package toml
import (
"fmt"
"strconv"
"strings"
"time"
"unicode/utf8"
"github.com/BurntSushi/toml/internal"
)
type parser struct {
lx *lexer
context Key // Full key for the current hash in scope.
currentKey string // Base key name for everything except hashes.
pos Position // Current position in the TOML file.
ordered []Key // List of keys in the order that they appear in the TOML data.
keyInfo map[string]keyInfo // Map keyname → info about the TOML key.
mapping map[string]interface{} // Map keyname → key value.
implicits map[string]struct{} // Record implicit keys (e.g. "key.group.names").
}
type keyInfo struct {
pos Position
tomlType tomlType
}
func parse(data string) (p *parser, err error) {
defer func() {
if r := recover(); r != nil {
if pErr, ok := r.(ParseError); ok {
pErr.input = data
err = pErr
return
}
panic(r)
}
}()
// Read over BOM; do this here as the lexer calls utf8.DecodeRuneInString()
// which mangles stuff.
if strings.HasPrefix(data, "\xff\xfe") || strings.HasPrefix(data, "\xfe\xff") {
data = data[2:]
}
// Examine first few bytes for NULL bytes; this probably means it's a UTF-16
// file (second byte in surrogate pair being NULL). Again, do this here to
// avoid having to deal with UTF-8/16 stuff in the lexer.
ex := 6
if len(data) < 6 {
ex = len(data)
}
if i := strings.IndexRune(data[:ex], 0); i > -1 {
return nil, ParseError{
Message: "files cannot contain NULL bytes; probably using UTF-16; TOML files must be UTF-8",
Position: Position{Line: 1, Start: i, Len: 1},
Line: 1,
input: data,
}
}
p = &parser{
keyInfo: make(map[string]keyInfo),
mapping: make(map[string]interface{}),
lx: lex(data),
ordered: make([]Key, 0),
implicits: make(map[string]struct{}),
}
for {
item := p.next()
if item.typ == itemEOF {
break
}
p.topLevel(item)
}
return p, nil
}
func (p *parser) panicErr(it item, err error) {
panic(ParseError{
err: err,
Position: it.pos,
Line: it.pos.Len,
LastKey: p.current(),
})
}
func (p *parser) panicItemf(it item, format string, v ...interface{}) {
panic(ParseError{
Message: fmt.Sprintf(format, v...),
Position: it.pos,
Line: it.pos.Len,
LastKey: p.current(),
})
}
func (p *parser) panicf(format string, v ...interface{}) {
panic(ParseError{
Message: fmt.Sprintf(format, v...),
Position: p.pos,
Line: p.pos.Line,
LastKey: p.current(),
})
}
func (p *parser) next() item {
it := p.lx.nextItem()
//fmt.Printf("ITEM %-18s line %-3d │ %q\n", it.typ, it.pos.Line, it.val)
if it.typ == itemError {
if it.err != nil {
panic(ParseError{
Position: it.pos,
Line: it.pos.Line,
LastKey: p.current(),
err: it.err,
})
}
p.panicItemf(it, "%s", it.val)
}
return it
}
func (p *parser) nextPos() item {
it := p.next()
p.pos = it.pos
return it
}
func (p *parser) bug(format string, v ...interface{}) {
panic(fmt.Sprintf("BUG: "+format+"\n\n", v...))
}
func (p *parser) expect(typ itemType) item {
it := p.next()
p.assertEqual(typ, it.typ)
return it
}
func (p *parser) assertEqual(expected, got itemType) {
if expected != got {
p.bug("Expected '%s' but got '%s'.", expected, got)
}
}
func (p *parser) topLevel(item item) {
switch item.typ {
case itemCommentStart: // # ..
p.expect(itemText)
case itemTableStart: // [ .. ]
name := p.nextPos()
var key Key
for ; name.typ != itemTableEnd && name.typ != itemEOF; name = p.next() {
key = append(key, p.keyString(name))
}
p.assertEqual(itemTableEnd, name.typ)
p.addContext(key, false)
p.setType("", tomlHash, item.pos)
p.ordered = append(p.ordered, key)
case itemArrayTableStart: // [[ .. ]]
name := p.nextPos()
var key Key
for ; name.typ != itemArrayTableEnd && name.typ != itemEOF; name = p.next() {
key = append(key, p.keyString(name))
}
p.assertEqual(itemArrayTableEnd, name.typ)
p.addContext(key, true)
p.setType("", tomlArrayHash, item.pos)
p.ordered = append(p.ordered, key)
case itemKeyStart: // key = ..
outerContext := p.context
/// Read all the key parts (e.g. 'a' and 'b' in 'a.b')
k := p.nextPos()
var key Key
for ; k.typ != itemKeyEnd && k.typ != itemEOF; k = p.next() {
key = append(key, p.keyString(k))
}
p.assertEqual(itemKeyEnd, k.typ)
/// The current key is the last part.
p.currentKey = key[len(key)-1]
/// All the other parts (if any) are the context; need to set each part
/// as implicit.
context := key[:len(key)-1]
for i := range context {
p.addImplicitContext(append(p.context, context[i:i+1]...))
}
/// Set value.
vItem := p.next()
val, typ := p.value(vItem, false)
p.set(p.currentKey, val, typ, vItem.pos)
p.ordered = append(p.ordered, p.context.add(p.currentKey))
/// Remove the context we added (preserving any context from [tbl] lines).
p.context = outerContext
p.currentKey = ""
default:
p.bug("Unexpected type at top level: %s", item.typ)
}
}
// Gets a string for a key (or part of a key in a table name).
func (p *parser) keyString(it item) string {
switch it.typ {
case itemText:
return it.val
case itemString, itemMultilineString,
itemRawString, itemRawMultilineString:
s, _ := p.value(it, false)
return s.(string)
default:
p.bug("Unexpected key type: %s", it.typ)
}
panic("unreachable")
}
var datetimeRepl = strings.NewReplacer(
"z", "Z",
"t", "T",
" ", "T")
// value translates an expected value from the lexer into a Go value wrapped
// as an empty interface.
func (p *parser) value(it item, parentIsArray bool) (interface{}, tomlType) {
switch it.typ {
case itemString:
return p.replaceEscapes(it, it.val), p.typeOfPrimitive(it)
case itemMultilineString:
return p.replaceEscapes(it, stripFirstNewline(p.stripEscapedNewlines(it.val))), p.typeOfPrimitive(it)
case itemRawString:
return it.val, p.typeOfPrimitive(it)
case itemRawMultilineString:
return stripFirstNewline(it.val), p.typeOfPrimitive(it)
case itemInteger:
return p.valueInteger(it)
case itemFloat:
return p.valueFloat(it)
case itemBool:
switch it.val {
case "true":
return true, p.typeOfPrimitive(it)
case "false":
return false, p.typeOfPrimitive(it)
default:
p.bug("Expected boolean value, but got '%s'.", it.val)
}
case itemDatetime:
return p.valueDatetime(it)
case itemArray:
return p.valueArray(it)
case itemInlineTableStart:
return p.valueInlineTable(it, parentIsArray)
default:
p.bug("Unexpected value type: %s", it.typ)
}
panic("unreachable")
}
func (p *parser) valueInteger(it item) (interface{}, tomlType) {
if !numUnderscoresOK(it.val) {
p.panicItemf(it, "Invalid integer %q: underscores must be surrounded by digits", it.val)
}
if numHasLeadingZero(it.val) {
p.panicItemf(it, "Invalid integer %q: cannot have leading zeroes", it.val)
}
num, err := strconv.ParseInt(it.val, 0, 64)
if err != nil {
// Distinguish integer values. Normally, it'd be a bug if the lexer
// provides an invalid integer, but it's possible that the number is
// out of range of valid values (which the lexer cannot determine).
// So mark the former as a bug but the latter as a legitimate user
// error.
if e, ok := err.(*strconv.NumError); ok && e.Err == strconv.ErrRange {
p.panicErr(it, errParseRange{i: it.val, size: "int64"})
} else {
p.bug("Expected integer value, but got '%s'.", it.val)
}
}
return num, p.typeOfPrimitive(it)
}
func (p *parser) valueFloat(it item) (interface{}, tomlType) {
parts := strings.FieldsFunc(it.val, func(r rune) bool {
switch r {
case '.', 'e', 'E':
return true
}
return false
})
for _, part := range parts {
if !numUnderscoresOK(part) {
p.panicItemf(it, "Invalid float %q: underscores must be surrounded by digits", it.val)
}
}
if len(parts) > 0 && numHasLeadingZero(parts[0]) {
p.panicItemf(it, "Invalid float %q: cannot have leading zeroes", it.val)
}
if !numPeriodsOK(it.val) {
// As a special case, numbers like '123.' or '1.e2',
// which are valid as far as Go/strconv are concerned,
// must be rejected because TOML says that a fractional
// part consists of '.' followed by 1+ digits.
p.panicItemf(it, "Invalid float %q: '.' must be followed by one or more digits", it.val)
}
val := strings.Replace(it.val, "_", "", -1)
if val == "+nan" || val == "-nan" { // Go doesn't support this, but TOML spec does.
val = "nan"
}
num, err := strconv.ParseFloat(val, 64)
if err != nil {
if e, ok := err.(*strconv.NumError); ok && e.Err == strconv.ErrRange {
p.panicErr(it, errParseRange{i: it.val, size: "float64"})
} else {
p.panicItemf(it, "Invalid float value: %q", it.val)
}
}
return num, p.typeOfPrimitive(it)
}
var dtTypes = []struct {
fmt string
zone *time.Location
}{
{time.RFC3339Nano, time.Local},
{"2006-01-02T15:04:05.999999999", internal.LocalDatetime},
{"2006-01-02", internal.LocalDate},
{"15:04:05.999999999", internal.LocalTime},
}
func (p *parser) valueDatetime(it item) (interface{}, tomlType) {
it.val = datetimeRepl.Replace(it.val)
var (
t time.Time
ok bool
err error
)
for _, dt := range dtTypes {
t, err = time.ParseInLocation(dt.fmt, it.val, dt.zone)
if err == nil {
ok = true
break
}
}
if !ok {
p.panicItemf(it, "Invalid TOML Datetime: %q.", it.val)
}
return t, p.typeOfPrimitive(it)
}
func (p *parser) valueArray(it item) (interface{}, tomlType) {
p.setType(p.currentKey, tomlArray, it.pos)
var (
types []tomlType
// Initialize to a non-nil empty slice. This makes it consistent with
// how S = [] decodes into a non-nil slice inside something like struct
// { S []string }. See #338
array = []interface{}{}
)
for it = p.next(); it.typ != itemArrayEnd; it = p.next() {
if it.typ == itemCommentStart {
p.expect(itemText)
continue
}
val, typ := p.value(it, true)
array = append(array, val)
types = append(types, typ)
// XXX: types isn't used here, we need it to record the accurate type
// information.
//
// Not entirely sure how to best store this; could use "key[0]",
// "key[1]" notation, or maybe store it on the Array type?
}
return array, tomlArray
}
func (p *parser) valueInlineTable(it item, parentIsArray bool) (interface{}, tomlType) {
var (
hash = make(map[string]interface{})
outerContext = p.context
outerKey = p.currentKey
)
p.context = append(p.context, p.currentKey)
prevContext := p.context
p.currentKey = ""
p.addImplicit(p.context)
p.addContext(p.context, parentIsArray)
/// Loop over all table key/value pairs.
for it := p.next(); it.typ != itemInlineTableEnd; it = p.next() {
if it.typ == itemCommentStart {
p.expect(itemText)
continue
}
/// Read all key parts.
k := p.nextPos()
var key Key
for ; k.typ != itemKeyEnd && k.typ != itemEOF; k = p.next() {
key = append(key, p.keyString(k))
}
p.assertEqual(itemKeyEnd, k.typ)
/// The current key is the last part.
p.currentKey = key[len(key)-1]
/// All the other parts (if any) are the context; need to set each part
/// as implicit.
context := key[:len(key)-1]
for i := range context {
p.addImplicitContext(append(p.context, context[i:i+1]...))
}
/// Set the value.
val, typ := p.value(p.next(), false)
p.set(p.currentKey, val, typ, it.pos)
p.ordered = append(p.ordered, p.context.add(p.currentKey))
hash[p.currentKey] = val
/// Restore context.
p.context = prevContext
}
p.context = outerContext
p.currentKey = outerKey
return hash, tomlHash
}
// numHasLeadingZero checks if this number has leading zeroes, allowing for '0',
// +/- signs, and base prefixes.
func numHasLeadingZero(s string) bool {
if len(s) > 1 && s[0] == '0' && !(s[1] == 'b' || s[1] == 'o' || s[1] == 'x') { // Allow 0b, 0o, 0x
return true
}
if len(s) > 2 && (s[0] == '-' || s[0] == '+') && s[1] == '0' {
return true
}
return false
}
// numUnderscoresOK checks whether each underscore in s is surrounded by
// characters that are not underscores.
func numUnderscoresOK(s string) bool {
switch s {
case "nan", "+nan", "-nan", "inf", "-inf", "+inf":
return true
}
accept := false
for _, r := range s {
if r == '_' {
if !accept {
return false
}
}
// isHexadecimal is a superset of all the permissable characters
// surrounding an underscore.
accept = isHexadecimal(r)
}
return accept
}
// numPeriodsOK checks whether every period in s is followed by a digit.
func numPeriodsOK(s string) bool {
period := false
for _, r := range s {
if period && !isDigit(r) {
return false
}
period = r == '.'
}
return !period
}
// Set the current context of the parser, where the context is either a hash or
// an array of hashes, depending on the value of the `array` parameter.
//
// Establishing the context also makes sure that the key isn't a duplicate, and
// will create implicit hashes automatically.
func (p *parser) addContext(key Key, array bool) {
var ok bool
// Always start at the top level and drill down for our context.
hashContext := p.mapping
keyContext := make(Key, 0)
// We only need implicit hashes for key[0:-1]
for _, k := range key[0 : len(key)-1] {
_, ok = hashContext[k]
keyContext = append(keyContext, k)
// No key? Make an implicit hash and move on.
if !ok {
p.addImplicit(keyContext)
hashContext[k] = make(map[string]interface{})
}
// If the hash context is actually an array of tables, then set
// the hash context to the last element in that array.
//
// Otherwise, it better be a table, since this MUST be a key group (by
// virtue of it not being the last element in a key).
switch t := hashContext[k].(type) {
case []map[string]interface{}:
hashContext = t[len(t)-1]
case map[string]interface{}:
hashContext = t
default:
p.panicf("Key '%s' was already created as a hash.", keyContext)
}
}
p.context = keyContext
if array {
// If this is the first element for this array, then allocate a new
// list of tables for it.
k := key[len(key)-1]
if _, ok := hashContext[k]; !ok {
hashContext[k] = make([]map[string]interface{}, 0, 4)
}
// Add a new table. But make sure the key hasn't already been used
// for something else.
if hash, ok := hashContext[k].([]map[string]interface{}); ok {
hashContext[k] = append(hash, make(map[string]interface{}))
} else {
p.panicf("Key '%s' was already created and cannot be used as an array.", key)
}
} else {
p.setValue(key[len(key)-1], make(map[string]interface{}))
}
p.context = append(p.context, key[len(key)-1])
}
// set calls setValue and setType.
func (p *parser) set(key string, val interface{}, typ tomlType, pos Position) {
p.setValue(key, val)
p.setType(key, typ, pos)
}
// setValue sets the given key to the given value in the current context.
// It will make sure that the key hasn't already been defined, account for
// implicit key groups.
func (p *parser) setValue(key string, value interface{}) {
var (
tmpHash interface{}
ok bool
hash = p.mapping
keyContext Key
)
for _, k := range p.context {
keyContext = append(keyContext, k)
if tmpHash, ok = hash[k]; !ok {
p.bug("Context for key '%s' has not been established.", keyContext)
}
switch t := tmpHash.(type) {
case []map[string]interface{}:
// The context is a table of hashes. Pick the most recent table
// defined as the current hash.
hash = t[len(t)-1]
case map[string]interface{}:
hash = t
default:
p.panicf("Key '%s' has already been defined.", keyContext)
}
}
keyContext = append(keyContext, key)
if _, ok := hash[key]; ok {
// Normally redefining keys isn't allowed, but the key could have been
// defined implicitly and it's allowed to be redefined concretely. (See
// the `valid/implicit-and-explicit-after.toml` in toml-test)
//
// But we have to make sure to stop marking it as an implicit. (So that
// another redefinition provokes an error.)
//
// Note that since it has already been defined (as a hash), we don't
// want to overwrite it. So our business is done.
if p.isArray(keyContext) {
p.removeImplicit(keyContext)
hash[key] = value
return
}
if p.isImplicit(keyContext) {
p.removeImplicit(keyContext)
return
}
// Otherwise, we have a concrete key trying to override a previous
// key, which is *always* wrong.
p.panicf("Key '%s' has already been defined.", keyContext)
}
hash[key] = value
}
// setType sets the type of a particular value at a given key. It should be
// called immediately AFTER setValue.
//
// Note that if `key` is empty, then the type given will be applied to the
// current context (which is either a table or an array of tables).
func (p *parser) setType(key string, typ tomlType, pos Position) {
keyContext := make(Key, 0, len(p.context)+1)
keyContext = append(keyContext, p.context...)
if len(key) > 0 { // allow type setting for hashes
keyContext = append(keyContext, key)
}
// Special case to make empty keys ("" = 1) work.
// Without it it will set "" rather than `""`.
// TODO: why is this needed? And why is this only needed here?
if len(keyContext) == 0 {
keyContext = Key{""}
}
p.keyInfo[keyContext.String()] = keyInfo{tomlType: typ, pos: pos}
}
// Implicit keys need to be created when tables are implied in "a.b.c.d = 1" and
// "[a.b.c]" (the "a", "b", and "c" hashes are never created explicitly).
func (p *parser) addImplicit(key Key) { p.implicits[key.String()] = struct{}{} }
func (p *parser) removeImplicit(key Key) { delete(p.implicits, key.String()) }
func (p *parser) isImplicit(key Key) bool { _, ok := p.implicits[key.String()]; return ok }
func (p *parser) isArray(key Key) bool { return p.keyInfo[key.String()].tomlType == tomlArray }
func (p *parser) addImplicitContext(key Key) {
p.addImplicit(key)
p.addContext(key, false)
}
// current returns the full key name of the current context.
func (p *parser) current() string {
if len(p.currentKey) == 0 {
return p.context.String()
}
if len(p.context) == 0 {
return p.currentKey
}
return fmt.Sprintf("%s.%s", p.context, p.currentKey)
}
func stripFirstNewline(s string) string {
if len(s) > 0 && s[0] == '\n' {
return s[1:]
}
if len(s) > 1 && s[0] == '\r' && s[1] == '\n' {
return s[2:]
}
return s
}
// Remove newlines inside triple-quoted strings if a line ends with "\".
func (p *parser) stripEscapedNewlines(s string) string {
split := strings.Split(s, "\n")
if len(split) < 1 {
return s
}
escNL := false // Keep track of the last non-blank line was escaped.
for i, line := range split {
line = strings.TrimRight(line, " \t\r")
if len(line) == 0 || line[len(line)-1] != '\\' {
split[i] = strings.TrimRight(split[i], "\r")
if !escNL && i != len(split)-1 {
split[i] += "\n"
}
continue
}
escBS := true
for j := len(line) - 1; j >= 0 && line[j] == '\\'; j-- {
escBS = !escBS
}
if escNL {
line = strings.TrimLeft(line, " \t\r")
}
escNL = !escBS
if escBS {
split[i] += "\n"
continue
}
if i == len(split)-1 {
p.panicf("invalid escape: '\\ '")
}
split[i] = line[:len(line)-1] // Remove \
if len(split)-1 > i {
split[i+1] = strings.TrimLeft(split[i+1], " \t\r")
}
}
return strings.Join(split, "")
}
func (p *parser) replaceEscapes(it item, str string) string {
replaced := make([]rune, 0, len(str))
s := []byte(str)
r := 0
for r < len(s) {
if s[r] != '\\' {
c, size := utf8.DecodeRune(s[r:])
r += size
replaced = append(replaced, c)
continue
}
r += 1
if r >= len(s) {
p.bug("Escape sequence at end of string.")
return ""
}
switch s[r] {
default:
p.bug("Expected valid escape code after \\, but got %q.", s[r])
case ' ', '\t':
p.panicItemf(it, "invalid escape: '\\%c'", s[r])
case 'b':
replaced = append(replaced, rune(0x0008))
r += 1
case 't':
replaced = append(replaced, rune(0x0009))
r += 1
case 'n':
replaced = append(replaced, rune(0x000A))
r += 1
case 'f':
replaced = append(replaced, rune(0x000C))
r += 1
case 'r':
replaced = append(replaced, rune(0x000D))
r += 1
case '"':
replaced = append(replaced, rune(0x0022))
r += 1
case '\\':
replaced = append(replaced, rune(0x005C))
r += 1
case 'u':
// At this point, we know we have a Unicode escape of the form
// `uXXXX` at [r, r+5). (Because the lexer guarantees this
// for us.)
escaped := p.asciiEscapeToUnicode(it, s[r+1:r+5])
replaced = append(replaced, escaped)
r += 5
case 'U':
// At this point, we know we have a Unicode escape of the form
// `uXXXX` at [r, r+9). (Because the lexer guarantees this
// for us.)
escaped := p.asciiEscapeToUnicode(it, s[r+1:r+9])
replaced = append(replaced, escaped)
r += 9
}
}
return string(replaced)
}
func (p *parser) asciiEscapeToUnicode(it item, bs []byte) rune {
s := string(bs)
hex, err := strconv.ParseUint(strings.ToLower(s), 16, 32)
if err != nil {
p.bug("Could not parse '%s' as a hexadecimal number, but the lexer claims it's OK: %s", s, err)
}
if !utf8.ValidRune(rune(hex)) {
p.panicItemf(it, "Escaped character '\\u%s' is not valid UTF-8.", s)
}
return rune(hex)
}
