InternetProgramming/Lab3/node_modules/jju/lib/parse.js
2023-12-15 14:42:22 +04:00

761 lines
18 KiB
JavaScript

// RTFM: http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf
var Uni = require('./unicode')
function isHexDigit(x) {
return (x >= '0' && x <= '9')
|| (x >= 'A' && x <= 'F')
|| (x >= 'a' && x <= 'f')
}
function isOctDigit(x) {
return x >= '0' && x <= '7'
}
function isDecDigit(x) {
return x >= '0' && x <= '9'
}
var unescapeMap = {
'\'': '\'',
'"' : '"',
'\\': '\\',
'b' : '\b',
'f' : '\f',
'n' : '\n',
'r' : '\r',
't' : '\t',
'v' : '\v',
'/' : '/',
}
function formatError(input, msg, position, lineno, column, json5) {
var result = msg + ' at ' + (lineno + 1) + ':' + (column + 1)
, tmppos = position - column - 1
, srcline = ''
, underline = ''
var isLineTerminator = json5 ? Uni.isLineTerminator : Uni.isLineTerminatorJSON
// output no more than 70 characters before the wrong ones
if (tmppos < position - 70) {
tmppos = position - 70
}
while (1) {
var chr = input[++tmppos]
if (isLineTerminator(chr) || tmppos === input.length) {
if (position >= tmppos) {
// ending line error, so show it after the last char
underline += '^'
}
break
}
srcline += chr
if (position === tmppos) {
underline += '^'
} else if (position > tmppos) {
underline += input[tmppos] === '\t' ? '\t' : ' '
}
// output no more than 78 characters on the string
if (srcline.length > 78) break
}
return result + '\n' + srcline + '\n' + underline
}
function parse(input, options) {
// parse as a standard JSON mode
var json5 = false
var cjson = false
if (options.legacy || options.mode === 'json') {
// use json
} else if (options.mode === 'cjson') {
cjson = true
} else if (options.mode === 'json5') {
json5 = true
} else {
// use it by default
json5 = true
}
var isLineTerminator = json5 ? Uni.isLineTerminator : Uni.isLineTerminatorJSON
var isWhiteSpace = json5 ? Uni.isWhiteSpace : Uni.isWhiteSpaceJSON
var length = input.length
, lineno = 0
, linestart = 0
, position = 0
, stack = []
var tokenStart = function() {}
var tokenEnd = function(v) {return v}
/* tokenize({
raw: '...',
type: 'whitespace'|'comment'|'key'|'literal'|'separator'|'newline',
value: 'number'|'string'|'whatever',
path: [...],
})
*/
if (options._tokenize) {
;(function() {
var start = null
tokenStart = function() {
if (start !== null) throw Error('internal error, token overlap')
start = position
}
tokenEnd = function(v, type) {
if (start != position) {
var hash = {
raw: input.substr(start, position-start),
type: type,
stack: stack.slice(0),
}
if (v !== undefined) hash.value = v
options._tokenize.call(null, hash)
}
start = null
return v
}
})()
}
function fail(msg) {
var column = position - linestart
if (!msg) {
if (position < length) {
var token = '\'' +
JSON
.stringify(input[position])
.replace(/^"|"$/g, '')
.replace(/'/g, "\\'")
.replace(/\\"/g, '"')
+ '\''
if (!msg) msg = 'Unexpected token ' + token
} else {
if (!msg) msg = 'Unexpected end of input'
}
}
var error = SyntaxError(formatError(input, msg, position, lineno, column, json5))
error.row = lineno + 1
error.column = column + 1
throw error
}
function newline(chr) {
// account for <cr><lf>
if (chr === '\r' && input[position] === '\n') position++
linestart = position
lineno++
}
function parseGeneric() {
var result
while (position < length) {
tokenStart()
var chr = input[position++]
if (chr === '"' || (chr === '\'' && json5)) {
return tokenEnd(parseString(chr), 'literal')
} else if (chr === '{') {
tokenEnd(undefined, 'separator')
return parseObject()
} else if (chr === '[') {
tokenEnd(undefined, 'separator')
return parseArray()
} else if (chr === '-'
|| chr === '.'
|| isDecDigit(chr)
// + number Infinity NaN
|| (json5 && (chr === '+' || chr === 'I' || chr === 'N'))
) {
return tokenEnd(parseNumber(), 'literal')
} else if (chr === 'n') {
parseKeyword('null')
return tokenEnd(null, 'literal')
} else if (chr === 't') {
parseKeyword('true')
return tokenEnd(true, 'literal')
} else if (chr === 'f') {
parseKeyword('false')
return tokenEnd(false, 'literal')
} else {
position--
return tokenEnd(undefined)
}
}
}
function parseKey() {
var result
while (position < length) {
tokenStart()
var chr = input[position++]
if (chr === '"' || (chr === '\'' && json5)) {
return tokenEnd(parseString(chr), 'key')
} else if (chr === '{') {
tokenEnd(undefined, 'separator')
return parseObject()
} else if (chr === '[') {
tokenEnd(undefined, 'separator')
return parseArray()
} else if (chr === '.'
|| isDecDigit(chr)
) {
return tokenEnd(parseNumber(true), 'key')
} else if (json5
&& Uni.isIdentifierStart(chr) || (chr === '\\' && input[position] === 'u')) {
// unicode char or a unicode sequence
var rollback = position - 1
var result = parseIdentifier()
if (result === undefined) {
position = rollback
return tokenEnd(undefined)
} else {
return tokenEnd(result, 'key')
}
} else {
position--
return tokenEnd(undefined)
}
}
}
function skipWhiteSpace() {
tokenStart()
while (position < length) {
var chr = input[position++]
if (isLineTerminator(chr)) {
position--
tokenEnd(undefined, 'whitespace')
tokenStart()
position++
newline(chr)
tokenEnd(undefined, 'newline')
tokenStart()
} else if (isWhiteSpace(chr)) {
// nothing
} else if (chr === '/'
&& (json5 || cjson)
&& (input[position] === '/' || input[position] === '*')
) {
position--
tokenEnd(undefined, 'whitespace')
tokenStart()
position++
skipComment(input[position++] === '*')
tokenEnd(undefined, 'comment')
tokenStart()
} else {
position--
break
}
}
return tokenEnd(undefined, 'whitespace')
}
function skipComment(multi) {
while (position < length) {
var chr = input[position++]
if (isLineTerminator(chr)) {
// LineTerminator is an end of singleline comment
if (!multi) {
// let parent function deal with newline
position--
return
}
newline(chr)
} else if (chr === '*' && multi) {
// end of multiline comment
if (input[position] === '/') {
position++
return
}
} else {
// nothing
}
}
if (multi) {
fail('Unclosed multiline comment')
}
}
function parseKeyword(keyword) {
// keyword[0] is not checked because it should've checked earlier
var _pos = position
var len = keyword.length
for (var i=1; i<len; i++) {
if (position >= length || keyword[i] != input[position]) {
position = _pos-1
fail()
}
position++
}
}
function parseObject() {
var result = options.null_prototype ? Object.create(null) : {}
, empty_object = {}
, is_non_empty = false
while (position < length) {
skipWhiteSpace()
var item1 = parseKey()
skipWhiteSpace()
tokenStart()
var chr = input[position++]
tokenEnd(undefined, 'separator')
if (chr === '}' && item1 === undefined) {
if (!json5 && is_non_empty) {
position--
fail('Trailing comma in object')
}
return result
} else if (chr === ':' && item1 !== undefined) {
skipWhiteSpace()
stack.push(item1)
var item2 = parseGeneric()
stack.pop()
if (item2 === undefined) fail('No value found for key ' + item1)
if (typeof(item1) !== 'string') {
if (!json5 || typeof(item1) !== 'number') {
fail('Wrong key type: ' + item1)
}
}
if ((item1 in empty_object || empty_object[item1] != null) && options.reserved_keys !== 'replace') {
if (options.reserved_keys === 'throw') {
fail('Reserved key: ' + item1)
} else {
// silently ignore it
}
} else {
if (typeof(options.reviver) === 'function') {
item2 = options.reviver.call(null, item1, item2)
}
if (item2 !== undefined) {
is_non_empty = true
Object.defineProperty(result, item1, {
value: item2,
enumerable: true,
configurable: true,
writable: true,
})
}
}
skipWhiteSpace()
tokenStart()
var chr = input[position++]
tokenEnd(undefined, 'separator')
if (chr === ',') {
continue
} else if (chr === '}') {
return result
} else {
fail()
}
} else {
position--
fail()
}
}
fail()
}
function parseArray() {
var result = []
while (position < length) {
skipWhiteSpace()
stack.push(result.length)
var item = parseGeneric()
stack.pop()
skipWhiteSpace()
tokenStart()
var chr = input[position++]
tokenEnd(undefined, 'separator')
if (item !== undefined) {
if (typeof(options.reviver) === 'function') {
item = options.reviver.call(null, String(result.length), item)
}
if (item === undefined) {
result.length++
item = true // hack for check below, not included into result
} else {
result.push(item)
}
}
if (chr === ',') {
if (item === undefined) {
fail('Elisions are not supported')
}
} else if (chr === ']') {
if (!json5 && item === undefined && result.length) {
position--
fail('Trailing comma in array')
}
return result
} else {
position--
fail()
}
}
}
function parseNumber() {
// rewind because we don't know first char
position--
var start = position
, chr = input[position++]
, t
var to_num = function(is_octal) {
var str = input.substr(start, position - start)
if (is_octal) {
var result = parseInt(str.replace(/^0o?/, ''), 8)
} else {
var result = Number(str)
}
if (Number.isNaN(result)) {
position--
fail('Bad numeric literal - "' + input.substr(start, position - start + 1) + '"')
} else if (!json5 && !str.match(/^-?(0|[1-9][0-9]*)(\.[0-9]+)?(e[+-]?[0-9]+)?$/i)) {
// additional restrictions imposed by json
position--
fail('Non-json numeric literal - "' + input.substr(start, position - start + 1) + '"')
} else {
return result
}
}
// ex: -5982475.249875e+29384
// ^ skipping this
if (chr === '-' || (chr === '+' && json5)) chr = input[position++]
if (chr === 'N' && json5) {
parseKeyword('NaN')
return NaN
}
if (chr === 'I' && json5) {
parseKeyword('Infinity')
// returning +inf or -inf
return to_num()
}
if (chr >= '1' && chr <= '9') {
// ex: -5982475.249875e+29384
// ^^^ skipping these
while (position < length && isDecDigit(input[position])) position++
chr = input[position++]
}
// special case for leading zero: 0.123456
if (chr === '0') {
chr = input[position++]
// new syntax, "0o777" old syntax, "0777"
var is_octal = chr === 'o' || chr === 'O' || isOctDigit(chr)
var is_hex = chr === 'x' || chr === 'X'
if (json5 && (is_octal || is_hex)) {
while (position < length
&& (is_hex ? isHexDigit : isOctDigit)( input[position] )
) position++
var sign = 1
if (input[start] === '-') {
sign = -1
start++
} else if (input[start] === '+') {
start++
}
return sign * to_num(is_octal)
}
}
if (chr === '.') {
// ex: -5982475.249875e+29384
// ^^^ skipping these
while (position < length && isDecDigit(input[position])) position++
chr = input[position++]
}
if (chr === 'e' || chr === 'E') {
chr = input[position++]
if (chr === '-' || chr === '+') position++
// ex: -5982475.249875e+29384
// ^^^ skipping these
while (position < length && isDecDigit(input[position])) position++
chr = input[position++]
}
// we have char in the buffer, so count for it
position--
return to_num()
}
function parseIdentifier() {
// rewind because we don't know first char
position--
var result = ''
while (position < length) {
var chr = input[position++]
if (chr === '\\'
&& input[position] === 'u'
&& isHexDigit(input[position+1])
&& isHexDigit(input[position+2])
&& isHexDigit(input[position+3])
&& isHexDigit(input[position+4])
) {
// UnicodeEscapeSequence
chr = String.fromCharCode(parseInt(input.substr(position+1, 4), 16))
position += 5
}
if (result.length) {
// identifier started
if (Uni.isIdentifierPart(chr)) {
result += chr
} else {
position--
return result
}
} else {
if (Uni.isIdentifierStart(chr)) {
result += chr
} else {
return undefined
}
}
}
fail()
}
function parseString(endChar) {
// 7.8.4 of ES262 spec
var result = ''
while (position < length) {
var chr = input[position++]
if (chr === endChar) {
return result
} else if (chr === '\\') {
if (position >= length) fail()
chr = input[position++]
if (unescapeMap[chr] && (json5 || (chr != 'v' && chr != "'"))) {
result += unescapeMap[chr]
} else if (json5 && isLineTerminator(chr)) {
// line continuation
newline(chr)
} else if (chr === 'u' || (chr === 'x' && json5)) {
// unicode/character escape sequence
var off = chr === 'u' ? 4 : 2
// validation for \uXXXX
for (var i=0; i<off; i++) {
if (position >= length) fail()
if (!isHexDigit(input[position])) fail('Bad escape sequence')
position++
}
result += String.fromCharCode(parseInt(input.substr(position-off, off), 16))
} else if (json5 && isOctDigit(chr)) {
if (chr < '4' && isOctDigit(input[position]) && isOctDigit(input[position+1])) {
// three-digit octal
var digits = 3
} else if (isOctDigit(input[position])) {
// two-digit octal
var digits = 2
} else {
var digits = 1
}
position += digits - 1
result += String.fromCharCode(parseInt(input.substr(position-digits, digits), 8))
/*if (!isOctDigit(input[position])) {
// \0 is allowed still
result += '\0'
} else {
fail('Octal literals are not supported')
}*/
} else if (json5) {
// \X -> x
result += chr
} else {
position--
fail()
}
} else if (isLineTerminator(chr)) {
fail()
} else {
if (!json5 && chr.charCodeAt(0) < 32) {
position--
fail('Unexpected control character')
}
// SourceCharacter but not one of " or \ or LineTerminator
result += chr
}
}
fail()
}
skipWhiteSpace()
var return_value = parseGeneric()
if (return_value !== undefined || position < length) {
skipWhiteSpace()
if (position >= length) {
if (typeof(options.reviver) === 'function') {
return_value = options.reviver.call(null, '', return_value)
}
return return_value
} else {
fail()
}
} else {
if (position) {
fail('No data, only a whitespace')
} else {
fail('No data, empty input')
}
}
}
/*
* parse(text, options)
* or
* parse(text, reviver)
*
* where:
* text - string
* options - object
* reviver - function
*/
module.exports.parse = function parseJSON(input, options) {
// support legacy functions
if (typeof(options) === 'function') {
options = {
reviver: options
}
}
if (input === undefined) {
// parse(stringify(x)) should be equal x
// with JSON functions it is not 'cause of undefined
// so we're fixing it
return undefined
}
// JSON.parse compat
if (typeof(input) !== 'string') input = String(input)
if (options == null) options = {}
if (options.reserved_keys == null) options.reserved_keys = 'ignore'
if (options.reserved_keys === 'throw' || options.reserved_keys === 'ignore') {
if (options.null_prototype == null) {
options.null_prototype = true
}
}
try {
return parse(input, options)
} catch(err) {
// jju is a recursive parser, so JSON.parse("{{{{{{{") could blow up the stack
//
// this catch is used to skip all those internal calls
if (err instanceof SyntaxError && err.row != null && err.column != null) {
var old_err = err
err = SyntaxError(old_err.message)
err.column = old_err.column
err.row = old_err.row
}
throw err
}
}
module.exports.tokenize = function tokenizeJSON(input, options) {
if (options == null) options = {}
options._tokenize = function(smth) {
if (options._addstack) smth.stack.unshift.apply(smth.stack, options._addstack)
tokens.push(smth)
}
var tokens = []
tokens.data = module.exports.parse(input, options)
return tokens
}