Straightening out a few small wrinkles that came up from testing against the BurntSushi testset.

.gitignore

@@ -1,3 +1,6 @@
+# Build output
+cmd/toml-test-decoder/toml-test-decoder
+
 # ---> Vim
 # Swap
 [._]*.s[a-v][a-z]

ast/ast.go

@@ -81,10 +81,10 @@ const (
 	TypeLocalTime ValueType = "time"
 
 	// TypeArrayOfTables identifies an [[array.of.tables]].
-	TypeArrayOfTables ValueType = "array"
+	TypeArrayOfTables ValueType = "arrayOfTables"
 
 	// TypeArray identifies ["an", "inline", "static", "array"].
-	TypeArray ValueType = "static array"
+	TypeArray ValueType = "array"
 
 	// TypeTable identifies an { "inline" = "table" } or [standard.table].
 	TypeTable ValueType = "table"
@@ -115,9 +115,9 @@ func (doc *Document) OpenTable(key Key) error {
 	doc.CurrentKey = nil
 	doc.Current = doc.Root
 	// Go over all requested levels of the key. For all levels, except the last
-	// one, it is okay if a Table already exists. For at least the last level,
-	// no table or value must exist, because that would mean we are overwriting
-	// an existing key/value pair, which is not allowed.
+	// one, it is okay if a Table or TableArray already exists. For at least the
+	// last level, no table or value must exist, because that would mean we are
+	// overwriting an existing key/value pair, which is not allowed.
 	node, lastKeyPart, err := doc.makeTablePath(key)
 	if err != nil {
 		return fmt.Errorf("invalid table: %s", err)
@@ -146,9 +146,9 @@ func (doc *Document) OpenArrayOfTables(key Key) error {
 	doc.CurrentKey = nil
 	doc.Current = doc.Root
 	// Go over all requested levels of the key. For all levels, except the last
-	// one, it is okay if a Table already exists. For the last level, either
-	// no value must exist (in which case a table array will be created), or a
-	// table array must exist.
+	// one, it is okay if a Table or ArrayOfTables already exists. For the last
+	// level, either no value must exist (in which case a table array will be
+	// created), or a table array must exist.
 	// Other cases would mean we are overwriting an existing key/value pair,
 	// which is not allowed.
 	node, lastKeyPart, err := doc.makeTablePath(key)
@@ -193,13 +193,21 @@ func (doc *Document) makeTablePath(key Key) (Table, string, error) {
 		}
 		if subValue, ok := node[keyPart]; ok {
 			// You cannot overwrite an already defined key, regardless its value.
-			// When a value already exists at the current key, this can only be a table.
-			if subValue.Type != TypeTable {
+			// When a value already exists at the current key, this can only be a table
+			// or an array of tables. In case of an array of tables, the last created
+			// table will be used.
+			if subValue.Type == TypeTable {
+				// A table was found, traverse to that table.
+				node = subValue.Data[0].(Table)
+			} else if subValue.Type == TypeArrayOfTables {
+				// An array of tables was found, traverse to the last table in the array.
+				lastValue := subValue.Data[len(subValue.Data)-1].(*Value)
+				lastTable := lastValue.Data[0].(Table)
+				node = lastTable
+			} else {
 				path := doc.formatKeyPath(key, i)
 				return nil, "", fmt.Errorf("%s value already exists at key %s", subValue.Type, path)
 			}
-			// All is okay, traverse to the subtable.
-			node = subValue.Data[0].(Table)
 		} else {
 			// The subtable does not exist yet. Create the subtable.
 			subTable := make(Table)

ast/ast_test.go

@@ -32,6 +32,55 @@ func Test_ConstructSlightlyComplexStructure(t *testing.T) {
 			`"key1": {"key2 a": {"dah": false, "dooh": true}, "key2 b": {"dieh": 1.111, "duh": 1.18e-12, "foo": {"bar": [1, 2]}}}}`)
 }
 
+// This document structure represents the actual structure of the example for nested
+// arrays of tables from the TOML 0.5.0 specficiation.
+func Test_ConstructNestedArraysOfTables(t *testing.T) {
+	testAST(t, func() (error, *ast.Document) {
+		p := ast.NewDocument()
+		p.OpenArrayOfTables(ast.NewKey("fruit"))
+		p.SetKeyValuePair(ast.NewKey("name"), ast.NewValue(ast.TypeString, "apple"))
+		p.OpenTable(ast.NewKey("fruit", "physical"))
+		p.SetKeyValuePair(ast.NewKey("color"), ast.NewValue(ast.TypeString, "red"))
+		p.SetKeyValuePair(ast.NewKey("shape"), ast.NewValue(ast.TypeString, "round"))
+		p.OpenArrayOfTables(ast.NewKey("fruit", "variety"))
+		p.SetKeyValuePair(ast.NewKey("name"), ast.NewValue(ast.TypeString, "red delicious"))
+		p.OpenArrayOfTables(ast.NewKey("fruit", "variety"))
+		p.SetKeyValuePair(ast.NewKey("name"), ast.NewValue(ast.TypeString, "granny smith"))
+		p.OpenArrayOfTables(ast.NewKey("fruit"))
+		p.SetKeyValuePair(ast.NewKey("name"), ast.NewValue(ast.TypeString, "banana"))
+		p.OpenArrayOfTables(ast.NewKey("fruit", "variety"))
+		p.SetKeyValuePair(ast.NewKey("name"), ast.NewValue(ast.TypeString, "plantain"))
+		return nil, p
+	},
+		"",
+		`{"fruit": [`+
+			`{"name": "apple", "physical": {"color": "red", "shape": "round"}, "variety": [{"name": "red delicious"}, {"name": "granny smith"}]}, `+
+			`{"name": "banana", "variety": [{"name": "plantain"}]}`+
+			`]}`)
+}
+
+// This is a case from the BurntSushi test set which my parser did not correctly
+// handle. From the specs, it was unclear to me that is was okay to handle things
+// in this way. The actual TOML document that would lead to this looks like:
+//
+//     [a.b.c]
+//     answer = 42
+//
+//     [a]
+//     better = 43
+func Test_ConstructExplicitTableAfterImplicitSubtable(t *testing.T) {
+	testAST(t, func() (error, *ast.Document) {
+		p := ast.NewDocument()
+		p.OpenTable(ast.NewKey("a", "b", "c"))
+		p.SetKeyValuePair(ast.NewKey("answer"), ast.NewValue(ast.TypeString, "42"))
+		p.OpenTable(ast.NewKey("a"))
+		p.SetKeyValuePair(ast.NewKey("better"), ast.NewValue(ast.TypeString, "43"))
+		return nil, p
+	},
+		"",
+		`{"a": {"b": {"c": {"answer": "42"}}, "better": "43"}}`)
+}
+
 func Test_EmptyKeyForCreatingTablePath_Panics(t *testing.T) {
 	defer func() {
 		r := recover()

cmd/toml-test-decoder/main.go

@@ -4,20 +4,14 @@
 package main
 
 import (
-	//"encoding/json"
-	"encoding/json"
 	"flag"
 	"fmt"
-	"sort"
-	"strings"
-	"time"
-
-	//"fmt"
 	"log"
 	"os"
 	"path"
-
-	//"time"
+	"sort"
+	"strings"
+	"time"
 
 	"git.makaay.nl/mauricem/go-toml/ast"
 	"git.makaay.nl/mauricem/go-toml/parse"
@@ -45,66 +39,12 @@ func main() {
 	toml, err := parse.Run(os.Stdin)
 	if err != nil {
 		log.Fatalf("Error decoding TOML: %s", err)
-	}
-
+	} else {
 		sushi := makeSushi(ast.NewValue(ast.TypeTable, toml))
-	var v = new(interface{})
-	if err := json.NewDecoder(strings.NewReader(sushi)).Decode(v); err != nil {
-		log.Fatalf("Error decoding JSON: %s\n%s\n", err, sushi)
-	}
-	encoder := json.NewEncoder(os.Stdout)
-	encoder.SetIndent("", "  ")
-	if err := encoder.Encode(v); err != nil {
-		log.Fatalf("Error encoding JSON: %s", err)
+		fmt.Println(sushi)
 	}
 }
 
-// func translate(node *ast.Value) interface{} {
-// 	switch node.Type {
-// 	case ast.TypeTable:
-// 		typed := make(map[string]interface{}, len(node.Data))
-// 		for k, v := range node.Data[0].(ast.Table) {
-// 			typed[k] = translate(v)
-// 		}
-// 		return typed
-// 	case ast.TypeArrayOfTables:
-// 		typed := make([]map[string]interface{}, len(node.Data))
-// 		for i, v := range node.Data {
-// 			value := v.(*ast.Value)
-// 			typed[i] = translate(value).(map[string]interface{})
-// 		}
-// 		return typed
-// 	case []interface{}:
-// 		typed := make([]interface{}, len(orig))
-// 		for i, v := range orig {
-// 			typed[i] = translate(v)
-// 		}
-
-// 		// We don't really need to tag arrays, but let's be future proof.
-// 		// (If TOML ever supports tuples, we'll need this.)
-// 		return tag("array", typed)
-// 	case time.Time:
-// 		return tag("datetime", orig.Format("2006-01-02T15:04:05Z"))
-// 	case bool:
-// 		return tag("bool", fmt.Sprintf("%v", orig))
-// 	case int64:
-// 		return tag("integer", fmt.Sprintf("%d", orig))
-// 	case float64:
-// 		return tag("float", fmt.Sprintf("%v", orig))
-// 	case string:
-// 		return tag("string", orig)
-// 	}
-
-// 	panic(fmt.Sprintf("Unknown type: %T", tomlData))
-// }
-
-// func tag(typeName string, data interface{}) map[string]interface{} {
-// 	return map[string]interface{}{
-// 		"type":  typeName,
-// 		"value": data,
-// 	}
-// }
-
 func makeSushi(value *ast.Value) string {
 	switch value.Type {
 	case ast.TypeString:
@@ -152,7 +92,7 @@ func makeSushi(value *ast.Value) string {
 		}
 		return fmt.Sprintf("{%s}", strings.Join(values, ", "))
 	default:
-		return renderValue(string(value.Type), fmt.Sprintf("%q", value.Data[0]))
+		panic(fmt.Sprintf("Unhandled data type: %s", value.Type))
 	}
 }
 

parse/comment_test.go

@@ -13,6 +13,7 @@ func TestComment(t *testing.T) {
 		{"# ending in EOL & EOF\r\n", `{}`, ``},
 		{`# \xxx/ \u can't escape/`, `{}`, ``},
 		{"# \tlexe\r accepts embedded ca\r\riage \returns\r\n", `{}`, ``},
+		{"   # multiple\n#lines\n \t\n\n\t#with\n ### comments!", `{}`, ``},
 		{"# with data and newline\ncode continues here", `{}`, `unexpected input (expected a value assignment) at line 2, column 5`},
 	} {
 		p := newParser()

parse/document.go

@@ -14,9 +14,9 @@ var (
 
 func (t *parser) startDocument(p *parse.API) {
 	for {
-		p.Accept(dropWhitespace)
-		p.Accept(dropComment)
 		switch {
+		case p.Accept(whitespaceOrComment):
+			// NOOP, skip these
 		case p.Peek(detectTableOrArrayOfTables):
 			p.Handle(t.startTable)
 		case p.Peek(detectKey):

parse/keyvaluepair.go

@@ -34,7 +34,7 @@ var (
 	keySeparatorDot = c.Seq(dropBlanks, a.Dot, dropBlanks)
 
 	// After a value, the line must end. There can be an optional comment.
-	endOfLineAfterValue = c.Seq(dropBlanks, a.EndOfLine.Or(dropComment))
+	endOfLineAfterValue = c.Seq(dropBlanks, a.EndOfLine.Or(comment))
 )
 
 func (t *parser) startKeyValuePair(p *parse.API) {

parse/parse.go

@@ -14,17 +14,26 @@ var (
 	// In this package, we name this a blank, to be in line with the
 	// terminology as used in parsekit.
 	blank          = a.Runes('\t', ' ')
+	blanks         = c.OneOrMore(blank)
+	optionalBlanks = c.ZeroOrMore(blank)
+	dropBlanks     = m.Drop(optionalBlanks)
 
 	// Newline means LF (0x0A) or CRLF (0x0D0A).
 	// This matches the default newline as defined by parsekit.
 	newline = a.Newline
 
-	dropBlanks     = m.Drop(c.ZeroOrMore(blank))
-	dropWhitespace = m.Drop(c.ZeroOrMore(blank.Or(newline)))
+	// Whitespace is defined as blanks + newlines.
+	whitespace         = c.OneOrMore(blank.Or(newline))
+	optionalWhitespace = c.ZeroOrMore(blank.Or(newline))
+	dropWhitespace     = m.Drop(optionalWhitespace)
 
 	// A '#' hash symbol marks the rest of the line as a comment.
 	// All characters up to the end of the line are included in the comment.
-	dropComment = m.Drop(c.Seq(a.Hash, c.ZeroOrMore(c.Not(a.EndOfLine)), m.Drop(a.EndOfLine)))
+	comment = c.Seq(a.Hash, c.ZeroOrMore(c.Not(a.EndOfLine)), m.Drop(a.EndOfLine))
+
+	endOfLineOrComment          = optionalBlanks.Then(a.EndOfLine.Or(comment))
+	whitespaceOrComment         = c.OneOrMore(c.Any(blank, newline, comment))
+	optionalWhitespaceOrComment = c.Optional(whitespaceOrComment)
 )
 
 // parser embeds the TOML ast.Document, so it can be extended with methods

parse/value_array.go

@@ -31,10 +31,9 @@ import (
 //       2, # this is ok
 //     ]
 var (
-	arraySpace     = c.ZeroOrMore(c.Any(blank, newline, dropComment))
-	arrayOpen      = a.SquareOpen.Then(arraySpace)
-	arraySeparator = c.Seq(arraySpace, a.Comma, arraySpace)
-	arrayClose     = c.Seq(c.Optional(arraySpace.Then(a.Comma)), arraySpace, a.SquareClose)
+	arrayOpen      = a.SquareOpen.Then(optionalWhitespaceOrComment)
+	arraySeparator = c.Seq(optionalWhitespaceOrComment, a.Comma, optionalWhitespaceOrComment)
+	arrayClose     = c.Seq(c.Optional(optionalWhitespaceOrComment.Then(a.Comma)), optionalWhitespaceOrComment, a.SquareClose)
 )
 
 func (t *parser) parseArray(p *parse.API) (*ast.Value, bool) {

parse/value_table.go

@@ -8,11 +8,11 @@ import (
 var (
 	// Opener and closer for [table].
 	tableOpen  = c.Seq(dropBlanks, a.SquareOpen, dropBlanks)
-	tableClose = c.Seq(dropBlanks, a.SquareClose, dropBlanks, a.EndOfLine.Or(dropComment))
+	tableClose = c.Seq(dropBlanks, a.SquareClose, dropBlanks)
 
 	// Opener and closer for [[array.of.tables]].
 	tableArrayOpen  = c.Seq(dropBlanks, a.SquareOpen, a.SquareOpen, dropBlanks)
-	tableArrayClose = c.Seq(dropBlanks, a.SquareClose, a.SquareClose, dropBlanks, a.EndOfLine.Or(dropComment))
+	tableArrayClose = c.Seq(dropBlanks, a.SquareClose, a.SquareClose, dropBlanks)
 
 	// Opener, separator and closer for { inline: "tables" }.
 	inlineTableOpen      = c.Seq(dropBlanks, a.CurlyOpen, dropBlanks)
@@ -75,6 +75,10 @@ func (t *parser) startArrayOfTables(p *parse.API) {
 			p.Expected("closing ']]' for array of tables name")
 			return
 		}
+		if !p.Accept(endOfLineOrComment) {
+			p.Expected("end of line or comment")
+			return
+		}
 		if err := t.OpenArrayOfTables(key); err != nil {
 			p.Error("%s", err)
 			return
@@ -127,6 +131,10 @@ func (t *parser) startPlainTable(p *parse.API) {
 			p.Expected("closing ']' for table name")
 			return
 		}
+		if !p.Accept(endOfLineOrComment) {
+			p.Expected("end of line or comment")
+			return
+		}
 		if err := t.OpenTable(key); err != nil {
 			p.Error("%s", err)
 			return