lexer.coffee | |
|---|---|
| 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: where locationData is {firstline, firstcolumn, lastline, lastcolumn}, which is a
format that can be fed directly into Jison. These
are read by jison in the | {Rewriter, INVERSES} = require './rewriter' |
| Import the helpers we need. | {count, starts, compact, last, locationDataToString} = 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 unless explicitly asked not to. | tokenize: (code, opts = {}) ->
@literate = opts.literate # Are we lexing literate CoffeeScript?
code = @clean code # The stripped, cleaned original source code.
@indent = 0 # The current indentation level.
@indebt = 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.
@ends = [] # The stack for pairing up tokens.
@tokens = [] # Stream of parsed tokens in the form `['TYPE', value, line]`.
@chunkLine =
opts.line or 0 # The start line for the current @chunk.
@chunkColumn =
opts.column or 0 # The start column of the current @chunk. |
| At every position, run through this list of attempted matches,
short-circuiting if any of them succeed. Their order determines precedence:
| i = 0
while @chunk = code[i..]
consumed = \
@identifierToken() or
@commentToken() or
@whitespaceToken() or
@lineToken() or
@heredocToken() or
@stringToken() or
@numberToken() or
@regexToken() or
@jsToken() or
@literalToken() |
| Update position | [@chunkLine, @chunkColumn] = @getLineAndColumnFromChunk consumed
i += consumed
@closeIndentation()
@error "missing #{tag}" if tag = @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) ->
code = code.slice(1) if code.charCodeAt(0) is BOM
code = "\n#{code}" if WHITESPACE.test code
code = code.replace(/\r/g, '').replace TRAILING_SPACES, ''
if @literate
lines = for line in code.split('\n')
if match = LITERATE.exec line
line[match[0].length..]
else
'# ' + line
code = lines.join '\n'
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 | identifierToken: ->
return 0 unless match = IDENTIFIER.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
forcedIdentifier = colon or
(prev = last @tokens) and (prev[0] in ['.', '?.', '::'] or
not prev.spaced and prev[0] is '@')
tag = 'IDENTIFIER'
if not forcedIdentifier and (id in JS_KEYWORDS or 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 = yes
else if tag is 'UNLESS'
tag = 'IF'
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()
id = '!' + id
if id in JS_FORBIDDEN
if forcedIdentifier
tag = 'IDENTIFIER'
id = new String id
id.reserved = yes
else if id in RESERVED
@error "reserved word \"#{id}\""
unless forcedIdentifier
id = COFFEE_ALIAS_MAP[id] if id in COFFEE_ALIASES
tag = switch id
when '!' then 'UNARY'
when '==', '!=' then 'COMPARE'
when '&&', '||' then 'LOGIC'
when 'true', 'false' then 'BOOL'
when 'break', 'continue' then 'STATEMENT'
else tag
tagToken = @token tag, id, 0, idLength
if poppedToken
[tagToken[2].first_line, tagToken[2].first_column] =
[poppedToken[2].first_line, poppedToken[2].first_column]
if colon
colonOffset = input.lastIndexOf ':'
@token ':', ':', colonOffset, colon.length
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]
if /^0[BOX]/.test number
@error "radix prefix '#{number}' must be lowercase"
else if /E/.test(number) and not /^0x/.test number
@error "exponential notation '#{number}' must be indicated with a lowercase 'e'"
else if /^0\d*[89]/.test number
@error "decimal literal '#{number}' must not be prefixed with '0'"
else if /^0\d+/.test number
@error "octal literal '#{number}' must be prefixed with '0o'"
lexedLength = number.length
if octalLiteral = /^0o([0-7]+)/.exec number
number = '0x' + (parseInt octalLiteral[1], 8).toString 16
if binaryLiteral = /^0b([01]+)/.exec number
number = '0x' + (parseInt binaryLiteral[1], 2).toString 16
@token 'NUMBER', number, 0, lexedLength
lexedLength |
| Matches strings, including multi-line strings. Ensures that quotation marks are balanced within the string's contents, and within nested interpolations. | stringToken: ->
switch @chunk.charAt 0
when "'"
return 0 unless match = SIMPLESTR.exec @chunk
string = match[0]
@token 'STRING', string.replace(MULTILINER, '\\\n'), 0, string.length
when '"'
return 0 unless string = @balancedString @chunk, '"'
if 0 < string.indexOf '#{', 1
@interpolateString string[1...-1], strOffset: 1, lexedLength: string.length
else
@token 'STRING', @escapeLines string, 0, string.length
else
return 0
if octalEsc = /^(?:\\.|[^\\])*\\(?:0[0-7]|[1-7])/.test string
@error "octal escape sequences #{string} are not allowed"
string.length |
| Matches heredocs, adjusting indentation to the correct level, as heredocs preserve whitespace, but ignore indentation to the left. | heredocToken: ->
return 0 unless match = HEREDOC.exec @chunk
heredoc = match[0]
quote = heredoc.charAt 0
doc = @sanitizeHeredoc match[2], quote: quote, indent: null
if quote is '"' and 0 <= doc.indexOf '#{'
@interpolateString doc, heredoc: yes, strOffset: 3, lexedLength: heredoc.length
else
@token 'STRING', @makeString(doc, quote, yes), 0, heredoc.length
heredoc.length |
| Matches and consumes comments. | commentToken: ->
return 0 unless match = @chunk.match COMMENT
[comment, here] = match
if here
@token 'HERECOMMENT',
(@sanitizeHeredoc here,
herecomment: true, indent: Array(@indent + 1).join(' ')),
0, comment.length
comment.length |
| Matches JavaScript interpolated directly into the source via backticks. | jsToken: ->
return 0 unless @chunk.charAt(0) is '`' and match = JSTOKEN.exec @chunk
@token 'JS', (script = match[0])[1...-1], 0, script.length
script.length |
| Matches regular expression literals. Lexing regular expressions is difficult to distinguish from division, so we borrow some basic heuristics from JavaScript and Ruby. | regexToken: ->
return 0 if @chunk.charAt(0) isnt '/'
if match = HEREGEX.exec @chunk
length = @heregexToken match
return length
prev = last @tokens
return 0 if prev and (prev[0] in (if prev.spaced then NOT_REGEX else NOT_SPACED_REGEX))
return 0 unless match = REGEX.exec @chunk
[match, regex, flags] = match
if regex[..1] is '/*' then @error 'regular expressions cannot begin with `*`'
if regex is '//' then regex = '/(?:)/'
@token 'REGEX', "#{regex}#{flags}", 0, match.length
match.length |
| Matches multiline extended regular expressions. | heregexToken: (match) ->
[heregex, body, flags] = match
if 0 > body.indexOf '#{'
re = body.replace(HEREGEX_OMIT, '').replace(/\//g, '\\/')
if re.match /^\*/ then @error 'regular expressions cannot begin with `*`'
@token 'REGEX', "/#{ re or '(?:)' }/#{flags}", 0, heregex.length
return heregex.length
@token 'IDENTIFIER', 'RegExp', 0, 0
@token 'CALL_START', '(', 0, 0
tokens = []
for token in @interpolateString(body, regex: yes)
[tag, value] = token
if tag is 'TOKENS'
tokens.push value...
else if tag is 'NEOSTRING'
continue unless value = value.replace HEREGEX_OMIT, '' |
| Convert NEOSTRING into STRING | value = value.replace /\\/g, '\\\\'
token[0] = 'STRING'
token[1] = @makeString(value, '"', yes)
tokens.push token
else
@error "Unexpected #{tag}"
prev = last @tokens
plusToken = ['+', '+']
plusToken[2] = prev[2] # Copy location data
tokens.push plusToken |
| Remove the extra "+" | tokens.pop()
unless tokens[0]?[0] is 'STRING'
@token 'STRING', '""', 0, 0
@token '+', '+', 0, 0
@tokens.push tokens...
if flags |
| Find the flags in the heregex | flagsOffset = heregex.lastIndexOf flags
@token ',', ',', flagsOffset, 0
@token 'STRING', '"' + flags + '"', flagsOffset, flags.length
@token ')', ')', heregex.length-1, 0
heregex.length |
| Matches newlines, indents, and outdents, and determines which is which. If we can detect that the current line is continued onto the the next line, then the newline is suppressed: 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: ->
return 0 unless match = MULTI_DENT.exec @chunk
indent = match[0]
@seenFor = no
size = indent.length - 1 - indent.lastIndexOf '\n'
noNewlines = @unfinished()
if size - @indebt is @indent
if noNewlines then @suppressNewlines() else @newlineToken 0
return indent.length
if size > @indent
if noNewlines
@indebt = size - @indent
@suppressNewlines()
return indent.length
diff = size - @indent + @outdebt
@token 'INDENT', diff, 0, indent.length
@indents.push diff
@ends.push 'OUTDENT'
@outdebt = @indebt = 0
else
@indebt = 0
@outdentToken @indent - size, noNewlines, indent.length
@indent = size
indent.length |
| Record an outdent token or multiple tokens, if we happen to be moving back inwards past several recorded indents. | outdentToken: (moveOut, noNewlines, outdentLength) ->
while moveOut > 0
len = @indents.length - 1
if @indents[len] is undefined
moveOut = 0
else if @indents[len] is @outdebt
moveOut -= @outdebt
@outdebt = 0
else if @indents[len] < @outdebt
@outdebt -= @indents[len]
moveOut -= @indents[len]
else
dent = @indents.pop() + @outdebt
moveOut -= dent
@outdebt = 0
@pair 'OUTDENT'
@token 'OUTDENT', dent, 0, outdentLength
@outdebt -= moveOut if dent
@tokens.pop() while @value() is ';'
@token 'TERMINATOR', '\n', outdentLength, 0 unless @tag() is 'TERMINATOR' or noNewlines
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 = last @tokens
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) ->
@tokens.pop() while @value() is ';'
@token 'TERMINATOR', '\n', offset, 0 unless @tag() is 'TERMINATOR'
this |
| Use a | suppressNewlines: ->
@tokens.pop() if @value() is '\\'
this |
| We treat all other single characters as a token. E.g.: | literalToken: ->
if match = OPERATOR.exec @chunk
[value] = match
@tagParameters() if CODE.test value
else
value = @chunk.charAt 0
tag = value
prev = last @tokens
if value is '=' and prev
if not prev[1].reserved and prev[1] in JS_FORBIDDEN
@error "reserved word \"#{@value()}\" can't be assigned"
if prev[1] in ['||', '&&']
prev[0] = 'COMPOUND_ASSIGN'
prev[1] += '='
return value.length
if value is ';'
@seenFor = no
tag = 'TERMINATOR'
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 SHIFT then tag = 'SHIFT'
else if value in LOGIC or value is '?' and prev?.spaced then tag = 'LOGIC'
else if prev and not prev.spaced
if value is '(' 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
tag = 'INDEX_START'
switch prev[0]
when '?' then prev[0] = 'INDEX_SOAK'
switch value
when '(', '{', '[' then @ends.push INVERSES[value]
when ')', '}', ']' then @pair value
@token tag, value
value.length |
Token Manipulators | |
| Sanitize a heredoc or herecomment by erasing all external indentation on the left-hand side. | sanitizeHeredoc: (doc, options) ->
{indent, herecomment} = options
if herecomment
if HEREDOC_ILLEGAL.test doc
@error "block comment cannot contain \"*/\", starting"
return doc if doc.indexOf('\n') < 0
else
while match = HEREDOC_INDENT.exec doc
attempt = match[1]
indent = attempt if indent is null or 0 < attempt.length < indent.length
doc = doc.replace /// \n #{indent} ///g, '\n' if indent
doc = doc.replace /^\n/, '' unless herecomment
doc |
| 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 this if @tag() isnt ')'
stack = []
{tokens} = this
i = tokens.length
tokens[--i][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 this
else return this
this |
| Close up all remaining open blocks at the end of the file. | closeIndentation: ->
@outdentToken @indent |
| Matches a balanced group such as a single or double-quoted string. Pass in a series of delimiters, all of which must be nested correctly within the contents of the string. This method allows us to have strings within interpolations within strings, ad infinitum. | balancedString: (str, end) ->
continueCount = 0
stack = [end]
for i in [1...str.length]
if continueCount
--continueCount
continue
switch letter = str.charAt i
when '\\'
++continueCount
continue
when end
stack.pop()
unless stack.length
return str[0..i]
end = stack[stack.length - 1]
continue
if end is '}' and letter in ['"', "'"]
stack.push end = letter
else if end is '}' and letter is '/' and match = (HEREGEX.exec(str[i..]) or REGEX.exec(str[i..]))
continueCount += match[0].length - 1
else if end is '}' and letter is '{'
stack.push end = '}'
else if end is '"' and prev is '#' and letter is '{'
stack.push end = '}'
prev = letter
@error "missing #{ stack.pop() }, starting" |
| Expand variables and expressions inside double-quoted strings using Ruby-like notation for substitution of arbitrary expressions. If it encounters an interpolation, this method will recursively create a new Lexer, tokenize the interpolated contents, and merge them into the token stream.
| interpolateString: (str, options = {}) ->
{heredoc, regex, offsetInChunk, strOffset, lexedLength} = options
offsetInChunk = offsetInChunk || 0
strOffset = strOffset || 0
lexedLength = lexedLength || str.length |
| Clip leading \n from heredoc | if heredoc and str.length > 0 and str[0] == '\n'
str = str[1...]
strOffset++ |
| Parse the string. | tokens = []
pi = 0
i = -1
while letter = str.charAt i += 1
if letter is '\\'
i += 1
continue
unless letter is '#' and str.charAt(i+1) is '{' and
(expr = @balancedString str[i + 1..], '}')
continue |
| NEOSTRING is a fake token. This will be converted to a string below. | tokens.push @makeToken('NEOSTRING', str[pi...i], strOffset + pi) if pi < i
inner = expr[1...-1]
if inner.length
[line, column] = @getLineAndColumnFromChunk(strOffset + i + 1)
nested = new Lexer().tokenize inner, line: line, column: column, rewrite: off
popped = nested.pop()
popped = nested.shift() if nested[0]?[0] is 'TERMINATOR'
if len = nested.length
if len > 1
nested.unshift @makeToken '(', '(', strOffset + i + 1, 0
nested.push @makeToken ')', ')', strOffset + i + 1 + inner.length, 0 |
| Push a fake 'TOKENS' token, which will get turned into real tokens below. | tokens.push ['TOKENS', nested]
i += expr.length
pi = i + 1
tokens.push @makeToken('NEOSTRING', str[pi..], strOffset + pi) if i > pi < str.length |
| If regex, then return now and let the regex code deal with all these fake tokens | return tokens if regex |
| If we didn't find any tokens, then just return an empty string. | return @token 'STRING', '""', offsetInChunk, lexedLength unless tokens.length |
| If the first token is not a string, add a fake empty string to the beginning. | tokens.unshift @makeToken('NEOSTRING', '', offsetInChunk) unless tokens[0][0] is 'NEOSTRING'
@token '(', '(', offsetInChunk, 0 if interpolated = tokens.length > 1 |
| Push all the tokens | for token, i in tokens
[tag, value] = token
if i |
| Create a 0-length "+" token. | plusToken = @token '+', '+' if i
locationToken = if tag == 'TOKENS' then value[0] else token
plusToken[2] =
first_line: locationToken[2].first_line
first_column: locationToken[2].first_column
last_line: locationToken[2].first_line
last_column: locationToken[2].first_column
if tag is 'TOKENS' |
| Push all the tokens in the fake 'TOKENS' token. These already have sane location data. | @tokens.push value...
else if tag is 'NEOSTRING' |
| Convert NEOSTRING into STRING | token[0] = 'STRING'
token[1] = @makeString value, '"', heredoc
@tokens.push token
else
@error "Unexpected #{tag}"
@token ')', ')', offsetInChunk + lexedLength, 0 if interpolated
tokens |
| Pairs up a closing token, ensuring that all listed pairs of tokens are correctly balanced throughout the course of the token stream. | pair: (tag) ->
unless tag is wanted = last @ends
@error "unmatched #{tag}" unless 'OUTDENT' is wanted |
| Auto-close INDENT to support syntax like this: | @indent -= size = last @indents
@outdentToken size, true
return @pair tag
@ends.pop() |
Helpers | |
| Returns the line and column number from an offset into the current chunk.
| getLineAndColumnFromChunk: (offset) ->
if offset is 0
return [@chunkLine, @chunkColumn]
if offset >= @chunk.length
string = @chunk
else
string = @chunk[..offset-1]
lineCount = count string, '\n'
column = @chunkColumn
if lineCount > 0
lines = string.split '\n'
column = (last lines).length
else
column += string.length
return [@chunkLine + lineCount, column] |
| Same as "token", exception this just returns the token without adding it to the results. | makeToken: (tag, value, offsetInChunk, length) ->
offsetInChunk = offsetInChunk || 0
if length is undefined then length = value.length
locationData = {}
[locationData.first_line, locationData.first_column] =
@getLineAndColumnFromChunk offsetInChunk |
| Use length - 1 for the final offset - we're supplying the lastline and the lastcolumn, so if lastcolumn == firstcolumn, 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] =
@getLineAndColumnFromChunk offsetInChunk + (length - 1)
token = [tag, value, locationData]
return token |
| Add a token to the results.
Returns the new token. | token: (tag, value, offsetInChunk, length) ->
token = @makeToken tag, value, offsetInChunk, length
@tokens.push token
return token |
| Peek at a tag in the current token stream. | tag: (index, tag) ->
(tok = last @tokens, index) and if tag then tok[0] = tag else tok[0] |
| Peek at a value in the current token stream. | value: (index, val) ->
(tok = last @tokens, index) and if val then tok[1] = val else tok[1] |
| Are we in the midst of an unfinished expression? | unfinished: ->
LINE_CONTINUER.test(@chunk) or
@tag() in ['\\', '.', '?.', 'UNARY', 'MATH', '+', '-', 'SHIFT', 'RELATION'
'COMPARE', 'LOGIC', 'THROW', 'EXTENDS'] |
| Converts newlines for string literals. | escapeLines: (str, heredoc) ->
str.replace MULTILINER, if heredoc then '\\n' else '' |
| Constructs a string token by escaping quotes and newlines. | makeString: (body, quote, heredoc) ->
return quote + quote unless body
body = body.replace /\\([\s\S])/g, (match, contents) ->
if contents in ['\n', quote] then contents else match
body = body.replace /// #{quote} ///g, '\\$&'
quote + @escapeLines(body, heredoc) + quote |
| Throws a syntax error on the current | error: (message) -> |
| TODO: Are there some cases we could improve the error line number by passing the offset in the chunk where the error happened? | throw SyntaxError "#{message} on line #{ @chunkLine + 1 }" |
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'
'if', 'else', 'switch', 'for', 'while', 'do', 'try', 'catch', 'finally'
'class', 'extends', 'super'
] |
| CoffeeScript-only keywords. | COFFEE_KEYWORDS = ['undefined', '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', 'default', 'function', 'var', 'void', 'with', 'const', 'let', 'enum'
'export', 'import', 'native', '__hasProp', '__extends', '__slice', '__bind'
'__indexOf', 'implements', 'interface', 'package', 'private', 'protected'
'public', 'static', 'yield'
]
STRICT_PROSCRIBED = ['arguments', 'eval'] |
| The superset of both JavaScript keywords and reserved words, none of which may be used as identifiers or properties. | JS_FORBIDDEN = JS_KEYWORDS.concat(RESERVED).concat(STRICT_PROSCRIBED)
exports.RESERVED = RESERVED.concat(JS_KEYWORDS).concat(COFFEE_KEYWORDS).concat(STRICT_PROSCRIBED)
exports.STRICT_PROSCRIBED = STRICT_PROSCRIBED |
| The character code of the nasty Microsoft madness otherwise known as the BOM. | BOM = 65279 |
| Token matching regexes. | IDENTIFIER = /// ^
( [$A-Za-z_\x7f-\uffff][$\w\x7f-\uffff]* )
( [^\n\S]* : (?!:) )? # Is this a property name?
///
NUMBER = ///
^ 0b[01]+ | # binary
^ 0o[0-7]+ | # octal
^ 0x[\da-f]+ | # hex
^ \d*\.?\d+ (?:e[+-]?\d+)? # decimal
///i
HEREDOC = /// ^ ("""|''') ([\s\S]*?) (?:\n[^\n\S]*)? \1 ///
OPERATOR = /// ^ (
?: [-=]> # function
| [-+*/%<>&|^!?=]= # compound assign / compare
| >>>=? # zero-fill right shift
| ([-+:])\1 # doubles
| ([&|<>])\2=? # logic / shift
| \?\. # soak access
| \.{2,3} # range or splat
) ///
WHITESPACE = /^[^\n\S]+/
COMMENT = /^###([^#][\s\S]*?)(?:###[^\n\S]*|(?:###)$)|^(?:\s*#(?!##[^#]).*)+/
LITERATE = /^([ ]{4}|\t)/
CODE = /^[-=]>/
MULTI_DENT = /^(?:\n[^\n\S]*)+/
SIMPLESTR = /^'[^\\']*(?:\\.[^\\']*)*'/
JSTOKEN = /^`[^\\`]*(?:\\.[^\\`]*)*`/ |
| Regex-matching-regexes. | REGEX = /// ^
(/ (?! [\s=] ) # disallow leading whitespace or equals signs
[^ [ / \n \\ ]* # every other thing
(?:
(?: \\[\s\S] # anything escaped
| \[ # character class
[^ \] \n \\ ]*
(?: \\[\s\S] [^ \] \n \\ ]* )*
]
) [^ [ / \n \\ ]*
)*
/) ([imgy]{0,4}) (?!\w)
///
HEREGEX = /// ^ /{3} ([\s\S]+?) /{3} ([imgy]{0,4}) (?!\w) ///
HEREGEX_OMIT = /\s+(?:#.*)?/g |
| Token cleaning regexes. | MULTILINER = /\n/g
HEREDOC_INDENT = /\n+([^\n\S]*)/g
HEREDOC_ILLEGAL = /\*\//
LINE_CONTINUER = /// ^ \s* (?: , | \??\.(?![.\d]) | :: ) ///
TRAILING_SPACES = /\s+$/ |
| Compound assignment tokens. | COMPOUND_ASSIGN = [
'-=', '+=', '/=', '*=', '%=', '||=', '&&=', '?=', '<<=', '>>=', '>>>=', '&=', '^=', '|='
] |
| Unary tokens. | UNARY = ['!', '~', 'NEW', 'TYPEOF', 'DELETE', 'DO'] |
| Logical tokens. | LOGIC = ['&&', '||', '&', '|', '^'] |
| Bit-shifting tokens. | SHIFT = ['<<', '>>', '>>>'] |
| Comparison tokens. | COMPARE = ['==', '!=', '<', '>', '<=', '>='] |
| Mathematical tokens. | MATH = ['*', '/', '%'] |
| Relational tokens that are negatable with | RELATION = ['IN', 'OF', 'INSTANCEOF'] |
| Boolean tokens. | BOOL = ['TRUE', 'FALSE'] |
| Tokens which a regular expression will never immediately follow, but which a division operator might. See: http://www.mozilla.org/js/language/js20-2002-04/rationale/syntax.html#regular-expressions Our list is shorter, due to sans-parentheses method calls. | NOT_REGEX = ['NUMBER', 'REGEX', 'BOOL', 'NULL', 'UNDEFINED', '++', '--', ']'] |
| If the previous token is not spaced, there are more preceding tokens that force a division parse: | NOT_SPACED_REGEX = NOT_REGEX.concat ')', '}', 'THIS', 'IDENTIFIER', 'STRING' |
| 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', 'STRING', 'REGEX', ')', ']', '}', '?', '::', '@', 'THIS', 'SUPER']
INDEXABLE = CALLABLE.concat 'NUMBER', 'BOOL', 'NULL', 'UNDEFINED' |
| Tokens that, when immediately preceding a | LINE_BREAK = ['INDENT', 'OUTDENT', 'TERMINATOR']
|