Clean up documentation (#168)

Fixes #135

README.md

@@ -17,64 +17,62 @@ Go-toml provides the following features for using data parsed from TOML document
 
 * Load TOML documents from files and string data
 * Easily navigate TOML structure using Tree
+* Mashaling and unmarshaling to and from data structures
 * Line & column position data for all parsed elements
 * [Query support similar to JSON-Path](query/)
 * Syntax errors contain line and column numbers
 
-Go-toml is designed to help cover use-cases not covered by reflection-based TOML parsing:
-
-* Semantic evaluation of parsed TOML
-* Informing a user of mistakes in the source document, after it has been parsed
-* Programatic handling of default values on a case-by-case basis
-* Using a TOML document as a flexible data-store
-
 ## Import
 
-    import "github.com/pelletier/go-toml"
-
-## Usage
-
-### Example
-
-Say you have a TOML file that looks like this:
-
-```toml
-[postgres]
-user = "pelletier"
-password = "mypassword"
+```go
+import "github.com/pelletier/go-toml"
 ```
 
-Read the username and password like this:
+## Usage example
+
+Read a TOML document:
 
 ```go
-import (
-    "fmt"
-    "github.com/pelletier/go-toml"
-)
+config, _ := toml.LoadString(`
+[postgres]
+user = "pelletier"
+password = "mypassword"`)
+// retrieve data directly
+user := config.Get("postgres.user").(string)
 
-config, err := toml.LoadFile("config.toml")
-if err != nil {
-    fmt.Println("Error ", err.Error())
-} else {
-    // retrieve data directly
-    user := config.Get("postgres.user").(string)
-    password := config.Get("postgres.password").(string)
+// or using an intermediate object
+postgresConfig := config.Get("postgres").(*toml.Tree)
+password = postgresConfig.Get("password").(string)
+```
 
-    // or using an intermediate object
-    configTree := config.Get("postgres").(*toml.Tree)
-    user = configTree.Get("user").(string)
-    password = configTree.Get("password").(string)
-    fmt.Println("User is ", user, ". Password is ", password)
+Or use Unmarshal:
 
-    // show where elements are in the file
-    fmt.Println("User position: %v", configTree.GetPosition("user"))
-    fmt.Println("Password position: %v", configTree.GetPosition("password"))
+```go
+type Postgres struct {
+    User     string
+    Password string
+}
+type Config struct {
+    Postgres Postgres
+}
 
-    // use a query to gather elements without walking the tree
-    results, _ := config.Query("$..[user,password]")
-    for ii, item := range results.Values() {
-      fmt.Println("Query result %d: %v", ii, item)
-    }
+doc := []byte(`
+[postgres]
+user = "pelletier"
+password = "mypassword"`)
+
+config := Config{}
+Unmarshal(doc, &config)
+fmt.Println("user=", config.Postgres.User)
+```
+
+Or use a query:
+
+```go
+// use a query to gather elements without walking the tree
+results, _ := config.Query("$..[user,password]")
+for ii, item := range results.Values() {
+    fmt.Println("Query result %d: %v", ii, item)
 }
 ```
 

cmd/tomljson/main.go

@@ -1,3 +1,8 @@
+// Tomljson reads TOML and converts to JSON.
+//
+// Usage:
+//   cat file.toml | tomljson > file.json
+//   tomljson file1.toml > file.json
 package main
 
 import (

cmd/tomll/main.go

@@ -1,3 +1,8 @@
+// Tomll is a linter for TOML
+//
+// Usage:
+//   cat file.toml | tomll > file_linted.toml
+//   tomll file1.toml file2.toml # lint the two files in place
 package main
 
 import (

doc.go

@@ -1,79 +1,18 @@
-// Package toml is a TOML markup language parser.
+// Package toml is a TOML parser and manipulation library.
 //
 // This version supports the specification as described in
 // https://github.com/toml-lang/toml/blob/master/versions/en/toml-v0.4.0.md
 //
-// TOML Parsing
+// Marshaling
 //
-// TOML data may be parsed in two ways: by file, or by string.
+// Go-toml can marshal and unmarshal TOML documents from and to data
+// structures.
 //
-//   // load TOML data by filename
-//   tree, err := toml.LoadFile("filename.toml")
+// TOML document as a tree
 //
-//   // load TOML data stored in a string
-//   tree, err := toml.Load(stringContainingTomlData)
-//
-// Either way, the result is a Tree object that can be used to navigate the
-// structure and data within the original document.
-//
-//
-// Getting data from the Tree
-//
-// After parsing TOML data with Load() or LoadFile(), use the Has() and Get()
-// methods on the returned Tree, to find your way through the document data.
-//
-//   if tree.Has("foo") {
-//     fmt.Println("foo is:", tree.Get("foo"))
-//   }
-//
-// Working with Paths
-//
-// Go-toml has support for basic dot-separated key paths on the Has(), Get(), Set()
-// and GetDefault() methods.  These are the same kind of key paths used within the
-// TOML specification for struct tames.
-//
-//   // looks for a key named 'baz', within struct 'bar', within struct 'foo'
-//   tree.Has("foo.bar.baz")
-//
-//   // returns the key at this path, if it is there
-//   tree.Get("foo.bar.baz")
-//
-// TOML allows keys to contain '.', which can cause this syntax to be problematic
-// for some documents.  In such cases, use the GetPath(), HasPath(), and SetPath(),
-// methods to explicitly define the path.  This form is also faster, since
-// it avoids having to parse the passed key for '.' delimiters.
-//
-//   // looks for a key named 'baz', within struct 'bar', within struct 'foo'
-//   tree.HasPath([]string{"foo","bar","baz"})
-//
-//   // returns the key at this path, if it is there
-//   tree.GetPath([]string{"foo","bar","baz"})
-//
-// Note that this is distinct from the heavyweight query syntax supported by
-// Tree.Query() and the Query() struct (see below).
-//
-// Position Support
-//
-// Each element within the Tree is stored with position metadata, which is
-// invaluable for providing semantic feedback to a user.  This helps in
-// situations where the TOML file parses correctly, but contains data that is
-// not correct for the application.  In such cases, an error message can be
-// generated that indicates the problem line and column number in the source
-// TOML document.
-//
-//   // load TOML data
-//   tree, _ := toml.Load("filename.toml")
-//
-//   // get an entry and report an error if it's the wrong type
-//   element := tree.Get("foo")
-//   if value, ok := element.(int64); !ok {
-//       return fmt.Errorf("%v: Element 'foo' must be an integer", tree.GetPosition("foo"))
-//   }
-//
-//   // report an error if an expected element is missing
-//   if !tree.Has("bar") {
-//      return fmt.Errorf("%v: Expected 'bar' element", tree.GetPosition(""))
-//   }
+// Go-toml can operate on a TOML document as a tree. Use one of the Load*
+// functions to parse TOML data and obtain a Tree instance, then one of its
+// methods to manipulate the tree.
 //
 // JSONPath-like queries
 //

doc_test.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 )
 
-func Example_comprehensiveExample() {
+func Example_tree() {
 	config, err := LoadFile("config.toml")
 
 	if err != nil {
@@ -20,10 +20,34 @@ func Example_comprehensiveExample() {
 		configTree := config.Get("postgres").(*Tree)
 		user = configTree.Get("user").(string)
 		password = configTree.Get("password").(string)
-		fmt.Println("User is ", user, ". Password is ", password)
+		fmt.Println("User is", user, " and password is", password)
 
 		// show where elements are in the file
 		fmt.Printf("User position: %v\n", configTree.GetPosition("user"))
 		fmt.Printf("Password position: %v\n", configTree.GetPosition("password"))
 	}
 }
+
+func Example_unmarshal() {
+	type Employer struct {
+		Name  string
+		Phone string
+	}
+	type Person struct {
+		Name     string
+		Age      int64
+		Employer Employer
+	}
+
+	document := []byte(`
+	name = "John"
+	age = 30
+	[employer]
+		name = "Company Inc."
+		phone = "+1 234 567 89012"
+	`)
+
+	person := Person{}
+	Unmarshal(document, &person)
+	fmt.Println(person.Name, "is", person.Age, "and works at", person.Employer.Name)
+}

marshal.go

@@ -9,24 +9,6 @@ import (
 	"time"
 )
 
-/*
-Tree structural types and corresponding marshal types
--------------------------------------------------------------------------------
-*Tree                        (*)struct, (*)map[string]interface{}
-[]*Tree                      (*)[](*)struct, (*)[](*)map[string]interface{}
-[]interface{} (as interface{})   (*)[]primitive, (*)[]([]interface{})
-interface{}                      (*)primitive
-
-Tree primitive types and  corresponding marshal types
------------------------------------------------------------
-uint64     uint, uint8-uint64, pointers to same
-int64      int, int8-uint64, pointers to same
-float64    float32, float64, pointers to same
-string     string, pointers to same
-bool       bool, pointers to same
-time.Time  time.Time{}, pointers to same
-*/
-
 type tomlOpts struct {
 	name      string
 	include   bool
@@ -115,6 +97,22 @@ function for sub-structs, and currently only definite types can be marshaled
 Note that pointers are automatically assigned the "omitempty" option, as TOML
 explicity does not handle null values (saying instead the label should be
 dropped).
+
+Tree structural types and corresponding marshal types:
+
+  *Tree                            (*)struct, (*)map[string]interface{}
+  []*Tree                          (*)[](*)struct, (*)[](*)map[string]interface{}
+  []interface{} (as interface{})   (*)[]primitive, (*)[]([]interface{})
+  interface{}                      (*)primitive
+
+Tree primitive types and corresponding marshal types:
+
+  uint64     uint, uint8-uint64, pointers to same
+  int64      int, int8-uint64, pointers to same
+  float64    float32, float64, pointers to same
+  string     string, pointers to same
+  bool       bool, pointers to same
+  time.Time  time.Time{}, pointers to same
 */
 func Marshal(v interface{}) ([]byte, error) {
 	mtype := reflect.TypeOf(v)
@@ -247,6 +245,8 @@ func (t *Tree) Unmarshal(v interface{}) error {
 // is no concept of an Unmarshaler interface or UnmarshalTOML function for
 // sub-structs, and currently only definite types can be unmarshaled to (i.e. no
 // `interface{}`).
+//
+// See Marshal() documentation for types mapping table.
 func Unmarshal(data []byte, v interface{}) error {
 	t, err := LoadReader(bytes.NewReader(data))
 	if err != nil {

marshal_test.go

@@ -177,6 +177,25 @@ func TestDocUnmarshal(t *testing.T) {
 	}
 }
 
+func ExampleUnmarshal() {
+	type Postgres struct {
+		User     string
+		Password string
+	}
+	type Config struct {
+		Postgres Postgres
+	}
+
+	doc := []byte(`
+	[postgres]
+	user = "pelletier"
+	password = "mypassword"`)
+
+	config := Config{}
+	Unmarshal(doc, &config)
+	fmt.Println("user=", config.Postgres.User)
+}
+
 func TestDocPartialUnmarshal(t *testing.T) {
 	result := testDocSubs{}
 

toml.go

@@ -54,8 +54,7 @@ func (t *Tree) HasPath(keys []string) bool {
 	return t.GetPath(keys) != nil
 }
 
-// Keys returns the keys of the toplevel tree.
-// Warning: this is a costly operation.
+// Keys returns the keys of the toplevel tree (does not recurse).
 func (t *Tree) Keys() []string {
 	keys := make([]string, len(t.values))
 	i := 0