# The CoffeeScript Lexer. Uses a series of token-matching regexes to attempt
# matches against the beginning of the source code. When a match is found,
# a token is produced, we consume the match, and start again. Tokens are in the
# form:
#
# [tag, value, locationData]
#
# where locationData is {first_line, first_column, last_line, last_column, last_line_exclusive, last_column_exclusive}, which is a
# format that can be fed directly into [Jison](https://github.com/zaach/jison). These
# are read by jison in the `parser.lexer` function defined in coffeescript.coffee.
{Rewriter, INVERSES, UNFINISHED} = require './rewriter'
# Import the helpers we need.
{count, starts, compact, repeat, invertLiterate, merge,
attachCommentsToNode, locationDataToString, throwSyntaxError
replaceUnicodeCodePointEscapes, flatten, parseNumber} = require './helpers'
# The Lexer Class
# ---------------
# The Lexer class reads a stream of CoffeeScript and divvies it up into tagged
# tokens. Some potential ambiguity in the grammar has been avoided by
# pushing some extra smarts into the Lexer.
exports.Lexer = class Lexer
# **tokenize** is the Lexer's main method. Scan by attempting to match tokens
# one at a time, using a regular expression anchored at the start of the
# remaining code, or a custom recursive token-matching method
# (for interpolations). When the next token has been recorded, we move forward
# within the code past the token, and begin again.
#
# Each tokenizing method is responsible for returning the number of characters
# it has consumed.
#
# Before returning the token stream, run it through the [Rewriter](rewriter.html).
tokenize: (code, opts = {}) ->
@literate = opts.literate # Are we lexing literate CoffeeScript?
@indent = 0 # The current indentation level.
@baseIndent = 0 # The overall minimum indentation level.
@continuationLineAdditionalIndent = 0 # The over-indentation at the current level.
@outdebt = 0 # The under-outdentation at the current level.
@indents = [] # The stack of all current indentation levels.
@indentLiteral = '' # The indentation.
@ends = [] # The stack for pairing up tokens.
@tokens = [] # Stream of parsed tokens in the form `['TYPE', value, location data]`.
@seenFor = no # Used to recognize `FORIN`, `FOROF` and `FORFROM` tokens.
@seenImport = no # Used to recognize `IMPORT FROM? AS?` tokens.
@seenExport = no # Used to recognize `EXPORT FROM? AS?` tokens.
@importSpecifierList = no # Used to identify when in an `IMPORT {...} FROM? ...`.
@exportSpecifierList = no # Used to identify when in an `EXPORT {...} FROM? ...`.
@jsxDepth = 0 # Used to optimize JSX checks, how deep in JSX we are.
@jsxObjAttribute = {} # Used to detect if JSX attributes is wrapped in {} (<div {props...} />).
@chunkLine =
opts.line or 0 # The start line for the current @chunk.
@chunkColumn =
opts.column or 0 # The start column of the current @chunk.
@chunkOffset =
opts.offset or 0 # The start offset for the current @chunk.
@locationDataCompensations =
opts.locationDataCompensations or {} # The location data compensations for the current @chunk.
code = @clean code # The stripped, cleaned original source code.
# At every position, run through this list of attempted matches,
# short-circuiting if any of them succeed. Their order determines precedence:
# `@literalToken` is the fallback catch-all.
i = 0
while @chunk = code[i..]
consumed = \
@identifierToken() or
@commentToken() or
@whitespaceToken() or
@lineToken() or
@stringToken() or
@numberToken() or
@jsxToken() or
@regexToken() or
@jsToken() or
@literalToken()
# Update position.
[@chunkLine, @chunkColumn, @chunkOffset] = @getLineAndColumnFromChunk consumed
i += consumed
return {@tokens, index: i} if opts.untilBalanced and @ends.length is 0
@closeIndentation()
@error "missing #{end.tag}", (end.origin ? end)[2] if end = @ends.pop()
return @tokens if opts.rewrite is off
(new Rewriter).rewrite @tokens
# Preprocess the code to remove leading and trailing whitespace, carriage
# returns, etc. If we’re lexing literate CoffeeScript, strip external Markdown
# by removing all lines that aren’t indented by at least four spaces or a tab.
clean: (code) ->
thusFar = 0
if code.charCodeAt(0) is BOM
code = code.slice 1
@locationDataCompensations[0] = 1
thusFar += 1
if WHITESPACE.test code
code = "\n#{code}"
@chunkLine--
@locationDataCompensations[0] ?= 0
@locationDataCompensations[0] -= 1
code = code
.replace /\r/g, (match, offset) =>
@locationDataCompensations[thusFar + offset] = 1
''
.replace TRAILING_SPACES, ''
code = invertLiterate code if @literate
code
# Tokenizers
# ----------
# Matches identifying literals: variables, keywords, method names, etc.
# Check to ensure that JavaScript reserved words aren’t being used as
# identifiers. Because CoffeeScript reserves a handful of keywords that are
# allowed in JavaScript, we’re careful not to tag them as keywords when
# referenced as property names here, so you can still do `jQuery.is()` even
# though `is` means `===` otherwise.
identifierToken: ->
inJSXTag = @atJSXTag()
regex = if inJSXTag then JSX_ATTRIBUTE else IDENTIFIER
return 0 unless match = regex.exec @chunk
[input, id, colon] = match
# Preserve length of id for location data
idLength = id.length
poppedToken = undefined
if id is 'own' and @tag() is 'FOR'
@token 'OWN', id
return id.length
if id is 'from' and @tag() is 'YIELD'
@token 'FROM', id
return id.length
if id is 'as' and @seenImport
if @value() is '*'
@tokens[@tokens.length - 1][0] = 'IMPORT_ALL'
else if @value(yes) in COFFEE_KEYWORDS
prev = @prev()
[prev[0], prev[1]] = ['IDENTIFIER', @value(yes)]
if @tag() in ['DEFAULT', 'IMPORT_ALL', 'IDENTIFIER']
@token 'AS', id
return id.length
if id is 'as' and @seenExport
if @tag() in ['IDENTIFIER', 'DEFAULT']
@token 'AS', id
return id.length
if @value(yes) in COFFEE_KEYWORDS
prev = @prev()
[prev[0], prev[1]] = ['IDENTIFIER', @value(yes)]
@token 'AS', id
return id.length
if id is 'default' and @seenExport and @tag() in ['EXPORT', 'AS']
@token 'DEFAULT', id
return id.length
if id is 'assert' and (@seenImport or @seenExport) and @tag() is 'STRING'
@token 'ASSERT', id
return id.length
if id is 'do' and regExSuper = /^(\s*super)(?!\(\))/.exec @chunk[3...]
@token 'SUPER', 'super'
@token 'CALL_START', '('
@token 'CALL_END', ')'
[input, sup] = regExSuper
return sup.length + 3
prev = @prev()
tag =
if colon or prev? and
(prev[0] in ['.', '?.', '::', '?::'] or
not prev.spaced and prev[0] is '@')
'PROPERTY'
else
'IDENTIFIER'
tokenData = {}
if tag is 'IDENTIFIER' and (id in JS_KEYWORDS or id in COFFEE_KEYWORDS) and
not (@exportSpecifierList and id in COFFEE_KEYWORDS)
tag = id.toUpperCase()
if tag is 'WHEN' and @tag() in LINE_BREAK
tag = 'LEADING_WHEN'
else if tag is 'FOR'
@seenFor = {endsLength: @ends.length}
else if tag is 'UNLESS'
tag = 'IF'
else if tag is 'IMPORT'
@seenImport = yes
else if tag is 'EXPORT'
@seenExport = yes
else if tag in UNARY
tag = 'UNARY'
else if tag in RELATION
if tag isnt 'INSTANCEOF' and @seenFor
tag = 'FOR' + tag
@seenFor = no
else
tag = 'RELATION'
if @value() is '!'
poppedToken = @tokens.pop()
tokenData.invert = poppedToken.data?.original ? poppedToken[1]
else if tag is 'IDENTIFIER' and @seenFor and id is 'from' and
isForFrom(prev)
tag = 'FORFROM'
@seenFor = no
# Throw an error on attempts to use `get` or `set` as keywords, or
# what CoffeeScript would normally interpret as calls to functions named
# `get` or `set`, i.e. `get({foo: function () {}})`.
else if tag is 'PROPERTY' and prev
if prev.spaced and prev[0] in CALLABLE and /^[gs]et$/.test(prev[1]) and
@tokens.length > 1 and @tokens[@tokens.length - 2][0] not in ['.', '?.', '@']
@error "'#{prev[1]}' cannot be used as a keyword, or as a function call
without parentheses", prev[2]
else if prev[0] is '.' and @tokens.length > 1 and (prevprev = @tokens[@tokens.length - 2])[0] is 'UNARY' and prevprev[1] is 'new'
prevprev[0] = 'NEW_TARGET'
else if prev[0] is '.' and @tokens.length > 1 and (prevprev = @tokens[@tokens.length - 2])[0] is 'IMPORT' and prevprev[1] is 'import'
@seenImport = no
prevprev[0] = 'IMPORT_META'
else if @tokens.length > 2
prevprev = @tokens[@tokens.length - 2]
if prev[0] in ['@', 'THIS'] and prevprev and prevprev.spaced and
/^[gs]et$/.test(prevprev[1]) and
@tokens[@tokens.length - 3][0] not in ['.', '?.', '@']
@error "'#{prevprev[1]}' cannot be used as a keyword, or as a
function call without parentheses", prevprev[2]
if tag is 'IDENTIFIER' and id in RESERVED and not inJSXTag
@error "reserved word '#{id}'", length: id.length
unless tag is 'PROPERTY' or @exportSpecifierList or @importSpecifierList
if id in COFFEE_ALIASES
alias = id
id = COFFEE_ALIAS_MAP[id]
tokenData.original = alias
tag = switch id
when '!' then 'UNARY'
when '==', '!=' then 'COMPARE'
when 'true', 'false' then 'BOOL'
when 'break', 'continue', \
'debugger' then 'STATEMENT'
when '&&', '||' then id
else tag
tagToken = @token tag, id, length: idLength, data: tokenData
tagToken.origin = [tag, alias, tagToken[2]] if alias
if poppedToken
[tagToken[2].first_line, tagToken[2].first_column, tagToken[2].range[0]] =
[poppedToken[2].first_line, poppedToken[2].first_column, poppedToken[2].range[0]]
if colon
colonOffset = input.lastIndexOf if inJSXTag then '=' else ':'
colonToken = @token ':', ':', offset: colonOffset
colonToken.jsxColon = yes if inJSXTag # used by rewriter
if inJSXTag and tag is 'IDENTIFIER' and prev[0] isnt ':'
@token ',', ',', length: 0, origin: tagToken, generated: yes
input.length
# Matches numbers, including decimals, hex, and exponential notation.
# Be careful not to interfere with ranges in progress.
numberToken: ->
return 0 unless match = NUMBER.exec @chunk
number = match[0]
lexedLength = number.length
switch
when /^0[BOX]/.test number
@error "radix prefix in '#{number}' must be lowercase", offset: 1
when /^0\d*[89]/.test number
@error "decimal literal '#{number}' must not be prefixed with '0'", length: lexedLength
when /^0\d+/.test number
@error "octal literal '#{number}' must be prefixed with '0o'", length: lexedLength
parsedValue = parseNumber number
tokenData = {parsedValue}
tag = if parsedValue is Infinity then 'INFINITY' else 'NUMBER'
if tag is 'INFINITY'
tokenData.original = number
@token tag, number,
length: lexedLength
data: tokenData
lexedLength
# Matches strings, including multiline strings, as well as heredocs, with or without
# interpolation.
stringToken: ->
[quote] = STRING_START.exec(@chunk) || []
return 0 unless quote
# If the preceding token is `from` and this is an import or export statement,
# properly tag the `from`.
prev = @prev()
if prev and @value() is 'from' and (@seenImport or @seenExport)
prev[0] = 'FROM'
regex = switch quote
when "'" then STRING_SINGLE
when '"' then STRING_DOUBLE
when "'''" then HEREDOC_SINGLE
when '"""' then HEREDOC_DOUBLE
{tokens, index: end} = @matchWithInterpolations regex, quote
heredoc = quote.length is 3
if heredoc
# Find the smallest indentation. It will be removed from all lines later.
indent = null
doc = (token[1] for token, i in tokens when token[0] is 'NEOSTRING').join '#{}'
while match = HEREDOC_INDENT.exec doc
attempt = match[1]
indent = attempt if indent is null or 0 < attempt.length < indent.length
delimiter = quote.charAt(0)
@mergeInterpolationTokens tokens, {quote, indent, endOffset: end}, (value) =>
@validateUnicodeCodePointEscapes value, delimiter: quote
if @atJSXTag()
@token ',', ',', length: 0, origin: @prev, generated: yes
end
# Matches and consumes comments. The comments are taken out of the token
# stream and saved for later, to be reinserted into the output after
# everything has been parsed and the JavaScript code generated.
commentToken: (chunk = @chunk, {heregex, returnCommentTokens = no, offsetInChunk = 0} = {}) ->
return 0 unless match = chunk.match COMMENT
[commentWithSurroundingWhitespace, hereLeadingWhitespace, hereComment, hereTrailingWhitespace, lineComment] = match
contents = null
# Does this comment follow code on the same line?
leadingNewline = /^\s*\n+\s*#/.test commentWithSurroundingWhitespace
if hereComment
matchIllegal = HERECOMMENT_ILLEGAL.exec hereComment
if matchIllegal
@error "block comments cannot contain #{matchIllegal[0]}",
offset: '###'.length + matchIllegal.index, length: matchIllegal[0].length
# Parse indentation or outdentation as if this block comment didn’t exist.
chunk = chunk.replace "####{hereComment}###", ''
# Remove leading newlines, like `Rewriter::removeLeadingNewlines`, to
# avoid the creation of unwanted `TERMINATOR` tokens.
chunk = chunk.replace /^\n+/, ''
@lineToken {chunk}
# Pull out the ###-style comment’s content, and format it.
content = hereComment
contents = [{
content
length: commentWithSurroundingWhitespace.length - hereLeadingWhitespace.length - hereTrailingWhitespace.length
leadingWhitespace: hereLeadingWhitespace
}]
else
# The `COMMENT` regex captures successive line comments as one token.
# Remove any leading newlines before the first comment, but preserve
# blank lines between line comments.
leadingNewlines = ''
content = lineComment.replace /^(\n*)/, (leading) ->
leadingNewlines = leading
''
precedingNonCommentLines = ''
hasSeenFirstCommentLine = no
contents =
content.split '\n'
.map (line, index) ->
unless line.indexOf('#') > -1
precedingNonCommentLines += "\n#{line}"
return
leadingWhitespace = ''
content = line.replace /^([ |\t]*)#/, (_, whitespace) ->
leadingWhitespace = whitespace
''
comment = {
content
length: '#'.length + content.length
leadingWhitespace: "#{unless hasSeenFirstCommentLine then leadingNewlines else ''}#{precedingNonCommentLines}#{leadingWhitespace}"
precededByBlankLine: !!precedingNonCommentLines
}
hasSeenFirstCommentLine = yes
precedingNonCommentLines = ''
comment
.filter (comment) -> comment
getIndentSize = ({leadingWhitespace, nonInitial}) ->
lastNewlineIndex = leadingWhitespace.lastIndexOf '\n'
if hereComment? or not nonInitial
return null unless lastNewlineIndex > -1
else
lastNewlineIndex ?= -1
leadingWhitespace.length - 1 - lastNewlineIndex
commentAttachments = for {content, length, leadingWhitespace, precededByBlankLine}, i in contents
nonInitial = i isnt 0
leadingNewlineOffset = if nonInitial then 1 else 0
offsetInChunk += leadingNewlineOffset + leadingWhitespace.length
indentSize = getIndentSize {leadingWhitespace, nonInitial}
noIndent = not indentSize? or indentSize is -1
commentAttachment = {
content
here: hereComment?
newLine: leadingNewline or nonInitial # Line comments after the first one start new lines, by definition.
locationData: @makeLocationData {offsetInChunk, length}
precededByBlankLine
indentSize
indented: not noIndent and indentSize > @indent
outdented: not noIndent and indentSize < @indent
}
commentAttachment.heregex = yes if heregex
offsetInChunk += length
commentAttachment
prev = @prev()
unless prev
# If there’s no previous token, create a placeholder token to attach
# this comment to; and follow with a newline.
commentAttachments[0].newLine = yes
@lineToken chunk: @chunk[commentWithSurroundingWhitespace.length..], offset: commentWithSurroundingWhitespace.length # Set the indent.
placeholderToken = @makeToken 'JS', '', offset: commentWithSurroundingWhitespace.length, generated: yes
placeholderToken.comments = commentAttachments
@tokens.push placeholderToken
@newlineToken commentWithSurroundingWhitespace.length
else
attachCommentsToNode commentAttachments, prev
return commentAttachments if returnCommentTokens
commentWithSurroundingWhitespace.length
# Matches JavaScript interpolated directly into the source via backticks.
jsToken: ->
return 0 unless @chunk.charAt(0) is '`' and
(match = (matchedHere = HERE_JSTOKEN.exec(@chunk)) or JSTOKEN.exec(@chunk))
# Convert escaped backticks to backticks, and escaped backslashes
# just before escaped backticks to backslashes
script = match[1]
{length} = match[0]
@token 'JS', script, {length, data: {here: !!matchedHere}}
length
# Matches regular expression literals, as well as multiline extended ones.
# Lexing regular expressions is difficult to distinguish from division, so we
# borrow some basic heuristics from JavaScript and Ruby.
regexToken: ->
switch
when match = REGEX_ILLEGAL.exec @chunk
@error "regular expressions cannot begin with #{match[2]}",
offset: match.index + match[1].length
when match = @matchWithInterpolations HEREGEX, '///'
{tokens, index} = match
comments = []
while matchedComment = HEREGEX_COMMENT.exec @chunk[0...index]
{index: commentIndex} = matchedComment
[fullMatch, leadingWhitespace, comment] = matchedComment
comments.push {comment, offsetInChunk: commentIndex + leadingWhitespace.length}
commentTokens = flatten(
for commentOpts in comments
@commentToken commentOpts.comment, Object.assign commentOpts, heregex: yes, returnCommentTokens: yes
)
when match = REGEX.exec @chunk
[regex, body, closed] = match
@validateEscapes body, isRegex: yes, offsetInChunk: 1
index = regex.length
prev = @prev()
if prev
if prev.spaced and prev[0] in CALLABLE
return 0 if not closed or POSSIBLY_DIVISION.test regex
else if prev[0] in NOT_REGEX
return 0
@error 'missing / (unclosed regex)' unless closed
else
return 0
[flags] = REGEX_FLAGS.exec @chunk[index..]
end = index + flags.length
origin = @makeToken 'REGEX', null, length: end
switch
when not VALID_FLAGS.test flags
@error "invalid regular expression flags #{flags}", offset: index, length: flags.length
when regex or tokens.length is 1
delimiter = if body then '/' else '///'
body ?= tokens[0][1]
@validateUnicodeCodePointEscapes body, {delimiter}
@token 'REGEX', "/#{body}/#{flags}", {length: end, origin, data: {delimiter}}
else
@token 'REGEX_START', '(', {length: 0, origin, generated: yes}
@token 'IDENTIFIER', 'RegExp', length: 0, generated: yes
@token 'CALL_START', '(', length: 0, generated: yes
@mergeInterpolationTokens tokens, {double: yes, heregex: {flags}, endOffset: end - flags.length, quote: '///'}, (str) =>
@validateUnicodeCodePointEscapes str, {delimiter}
if flags
@token ',', ',', offset: index - 1, length: 0, generated: yes
@token 'STRING', '"' + flags + '"', offset: index, length: flags.length
@token ')', ')', offset: end, length: 0, generated: yes
@token 'REGEX_END', ')', offset: end, length: 0, generated: yes
# Explicitly attach any heregex comments to the REGEX/REGEX_END token.
if commentTokens?.length
addTokenData @tokens[@tokens.length - 1],
heregexCommentTokens: commentTokens
end
# Matches newlines, indents, and outdents, and determines which is which.
# If we can detect that the current line is continued onto the next line,
# then the newline is suppressed:
#
# elements
# .each( ... )
# .map( ... )
#
# Keeps track of the level of indentation, because a single outdent token
# can close multiple indents, so we need to know how far in we happen to be.
lineToken: ({chunk = @chunk, offset = 0} = {}) ->
return 0 unless match = MULTI_DENT.exec chunk
indent = match[0]
prev = @prev()
backslash = prev?[0] is '\\'
@seenFor = no unless (backslash or @seenFor?.endsLength < @ends.length) and @seenFor
@seenImport = no unless (backslash and @seenImport) or @importSpecifierList
@seenExport = no unless (backslash and @seenExport) or @exportSpecifierList
size = indent.length - 1 - indent.lastIndexOf '\n'
noNewlines = @unfinished()
newIndentLiteral = if size > 0 then indent[-size..] else ''
unless /^(.?)\1*$/.exec newIndentLiteral
@error 'mixed indentation', offset: indent.length
return indent.length
minLiteralLength = Math.min newIndentLiteral.length, @indentLiteral.length
if newIndentLiteral[...minLiteralLength] isnt @indentLiteral[...minLiteralLength]
@error 'indentation mismatch', offset: indent.length
return indent.length
if size - @continuationLineAdditionalIndent is @indent
if noNewlines then @suppressNewlines() else @newlineToken offset
return indent.length
if size > @indent
if noNewlines
@continuationLineAdditionalIndent = size - @indent unless backslash
if @continuationLineAdditionalIndent
prev.continuationLineIndent = @indent + @continuationLineAdditionalIndent
@suppressNewlines()
return indent.length
unless @tokens.length
@baseIndent = @indent = size
@indentLiteral = newIndentLiteral
return indent.length
diff = size - @indent + @outdebt
@token 'INDENT', diff, offset: offset + indent.length - size, length: size
@indents.push diff
@ends.push {tag: 'OUTDENT'}
@outdebt = @continuationLineAdditionalIndent = 0
@indent = size
@indentLiteral = newIndentLiteral
else if size < @baseIndent
@error 'missing indentation', offset: offset + indent.length
else
endsContinuationLineIndentation = @continuationLineAdditionalIndent > 0
@continuationLineAdditionalIndent = 0
@outdentToken {moveOut: @indent - size, noNewlines, outdentLength: indent.length, offset, indentSize: size, endsContinuationLineIndentation}
indent.length
# Record an outdent token or multiple tokens, if we happen to be moving back
# inwards past several recorded indents. Sets new @indent value.
outdentToken: ({moveOut, noNewlines, outdentLength = 0, offset = 0, indentSize, endsContinuationLineIndentation}) ->
decreasedIndent = @indent - moveOut
while moveOut > 0
lastIndent = @indents[@indents.length - 1]
if not lastIndent
@outdebt = moveOut = 0
else if @outdebt and moveOut <= @outdebt
@outdebt -= moveOut
moveOut = 0
else
dent = @indents.pop() + @outdebt
if outdentLength and @chunk[outdentLength] in INDENTABLE_CLOSERS
decreasedIndent -= dent - moveOut
moveOut = dent
@outdebt = 0
# pair might call outdentToken, so preserve decreasedIndent
@pair 'OUTDENT'
@token 'OUTDENT', moveOut, length: outdentLength, indentSize: indentSize + moveOut - dent
moveOut -= dent
@outdebt -= moveOut if dent
@suppressSemicolons()
unless @tag() is 'TERMINATOR' or noNewlines
terminatorToken = @token 'TERMINATOR', '\n', offset: offset + outdentLength, length: 0
terminatorToken.endsContinuationLineIndentation = {preContinuationLineIndent: @indent} if endsContinuationLineIndentation
@indent = decreasedIndent
@indentLiteral = @indentLiteral[...decreasedIndent]
this
# Matches and consumes non-meaningful whitespace. Tag the previous token
# as being “spaced”, because there are some cases where it makes a difference.
whitespaceToken: ->
return 0 unless (match = WHITESPACE.exec @chunk) or
(nline = @chunk.charAt(0) is '\n')
prev = @prev()
prev[if match then 'spaced' else 'newLine'] = true if prev
if match then match[0].length else 0
# Generate a newline token. Consecutive newlines get merged together.
newlineToken: (offset) ->
@suppressSemicolons()
@token 'TERMINATOR', '\n', {offset, length: 0} unless @tag() is 'TERMINATOR'
this
# Use a `\` at a line-ending to suppress the newline.
# The slash is removed here once its job is done.
suppressNewlines: ->
prev = @prev()
if prev[1] is '\\'
if prev.comments and @tokens.length > 1
# `@tokens.length` should be at least 2 (some code, then `\`).
# If something puts a `\` after nothing, they deserve to lose any
# comments that trail it.
attachCommentsToNode prev.comments, @tokens[@tokens.length - 2]
@tokens.pop()
this
jsxToken: ->
firstChar = @chunk[0]
# Check the previous token to detect if attribute is spread.
prevChar = if @tokens.length > 0 then @tokens[@tokens.length - 1][0] else ''
if firstChar is '<'
match = JSX_IDENTIFIER.exec(@chunk[1...]) or JSX_FRAGMENT_IDENTIFIER.exec(@chunk[1...])
return 0 unless match and (
@jsxDepth > 0 or
# Not the right hand side of an unspaced comparison (i.e. `a<b`).
not (prev = @prev()) or
prev.spaced or
prev[0] not in COMPARABLE_LEFT_SIDE
)
[input, id] = match
fullId = id
if '.' in id
[id, properties...] = id.split '.'
else
properties = []
tagToken = @token 'JSX_TAG', id,
length: id.length + 1
data:
openingBracketToken: @makeToken '<', '<'
tagNameToken: @makeToken 'IDENTIFIER', id, offset: 1
offset = id.length + 1
for property in properties
@token '.', '.', {offset}
offset += 1
@token 'PROPERTY', property, {offset}
offset += property.length
@token 'CALL_START', '(', generated: yes
@token '[', '[', generated: yes
@ends.push {tag: '/>', origin: tagToken, name: id, properties}
@jsxDepth++
return fullId.length + 1
else if jsxTag = @atJSXTag()
if @chunk[...2] is '/>' # Self-closing tag.
@pair '/>'
@token ']', ']',
length: 2
generated: yes
@token 'CALL_END', ')',
length: 2
generated: yes
data:
selfClosingSlashToken: @makeToken '/', '/'
closingBracketToken: @makeToken '>', '>', offset: 1
@jsxDepth--
return 2
else if firstChar is '{'
if prevChar is ':'
# This token represents the start of a JSX attribute value
# that’s an expression (e.g. the `{b}` in `<div a={b} />`).
# Our grammar represents the beginnings of expressions as `(`
# tokens, so make this into a `(` token that displays as `{`.
token = @token '(', '{'
@jsxObjAttribute[@jsxDepth] = no
# tag attribute name as JSX
addTokenData @tokens[@tokens.length - 3],
jsx: yes
else
token = @token '{', '{'
@jsxObjAttribute[@jsxDepth] = yes
@ends.push {tag: '}', origin: token}
return 1
else if firstChar is '>' # end of opening tag
# Ignore terminators inside a tag.
{origin: openingTagToken} = @pair '/>' # As if the current tag was self-closing.
@token ']', ']',
generated: yes
data:
closingBracketToken: @makeToken '>', '>'
@token ',', 'JSX_COMMA', generated: yes
{tokens, index: end} =
@matchWithInterpolations INSIDE_JSX, '>', '</', JSX_INTERPOLATION
@mergeInterpolationTokens tokens, {endOffset: end, jsx: yes}, (value) =>
@validateUnicodeCodePointEscapes value, delimiter: '>'
match = JSX_IDENTIFIER.exec(@chunk[end...]) or JSX_FRAGMENT_IDENTIFIER.exec(@chunk[end...])
if not match or match[1] isnt "#{jsxTag.name}#{(".#{property}" for property in jsxTag.properties).join ''}"
@error "expected corresponding JSX closing tag for #{jsxTag.name}",
jsxTag.origin.data.tagNameToken[2]
[, fullTagName] = match
afterTag = end + fullTagName.length
if @chunk[afterTag] isnt '>'
@error "missing closing > after tag name", offset: afterTag, length: 1
# -2/+2 for the opening `</` and +1 for the closing `>`.
endToken = @token 'CALL_END', ')',
offset: end - 2
length: fullTagName.length + 3
generated: yes
data:
closingTagOpeningBracketToken: @makeToken '<', '<', offset: end - 2
closingTagSlashToken: @makeToken '/', '/', offset: end - 1
# TODO: individual tokens for complex tag name? eg < / A . B >
closingTagNameToken: @makeToken 'IDENTIFIER', fullTagName, offset: end
closingTagClosingBracketToken: @makeToken '>', '>', offset: end + fullTagName.length
# make the closing tag location data more easily accessible to the grammar
addTokenData openingTagToken, endToken.data
@jsxDepth--
return afterTag + 1
else
return 0
else if @atJSXTag 1
if firstChar is '}'
@pair firstChar
if @jsxObjAttribute[@jsxDepth]
@token '}', '}'
@jsxObjAttribute[@jsxDepth] = no
else
@token ')', '}'
@token ',', ',', generated: yes
return 1
else
return 0
else
return 0
atJSXTag: (depth = 0) ->
return no if @jsxDepth is 0
i = @ends.length - 1
i-- while @ends[i]?.tag is 'OUTDENT' or depth-- > 0 # Ignore indents.
last = @ends[i]
last?.tag is '/>' and last
# We treat all other single characters as a token. E.g.: `( ) , . !`
# Multi-character operators are also literal tokens, so that Jison can assign
# the proper order of operations. There are some symbols that we tag specially
# here. `;` and newlines are both treated as a `TERMINATOR`, we distinguish
# parentheses that indicate a method call from regular parentheses, and so on.
literalToken: ->
if match = OPERATOR.exec @chunk
[value] = match
@tagParameters() if CODE.test value
else
value = @chunk.charAt 0
tag = value
prev = @prev()
if prev and value in ['=', COMPOUND_ASSIGN...]
skipToken = false
if value is '=' and prev[1] in ['||', '&&'] and not prev.spaced
prev[0] = 'COMPOUND_ASSIGN'
prev[1] += '='
prev.data.original += '=' if prev.data?.original
prev[2].range = [
prev[2].range[0]
prev[2].range[1] + 1
]
prev[2].last_column += 1
prev[2].last_column_exclusive += 1
prev = @tokens[@tokens.length - 2]
skipToken = true
if prev and prev[0] isnt 'PROPERTY'
origin = prev.origin ? prev
message = isUnassignable prev[1], origin[1]
@error message, origin[2] if message
return value.length if skipToken
if value is '(' and prev?[0] is 'IMPORT'
prev[0] = 'DYNAMIC_IMPORT'
if value is '{' and @seenImport
@importSpecifierList = yes
else if @importSpecifierList and value is '}'
@importSpecifierList = no
else if value is '{' and prev?[0] is 'EXPORT'
@exportSpecifierList = yes
else if @exportSpecifierList and value is '}'
@exportSpecifierList = no
if value is ';'
@error 'unexpected ;' if prev?[0] in ['=', UNFINISHED...]
@seenFor = @seenImport = @seenExport = no
tag = 'TERMINATOR'
else if value is '*' and prev?[0] is 'EXPORT'
tag = 'EXPORT_ALL'
else if value in MATH then tag = 'MATH'
else if value in COMPARE then tag = 'COMPARE'
else if value in COMPOUND_ASSIGN then tag = 'COMPOUND_ASSIGN'
else if value in UNARY then tag = 'UNARY'
else if value in UNARY_MATH then tag = 'UNARY_MATH'
else if value in SHIFT then tag = 'SHIFT'
else if value is '?' and prev?.spaced then tag = 'BIN?'
else if prev
if value is '(' and not prev.spaced and prev[0] in CALLABLE
prev[0] = 'FUNC_EXIST' if prev[0] is '?'
tag = 'CALL_START'
else if value is '[' and ((prev[0] in INDEXABLE and not prev.spaced) or
(prev[0] is '::')) # `.prototype` can’t be a method you can call.
tag = 'INDEX_START'
switch prev[0]
when '?' then prev[0] = 'INDEX_SOAK'
token = @makeToken tag, value
switch value
when '(', '{', '[' then @ends.push {tag: INVERSES[value], origin: token}
when ')', '}', ']' then @pair value
@tokens.push @makeToken tag, value
value.length
# Token Manipulators
# ------------------
# A source of ambiguity in our grammar used to be parameter lists in function
# definitions versus argument lists in function calls. Walk backwards, tagging
# parameters specially in order to make things easier for the parser.
tagParameters: ->
return @tagDoIife() if @tag() isnt ')'
stack = []
{tokens} = this
i = tokens.length
paramEndToken = tokens[--i]
paramEndToken[0] = 'PARAM_END'
while tok = tokens[--i]
switch tok[0]
when ')'
stack.push tok
when '(', 'CALL_START'
if stack.length then stack.pop()
else if tok[0] is '('
tok[0] = 'PARAM_START'
return @tagDoIife i - 1
else
paramEndToken[0] = 'CALL_END'
return this
this
# Tag `do` followed by a function differently than `do` followed by eg an
# identifier to allow for different grammar precedence
tagDoIife: (tokenIndex) ->
tok = @tokens[tokenIndex ? @tokens.length - 1]
return this unless tok?[0] is 'DO'
tok[0] = 'DO_IIFE'
this
# Close up all remaining open blocks at the end of the file.
closeIndentation: ->
@outdentToken moveOut: @indent, indentSize: 0
# Match the contents of a delimited token and expand variables and expressions
# inside it using Ruby-like notation for substitution of arbitrary
# expressions.
#
# "Hello #{name.capitalize()}."
#
# If it encounters an interpolation, this method will recursively create a new
# Lexer and tokenize until the `{` of `#{` is balanced with a `}`.
#
# - `regex` matches the contents of a token (but not `delimiter`, and not
# `#{` if interpolations are desired).
# - `delimiter` is the delimiter of the token. Examples are `'`, `"`, `'''`,
# `"""` and `///`.
# - `closingDelimiter` is different from `delimiter` only in JSX
# - `interpolators` matches the start of an interpolation, for JSX it's both
# `{` and `<` (i.e. nested JSX tag)
#
# This method allows us to have strings within interpolations within strings,
# ad infinitum.
matchWithInterpolations: (regex, delimiter, closingDelimiter = delimiter, interpolators = /^#\{/) ->
tokens = []
offsetInChunk = delimiter.length
return null unless @chunk[...offsetInChunk] is delimiter
str = @chunk[offsetInChunk..]
loop
[strPart] = regex.exec str
@validateEscapes strPart, {isRegex: delimiter.charAt(0) is '/', offsetInChunk}
# Push a fake `'NEOSTRING'` token, which will get turned into a real string later.
tokens.push @makeToken 'NEOSTRING', strPart, offset: offsetInChunk
str = str[strPart.length..]
offsetInChunk += strPart.length
break unless match = interpolators.exec str
[interpolator] = match
# To remove the `#` in `#{`.
interpolationOffset = interpolator.length - 1
[line, column, offset] = @getLineAndColumnFromChunk offsetInChunk + interpolationOffset
rest = str[interpolationOffset..]
{tokens: nested, index} =
new Lexer().tokenize rest, {line, column, offset, untilBalanced: on, @locationDataCompensations}
# Account for the `#` in `#{`.
index += interpolationOffset
braceInterpolator = str[index - 1] is '}'
if braceInterpolator
# Turn the leading and trailing `{` and `}` into parentheses. Unnecessary
# parentheses will be removed later.
[open, ..., close] = nested
open[0] = 'INTERPOLATION_START'
open[1] = '('
open[2].first_column -= interpolationOffset
open[2].range = [
open[2].range[0] - interpolationOffset
open[2].range[1]
]
close[0] = 'INTERPOLATION_END'
close[1] = ')'
close.origin = ['', 'end of interpolation', close[2]]
# Remove leading `'TERMINATOR'` (if any).
nested.splice 1, 1 if nested[1]?[0] is 'TERMINATOR'
# Remove trailing `'INDENT'/'OUTDENT'` pair (if any).
nested.splice -3, 2 if nested[nested.length - 3]?[0] is 'INDENT' and nested[nested.length - 2][0] is 'OUTDENT'
unless braceInterpolator
# We are not using `{` and `}`, so wrap the interpolated tokens instead.
open = @makeToken 'INTERPOLATION_START', '(', offset: offsetInChunk, length: 0, generated: yes
close = @makeToken 'INTERPOLATION_END', ')', offset: offsetInChunk + index, length: 0, generated: yes
nested = [open, nested..., close]
# Push a fake `'TOKENS'` token, which will get turned into real tokens later.
tokens.push ['TOKENS', nested]
str = str[index..]
offsetInChunk += index
unless str[...closingDelimiter.length] is closingDelimiter
@error "missing #{closingDelimiter}", length: delimiter.length
{tokens, index: offsetInChunk + closingDelimiter.length}
# Merge the array `tokens` of the fake token types `'TOKENS'` and `'NEOSTRING'`
# (as returned by `matchWithInterpolations`) into the token stream. The value
# of `'NEOSTRING'`s are converted using `fn` and turned into strings using
# `options` first.
mergeInterpolationTokens: (tokens, options, fn) ->
{quote, indent, double, heregex, endOffset, jsx} = options
if tokens.length > 1
lparen = @token 'STRING_START', '(', length: quote?.length ? 0, data: {quote}, generated: not quote?.length
firstIndex = @tokens.length
$ = tokens.length - 1
for token, i in tokens
[tag, value] = token
switch tag
when 'TOKENS'
# There are comments (and nothing else) in this interpolation.
if value.length is 2 and (value[0].comments or value[1].comments)
placeholderToken = @makeToken 'JS', '', generated: yes
# Use the same location data as the first parenthesis.
placeholderToken[2] = value[0][2]
for val in value when val.comments
placeholderToken.comments ?= []
placeholderToken.comments.push val.comments...
value.splice 1, 0, placeholderToken
# Push all the tokens in the fake `'TOKENS'` token. These already have
# sane location data.
locationToken = value[0]
tokensToPush = value
when 'NEOSTRING'
# Convert `'NEOSTRING'` into `'STRING'`.
converted = fn.call this, token[1], i
addTokenData token, initialChunk: yes if i is 0
addTokenData token, finalChunk: yes if i is $
addTokenData token, {indent, quote, double}
addTokenData token, {heregex} if heregex
addTokenData token, {jsx} if jsx
token[0] = 'STRING'
token[1] = '"' + converted + '"'
if tokens.length is 1 and quote?
token[2].first_column -= quote.length
if token[1].substr(-2, 1) is '\n'
token[2].last_line += 1
token[2].last_column = quote.length - 1
else
token[2].last_column += quote.length
token[2].last_column -= 1 if token[1].length is 2
token[2].last_column_exclusive += quote.length
token[2].range = [
token[2].range[0] - quote.length
token[2].range[1] + quote.length
]
locationToken = token
tokensToPush = [token]
@tokens.push tokensToPush...
if lparen
[..., lastToken] = tokens
lparen.origin = ['STRING', null,
first_line: lparen[2].first_line
first_column: lparen[2].first_column
last_line: lastToken[2].last_line
last_column: lastToken[2].last_column
last_line_exclusive: lastToken[2].last_line_exclusive
last_column_exclusive: lastToken[2].last_column_exclusive
range: [
lparen[2].range[0]
lastToken[2].range[1]
]
]
lparen[2] = lparen.origin[2] unless quote?.length
rparen = @token 'STRING_END', ')', offset: endOffset - (quote ? '').length, length: quote?.length ? 0, generated: not quote?.length
# Pairs up a closing token, ensuring that all listed pairs of tokens are
# correctly balanced throughout the course of the token stream.
pair: (tag) ->
[..., prev] = @ends
unless tag is wanted = prev?.tag
@error "unmatched #{tag}" unless 'OUTDENT' is wanted
# Auto-close `INDENT` to support syntax like this:
#
# el.click((event) ->
# el.hide())
#
[..., lastIndent] = @indents
@outdentToken moveOut: lastIndent, noNewlines: true
return @pair tag
@ends.pop()
# Helpers
# -------
# Compensate for the things we strip out initially (e.g. carriage returns)
# so that location data stays accurate with respect to the original source file.
getLocationDataCompensation: (start, end) ->
totalCompensation = 0
initialEnd = end
current = start
while current <= end
break if current is end and start isnt initialEnd
compensation = @locationDataCompensations[current]
if compensation?
totalCompensation += compensation
end += compensation
current++
return totalCompensation
# Returns the line and column number from an offset into the current chunk.
#
# `offset` is a number of characters into `@chunk`.
getLineAndColumnFromChunk: (offset) ->
compensation = @getLocationDataCompensation @chunkOffset, @chunkOffset + offset
if offset is 0
return [@chunkLine, @chunkColumn + compensation, @chunkOffset + compensation]
if offset >= @chunk.length
string = @chunk
else
string = @chunk[..offset-1]
lineCount = count string, '\n'
column = @chunkColumn
if lineCount > 0
[..., lastLine] = string.split '\n'
column = lastLine.length
previousLinesCompensation = @getLocationDataCompensation @chunkOffset, @chunkOffset + offset - column
# Don't recompensate for initially inserted newline.
previousLinesCompensation = 0 if previousLinesCompensation < 0
columnCompensation = @getLocationDataCompensation(
@chunkOffset + offset + previousLinesCompensation - column
@chunkOffset + offset + previousLinesCompensation
)
else
column += string.length
columnCompensation = compensation
[@chunkLine + lineCount, column + columnCompensation, @chunkOffset + offset + compensation]
makeLocationData: ({ offsetInChunk, length }) ->
locationData = range: []
[locationData.first_line, locationData.first_column, locationData.range[0]] =
@getLineAndColumnFromChunk offsetInChunk
# Use length - 1 for the final offset - we’re supplying the last_line and the last_column,
# so if last_column == first_column, then we’re looking at a character of length 1.
lastCharacter = if length > 0 then (length - 1) else 0
[locationData.last_line, locationData.last_column, endOffset] =
@getLineAndColumnFromChunk offsetInChunk + lastCharacter
[locationData.last_line_exclusive, locationData.last_column_exclusive] =
@getLineAndColumnFromChunk offsetInChunk + lastCharacter + (if length > 0 then 1 else 0)
locationData.range[1] = if length > 0 then endOffset + 1 else endOffset
locationData
# Same as `token`, except this just returns the token without adding it
# to the results.
makeToken: (tag, value, {offset: offsetInChunk = 0, length = value.length, origin, generated, indentSize} = {}) ->
token = [tag, value, @makeLocationData {offsetInChunk, length}]
token.origin = origin if origin
token.generated = yes if generated
token.indentSize = indentSize if indentSize?
token
# Add a token to the results.
# `offset` is the offset into the current `@chunk` where the token starts.
# `length` is the length of the token in the `@chunk`, after the offset. If
# not specified, the length of `value` will be used.
#
# Returns the new token.
token: (tag, value, {offset, length, origin, data, generated, indentSize} = {}) ->
token = @makeToken tag, value, {offset, length, origin, generated, indentSize}
addTokenData token, data if data
@tokens.push token
token
# Peek at the last tag in the token stream.
tag: ->
[..., token] = @tokens
token?[0]
# Peek at the last value in the token stream.
value: (useOrigin = no) ->
[..., token] = @tokens
if useOrigin and token?.origin?
token.origin[1]
else
token?[1]
# Get the previous token in the token stream.
prev: ->
@tokens[@tokens.length - 1]
# Are we in the midst of an unfinished expression?
unfinished: ->
LINE_CONTINUER.test(@chunk) or
@tag() in UNFINISHED
validateUnicodeCodePointEscapes: (str, options) ->
replaceUnicodeCodePointEscapes str, merge options, {@error}
# Validates escapes in strings and regexes.
validateEscapes: (str, options = {}) ->
invalidEscapeRegex =
if options.isRegex
REGEX_INVALID_ESCAPE
else
STRING_INVALID_ESCAPE
match = invalidEscapeRegex.exec str
return unless match
[[], before, octal, hex, unicodeCodePoint, unicode] = match
message =
if octal
"octal escape sequences are not allowed"
else
"invalid escape sequence"
invalidEscape = "\\#{octal or hex or unicodeCodePoint or unicode}"
@error "#{message} #{invalidEscape}",
offset: (options.offsetInChunk ? 0) + match.index + before.length
length: invalidEscape.length
suppressSemicolons: ->
while @value() is ';'
@tokens.pop()
@error 'unexpected ;' if @prev()?[0] in ['=', UNFINISHED...]
# Throws an error at either a given offset from the current chunk or at the
# location of a token (`token[2]`).
error: (message, options = {}) =>
location =
if 'first_line' of options
options
else
[first_line, first_column] = @getLineAndColumnFromChunk options.offset ? 0
{first_line, first_column, last_column: first_column + (options.length ? 1) - 1}
throwSyntaxError message, location
# Helper functions
# ----------------
isUnassignable = (name, displayName = name) -> switch
when name in [JS_KEYWORDS..., COFFEE_KEYWORDS...]
"keyword '#{displayName}' can't be assigned"
when name in STRICT_PROSCRIBED
"'#{displayName}' can't be assigned"
when name in RESERVED
"reserved word '#{displayName}' can't be assigned"
else
false
exports.isUnassignable = isUnassignable
# `from` isn’t a CoffeeScript keyword, but it behaves like one in `import` and
# `export` statements (handled above) and in the declaration line of a `for`
# loop. Try to detect when `from` is a variable identifier and when it is this
# “sometimes” keyword.
isForFrom = (prev) ->
# `for i from iterable`
if prev[0] is 'IDENTIFIER'
yes
# `for from…`
else if prev[0] is 'FOR'
no
# `for {from}…`, `for [from]…`, `for {a, from}…`, `for {a: from}…`
else if prev[1] in ['{', '[', ',', ':']
no
else
yes
addTokenData = (token, data) ->
Object.assign (token.data ?= {}), data
# Constants
# ---------
# Keywords that CoffeeScript shares in common with JavaScript.
JS_KEYWORDS = [
'true', 'false', 'null', 'this'
'new', 'delete', 'typeof', 'in', 'instanceof'
'return', 'throw', 'break', 'continue', 'debugger', 'yield', 'await'
'if', 'else', 'switch', 'for', 'while', 'do', 'try', 'catch', 'finally'
'class', 'extends', 'super'
'import', 'export', 'default'
]
# CoffeeScript-only keywords.
COFFEE_KEYWORDS = [
'undefined', 'Infinity', 'NaN'
'then', 'unless', 'until', 'loop', 'of', 'by', 'when'
]
COFFEE_ALIAS_MAP =
and : '&&'
or : '||'
is : '=='
isnt : '!='
not : '!'
yes : 'true'
no : 'false'
on : 'true'
off : 'false'
COFFEE_ALIASES = (key for key of COFFEE_ALIAS_MAP)
COFFEE_KEYWORDS = COFFEE_KEYWORDS.concat COFFEE_ALIASES
# The list of keywords that are reserved by JavaScript, but not used, or are
# used by CoffeeScript internally. We throw an error when these are encountered,
# to avoid having a JavaScript error at runtime.
RESERVED = [
'case', 'function', 'var', 'void', 'with', 'const', 'let', 'enum'
'native', 'implements', 'interface', 'package', 'private'
'protected', 'public', 'static'
]
STRICT_PROSCRIBED = ['arguments', 'eval']
# The superset of both JavaScript keywords and reserved words, none of which may
# be used as identifiers or properties.
exports.JS_FORBIDDEN = JS_KEYWORDS.concat(RESERVED).concat(STRICT_PROSCRIBED)
# The character code of the nasty Microsoft madness otherwise known as the BOM.
BOM = 65279
# Token matching regexes.
IDENTIFIER = /// ^
(?!\d)
( (?: (?!\s)[$\w\x7f-\uffff] )+ )
( [^\n\S]* : (?!:) )? # Is this a property name?
///
# Like `IDENTIFIER`, but includes `-`s
JSX_IDENTIFIER_PART = /// (?: (?!\s)[\-$\w\x7f-\uffff] )+ ///.source
# In https://facebook.github.io/jsx/ spec, JSXElementName can be
# JSXIdentifier, JSXNamespacedName (JSXIdentifier : JSXIdentifier), or
# JSXMemberExpression (two or more JSXIdentifier connected by `.`s).
JSX_IDENTIFIER = /// ^
(?![\d<]) # Must not start with `<`.
( #{JSX_IDENTIFIER_PART}
(?: \s* : \s* #{JSX_IDENTIFIER_PART} # JSXNamespacedName
| (?: \s* \. \s* #{JSX_IDENTIFIER_PART} )+ # JSXMemberExpression
)? )
///
# Fragment: <></>
JSX_FRAGMENT_IDENTIFIER = /// ^
()> # Ends immediately with `>`.
///
# In https://facebook.github.io/jsx/ spec, JSXAttributeName can be either
# JSXIdentifier or JSXNamespacedName which is JSXIdentifier : JSXIdentifier
JSX_ATTRIBUTE = /// ^
(?!\d)
( #{JSX_IDENTIFIER_PART}
(?: \s* : \s* #{JSX_IDENTIFIER_PART} # JSXNamespacedName
)? )
( [^\S]* = (?!=) )? # Is this an attribute with a value?
///
NUMBER = ///
^ 0b[01](?:_?[01])*n? | # binary
^ 0o[0-7](?:_?[0-7])*n? | # octal
^ 0x[\da-f](?:_?[\da-f])*n? | # hex
^ \d+(?:_\d+)*n | # decimal bigint
^ (?:\d+(?:_\d+)*)? \.? \d+(?:_\d+)* # decimal
(?:e[+-]? \d+(?:_\d+)* )?
# decimal without support for numeric literal separators for reference:
# \d*\.?\d+ (?:e[+-]?\d+)?
///i
OPERATOR = /// ^ (
?: [-=]> # function
| [-+*/%<>&|^!?=]= # compound assign / compare
| >>>=? # zero-fill right shift
| ([-+:])\1 # doubles
| ([&|<>*/%])\2=? # logic / shift / power / floor division / modulo
| \?(\.|::) # soak access
| \.{2,3} # range or splat
) ///
WHITESPACE = /^[^\n\S]+/
COMMENT = /^(\s*)###([^#][\s\S]*?)(?:###([^\n\S]*)|###$)|^((?:\s*#(?!##[^#]).*)+)/
CODE = /^[-=]>/
MULTI_DENT = /^(?:\n[^\n\S]*)+/
JSTOKEN = ///^ `(?!``) ((?: [^`\\] | \\[\s\S] )*) ` ///
HERE_JSTOKEN = ///^ ``` ((?: [^`\\] | \\[\s\S] | `(?!``) )*) ``` ///
# String-matching-regexes.
STRING_START = /^(?:'''|"""|'|")/
STRING_SINGLE = /// ^(?: [^\\'] | \\[\s\S] )* ///
STRING_DOUBLE = /// ^(?: [^\\"#] | \\[\s\S] | \#(?!\{) )* ///
HEREDOC_SINGLE = /// ^(?: [^\\'] | \\[\s\S] | '(?!'') )* ///
HEREDOC_DOUBLE = /// ^(?: [^\\"#] | \\[\s\S] | "(?!"") | \#(?!\{) )* ///
INSIDE_JSX = /// ^(?:
[^
\{ # Start of CoffeeScript interpolation.
< # Maybe JSX tag (`<` not allowed even if bare).
]
)* /// # Similar to `HEREDOC_DOUBLE` but there is no escaping.
JSX_INTERPOLATION = /// ^(?:
\{ # CoffeeScript interpolation.
| <(?!/) # JSX opening tag.
)///
HEREDOC_INDENT = /\n+([^\n\S]*)(?=\S)/g
# Regex-matching-regexes.
REGEX = /// ^
/ (?!/) ((
?: [^ [ / \n \\ ] # Every other thing.
| \\[^\n] # Anything but newlines escaped.
| \[ # Character class.
(?: \\[^\n] | [^ \] \n \\ ] )*
\]
)*) (/)?
///
REGEX_FLAGS = /^\w*/
VALID_FLAGS = /^(?!.*(.).*\1)[gimsuy]*$/
HEREGEX = /// ^
(?:
# Match any character, except those that need special handling below.
[^\\/#\s]
# Match `\` followed by any character.
| \\[\s\S]
# Match any `/` except `///`.
| /(?!//)
# Match `#` which is not part of interpolation, e.g. `#{}`.
| \#(?!\{)
# Comments consume everything until the end of the line, including `///`.
| \s+(?:#(?!\{).*)?
)*
///
HEREGEX_COMMENT = /(\s+)(#(?!{).*)/gm
REGEX_ILLEGAL = /// ^ ( / | /{3}\s*) (\*) ///
POSSIBLY_DIVISION = /// ^ /=?\s ///
# Other regexes.
HERECOMMENT_ILLEGAL = /\*\//
LINE_CONTINUER = /// ^ \s* (?: , | \??\.(?![.\d]) | \??:: ) ///
STRING_INVALID_ESCAPE = ///
( (?:^|[^\\]) (?:\\\\)* ) # Make sure the escape isn’t escaped.
\\ (
?: (0\d|[1-7]) # octal escape
| (x(?![\da-fA-F]{2}).{0,2}) # hex escape
| (u\{(?![\da-fA-F]{1,}\})[^}]*\}?) # unicode code point escape
| (u(?!\{|[\da-fA-F]{4}).{0,4}) # unicode escape
)
///
REGEX_INVALID_ESCAPE = ///
( (?:^|[^\\]) (?:\\\\)* ) # Make sure the escape isn’t escaped.
\\ (
?: (0\d) # octal escape
| (x(?![\da-fA-F]{2}).{0,2}) # hex escape
| (u\{(?![\da-fA-F]{1,}\})[^}]*\}?) # unicode code point escape
| (u(?!\{|[\da-fA-F]{4}).{0,4}) # unicode escape
)
///
TRAILING_SPACES = /\s+$/
# Compound assignment tokens.
COMPOUND_ASSIGN = [
'-=', '+=', '/=', '*=', '%=', '||=', '&&=', '?=', '<<=', '>>=', '>>>='
'&=', '^=', '|=', '**=', '//=', '%%='
]
# Unary tokens.
UNARY = ['NEW', 'TYPEOF', 'DELETE']
UNARY_MATH = ['!', '~']
# Bit-shifting tokens.
SHIFT = ['<<', '>>', '>>>']
# Comparison tokens.
COMPARE = ['==', '!=', '<', '>', '<=', '>=']
# Mathematical tokens.
MATH = ['*', '/', '%', '//', '%%']
# Relational tokens that are negatable with `not` prefix.
RELATION = ['IN', 'OF', 'INSTANCEOF']
# Boolean tokens.
BOOL = ['TRUE', 'FALSE']
# Tokens which could legitimately be invoked or indexed. An opening
# parentheses or bracket following these tokens will be recorded as the start
# of a function invocation or indexing operation.
CALLABLE = ['IDENTIFIER', 'PROPERTY', ')', ']', '?', '@', 'THIS', 'SUPER', 'DYNAMIC_IMPORT']
INDEXABLE = CALLABLE.concat [
'NUMBER', 'INFINITY', 'NAN', 'STRING', 'STRING_END', 'REGEX', 'REGEX_END'
'BOOL', 'NULL', 'UNDEFINED', '}', '::'
]
# Tokens which can be the left-hand side of a less-than comparison, i.e. `a<b`.
COMPARABLE_LEFT_SIDE = ['IDENTIFIER', ')', ']', 'NUMBER']
# Tokens which a regular expression will never immediately follow (except spaced
# CALLABLEs in some cases), but which a division operator can.
#
# See: http://www-archive.mozilla.org/js/language/js20-2002-04/rationale/syntax.html#regular-expressions
NOT_REGEX = INDEXABLE.concat ['++', '--']
# Tokens that, when immediately preceding a `WHEN`, indicate that the `WHEN`
# occurs at the start of a line. We disambiguate these from trailing whens to
# avoid an ambiguity in the grammar.
LINE_BREAK = ['INDENT', 'OUTDENT', 'TERMINATOR']
# Additional indent in front of these is ignored.
INDENTABLE_CLOSERS = [')', '}', ']']