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gitea/vendor/github.com/pelletier/go-toml/parser.go
2020-09-01 10:01:23 -04:00

494 lines
12 KiB
Go
Vendored

// TOML Parser.
package toml
import (
"errors"
"fmt"
"math"
"reflect"
"regexp"
"strconv"
"strings"
"time"
)
type tomlParser struct {
flowIdx int
flow []token
tree *Tree
currentTable []string
seenTableKeys []string
}
type tomlParserStateFn func() tomlParserStateFn
// Formats and panics an error message based on a token
func (p *tomlParser) raiseError(tok *token, msg string, args ...interface{}) {
panic(tok.Position.String() + ": " + fmt.Sprintf(msg, args...))
}
func (p *tomlParser) run() {
for state := p.parseStart; state != nil; {
state = state()
}
}
func (p *tomlParser) peek() *token {
if p.flowIdx >= len(p.flow) {
return nil
}
return &p.flow[p.flowIdx]
}
func (p *tomlParser) assume(typ tokenType) {
tok := p.getToken()
if tok == nil {
p.raiseError(tok, "was expecting token %s, but token stream is empty", tok)
}
if tok.typ != typ {
p.raiseError(tok, "was expecting token %s, but got %s instead", typ, tok)
}
}
func (p *tomlParser) getToken() *token {
tok := p.peek()
if tok == nil {
return nil
}
p.flowIdx++
return tok
}
func (p *tomlParser) parseStart() tomlParserStateFn {
tok := p.peek()
// end of stream, parsing is finished
if tok == nil {
return nil
}
switch tok.typ {
case tokenDoubleLeftBracket:
return p.parseGroupArray
case tokenLeftBracket:
return p.parseGroup
case tokenKey:
return p.parseAssign
case tokenEOF:
return nil
case tokenError:
p.raiseError(tok, "parsing error: %s", tok.String())
default:
p.raiseError(tok, "unexpected token %s", tok.typ)
}
return nil
}
func (p *tomlParser) parseGroupArray() tomlParserStateFn {
startToken := p.getToken() // discard the [[
key := p.getToken()
if key.typ != tokenKeyGroupArray {
p.raiseError(key, "unexpected token %s, was expecting a table array key", key)
}
// get or create table array element at the indicated part in the path
keys, err := parseKey(key.val)
if err != nil {
p.raiseError(key, "invalid table array key: %s", err)
}
p.tree.createSubTree(keys[:len(keys)-1], startToken.Position) // create parent entries
destTree := p.tree.GetPath(keys)
var array []*Tree
if destTree == nil {
array = make([]*Tree, 0)
} else if target, ok := destTree.([]*Tree); ok && target != nil {
array = destTree.([]*Tree)
} else {
p.raiseError(key, "key %s is already assigned and not of type table array", key)
}
p.currentTable = keys
// add a new tree to the end of the table array
newTree := newTree()
newTree.position = startToken.Position
array = append(array, newTree)
p.tree.SetPath(p.currentTable, array)
// remove all keys that were children of this table array
prefix := key.val + "."
found := false
for ii := 0; ii < len(p.seenTableKeys); {
tableKey := p.seenTableKeys[ii]
if strings.HasPrefix(tableKey, prefix) {
p.seenTableKeys = append(p.seenTableKeys[:ii], p.seenTableKeys[ii+1:]...)
} else {
found = (tableKey == key.val)
ii++
}
}
// keep this key name from use by other kinds of assignments
if !found {
p.seenTableKeys = append(p.seenTableKeys, key.val)
}
// move to next parser state
p.assume(tokenDoubleRightBracket)
return p.parseStart
}
func (p *tomlParser) parseGroup() tomlParserStateFn {
startToken := p.getToken() // discard the [
key := p.getToken()
if key.typ != tokenKeyGroup {
p.raiseError(key, "unexpected token %s, was expecting a table key", key)
}
for _, item := range p.seenTableKeys {
if item == key.val {
p.raiseError(key, "duplicated tables")
}
}
p.seenTableKeys = append(p.seenTableKeys, key.val)
keys, err := parseKey(key.val)
if err != nil {
p.raiseError(key, "invalid table array key: %s", err)
}
if err := p.tree.createSubTree(keys, startToken.Position); err != nil {
p.raiseError(key, "%s", err)
}
destTree := p.tree.GetPath(keys)
if target, ok := destTree.(*Tree); ok && target != nil && target.inline {
p.raiseError(key, "could not re-define exist inline table or its sub-table : %s",
strings.Join(keys, "."))
}
p.assume(tokenRightBracket)
p.currentTable = keys
return p.parseStart
}
func (p *tomlParser) parseAssign() tomlParserStateFn {
key := p.getToken()
p.assume(tokenEqual)
parsedKey, err := parseKey(key.val)
if err != nil {
p.raiseError(key, "invalid key: %s", err.Error())
}
value := p.parseRvalue()
var tableKey []string
if len(p.currentTable) > 0 {
tableKey = p.currentTable
} else {
tableKey = []string{}
}
prefixKey := parsedKey[0 : len(parsedKey)-1]
tableKey = append(tableKey, prefixKey...)
// find the table to assign, looking out for arrays of tables
var targetNode *Tree
switch node := p.tree.GetPath(tableKey).(type) {
case []*Tree:
targetNode = node[len(node)-1]
case *Tree:
targetNode = node
case nil:
// create intermediate
if err := p.tree.createSubTree(tableKey, key.Position); err != nil {
p.raiseError(key, "could not create intermediate group: %s", err)
}
targetNode = p.tree.GetPath(tableKey).(*Tree)
default:
p.raiseError(key, "Unknown table type for path: %s",
strings.Join(tableKey, "."))
}
if targetNode.inline {
p.raiseError(key, "could not add key or sub-table to exist inline table or its sub-table : %s",
strings.Join(tableKey, "."))
}
// assign value to the found table
keyVal := parsedKey[len(parsedKey)-1]
localKey := []string{keyVal}
finalKey := append(tableKey, keyVal)
if targetNode.GetPath(localKey) != nil {
p.raiseError(key, "The following key was defined twice: %s",
strings.Join(finalKey, "."))
}
var toInsert interface{}
switch value.(type) {
case *Tree, []*Tree:
toInsert = value
default:
toInsert = &tomlValue{value: value, position: key.Position}
}
targetNode.values[keyVal] = toInsert
return p.parseStart
}
var numberUnderscoreInvalidRegexp *regexp.Regexp
var hexNumberUnderscoreInvalidRegexp *regexp.Regexp
func numberContainsInvalidUnderscore(value string) error {
if numberUnderscoreInvalidRegexp.MatchString(value) {
return errors.New("invalid use of _ in number")
}
return nil
}
func hexNumberContainsInvalidUnderscore(value string) error {
if hexNumberUnderscoreInvalidRegexp.MatchString(value) {
return errors.New("invalid use of _ in hex number")
}
return nil
}
func cleanupNumberToken(value string) string {
cleanedVal := strings.Replace(value, "_", "", -1)
return cleanedVal
}
func (p *tomlParser) parseRvalue() interface{} {
tok := p.getToken()
if tok == nil || tok.typ == tokenEOF {
p.raiseError(tok, "expecting a value")
}
switch tok.typ {
case tokenString:
return tok.val
case tokenTrue:
return true
case tokenFalse:
return false
case tokenInf:
if tok.val[0] == '-' {
return math.Inf(-1)
}
return math.Inf(1)
case tokenNan:
return math.NaN()
case tokenInteger:
cleanedVal := cleanupNumberToken(tok.val)
var err error
var val int64
if len(cleanedVal) >= 3 && cleanedVal[0] == '0' {
switch cleanedVal[1] {
case 'x':
err = hexNumberContainsInvalidUnderscore(tok.val)
if err != nil {
p.raiseError(tok, "%s", err)
}
val, err = strconv.ParseInt(cleanedVal[2:], 16, 64)
case 'o':
err = numberContainsInvalidUnderscore(tok.val)
if err != nil {
p.raiseError(tok, "%s", err)
}
val, err = strconv.ParseInt(cleanedVal[2:], 8, 64)
case 'b':
err = numberContainsInvalidUnderscore(tok.val)
if err != nil {
p.raiseError(tok, "%s", err)
}
val, err = strconv.ParseInt(cleanedVal[2:], 2, 64)
default:
panic("invalid base") // the lexer should catch this first
}
} else {
err = numberContainsInvalidUnderscore(tok.val)
if err != nil {
p.raiseError(tok, "%s", err)
}
val, err = strconv.ParseInt(cleanedVal, 10, 64)
}
if err != nil {
p.raiseError(tok, "%s", err)
}
return val
case tokenFloat:
err := numberContainsInvalidUnderscore(tok.val)
if err != nil {
p.raiseError(tok, "%s", err)
}
cleanedVal := cleanupNumberToken(tok.val)
val, err := strconv.ParseFloat(cleanedVal, 64)
if err != nil {
p.raiseError(tok, "%s", err)
}
return val
case tokenDate:
layout := time.RFC3339Nano
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)
isDateTime := false
isTime := false
for _, c := range v {
if c == 'T' || c == 't' {
isDateTime = true
break
}
if c == ':' {
isTime = true
break
}
}
var val interface{}
var err error
if isDateTime {
val, err = ParseLocalDateTime(v)
} else if isTime {
val, err = ParseLocalTime(v)
} else {
val, err = ParseLocalDate(v)
}
if err != nil {
p.raiseError(tok, "%s", err)
}
return val
case tokenLeftBracket:
return p.parseArray()
case tokenLeftCurlyBrace:
return p.parseInlineTable()
case tokenEqual:
p.raiseError(tok, "cannot have multiple equals for the same key")
case tokenError:
p.raiseError(tok, "%s", tok)
}
p.raiseError(tok, "never reached")
return nil
}
func tokenIsComma(t *token) bool {
return t != nil && t.typ == tokenComma
}
func (p *tomlParser) parseInlineTable() *Tree {
tree := newTree()
var previous *token
Loop:
for {
follow := p.peek()
if follow == nil || follow.typ == tokenEOF {
p.raiseError(follow, "unterminated inline table")
}
switch follow.typ {
case tokenRightCurlyBrace:
p.getToken()
break Loop
case tokenKey, tokenInteger, tokenString:
if !tokenIsComma(previous) && previous != nil {
p.raiseError(follow, "comma expected between fields in inline table")
}
key := p.getToken()
p.assume(tokenEqual)
parsedKey, err := parseKey(key.val)
if err != nil {
p.raiseError(key, "invalid key: %s", err)
}
value := p.parseRvalue()
tree.SetPath(parsedKey, value)
case tokenComma:
if tokenIsComma(previous) {
p.raiseError(follow, "need field between two commas in inline table")
}
p.getToken()
default:
p.raiseError(follow, "unexpected token type in inline table: %s", follow.String())
}
previous = follow
}
if tokenIsComma(previous) {
p.raiseError(previous, "trailing comma at the end of inline table")
}
tree.inline = true
return tree
}
func (p *tomlParser) parseArray() interface{} {
var array []interface{}
arrayType := reflect.TypeOf(newTree())
for {
follow := p.peek()
if follow == nil || follow.typ == tokenEOF {
p.raiseError(follow, "unterminated array")
}
if follow.typ == tokenRightBracket {
p.getToken()
break
}
val := p.parseRvalue()
if reflect.TypeOf(val) != arrayType {
arrayType = nil
}
array = append(array, val)
follow = p.peek()
if follow == nil || follow.typ == tokenEOF {
p.raiseError(follow, "unterminated array")
}
if follow.typ != tokenRightBracket && follow.typ != tokenComma {
p.raiseError(follow, "missing comma")
}
if follow.typ == tokenComma {
p.getToken()
}
}
// if the array is a mixed-type array or its length is 0,
// don't convert it to a table array
if len(array) <= 0 {
arrayType = nil
}
// An array of Trees is actually an array of inline
// tables, which is a shorthand for a table array. If the
// array was not converted from []interface{} to []*Tree,
// the two notations would not be equivalent.
if arrayType == reflect.TypeOf(newTree()) {
tomlArray := make([]*Tree, len(array))
for i, v := range array {
tomlArray[i] = v.(*Tree)
}
return tomlArray
}
return array
}
func parseToml(flow []token) *Tree {
result := newTree()
result.position = Position{1, 1}
parser := &tomlParser{
flowIdx: 0,
flow: flow,
tree: result,
currentTable: make([]string, 0),
seenTableKeys: make([]string, 0),
}
parser.run()
return result
}
func init() {
numberUnderscoreInvalidRegexp = regexp.MustCompile(`([^\d]_|_[^\d])|_$|^_`)
hexNumberUnderscoreInvalidRegexp = regexp.MustCompile(`(^0x_)|([^\da-f]_|_[^\da-f])|_$|^_`)
}