64) == len(n) {
+		return f64
+	} else if len(bl) == len(n) {
+		return bl
+	}
+	return n
+}
+
 // GetPosition returns the position of the given key.
 func (t *Tree) GetPosition(key string) Position {
 	if key == "" {
@@ -130,6 +214,50 @@ func (t *Tree) GetPosition(key string) Position {
 	return t.GetPositionPath(strings.Split(key, "."))
 }
 
+// SetPositionPath sets the position of element in the tree indicated by 'keys'.
+// If keys is of length zero, the current tree position is set.
+func (t *Tree) SetPositionPath(keys []string, pos Position) {
+	if len(keys) == 0 {
+		t.position = pos
+		return
+	}
+	subtree := t
+	for _, intermediateKey := range keys[:len(keys)-1] {
+		value, exists := subtree.values[intermediateKey]
+		if !exists {
+			return
+		}
+		switch node := value.(type) {
+		case *Tree:
+			subtree = node
+		case []*Tree:
+			// go to most recent element
+			if len(node) == 0 {
+				return
+			}
+			subtree = node[len(node)-1]
+		default:
+			return
+		}
+	}
+	// branch based on final node type
+	switch node := subtree.values[keys[len(keys)-1]].(type) {
+	case *tomlValue:
+		node.position = pos
+		return
+	case *Tree:
+		node.position = pos
+		return
+	case []*Tree:
+		// go to most recent element
+		if len(node) == 0 {
+			return
+		}
+		node[len(node)-1].position = pos
+		return
+	}
+}
+
 // GetPositionPath returns the element in the tree indicated by 'keys'.
 // If keys is of length zero, the current tree is returned.
 func (t *Tree) GetPositionPath(keys []string) Position {
@@ -187,6 +315,7 @@ type SetOptions struct {
 	Comment   string
 	Commented bool
 	Multiline bool
+	Literal   bool
 }
 
 // SetWithOptions is the same as Set, but allows you to provide formatting
@@ -212,7 +341,8 @@ func (t *Tree) SetPathWithOptions(keys []string, opts SetOptions, value interfac
 			// go to most recent element
 			if len(node) == 0 {
 				// create element if it does not exist
-				subtree.values[intermediateKey] = append(node, newTreeWithPosition(Position{Line: t.position.Line + i, Col: t.position.Col}))
+				node = append(node, newTreeWithPosition(Position{Line: t.position.Line + i, Col: t.position.Col}))
+				subtree.values[intermediateKey] = node
 			}
 			subtree = node[len(node)-1]
 		}
@@ -232,12 +362,16 @@ func (t *Tree) SetPathWithOptions(keys []string, opts SetOptions, value interfac
 		toInsert = value
 	case *tomlValue:
 		v.comment = opts.Comment
+		v.commented = opts.Commented
+		v.multiline = opts.Multiline
+		v.literal = opts.Literal
 		toInsert = v
 	default:
 		toInsert = &tomlValue{value: value,
 			comment:   opts.Comment,
 			commented: opts.Commented,
 			multiline: opts.Multiline,
+			literal:   opts.Literal,
 			position:  Position{Line: subtree.position.Line + len(subtree.values) + 1, Col: subtree.position.Col}}
 	}
 

toml_test.go

@@ -3,6 +3,7 @@
 package toml
 
 import (
+	"reflect"
 	"testing"
 )
 
@@ -39,6 +40,41 @@ func TestTomlGet(t *testing.T) {
 	}
 }
 
+func TestTomlGetArray(t *testing.T) {
+	tree, _ := Load(`
+		[test]
+		key = ["one", "two"]
+		key2 = [true, false, false]
+		key3 = [1.5,2.5]
+	`)
+
+	if tree.GetArray("") != tree {
+		t.Errorf("GetArray should return the tree itself when given an empty path")
+	}
+
+	expect := []string{"one", "two"}
+	actual := tree.GetArray("test.key").([]string)
+	if !reflect.DeepEqual(actual, expect) {
+		t.Errorf("GetArray should return the []string value")
+	}
+
+	expect2 := []bool{true, false, false}
+	actual2 := tree.GetArray("test.key2").([]bool)
+	if !reflect.DeepEqual(actual2, expect2) {
+		t.Errorf("GetArray should return the []bool value")
+	}
+
+	expect3 := []float64{1.5, 2.5}
+	actual3 := tree.GetArray("test.key3").([]float64)
+	if !reflect.DeepEqual(actual3, expect3) {
+		t.Errorf("GetArray should return the []float64 value")
+	}
+
+	if tree.GetArray(`\`) != nil {
+		t.Errorf("should return nil when the key is malformed")
+	}
+}
+
 func TestTomlGetDefault(t *testing.T) {
 	tree, _ := Load(`
 		[test]
@@ -148,6 +184,51 @@ func TestTomlGetPath(t *testing.T) {
 	}
 }
 
+func TestTomlGetArrayPath(t *testing.T) {
+	for idx, item := range []struct {
+		Name string
+		Path []string
+		Make func() (tree *Tree, expected interface{})
+	}{
+		{
+			Name: "empty",
+			Path: []string{},
+			Make: func() (tree *Tree, expected interface{}) {
+				tree = newTree()
+				expected = tree
+				return
+			},
+		},
+		{
+			Name: "int64",
+			Path: []string{"a"},
+			Make: func() (tree *Tree, expected interface{}) {
+				var err error
+				tree, err = Load(`a = [1,2,3]`)
+				if err != nil {
+					panic(err)
+				}
+				expected = []int64{1, 2, 3}
+				return
+			},
+		},
+	} {
+		t.Run(item.Name, func(t *testing.T) {
+			tree, expected := item.Make()
+			result := tree.GetArrayPath(item.Path)
+			if !reflect.DeepEqual(result, expected) {
+				t.Errorf("GetArrayPath[%d] %v - expected %#v, got %#v instead.", idx, item.Path, expected, result)
+			}
+		})
+	}
+
+	tree, _ := Load("[foo.bar]\na=1\nb=2\n[baz.foo]\na=3\nb=4\n[gorf.foo]\na=5\nb=6")
+	if tree.GetArrayPath([]string{"whatever"}) != nil {
+		t.Error("GetArrayPath should return nil when the key does not exist")
+	}
+
+}
+
 func TestTomlFromMap(t *testing.T) {
 	simpleMap := map[string]interface{}{"hello": 42}
 	tree, err := TreeFromMap(simpleMap)

toml_testgen_support_test.go

@@ -8,8 +8,6 @@ import (
 	"reflect"
 	"testing"
 	"time"
-
-	"github.com/davecgh/go-spew/spew"
 )
 
 func testgenInvalid(t *testing.T, input string) {
@@ -56,7 +54,7 @@ func testgenValid(t *testing.T, input string, jsonRef string) {
 	}
 
 	if !reflect.DeepEqual(jsonExpected, jsonTest) {
-		t.Logf("Diff:\n%s", spew.Sdump(jsonExpected, jsonTest))
+		t.Logf("Diff:\n%#+v\n%#+v", jsonExpected, jsonTest)
 		t.Fatal("parsed TOML tree is different than expected structure")
 	}
 }

tomlpub.go

@@ -0,0 +1,71 @@
+package toml
+
+// PubTOMLValue wrapping tomlValue in order to access all properties from outside.
+type PubTOMLValue = tomlValue
+
+func (ptv *PubTOMLValue) Value() interface{} {
+	return ptv.value
+}
+func (ptv *PubTOMLValue) Comment() string {
+	return ptv.comment
+}
+func (ptv *PubTOMLValue) Commented() bool {
+	return ptv.commented
+}
+func (ptv *PubTOMLValue) Multiline() bool {
+	return ptv.multiline
+}
+func (ptv *PubTOMLValue) Position() Position {
+	return ptv.position
+}
+
+func (ptv *PubTOMLValue) SetValue(v interface{}) {
+	ptv.value = v
+}
+func (ptv *PubTOMLValue) SetComment(s string) {
+	ptv.comment = s
+}
+func (ptv *PubTOMLValue) SetCommented(c bool) {
+	ptv.commented = c
+}
+func (ptv *PubTOMLValue) SetMultiline(m bool) {
+	ptv.multiline = m
+}
+func (ptv *PubTOMLValue) SetPosition(p Position) {
+	ptv.position = p
+}
+
+// PubTree wrapping Tree in order to access all properties from outside.
+type PubTree = Tree
+
+func (pt *PubTree) Values() map[string]interface{} {
+	return pt.values
+}
+
+func (pt *PubTree) Comment() string {
+	return pt.comment
+}
+
+func (pt *PubTree) Commented() bool {
+	return pt.commented
+}
+
+func (pt *PubTree) Inline() bool {
+	return pt.inline
+}
+
+func (pt *PubTree) SetValues(v map[string]interface{}) {
+	pt.values = v
+}
+
+func (pt *PubTree) SetComment(c string) {
+	pt.comment = c
+}
+
+func (pt *PubTree) SetCommented(c bool) {
+	pt.commented = c
+}
+
+func (pt *PubTree) SetInline(i bool) {
+	pt.inline = i
+}

tomltree_create.go

@@ -57,6 +57,19 @@ func simpleValueCoercion(object interface{}) (interface{}, error) {
 		return float64(original), nil
 	case fmt.Stringer:
 		return original.String(), nil
+	case []interface{}:
+		value := reflect.ValueOf(original)
+		length := value.Len()
+		arrayValue := reflect.MakeSlice(value.Type(), 0, length)
+		for i := 0; i < length; i++ {
+			val := value.Index(i).Interface()
+			simpleValue, err := simpleValueCoercion(val)
+			if err != nil {
+				return nil, err
+			}
+			arrayValue = reflect.Append(arrayValue, reflect.ValueOf(simpleValue))
+		}
+		return arrayValue.Interface(), nil
 	default:
 		return nil, fmt.Errorf("cannot convert type %T to Tree", object)
 	}

tomltree_create_test.go

@@ -1,6 +1,7 @@
 package toml
 
 import (
+	"reflect"
 	"strconv"
 	"testing"
 	"time"
@@ -124,3 +125,119 @@ func TestRoundTripArrayOfTables(t *testing.T) {
 		t.Errorf("want:\n%s\ngot:\n%s", want, got)
 	}
 }
+
+func TestTomlSliceOfSlice(t *testing.T) {
+	tree, err := Load(` hosts=[["10.1.0.107:9092","10.1.0.107:9093", "192.168.0.40:9094"] ] `)
+	m := tree.ToMap()
+	tree, err = TreeFromMap(m)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+	type Struct struct {
+		Hosts [][]string
+	}
+	var actual Struct
+	tree.Unmarshal(&actual)
+
+	expected := Struct{Hosts: [][]string{[]string{"10.1.0.107:9092", "10.1.0.107:9093", "192.168.0.40:9094"}}}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
+	}
+}
+
+func TestTomlSliceOfSliceOfSlice(t *testing.T) {
+	tree, err := Load(` hosts=[[["10.1.0.107:9092","10.1.0.107:9093", "192.168.0.40:9094"] ]] `)
+	m := tree.ToMap()
+	tree, err = TreeFromMap(m)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+	type Struct struct {
+		Hosts [][][]string
+	}
+	var actual Struct
+	tree.Unmarshal(&actual)
+
+	expected := Struct{Hosts: [][][]string{[][]string{[]string{"10.1.0.107:9092", "10.1.0.107:9093", "192.168.0.40:9094"}}}}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
+	}
+}
+
+func TestTomlSliceOfSliceInt(t *testing.T) {
+	tree, err := Load(` hosts=[[1,2,3],[4,5,6] ] `)
+	m := tree.ToMap()
+	tree, err = TreeFromMap(m)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+	type Struct struct {
+		Hosts [][]int
+	}
+	var actual Struct
+	err = tree.Unmarshal(&actual)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+
+	expected := Struct{Hosts: [][]int{[]int{1, 2, 3}, []int{4, 5, 6}}}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
+	}
+
+}
+func TestTomlSliceOfSliceInt64(t *testing.T) {
+	tree, err := Load(` hosts=[[1,2,3],[4,5,6] ] `)
+	m := tree.ToMap()
+	tree, err = TreeFromMap(m)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+	type Struct struct {
+		Hosts [][]int64
+	}
+	var actual Struct
+	err = tree.Unmarshal(&actual)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+
+	expected := Struct{Hosts: [][]int64{[]int64{1, 2, 3}, []int64{4, 5, 6}}}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
+	}
+
+}
+
+func TestTomlSliceOfSliceInt64FromMap(t *testing.T) {
+	tree, err := TreeFromMap(map[string]interface{}{"hosts": [][]interface{}{[]interface{}{int32(1), int8(2), 3}}})
+	if err != nil {
+		t.Error("should not error", err)
+	}
+	type Struct struct {
+		Hosts [][]int64
+	}
+	var actual Struct
+	err = tree.Unmarshal(&actual)
+	if err != nil {
+		t.Error("should not error", err)
+	}
+
+	expected := Struct{Hosts: [][]int64{[]int64{1, 2, 3}}}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Errorf("Bad unmarshal: expected %+v, got %+v", expected, actual)
+	}
+
+}
+func TestTomlSliceOfSliceError(t *testing.T) { // make Codecov happy
+	_, err := TreeFromMap(map[string]interface{}{"hosts": [][]interface{}{[]interface{}{1, 2, []struct{}{}}}})
+	expected := "cannot convert type []struct {} to Tree"
+	if err.Error() != expected {
+		t.Fatalf("unexpected error: %s", err)
+	}
+}

tomltree_write.go

@@ -103,7 +103,7 @@ func encodeTomlString(value string) string {
 	return b.String()
 }
 
-func tomlTreeStringRepresentation(t *Tree, ord marshalOrder) (string, error) {
+func tomlTreeStringRepresentation(t *Tree, ord MarshalOrder) (string, error) {
 	var orderedVals []sortNode
 	switch ord {
 	case OrderPreserve:
@@ -126,7 +126,7 @@ func tomlTreeStringRepresentation(t *Tree, ord marshalOrder) (string, error) {
 	return "{ " + strings.Join(values, ", ") + " }", nil
 }
 
-func tomlValueStringRepresentation(v interface{}, commented string, indent string, ord marshalOrder, arraysOneElementPerLine bool) (string, error) {
+func tomlValueStringRepresentation(v interface{}, commented string, indent string, ord MarshalOrder, arraysOneElementPerLine bool) (string, error) {
 	// this interface check is added to dereference the change made in the writeTo function.
 	// That change was made to allow this function to see formatting options.
 	tv, ok := v.(*tomlValue)
@@ -158,12 +158,20 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 		return strings.ToLower(strconv.FormatFloat(value, 'f', -1, bits)), nil
 	case string:
 		if tv.multiline {
-			return "\"\"\"\n" + encodeMultilineTomlString(value, commented) + "\"\"\"", nil
+			if tv.literal {
+				b := strings.Builder{}
+				b.WriteString("'''\n")
+				b.Write([]byte(value))
+				b.WriteString("\n'''")
+				return b.String(), nil
+			} else {
+				return "\"\"\"\n" + encodeMultilineTomlString(value, commented) + "\"\"\"", nil
+			}
 		}
 		return "\"" + encodeTomlString(value) + "\"", nil
 	case []byte:
 		b, _ := v.([]byte)
-		return tomlValueStringRepresentation(string(b), commented, indent, ord, arraysOneElementPerLine)
+		return string(b), nil
 	case bool:
 		if value {
 			return "true", nil
@@ -218,7 +226,9 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 }
 
 func getTreeArrayLine(trees []*Tree) (line int) {
-	// get lowest line number that is not 0
+	// Prevent returning 0 for empty trees
+	line = int(^uint(0) >> 1)
+	// get lowest line number >= 0
 	for _, tv := range trees {
 		if tv.position.Line < line || line == 0 {
 			line = tv.position.Line
@@ -307,10 +317,10 @@ func sortAlphabetical(t *Tree) (vals []sortNode) {
 }
 
 func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool) (int64, error) {
-	return t.writeToOrdered(w, indent, keyspace, bytesCount, arraysOneElementPerLine, OrderAlphabetical, "  ", false)
+	return t.writeToOrdered(w, indent, keyspace, bytesCount, arraysOneElementPerLine, OrderAlphabetical, "  ", false, false)
 }
 
-func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool, ord marshalOrder, indentString string, parentCommented bool) (int64, error) {
+func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool, ord MarshalOrder, indentString string, compactComments, parentCommented bool) (int64, error) {
 	var orderedVals []sortNode
 
 	switch ord {
@@ -360,7 +370,7 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 				if err != nil {
 					return bytesCount, err
 				}
-				bytesCount, err = node.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, parentCommented || t.commented || tv.commented)
+				bytesCount, err = node.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, compactComments, parentCommented || t.commented || tv.commented)
 				if err != nil {
 					return bytesCount, err
 				}
@@ -376,7 +386,7 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 						return bytesCount, err
 					}
 
-					bytesCount, err = subTree.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, parentCommented || t.commented || subTree.commented)
+					bytesCount, err = subTree.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, compactComments, parentCommented || t.commented || subTree.commented)
 					if err != nil {
 						return bytesCount, err
 					}
@@ -404,7 +414,14 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 				if strings.HasPrefix(comment, "#") {
 					start = ""
 				}
-				writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment, "\n")
+				if !compactComments {
+					writtenBytesCountComment, errc := writeStrings(w, "\n")
+					bytesCount += int64(writtenBytesCountComment)
+					if errc != nil {
+						return bytesCount, errc
+					}
+				}
+				writtenBytesCountComment, errc := writeStrings(w, indent, start, comment, "\n")
 				bytesCount += int64(writtenBytesCountComment)
 				if errc != nil {
 					return bytesCount, errc
@@ -510,8 +527,26 @@ func (t *Tree) ToMap() map[string]interface{} {
 		case *Tree:
 			result[k] = node.ToMap()
 		case *tomlValue:
-			result[k] = node.value
+			result[k] = tomlValueToGo(node.value)
 		}
 	}
 	return result
 }
+
+func tomlValueToGo(v interface{}) interface{} {
+	if tree, ok := v.(*Tree); ok {
+		return tree.ToMap()
+	}
+
+	rv := reflect.ValueOf(v)
+
+	if rv.Kind() != reflect.Slice {
+		return v
+	}
+	values := make([]interface{}, rv.Len())
+	for i := 0; i < rv.Len(); i++ {
+		item := rv.Index(i).Interface()
+		values[i] = tomlValueToGo(item)
+	}
+	return values
+}

tomltree_write_test.go

@@ -295,6 +295,42 @@ func TestTreeWriteToMapWithArrayOfInlineTables(t *testing.T) {
 	testMaps(t, treeMap, expected)
 }
 
+func TestTreeWriteToMapWithTableInMixedArray(t *testing.T) {
+	tree, _ := Load(`a = [
+		"foo",
+		[
+			"bar",
+			{baz = "quux"},
+		],
+		[
+			{a = "b"},
+			{c = "d"},
+		],
+	]`)
+	expected := map[string]interface{}{
+		"a": []interface{}{
+			"foo",
+			[]interface{}{
+				"bar",
+				map[string]interface{}{
+					"baz": "quux",
+				},
+			},
+			[]interface{}{
+				map[string]interface{}{
+					"a": "b",
+				},
+				map[string]interface{}{
+					"c": "d",
+				},
+			},
+		},
+	}
+	treeMap := tree.ToMap()
+
+	testMaps(t, treeMap, expected)
+}
+
 func TestTreeWriteToFloat(t *testing.T) {
 	tree, err := Load(`a = 3.0`)
 	if err != nil {
@@ -328,6 +364,55 @@ c = nan`
 	}
 }
 
+func TestOrderedEmptyTrees(t *testing.T) {
+	type val struct {
+		Key string `toml:"key"`
+	}
+	type structure struct {
+		First val   `toml:"first"`
+		Empty []val `toml:"empty"`
+	}
+	input := structure{First: val{Key: "value"}}
+	buf := new(bytes.Buffer)
+	err := NewEncoder(buf).Order(OrderPreserve).Encode(input)
+	if err != nil {
+		t.Fatal("failed to encode input")
+	}
+	expected := `
+[first]
+  key = "value"
+`
+	if expected != buf.String() {
+		t.Fatal("expected and encoded body aren't equal: ", expected, buf.String())
+	}
+}
+
+func TestOrderedNonIncreasedLine(t *testing.T) {
+	type NiceMap map[string]string
+	type Manifest struct {
+		NiceMap `toml:"dependencies"`
+		Build   struct {
+			BuildCommand string `toml:"build-command"`
+		} `toml:"build"`
+	}
+
+	test := &Manifest{}
+	test.Build.BuildCommand = "test"
+	buf := new(bytes.Buffer)
+	if err := NewEncoder(buf).Order(OrderPreserve).Encode(test); err != nil {
+		panic(err)
+	}
+	expected := `
+[dependencies]
+
+[build]
+  build-command = "test"
+`
+	if expected != buf.String() {
+		t.Fatal("expected and encoded body aren't equal: ", expected, buf.String())
+	}
+}
+
 func TestIssue290(t *testing.T) {
 	tomlString :=
 		`[table]

tomltree_writepub.go

@@ -0,0 +1,6 @@
+package toml
+
+// ValueStringRepresentation transforms an interface{} value into its toml string representation.
+func ValueStringRepresentation(v interface{}, commented string, indent string, ord MarshalOrder, arraysOneElementPerLine bool) (string, error) {
+	return tomlValueStringRepresentation(v, commented, indent, ord, arraysOneElementPerLine)
+}