196 lines (165 sloc) 6.61 KB
# This file contains the common helper functions that we'd like to share among
# the **Lexer**, **Rewriter**, and the **Nodes**. Merge objects, flatten
# arrays, count characters, that sort of thing.
# Peek at the beginning of a given string to see if it matches a sequence.
exports.starts = (string, literal, start) ->
literal is string.substr start, literal.length
# Peek at the end of a given string to see if it matches a sequence.
exports.ends = (string, literal, back) ->
len = literal.length
literal is string.substr string.length - len - (back or 0), len
# Repeat a string `n` times.
exports.repeat = repeat = (str, n) ->
# Use clever algorithm to have O(log(n)) string concatenation operations.
res = ''
while n > 0
res += str if n & 1
n >>>= 1
str += str
# Trim out all falsy values from an array.
exports.compact = (array) ->
item for item in array when item
# Count the number of occurrences of a string in a string.
exports.count = (string, substr) ->
num = pos = 0
return 1/0 unless substr.length
num++ while pos = 1 + string.indexOf substr, pos
# Merge objects, returning a fresh copy with attributes from both sides.
# Used every time `Base#compile` is called, to allow properties in the
# options hash to propagate down the tree without polluting other branches.
exports.merge = (options, overrides) ->
extend (extend {}, options), overrides
# Extend a source object with the properties of another object (shallow copy).
extend = exports.extend = (object, properties) ->
for key, val of properties
object[key] = val
# Return a flattened version of an array.
# Handy for getting a list of `children` from the nodes.
exports.flatten = flatten = (array) ->
flattened = []
for element in array
if '[object Array]' is element
flattened = flattened.concat flatten element
flattened.push element
# Delete a key from an object, returning the value. Useful when a node is
# looking for a particular method in an options hash.
exports.del = (obj, key) ->
val = obj[key]
delete obj[key]
# Typical Array::some
exports.some = Array::some ? (fn) ->
return true for e in this when fn e
# Simple function for inverting Literate CoffeeScript code by putting the
# documentation in comments, producing a string of CoffeeScript code that
# can be compiled "normally".
exports.invertLiterate = (code) ->
maybe_code = true
lines = for line in code.split('\n')
if maybe_code and /^([ ]{4}|[ ]{0,3}\t)/.test line
else if maybe_code = /^\s*$/.test line
'# ' + line
lines.join '\n'
# Merge two jison-style location data objects together.
# If `last` is not provided, this will simply return `first`.
buildLocationData = (first, last) ->
if not last
first_line: first.first_line
first_column: first.first_column
last_line: last.last_line
last_column: last.last_column
# This returns a function which takes an object as a parameter, and if that
# object is an AST node, updates that object's locationData.
# The object is returned either way.
exports.addLocationDataFn = (first, last) ->
(obj) ->
if ((typeof obj) is 'object') and (!!obj['updateLocationDataIfMissing'])
obj.updateLocationDataIfMissing buildLocationData(first, last)
return obj
# Convert jison location data to a string.
# `obj` can be a token, or a locationData.
exports.locationDataToString = (obj) ->
if ("2" of obj) and ("first_line" of obj[2]) then locationData = obj[2]
else if "first_line" of obj then locationData = obj
if locationData
"#{locationData.first_line + 1}:#{locationData.first_column + 1}-" +
"#{locationData.last_line + 1}:#{locationData.last_column + 1}"
"No location data"
# A `` compatible version of `basename`, that returns the file sans-extension.
exports.baseFileName = (file, stripExt = no, useWinPathSep = no) ->
pathSep = if useWinPathSep then /\\|\// else /\//
parts = file.split(pathSep)
file = parts[parts.length - 1]
return file unless stripExt and file.indexOf('.') >= 0
parts = file.split('.')
parts.pop() if parts[parts.length - 1] is 'coffee' and parts.length > 1
# Determine if a filename represents a CoffeeScript file.
exports.isCoffee = (file) -> /\.((lit)?coffee|coffee\.md)$/.test file
# Determine if a filename represents a Literate CoffeeScript file.
exports.isLiterate = (file) -> /\.(litcoffee|coffee\.md)$/.test file
# Throws a SyntaxError from a given location.
# The error's `toString` will return an error message following the "standard"
# format <filename>:<line>:<col>: <message> plus the line with the error and a
# marker showing where the error is.
exports.throwSyntaxError = (message, location) ->
error = new SyntaxError message
error.location = location
error.toString = syntaxErrorToString
# Instead of showing the compiler's stacktrace, show our custom error message
# (this is useful when the error bubbles up in Node.js applications that
# compile CoffeeScript for example).
error.stack = error.toString()
throw error
# Update a compiler SyntaxError with source code information if it didn't have
# it already.
exports.updateSyntaxError = (error, code, filename) ->
# Avoid screwing up the `stack` property of other errors (i.e. possible bugs).
if error.toString is syntaxErrorToString
error.code or= code
error.filename or= filename
error.stack = error.toString()
syntaxErrorToString = ->
return @ unless @code and @location
{first_line, first_column, last_line, last_column} = @location
last_line ?= first_line
last_column ?= first_column
filename = @filename or '[stdin]'
codeLine = @code.split('\n')[first_line]
start = first_column
# Show only the first line on multi-line errors.
end = if first_line is last_line then last_column + 1 else codeLine.length
marker = codeLine[...start].replace(/[^\s]/g, ' ') + repeat('^', end - start)
# Check to see if we're running on a color-enabled TTY.
if process?
colorsEnabled = process.stdout?.isTTY and not process.env?.NODE_DISABLE_COLORS
if @colorful ? colorsEnabled
colorize = (str) -> "\x1B[1;31m#{str}\x1B[0m"
codeLine = codeLine[...start] + colorize(codeLine[start...end]) + codeLine[end..]
marker = colorize marker
#{filename}:#{first_line + 1}:#{first_column + 1}: error: #{@message}
exports.nameWhitespaceCharacter = (string) ->
switch string
when ' ' then 'space'
when '\n' then 'newline'
when '\r' then 'carriage return'
when '\t' then 'tab'
else string