Make all nodes contain Raw

Also has the perks of reducing the overhead of FindByIndex:

```
name                                old time/op    new time/op    delta
UnmarshalDataset/config-32            17.0ms ± 1%    17.0ms ± 1%    ~     (p=1.000 n=5+5)
UnmarshalDataset/canada-32            71.6ms ± 1%    71.4ms ± 1%    ~     (p=1.000 n=5+5)
UnmarshalDataset/citm_catalog-32      24.2ms ± 3%    23.5ms ± 2%  -3.03%  (p=0.032 n=5+5)
UnmarshalDataset/twitter-32           9.37ms ± 1%    9.09ms ± 2%  -2.97%  (p=0.032 n=5+5)
UnmarshalDataset/code-32              75.4ms ± 2%    74.9ms ± 0%    ~     (p=0.222 n=5+5)
UnmarshalDataset/example-32            147µs ±10%     136µs ± 1%  -7.14%  (p=0.008 n=5+5)
Unmarshal/SimpleDocument/struct-32     512ns ± 2%     500ns ± 0%  -2.35%  (p=0.008 n=5+5)
Unmarshal/SimpleDocument/map-32        721ns ± 2%     702ns ± 1%  -2.68%  (p=0.008 n=5+5)
Unmarshal/ReferenceFile/struct-32     40.1µs ± 0%    39.6µs ± 0%  -1.30%  (p=0.008 n=5+5)
Unmarshal/ReferenceFile/map-32        62.3µs ± 1%    60.6µs ± 0%  -2.83%  (p=0.008 n=5+5)
Unmarshal/HugoFrontMatter-32          10.8µs ± 1%    10.5µs ± 1%  -2.86%  (p=0.008 n=5+5)

name                                old speed      new speed      delta
UnmarshalDataset/config-32          61.8MB/s ± 1%  61.8MB/s ± 1%    ~     (p=1.000 n=5+5)
UnmarshalDataset/canada-32          30.8MB/s ± 1%  30.8MB/s ± 1%    ~     (p=1.000 n=5+5)
UnmarshalDataset/citm_catalog-32    23.0MB/s ± 3%  23.8MB/s ± 2%  +3.09%  (p=0.032 n=5+5)
UnmarshalDataset/twitter-32         47.2MB/s ± 1%  48.6MB/s ± 2%  +3.09%  (p=0.032 n=5+5)
UnmarshalDataset/code-32            35.6MB/s ± 2%  35.9MB/s ± 0%    ~     (p=0.222 n=5+5)
UnmarshalDataset/example-32         55.3MB/s ±10%  59.4MB/s ± 1%  +7.36%  (p=0.008 n=5+5)
Unmarshal/SimpleDocument/struct-32  21.5MB/s ± 2%  22.0MB/s ± 0%  +2.41%  (p=0.008 n=5+5)
Unmarshal/SimpleDocument/map-32     15.2MB/s ± 2%  15.7MB/s ± 1%  +2.74%  (p=0.008 n=5+5)
Unmarshal/ReferenceFile/struct-32    131MB/s ± 0%   132MB/s ± 0%  +1.31%  (p=0.008 n=5+5)
Unmarshal/ReferenceFile/map-32      84.1MB/s ± 1%  86.6MB/s ± 0%  +2.91%  (p=0.008 n=5+5)
Unmarshal/HugoFrontMatter-32        50.6MB/s ± 1%  52.1MB/s ± 1%  +2.93%  (p=0.008 n=5+5)

name                                old alloc/op   new alloc/op   delta
UnmarshalDataset/config-32            5.86MB ± 0%    5.86MB ± 0%    ~     (p=0.579 n=5+5)
UnmarshalDataset/canada-32            83.0MB ± 0%    83.0MB ± 0%    ~     (p=0.651 n=5+5)
UnmarshalDataset/citm_catalog-32      34.7MB ± 0%    34.7MB ± 0%    ~     (p=0.548 n=5+5)
UnmarshalDataset/twitter-32           12.7MB ± 0%    12.7MB ± 0%    ~     (p=1.000 n=5+5)
UnmarshalDataset/code-32              22.2MB ± 0%    22.2MB ± 0%    ~     (p=0.841 n=5+5)
UnmarshalDataset/example-32            186kB ± 0%     186kB ± 0%    ~     (p=0.111 n=5+5)
Unmarshal/SimpleDocument/struct-32      805B ± 0%      805B ± 0%    ~     (all equal)
Unmarshal/SimpleDocument/map-32       1.13kB ± 0%    1.13kB ± 0%    ~     (all equal)
Unmarshal/ReferenceFile/struct-32     20.9kB ± 0%    20.9kB ± 0%    ~     (p=0.643 n=5+5)
Unmarshal/ReferenceFile/map-32        38.3kB ± 0%    38.3kB ± 0%    ~     (p=0.397 n=5+5)
Unmarshal/HugoFrontMatter-32          7.44kB ± 0%    7.44kB ± 0%    ~     (all equal)

name                                old allocs/op  new allocs/op  delta
UnmarshalDataset/config-32              227k ± 0%      227k ± 0%    ~     (p=1.000 n=5+5)
UnmarshalDataset/canada-32              782k ± 0%      782k ± 0%    ~     (all equal)
UnmarshalDataset/citm_catalog-32        192k ± 0%      192k ± 0%    ~     (p=0.968 n=4+5)
UnmarshalDataset/twitter-32            56.9k ± 0%     56.9k ± 0%    ~     (p=0.429 n=4+5)
UnmarshalDataset/code-32               1.05M ± 0%     1.05M ± 0%    ~     (p=0.556 n=4+5)
UnmarshalDataset/example-32            1.36k ± 0%     1.36k ± 0%    ~     (all equal)
Unmarshal/SimpleDocument/struct-32      9.00 ± 0%      9.00 ± 0%    ~     (all equal)
Unmarshal/SimpleDocument/map-32         13.0 ± 0%      13.0 ± 0%    ~     (all equal)
Unmarshal/ReferenceFile/struct-32        183 ± 0%       183 ± 0%    ~     (all equal)
Unmarshal/ReferenceFile/map-32           642 ± 0%       642 ± 0%    ~     (all equal)
Unmarshal/HugoFrontMatter-32             141 ± 0%       141 ± 0%    ~     (all equal)
```

Fixes #807

fuzz_test.go

@@ -1,4 +1,5 @@
 //go:build go1.18 || go1.19
+// +build go1.18 go1.19
 
 package toml_test
 

parser.go

@@ -28,6 +28,11 @@ func (p *parser) Raw(raw ast.Range) []byte {
 	return p.data[raw.Offset : raw.Offset+raw.Length]
 }
 
+func (p *parser) SetRaw(ref ast.Reference, from []byte, to []byte) {
+	b := danger.BytesRange(from, to)
+	p.builder.NodeAt(ref).Raw = p.Range(b)
+}
+
 func (p *parser) Reset(b []byte) {
 	p.builder.Reset()
 	p.ref = ast.InvalidReference
@@ -152,12 +157,14 @@ func (p *parser) parseArrayTable(b []byte) (ast.Reference, []byte, error) {
 	ref := p.builder.Push(ast.Node{
 		Kind: ast.ArrayTable,
 	})
+	start := b
 
 	b = b[2:]
 	b = p.parseWhitespace(b)
 
 	k, b, err := p.parseKey(b)
 	if err != nil {
+		p.SetRaw(ref, start, b)
 		return ref, nil, err
 	}
 
@@ -166,11 +173,12 @@ func (p *parser) parseArrayTable(b []byte) (ast.Reference, []byte, error) {
 
 	b, err = expect(']', b)
 	if err != nil {
+		p.SetRaw(ref, start, b)
 		return ref, nil, err
 	}
 
 	b, err = expect(']', b)
-
+	p.SetRaw(ref, start, b)
 	return ref, b, err
 }
 
@@ -181,12 +189,14 @@ func (p *parser) parseStdTable(b []byte) (ast.Reference, []byte, error) {
 	ref := p.builder.Push(ast.Node{
 		Kind: ast.Table,
 	})
+	start := b
 
 	b = b[1:]
 	b = p.parseWhitespace(b)
 
 	key, b, err := p.parseKey(b)
 	if err != nil {
+		p.SetRaw(ref, start, b)
 		return ref, nil, err
 	}
 
@@ -196,6 +206,7 @@ func (p *parser) parseStdTable(b []byte) (ast.Reference, []byte, error) {
 
 	b, err = expect(']', b)
 
+	p.SetRaw(ref, start, b)
 	return ref, b, err
 }
 
@@ -204,10 +215,12 @@ func (p *parser) parseKeyval(b []byte) (ast.Reference, []byte, error) {
 	ref := p.builder.Push(ast.Node{
 		Kind: ast.KeyValue,
 	})
+	start := b
 
 	key, b, err := p.parseKey(b)
 	if err != nil {
-		return ast.InvalidReference, nil, err
+		p.SetRaw(ref, start, b)
+		return ast.InvalidReference, b, err
 	}
 
 	// keyval-sep = ws %x3D ws ; =
@@ -215,24 +228,28 @@ func (p *parser) parseKeyval(b []byte) (ast.Reference, []byte, error) {
 	b = p.parseWhitespace(b)
 
 	if len(b) == 0 {
-		return ast.InvalidReference, nil, newDecodeError(b, "expected = after a key, but the document ends there")
+		p.SetRaw(ref, start, b)
+		return ast.InvalidReference, b, newDecodeError(b, "expected = after a key, but the document ends there")
 	}
 
 	b, err = expect('=', b)
 	if err != nil {
-		return ast.InvalidReference, nil, err
+		p.SetRaw(ref, start, b)
+		return ast.InvalidReference, b, err
 	}
 
 	b = p.parseWhitespace(b)
 
 	valRef, b, err := p.parseVal(b)
 	if err != nil {
+		p.SetRaw(ref, start, b)
 		return ref, b, err
 	}
 
 	p.builder.Chain(valRef, key)
 	p.builder.AttachChild(ref, valRef)
 
+	p.SetRaw(ref, start, b)
 	return ref, b, err
 }
 
@@ -242,7 +259,7 @@ func (p *parser) parseVal(b []byte) (ast.Reference, []byte, error) {
 	ref := ast.InvalidReference
 
 	if len(b) == 0 {
-		return ref, nil, newDecodeError(b, "expected value, not eof")
+		return ref, b, newDecodeError(b, "expected value, not eof")
 	}
 
 	var err error
@@ -287,23 +304,25 @@ func (p *parser) parseVal(b []byte) (ast.Reference, []byte, error) {
 		return ref, b, err
 	case 't':
 		if !scanFollowsTrue(b) {
-			return ref, nil, newDecodeError(atmost(b, 4), "expected 'true'")
+			return ref, b, newDecodeError(atmost(b, 4), "expected 'true'")
 		}
 
 		ref = p.builder.Push(ast.Node{
 			Kind: ast.Bool,
 			Data: b[:4],
+			Raw:  p.Range(b[:4]),
 		})
 
 		return ref, b[4:], nil
 	case 'f':
 		if !scanFollowsFalse(b) {
-			return ref, nil, newDecodeError(atmost(b, 5), "expected 'false'")
+			return ref, b, newDecodeError(atmost(b, 5), "expected 'false'")
 		}
 
 		ref = p.builder.Push(ast.Node{
 			Kind: ast.Bool,
 			Data: b[:5],
+			Raw:  p.Range(b[:5]),
 		})
 
 		return ref, b[5:], nil
@@ -327,7 +346,7 @@ func atmost(b []byte, n int) []byte {
 func (p *parser) parseLiteralString(b []byte) ([]byte, []byte, []byte, error) {
 	v, rest, err := scanLiteralString(b)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, rest, err
 	}
 
 	return v, v[1 : len(v)-1], rest, nil
@@ -342,6 +361,7 @@ func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) {
 	parent := p.builder.Push(ast.Node{
 		Kind: ast.InlineTable,
 	})
+	start := b
 
 	first := true
 
@@ -356,7 +376,8 @@ func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) {
 		b = p.parseWhitespace(b)
 
 		if len(b) == 0 {
-			return parent, nil, newDecodeError(previousB[:1], "inline table is incomplete")
+			p.SetRaw(parent, start, b)
+			return parent, b, newDecodeError(previousB[:1], "inline table is incomplete")
 		}
 
 		if b[0] == '}' {
@@ -366,7 +387,8 @@ func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) {
 		if !first {
 			b, err = expect(',', b)
 			if err != nil {
-				return parent, nil, err
+				p.SetRaw(parent, start, b)
+				return parent, b, err
 			}
 			b = p.parseWhitespace(b)
 		}
@@ -375,7 +397,8 @@ func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) {
 
 		kv, b, err = p.parseKeyval(b)
 		if err != nil {
-			return parent, nil, err
+			p.SetRaw(parent, start, b)
+			return parent, b, err
 		}
 
 		if first {
@@ -390,6 +413,7 @@ func (p *parser) parseInlineTable(b []byte) (ast.Reference, []byte, error) {
 
 	rest, err := expect('}', b)
 
+	p.SetRaw(parent, start, b)
 	return parent, rest, err
 }
 
@@ -403,6 +427,7 @@ func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) {
 	// array-sep = %x2C  ; , Comma
 	// ws-comment-newline = *( wschar / [ comment ] newline )
 	arrayStart := b
+	start := b
 	b = b[1:]
 
 	parent := p.builder.Push(ast.Node{
@@ -417,11 +442,13 @@ func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) {
 	for len(b) > 0 {
 		b, err = p.parseOptionalWhitespaceCommentNewline(b)
 		if err != nil {
-			return parent, nil, err
+			p.SetRaw(parent, start, b)
+			return parent, b, err
 		}
 
 		if len(b) == 0 {
-			return parent, nil, newDecodeError(arrayStart[:1], "array is incomplete")
+			p.SetRaw(parent, start, b)
+			return parent, b, newDecodeError(arrayStart[:1], "array is incomplete")
 		}
 
 		if b[0] == ']' {
@@ -430,16 +457,19 @@ func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) {
 
 		if b[0] == ',' {
 			if first {
-				return parent, nil, newDecodeError(b[0:1], "array cannot start with comma")
+				p.SetRaw(parent, start, b)
+				return parent, b, newDecodeError(b[0:1], "array cannot start with comma")
 			}
 			b = b[1:]
 
 			b, err = p.parseOptionalWhitespaceCommentNewline(b)
 			if err != nil {
-				return parent, nil, err
+				p.SetRaw(parent, start, b)
+				return parent, b, err
 			}
 		} else if !first {
-			return parent, nil, newDecodeError(b[0:1], "array elements must be separated by commas")
+			p.SetRaw(parent, start, b)
+			return parent, b, newDecodeError(b[0:1], "array elements must be separated by commas")
 		}
 
 		// TOML allows trailing commas in arrays.
@@ -450,7 +480,8 @@ func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) {
 		var valueRef ast.Reference
 		valueRef, b, err = p.parseVal(b)
 		if err != nil {
-			return parent, nil, err
+			p.SetRaw(parent, start, b)
+			return parent, b, err
 		}
 
 		if first {
@@ -462,13 +493,16 @@ func (p *parser) parseValArray(b []byte) (ast.Reference, []byte, error) {
 
 		b, err = p.parseOptionalWhitespaceCommentNewline(b)
 		if err != nil {
-			return parent, nil, err
+			p.SetRaw(parent, start, b)
+			return parent, b, err
 		}
 		first = false
 	}
 
 	rest, err := expect(']', b)
 
+	p.SetRaw(parent, start, rest)
+
 	return parent, rest, err
 }
 
@@ -480,7 +514,7 @@ func (p *parser) parseOptionalWhitespaceCommentNewline(b []byte) ([]byte, error)
 		if len(b) > 0 && b[0] == '#' {
 			_, b, err = scanComment(b)
 			if err != nil {
-				return nil, err
+				return b, err
 			}
 		}
 
@@ -491,7 +525,7 @@ func (p *parser) parseOptionalWhitespaceCommentNewline(b []byte) ([]byte, error)
 		if b[0] == '\n' || b[0] == '\r' {
 			b, err = p.parseNewline(b)
 			if err != nil {
-				return nil, err
+				return b, err
 			}
 		} else {
 			break
@@ -504,7 +538,7 @@ func (p *parser) parseOptionalWhitespaceCommentNewline(b []byte) ([]byte, error)
 func (p *parser) parseMultilineLiteralString(b []byte) ([]byte, []byte, []byte, error) {
 	token, rest, err := scanMultilineLiteralString(b)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, rest, err
 	}
 
 	i := 3
@@ -533,7 +567,7 @@ func (p *parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, er
 	// mlb-escaped-nl = escape ws newline *( wschar / newline )
 	token, escaped, rest, err := scanMultilineBasicString(b)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, rest, err
 	}
 
 	i := 3
@@ -555,7 +589,7 @@ func (p *parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, er
 		if verr.Zero() {
 			return token, str, rest, nil
 		}
-		return nil, nil, nil, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8")
+		return nil, nil, rest, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8")
 	}
 
 	var builder bytes.Buffer
@@ -622,26 +656,26 @@ func (p *parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, er
 			case 'u':
 				x, err := hexToRune(atmost(token[i+1:], 4), 4)
 				if err != nil {
-					return nil, nil, nil, err
+					return nil, nil, rest, err
 				}
 				builder.WriteRune(x)
 				i += 4
 			case 'U':
 				x, err := hexToRune(atmost(token[i+1:], 8), 8)
 				if err != nil {
-					return nil, nil, nil, err
+					return nil, nil, rest, err
 				}
 
 				builder.WriteRune(x)
 				i += 8
 			default:
-				return nil, nil, nil, newDecodeError(token[i:i+1], "invalid escaped character %#U", c)
+				return nil, nil, rest, newDecodeError(token[i:i+1], "invalid escaped character %#U", c)
 			}
 			i++
 		} else {
 			size := utf8ValidNext(token[i:])
 			if size == 0 {
-				return nil, nil, nil, newDecodeError(token[i:i+1], "invalid character %#U", c)
+				return nil, nil, rest, newDecodeError(token[i:i+1], "invalid character %#U", c)
 			}
 			builder.Write(token[i : i+size])
 			i += size
@@ -662,7 +696,7 @@ func (p *parser) parseKey(b []byte) (ast.Reference, []byte, error) {
 	// dot-sep   = ws %x2E ws  ; . Period
 	raw, key, b, err := p.parseSimpleKey(b)
 	if err != nil {
-		return ast.InvalidReference, nil, err
+		return ast.InvalidReference, b, err
 	}
 
 	ref := p.builder.Push(ast.Node{
@@ -678,7 +712,7 @@ func (p *parser) parseKey(b []byte) (ast.Reference, []byte, error) {
 
 			raw, key, b, err = p.parseSimpleKey(b)
 			if err != nil {
-				return ref, nil, err
+				return ref, b, err
 			}
 
 			p.builder.PushAndChain(ast.Node{
@@ -696,7 +730,7 @@ func (p *parser) parseKey(b []byte) (ast.Reference, []byte, error) {
 
 func (p *parser) parseSimpleKey(b []byte) (raw, key, rest []byte, err error) {
 	if len(b) == 0 {
-		return nil, nil, nil, newDecodeError(b, "expected key but found none")
+		return nil, nil, b, newDecodeError(b, "expected key but found none")
 	}
 
 	// simple-key = quoted-key / unquoted-key
@@ -711,7 +745,7 @@ func (p *parser) parseSimpleKey(b []byte) (raw, key, rest []byte, err error) {
 		key, rest = scanUnquotedKey(b)
 		return key, key, rest, nil
 	default:
-		return nil, nil, nil, newDecodeError(b[0:1], "invalid character at start of key: %c", b[0])
+		return nil, nil, b[1:], newDecodeError(b[0:1], "invalid character at start of key: %c", b[0])
 	}
 }
 
@@ -733,7 +767,7 @@ func (p *parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) {
 	// escape-seq-char =/ %x55 8HEXDIG ; UXXXXXXXX            U+XXXXXXXX
 	token, escaped, rest, err := scanBasicString(b)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, rest, err
 	}
 
 	startIdx := len(`"`)
@@ -748,7 +782,7 @@ func (p *parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) {
 		if verr.Zero() {
 			return token, str, rest, nil
 		}
-		return nil, nil, nil, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8")
+		return nil, nil, rest, newDecodeError(str[verr.Index:verr.Index+verr.Size], "invalid UTF-8")
 	}
 
 	i := startIdx
@@ -781,7 +815,7 @@ func (p *parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) {
 			case 'u':
 				x, err := hexToRune(token[i+1:len(token)-1], 4)
 				if err != nil {
-					return nil, nil, nil, err
+					return nil, nil, rest, err
 				}
 
 				builder.WriteRune(x)
@@ -789,19 +823,19 @@ func (p *parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) {
 			case 'U':
 				x, err := hexToRune(token[i+1:len(token)-1], 8)
 				if err != nil {
-					return nil, nil, nil, err
+					return nil, nil, rest, err
 				}
 
 				builder.WriteRune(x)
 				i += 8
 			default:
-				return nil, nil, nil, newDecodeError(token[i:i+1], "invalid escaped character %#U", c)
+				return nil, nil, rest, newDecodeError(token[i:i+1], "invalid escaped character %#U", c)
 			}
 			i++
 		} else {
 			size := utf8ValidNext(token[i:])
 			if size == 0 {
-				return nil, nil, nil, newDecodeError(token[i:i+1], "invalid character %#U", c)
+				return nil, nil, rest, newDecodeError(token[i:i+1], "invalid character %#U", c)
 			}
 			builder.Write(token[i : i+size])
 			i += size
@@ -854,21 +888,23 @@ func (p *parser) parseIntOrFloatOrDateTime(b []byte) (ast.Reference, []byte, err
 	switch b[0] {
 	case 'i':
 		if !scanFollowsInf(b) {
-			return ast.InvalidReference, nil, newDecodeError(atmost(b, 3), "expected 'inf'")
+			return ast.InvalidReference, b, newDecodeError(atmost(b, 3), "expected 'inf'")
 		}
 
 		return p.builder.Push(ast.Node{
 			Kind: ast.Float,
 			Data: b[:3],
+			Raw:  p.Range(b[:3]),
 		}), b[3:], nil
 	case 'n':
 		if !scanFollowsNan(b) {
-			return ast.InvalidReference, nil, newDecodeError(atmost(b, 3), "expected 'nan'")
+			return ast.InvalidReference, b, newDecodeError(atmost(b, 3), "expected 'nan'")
 		}
 
 		return p.builder.Push(ast.Node{
 			Kind: ast.Float,
 			Data: b[:3],
+			Raw:  p.Range(b[:3]),
 		}), b[3:], nil
 	case '+', '-':
 		return p.scanIntOrFloat(b)
@@ -960,6 +996,7 @@ byteLoop:
 	return p.builder.Push(ast.Node{
 		Kind: kind,
 		Data: b[:i],
+		Raw:  p.Range(b[:i]),
 	}), b[i:], nil
 }
 
@@ -993,6 +1030,7 @@ func (p *parser) scanIntOrFloat(b []byte) (ast.Reference, []byte, error) {
 		return p.builder.Push(ast.Node{
 			Kind: ast.Integer,
 			Data: b[:i],
+			Raw:  p.Range(b[:i]),
 		}), b[i:], nil
 	}
 
@@ -1016,10 +1054,11 @@ func (p *parser) scanIntOrFloat(b []byte) (ast.Reference, []byte, error) {
 				return p.builder.Push(ast.Node{
 					Kind: ast.Float,
 					Data: b[:i+3],
+					Raw:  p.Range(b[:i+3]),
 				}), b[i+3:], nil
 			}
 
-			return ast.InvalidReference, nil, newDecodeError(b[i:i+1], "unexpected character 'i' while scanning for a number")
+			return ast.InvalidReference, b[i:], newDecodeError(b[i:i+1], "unexpected character 'i' while scanning for a number")
 		}
 
 		if c == 'n' {
@@ -1027,10 +1066,11 @@ func (p *parser) scanIntOrFloat(b []byte) (ast.Reference, []byte, error) {
 				return p.builder.Push(ast.Node{
 					Kind: ast.Float,
 					Data: b[:i+3],
+					Raw:  p.Range(b[:i+3]),
 				}), b[i+3:], nil
 			}
 
-			return ast.InvalidReference, nil, newDecodeError(b[i:i+1], "unexpected character 'n' while scanning for a number")
+			return ast.InvalidReference, b[i:], newDecodeError(b[i:i+1], "unexpected character 'n' while scanning for a number")
 		}
 
 		break
@@ -1049,6 +1089,7 @@ func (p *parser) scanIntOrFloat(b []byte) (ast.Reference, []byte, error) {
 	return p.builder.Push(ast.Node{
 		Kind: kind,
 		Data: b[:i],
+		Raw:  p.Range(b[:i]),
 	}), b[i:], nil
 }
 
@@ -1075,11 +1116,11 @@ func isValidBinaryRune(r byte) bool {
 
 func expect(x byte, b []byte) ([]byte, error) {
 	if len(b) == 0 {
-		return nil, newDecodeError(b, "expected character %c but the document ended here", x)
+		return b, newDecodeError(b, "expected character %c but the document ended here", x)
 	}
 
 	if b[0] != x {
-		return nil, newDecodeError(b[0:1], "expected character %c", x)
+		return b, newDecodeError(b[0:1], "expected character %c", x)
 	}
 
 	return b[1:], nil

scanner.go

@@ -54,16 +54,16 @@ func scanLiteralString(b []byte) ([]byte, []byte, error) {
 		case '\'':
 			return b[:i+1], b[i+1:], nil
 		case '\n', '\r':
-			return nil, nil, newDecodeError(b[i:i+1], "literal strings cannot have new lines")
+			return nil, b[i+1:], newDecodeError(b[i:i+1], "literal strings cannot have new lines")
 		}
 		size := utf8ValidNext(b[i:])
 		if size == 0 {
-			return nil, nil, newDecodeError(b[i:i+1], "invalid character")
+			return nil, b[i+1:], newDecodeError(b[i:i+1], "invalid character")
 		}
 		i += size
 	}
 
-	return nil, nil, newDecodeError(b[len(b):], "unterminated literal string")
+	return nil, b[len(b):], newDecodeError(b[len(b):], "unterminated literal string")
 }
 
 func scanMultilineLiteralString(b []byte) ([]byte, []byte, error) {
@@ -98,39 +98,39 @@ func scanMultilineLiteralString(b []byte) ([]byte, []byte, error) {
 				i++
 
 				if i < len(b) && b[i] == '\'' {
-					return nil, nil, newDecodeError(b[i-3:i+1], "''' not allowed in multiline literal string")
+					return nil, b[i:], newDecodeError(b[i-3:i+1], "''' not allowed in multiline literal string")
 				}
 
 				return b[:i], b[i:], nil
 			}
 		case '\r':
 			if len(b) < i+2 {
-				return nil, nil, newDecodeError(b[len(b):], `need a \n after \r`)
+				return nil, b[i:], newDecodeError(b[len(b):], `need a \n after \r`)
 			}
 			if b[i+1] != '\n' {
-				return nil, nil, newDecodeError(b[i:i+2], `need a \n after \r`)
+				return nil, b[i+2:], newDecodeError(b[i:i+2], `need a \n after \r`)
 			}
 			i += 2 // skip the \n
 			continue
 		}
 		size := utf8ValidNext(b[i:])
 		if size == 0 {
-			return nil, nil, newDecodeError(b[i:i+1], "invalid character")
+			return nil, b[i:], newDecodeError(b[i:i+1], "invalid character")
 		}
 		i += size
 	}
 
-	return nil, nil, newDecodeError(b[len(b):], `multiline literal string not terminated by '''`)
+	return nil, b[len(b):], newDecodeError(b[len(b):], `multiline literal string not terminated by '''`)
 }
 
 func scanWindowsNewline(b []byte) ([]byte, []byte, error) {
 	const lenCRLF = 2
 	if len(b) < lenCRLF {
-		return nil, nil, newDecodeError(b, "windows new line expected")
+		return nil, b, newDecodeError(b, "windows new line expected")
 	}
 
 	if b[1] != '\n' {
-		return nil, nil, newDecodeError(b, `windows new line should be \r\n`)
+		return nil, b[2:], newDecodeError(b, `windows new line should be \r\n`)
 	}
 
 	return b[:lenCRLF], b[lenCRLF:], nil
@@ -169,7 +169,7 @@ func scanComment(b []byte) ([]byte, []byte, error) {
 		}
 		size := utf8ValidNext(b[i:])
 		if size == 0 {
-			return nil, nil, newDecodeError(b[i:i+1], "invalid character in comment")
+			return nil, b[i+1:], newDecodeError(b[i:i+1], "invalid character in comment")
 		}
 
 		i += size
@@ -192,17 +192,17 @@ func scanBasicString(b []byte) ([]byte, bool, []byte, error) {
 		case '"':
 			return b[:i+1], escaped, b[i+1:], nil
 		case '\n', '\r':
-			return nil, escaped, nil, newDecodeError(b[i:i+1], "basic strings cannot have new lines")
+			return nil, escaped, b[i+1:], newDecodeError(b[i:i+1], "basic strings cannot have new lines")
 		case '\\':
 			if len(b) < i+2 {
-				return nil, escaped, nil, newDecodeError(b[i:i+1], "need a character after \\")
+				return nil, escaped, b[i+1:], newDecodeError(b[i:i+1], "need a character after \\")
 			}
 			escaped = true
 			i++ // skip the next character
 		}
 	}
 
-	return nil, escaped, nil, newDecodeError(b[len(b):], `basic string not terminated by "`)
+	return nil, escaped, b[len(b):], newDecodeError(b[len(b):], `basic string not terminated by "`)
 }
 
 func scanMultilineBasicString(b []byte) ([]byte, bool, []byte, error) {
@@ -243,27 +243,27 @@ func scanMultilineBasicString(b []byte) ([]byte, bool, []byte, error) {
 				i++
 
 				if i < len(b) && b[i] == '"' {
-					return nil, escaped, nil, newDecodeError(b[i-3:i+1], `""" not allowed in multiline basic string`)
+					return nil, escaped, b[i+1:], newDecodeError(b[i-3:i+1], `""" not allowed in multiline basic string`)
 				}
 
 				return b[:i], escaped, b[i:], nil
 			}
 		case '\\':
 			if len(b) < i+2 {
-				return nil, escaped, nil, newDecodeError(b[len(b):], "need a character after \\")
+				return nil, escaped, b[len(b):], newDecodeError(b[len(b):], "need a character after \\")
 			}
 			escaped = true
 			i++ // skip the next character
 		case '\r':
 			if len(b) < i+2 {
-				return nil, escaped, nil, newDecodeError(b[len(b):], `need a \n after \r`)
+				return nil, escaped, b[len(b):], newDecodeError(b[len(b):], `need a \n after \r`)
 			}
 			if b[i+1] != '\n' {
-				return nil, escaped, nil, newDecodeError(b[i:i+2], `need a \n after \r`)
+				return nil, escaped, b[i+2:], newDecodeError(b[i:i+2], `need a \n after \r`)
 			}
 			i++ // skip the \n
 		}
 	}
 
-	return nil, escaped, nil, newDecodeError(b[len(b):], `multiline basic string not terminated by """`)
+	return nil, escaped, b[len(b):], newDecodeError(b[len(b):], `multiline basic string not terminated by """`)
 }

unmarshaler.go

@@ -123,7 +123,7 @@ type decoder struct {
 	stashedExpr bool
 
 	// Skip expressions until a table is found. This is set to true when a
-	// table could not be create (missing field in map), so all KV expressions
+	// table could not be created (missing field in map), so all KV expressions
 	// need to be skipped.
 	skipUntilTable bool
 
@@ -483,7 +483,7 @@ func (d *decoder) handleKeyPart(key ast.Iterator, v reflect.Value, nextFn handle
 		d.errorContext.Struct = t
 		d.errorContext.Field = path
 
-		f := v.FieldByIndex(path)
+		f := fieldByIndex(v, path)
 		x, err := nextFn(key, f)
 		if err != nil || d.skipUntilTable {
 			return reflect.Value{}, err
@@ -1071,7 +1071,7 @@ func (d *decoder) handleKeyValuePart(key ast.Iterator, value *ast.Node, v reflec
 		d.errorContext.Struct = t
 		d.errorContext.Field = path
 
-		f := v.FieldByIndex(path)
+		f := fieldByIndex(v, path)
 		x, err := d.handleKeyValueInner(key, value, f)
 		if err != nil {
 			return reflect.Value{}, err
@@ -1135,6 +1135,21 @@ func initAndDereferencePointer(v reflect.Value) reflect.Value {
 	return elem
 }
 
+// Same as reflect.Value.FieldByIndex, but creates pointers if needed.
+func fieldByIndex(v reflect.Value, path []int) reflect.Value {
+	for i, x := range path {
+		v = v.Field(x)
+
+		if i < len(path)-1 && v.Kind() == reflect.Pointer {
+			if v.IsNil() {
+				v.Set(reflect.New(v.Type().Elem()))
+			}
+			v = v.Elem()
+		}
+	}
+	return v
+}
+
 type fieldPathsMap = map[string][]int
 
 var globalFieldPathsCache atomic.Value // map[danger.TypeID]fieldPathsMap
@@ -1192,7 +1207,14 @@ func forEachField(t reflect.Type, path []int, do func(name string, path []int))
 		}
 
 		if f.Anonymous && name == "" {
-			forEachField(f.Type, fieldPath, do)
+			t2 := f.Type
+			if t2.Kind() == reflect.Pointer {
+				t2 = t2.Elem()
+			}
+
+			if t2.Kind() == reflect.Struct {
+				forEachField(t2, fieldPath, do)
+			}
 			continue
 		}
 

unmarshaler_test.go

@@ -2451,6 +2451,21 @@ answer = 42
 	require.Error(t, err)
 }
 
+func TestIssue807(t *testing.T) {
+	type A struct {
+		Name string `toml:"name"`
+	}
+
+	type M struct {
+		*A
+	}
+
+	var m M
+	err := toml.Unmarshal([]byte(`name = 'foo'`), &m)
+	require.NoError(t, err)
+	require.Equal(t, "foo", m.Name)
+}
+
 func TestUnmarshalDecodeErrors(t *testing.T) {
 	examples := []struct {
 		desc string
@@ -3273,3 +3288,16 @@ func TestUnmarshal_RecursiveTableArray(t *testing.T) {
 		})
 	}
 }
+
+func TestUnmarshalEmbedNonString(t *testing.T) {
+	type Foo []byte
+	type doc struct {
+		Foo
+	}
+
+	d := doc{}
+
+	err := toml.Unmarshal([]byte(`foo = 'bar'`), &d)
+	require.NoError(t, err)
+	require.Nil(t, d.Foo)
+}