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less.js/lib/less/parser.js
2013-10-30 08:09:17 +01:00

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var less, tree;
// Node.js does not have a header file added which defines less
if (less === undefined) {
less = exports;
tree = require('./tree');
less.mode = 'node';
}
//
// less.js - parser
//
// A relatively straight-forward predictive parser.
// There is no tokenization/lexing stage, the input is parsed
// in one sweep.
//
// To make the parser fast enough to run in the browser, several
// optimization had to be made:
//
// - Matching and slicing on a huge input is often cause of slowdowns.
// The solution is to chunkify the input into smaller strings.
// The chunks are stored in the `chunks` var,
// `j` holds the current chunk index, and `currentPos` holds
// the index of the current chunk in relation to `input`.
// This gives us an almost 4x speed-up.
//
// - In many cases, we don't need to match individual tokens;
// for example, if a value doesn't hold any variables, operations
// or dynamic references, the parser can effectively 'skip' it,
// treating it as a literal.
// An example would be '1px solid #000' - which evaluates to itself,
// we don't need to know what the individual components are.
// The drawback, of course is that you don't get the benefits of
// syntax-checking on the CSS. This gives us a 50% speed-up in the parser,
// and a smaller speed-up in the code-gen.
//
//
// Token matching is done with the `$` function, which either takes
// a terminal string or regexp, or a non-terminal function to call.
// It also takes care of moving all the indices forwards.
//
//
less.Parser = function Parser(env) {
var input, // LeSS input string
i, // current index in `input`
j, // current chunk
temp, // temporarily holds a chunk's state, for backtracking
memo, // temporarily holds `i`, when backtracking
furthest, // furthest index the parser has gone to
chunks, // chunkified input
current, // current chunk
currentPos, // index of current chunk, in `input`
parser,
parsers,
rootFilename = env && env.filename;
// Top parser on an import tree must be sure there is one "env"
// which will then be passed around by reference.
if (!(env instanceof tree.parseEnv)) {
env = new tree.parseEnv(env);
}
var imports = this.imports = {
paths: env.paths || [], // Search paths, when importing
queue: [], // Files which haven't been imported yet
files: env.files, // Holds the imported parse trees
contents: env.contents, // Holds the imported file contents
mime: env.mime, // MIME type of .less files
error: null, // Error in parsing/evaluating an import
push: function (path, currentFileInfo, importOptions, callback) {
var parserImports = this;
this.queue.push(path);
var fileParsedFunc = function (e, root, fullPath) {
parserImports.queue.splice(parserImports.queue.indexOf(path), 1); // Remove the path from the queue
var importedPreviously = fullPath in parserImports.files || fullPath === rootFilename;
parserImports.files[fullPath] = root; // Store the root
if (e && !parserImports.error) { parserImports.error = e; }
callback(e, root, importedPreviously, fullPath);
};
if (less.Parser.importer) {
less.Parser.importer(path, currentFileInfo, fileParsedFunc, env);
} else {
less.Parser.fileLoader(path, currentFileInfo, function(e, contents, fullPath, newFileInfo) {
if (e) {fileParsedFunc(e); return;}
var newEnv = new tree.parseEnv(env);
newEnv.currentFileInfo = newFileInfo;
newEnv.processImports = false;
newEnv.contents[fullPath] = contents;
if (currentFileInfo.reference || importOptions.reference) {
newFileInfo.reference = true;
}
if (importOptions.inline) {
fileParsedFunc(null, contents, fullPath);
} else {
new(less.Parser)(newEnv).parse(contents, function (e, root) {
fileParsedFunc(e, root, fullPath);
});
}
}, env);
}
}
};
function save() { temp = current, memo = currentPos = i; }
function restore() { current = temp, currentPos = i = memo; }
function sync() {
if (i > currentPos) {
current = current.slice(i - currentPos);
currentPos = i;
}
}
function isWhitespace(str, pos) {
var code = str.charCodeAt(pos | 0);
return (code <= 32) && (code === 32 || code === 10 || code === 9);
}
//
// Parse from a token, regexp or string, and move forward if match
//
function $(tok) {
var tokType = typeof tok,
match, length;
// Either match a single character in the input,
// or match a regexp in the current chunk (`current`).
//
if (tokType === "string") {
if (input.charAt(i) !== tok) {
return null;
}
skipWhitespace(1);
return tok;
}
// regexp
sync ();
if (! (match = tok.exec(current))) {
return null;
}
length = match[0].length;
// The match is confirmed, add the match length to `i`,
// and consume any extra white-space characters (' ' || '\n')
// which come after that. The reason for this is that LeSS's
// grammar is mostly white-space insensitive.
//
skipWhitespace(length);
if(typeof(match) === 'string') {
return match;
} else {
return match.length === 1 ? match[0] : match;
}
}
// Specialization of $(tok)
function $re(tok) {
if (i > currentPos) {
current = current.slice(i - currentPos);
currentPos = i;
}
var m = tok.exec(current);
if (!m) {
return null;
}
skipWhitespace(m[0].length);
if(typeof m === "string") {
return m;
}
return m.length === 1 ? m[0] : m;
}
var _$re = $re;
// Specialization of $(tok)
function $char(tok) {
if (input.charAt(i) !== tok) {
return null;
}
skipWhitespace(1);
return tok;
}
function skipWhitespace(length) {
var oldi = i, oldj = j,
curr = i - currentPos,
endIndex = i + current.length - curr,
mem = (i += length),
inp = input,
c;
for (; i < endIndex; i++) {
c = inp.charCodeAt(i);
if (c > 32) {
break;
}
if ((c !== 32) && (c !== 10) && (c !== 9) && (c !== 13)) {
break;
}
}
current = current.slice(length + i - mem + curr);
currentPos = i;
if (!current.length && (j < chunks.length - 1)) {
current = chunks[++j];
}
return oldi !== i || oldj !== j;
}
function expect(arg, msg) {
var result = (typeof arg === "function") ? arg.call(parsers) : $(arg);
if (result) {
return result;
}
error(msg || (typeof(arg) === 'string' ? "expected '" + arg + "' got '" + input.charAt(i) + "'"
: "unexpected token"));
}
// Specialization of expect()
function expectChar(arg, msg) {
if (input.charAt(i) === arg) {
skipWhitespace(1);
return arg;
}
error(msg || "expected '" + arg + "' got '" + input.charAt(i) + "'");
}
function error(msg, type) {
var e = new Error(msg);
e.index = i;
e.type = type || 'Syntax';
throw e;
}
// Same as $(), but don't change the state of the parser,
// just return the match.
function peek(tok) {
if (typeof(tok) === 'string') {
return input.charAt(i) === tok;
} else {
return tok.test(current);
}
}
// Specialization of peek()
function peekChar(tok) {
return input.charAt(i) === tok;
}
function getInput(e, env) {
if (e.filename && env.currentFileInfo.filename && (e.filename !== env.currentFileInfo.filename)) {
return parser.imports.contents[e.filename];
} else {
return input;
}
}
function getLocation(index, inputStream) {
var n = index + 1,
line = null,
column = -1;
while (--n >= 0 && inputStream.charAt(n) !== '\n') {
column++;
}
if (typeof index === 'number') {
line = (inputStream.slice(0, index).match(/\n/g) || "").length;
}
return {
line: line,
column: column
};
}
function getDebugInfo(index, inputStream, env) {
var filename = env.currentFileInfo.filename;
if(less.mode !== 'browser' && less.mode !== 'rhino') {
filename = require('path').resolve(filename);
}
return {
lineNumber: getLocation(index, inputStream).line + 1,
fileName: filename
};
}
function LessError(e, env) {
var input = getInput(e, env),
loc = getLocation(e.index, input),
line = loc.line,
col = loc.column,
callLine = e.call && getLocation(e.call, input).line,
lines = input.split('\n');
this.type = e.type || 'Syntax';
this.message = e.message;
this.filename = e.filename || env.currentFileInfo.filename;
this.index = e.index;
this.line = typeof(line) === 'number' ? line + 1 : null;
this.callLine = callLine + 1;
this.callExtract = lines[callLine];
this.stack = e.stack;
this.column = col;
this.extract = [
lines[line - 1],
lines[line],
lines[line + 1]
];
}
LessError.prototype = new Error();
LessError.prototype.constructor = LessError;
this.env = env = env || {};
// The optimization level dictates the thoroughness of the parser,
// the lower the number, the less nodes it will create in the tree.
// This could matter for debugging, or if you want to access
// the individual nodes in the tree.
this.optimization = ('optimization' in this.env) ? this.env.optimization : 1;
//
// The Parser
//
return parser = {
imports: imports,
//
// Parse an input string into an abstract syntax tree,
// call `callback` when done.
//
parse: function (str, callback) {
var root, line, lines, error = null;
i = j = currentPos = furthest = 0;
str = str.replace(/\r\n/g, '\n');
// Remove potential UTF Byte Order Mark
input = str = str.replace(/^\uFEFF/, '');
parser.imports.contents[env.currentFileInfo.filename] = str;
// Split the input into chunks.
chunks = (function (chunks, input) {
var j = 0,
skip = /(?:@\{[\w-]+\}|[^"'`\{\}\/\(\)\\])+/g,
comment = /\/\*(?:[^*]|\*+[^\/*])*\*+\/|\/\/.*/g,
string = /"((?:[^"\\\r\n]|\\.)*)"|'((?:[^'\\\r\n]|\\.)*)'|`((?:[^`]|\\.)*)`/g,
level = 0,
match,
chunk = chunks[0],
inputLen = input.length,
inParam;
for (var i = 0, c, cc; i < inputLen;) {
skip.lastIndex = i;
if (match = skip.exec(input)) {
if (match.index === i) {
i += match[0].length;
chunk.push(match[0]);
}
}
c = input.charAt(i);
comment.lastIndex = string.lastIndex = i;
if (match = string.exec(input)) {
if (match.index === i) {
i += match[0].length;
chunk.push(match[0]);
continue;
}
}
if (!inParam && c === '/') {
cc = input.charAt(i + 1);
if (cc === '/' || cc === '*') {
if (match = comment.exec(input)) {
if (match.index === i) {
i += match[0].length;
chunk.push(match[0]);
continue;
}
}
}
}
switch (c) {
case '{':
if (!inParam) {
level++;
chunk.push(c);
break;
}
/* falls through */
case '}':
if (!inParam) {
level--;
chunk.push(c);
chunks[++j] = chunk = [];
break;
}
/* falls through */
case '(':
if (!inParam) {
inParam = true;
chunk.push(c);
break;
}
/* falls through */
case ')':
if (inParam) {
inParam = false;
chunk.push(c);
break;
}
/* falls through */
default:
chunk.push(c);
}
i++;
}
if (level !== 0) {
error = new(LessError)({
index: i-1,
type: 'Parse',
message: (level > 0) ? "missing closing `}`" : "missing opening `{`",
filename: env.currentFileInfo.filename
}, env);
}
return chunks.map(function (c) { return c.join(''); });
})([[]], str);
current = chunks[0];
if (error) {
return callback(new(LessError)(error, env));
}
// Start with the primary rule.
// The whole syntax tree is held under a Ruleset node,
// with the `root` property set to true, so no `{}` are
// output. The callback is called when the input is parsed.
try {
root = new(tree.Ruleset)(null, this.parsers.primary());
root.root = true;
root.firstRoot = true;
} catch (e) {
return callback(new(LessError)(e, env));
}
root.toCSS = (function (evaluate) {
return function (options, variables) {
options = options || {};
var evaldRoot,
css,
evalEnv = new tree.evalEnv(options);
//
// Allows setting variables with a hash, so:
//
// `{ color: new(tree.Color)('#f01') }` will become:
//
// new(tree.Rule)('@color',
// new(tree.Value)([
// new(tree.Expression)([
// new(tree.Color)('#f01')
// ])
// ])
// )
//
if (typeof(variables) === 'object' && !Array.isArray(variables)) {
variables = Object.keys(variables).map(function (k) {
var value = variables[k];
if (! (value instanceof tree.Value)) {
if (! (value instanceof tree.Expression)) {
value = new(tree.Expression)([value]);
}
value = new(tree.Value)([value]);
}
return new(tree.Rule)('@' + k, value, false, null, 0);
});
evalEnv.frames = [new(tree.Ruleset)(null, variables)];
}
try {
evaldRoot = evaluate.call(this, evalEnv);
new(tree.joinSelectorVisitor)()
.run(evaldRoot);
new(tree.processExtendsVisitor)()
.run(evaldRoot);
new(tree.toCSSVisitor)({compress: Boolean(options.compress)})
.run(evaldRoot);
if (options.sourceMap) {
evaldRoot = new tree.sourceMapOutput(
{
writeSourceMap: options.writeSourceMap,
rootNode: evaldRoot,
contentsMap: parser.imports.contents,
sourceMapFilename: options.sourceMapFilename,
outputFilename: options.sourceMapOutputFilename,
sourceMapBasepath: options.sourceMapBasepath,
sourceMapRootpath: options.sourceMapRootpath,
outputSourceFiles: options.outputSourceFiles,
sourceMapGenerator: options.sourceMapGenerator
});
}
css = evaldRoot.toCSS({
compress: Boolean(options.compress),
dumpLineNumbers: env.dumpLineNumbers,
strictUnits: Boolean(options.strictUnits)});
} catch (e) {
throw new(LessError)(e, env);
}
if (options.cleancss && less.mode === 'node') {
return require('clean-css').process(css);
} else if (options.compress) {
return css.replace(/(^(\s)+)|((\s)+$)/g, "");
} else {
return css;
}
};
})(root.eval);
// If `i` is smaller than the `input.length - 1`,
// it means the parser wasn't able to parse the whole
// string, so we've got a parsing error.
//
// We try to extract a \n delimited string,
// showing the line where the parse error occured.
// We split it up into two parts (the part which parsed,
// and the part which didn't), so we can color them differently.
if (i < input.length - 1) {
i = furthest;
var loc = getLocation(i, input);
lines = input.split('\n');
line = loc.line + 1;
error = {
type: "Parse",
message: "Unrecognised input",
index: i,
filename: env.currentFileInfo.filename,
line: line,
column: loc.column,
extract: [
lines[line - 2],
lines[line - 1],
lines[line]
]
};
}
var finish = function (e) {
e = error || e || parser.imports.error;
if (e) {
if (!(e instanceof LessError)) {
e = new(LessError)(e, env);
}
return callback(e);
}
else {
return callback(null, root);
}
};
if (env.processImports !== false) {
new tree.importVisitor(this.imports, finish)
.run(root);
} else {
return finish();
}
},
//
// Here in, the parsing rules/functions
//
// The basic structure of the syntax tree generated is as follows:
//
// Ruleset -> Rule -> Value -> Expression -> Entity
//
// Here's some LESS code:
//
// .class {
// color: #fff;
// border: 1px solid #000;
// width: @w + 4px;
// > .child {...}
// }
//
// And here's what the parse tree might look like:
//
// Ruleset (Selector '.class', [
// Rule ("color", Value ([Expression [Color #fff]]))
// Rule ("border", Value ([Expression [Dimension 1px][Keyword "solid"][Color #000]]))
// Rule ("width", Value ([Expression [Operation "+" [Variable "@w"][Dimension 4px]]]))
// Ruleset (Selector [Element '>', '.child'], [...])
// ])
//
// In general, most rules will try to parse a token with the `$()` function, and if the return
// value is truly, will return a new node, of the relevant type. Sometimes, we need to check
// first, before parsing, that's when we use `peek()`.
//
parsers: parsers = {
//
// The `primary` rule is the *entry* and *exit* point of the parser.
// The rules here can appear at any level of the parse tree.
//
// The recursive nature of the grammar is an interplay between the `block`
// rule, which represents `{ ... }`, the `ruleset` rule, and this `primary` rule,
// as represented by this simplified grammar:
//
// primary → (ruleset | rule)+
// ruleset → selector+ block
// block → '{' primary '}'
//
// Only at one point is the primary rule not called from the
// block rule: at the root level.
//
primary: function () {
var mixin = this.mixin, $re = _$re, root = [], node;
while (((node = (this.extendRule() || mixin.definition() || this.rule() || this.ruleset() ||
mixin.call() || this.comment() || this.directive()))
&& root.push(node)) || $re(/^[\s\n]+/) || $re(/^;+/))
{}
return root;
},
// We create a Comment node for CSS comments `/* */`,
// but keep the LeSS comments `//` silent, by just skipping
// over them.
comment: function () {
var comment;
if (input.charAt(i) !== '/') { return; }
if (input.charAt(i + 1) === '/') {
return new(tree.Comment)($re(/^\/\/.*/), true, i, env.currentFileInfo);
} else if (comment = $re(/^\/\*(?:[^*]|\*+[^\/*])*\*+\/\n?/)) {
return new(tree.Comment)(comment, false, i, env.currentFileInfo);
}
},
comments: function () {
var comment, comments = [];
while(comment = this.comment()) {
comments.push(comment);
}
return comments;
},
//
// Entities are tokens which can be found inside an Expression
//
entities: {
//
// A string, which supports escaping " and '
//
// "milky way" 'he\'s the one!'
//
quoted: function () {
var str, j = i, e, index = i;
if (input.charAt(j) === '~') { j++, e = true; } // Escaped strings
if (input.charAt(j) !== '"' && input.charAt(j) !== "'") { return; }
e && $char('~');
if (str = $re(/^"((?:[^"\\\r\n]|\\.)*)"|'((?:[^'\\\r\n]|\\.)*)'/)) {
return new(tree.Quoted)(str[0], str[1] || str[2], e, index, env.currentFileInfo);
}
},
//
// A catch-all word, such as:
//
// black border-collapse
//
keyword: function () {
var k;
if (k = $re(/^[_A-Za-z-][_A-Za-z0-9-]*/)) {
var color = tree.Color.fromKeyword(k);
if (color) {
return color;
}
return new(tree.Keyword)(k);
}
},
//
// A function call
//
// rgb(255, 0, 255)
//
// We also try to catch IE's `alpha()`, but let the `alpha` parser
// deal with the details.
//
// The arguments are parsed with the `entities.arguments` parser.
//
call: function () {
var name, nameLC, args, alpha_ret, index = i;
if (! (name = /^([\w-]+|%|progid:[\w\.]+)\(/.exec(current))) { return; }
name = name[1];
nameLC = name.toLowerCase();
if (nameLC === 'url') {
return null;
}
i += name.length;
if (nameLC === 'alpha') {
alpha_ret = parsers.alpha();
if(typeof alpha_ret !== 'undefined') {
return alpha_ret;
}
}
$char('('); // Parse the '(' and consume whitespace.
args = this.arguments();
if (! $char(')')) {
return;
}
if (name) { return new(tree.Call)(name, args, index, env.currentFileInfo); }
},
arguments: function () {
var args = [], arg;
while (arg = this.assignment() || parsers.expression()) {
args.push(arg);
if (! $char(',')) {
break;
}
}
return args;
},
literal: function () {
return this.dimension() ||
this.color() ||
this.quoted() ||
this.unicodeDescriptor();
},
// Assignments are argument entities for calls.
// They are present in ie filter properties as shown below.
//
// filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
//
assignment: function () {
var key, value;
if ((key = $re(/^\w+(?=\s?=)/i)) && $char('=') && (value = parsers.entity())) {
return new(tree.Assignment)(key, value);
}
},
//
// Parse url() tokens
//
// We use a specific rule for urls, because they don't really behave like
// standard function calls. The difference is that the argument doesn't have
// to be enclosed within a string, so it can't be parsed as an Expression.
//
url: function () {
var value;
if (input.charAt(i) !== 'u' || !$re(/^url\(/)) {
return;
}
value = this.quoted() || this.variable() ||
$re(/^(?:(?:\\[\(\)'"])|[^\(\)'"])+/) || "";
expectChar(')');
/*jshint eqnull:true */
return new(tree.URL)((value.value != null || value instanceof tree.Variable)
? value : new(tree.Anonymous)(value), env.currentFileInfo);
},
//
// A Variable entity, such as `@fink`, in
//
// width: @fink + 2px
//
// We use a different parser for variable definitions,
// see `parsers.variable`.
//
variable: function () {
var name, index = i;
if (input.charAt(i) === '@' && (name = $re(/^@@?[\w-]+/))) {
return new(tree.Variable)(name, index, env.currentFileInfo);
}
},
// A variable entity useing the protective {} e.g. @{var}
variableCurly: function () {
var curly, index = i;
if (input.charAt(i) === '@' && (curly = $re(/^@\{([\w-]+)\}/))) {
return new(tree.Variable)("@" + curly[1], index, env.currentFileInfo);
}
},
//
// A Hexadecimal color
//
// #4F3C2F
//
// `rgb` and `hsl` colors are parsed through the `entities.call` parser.
//
color: function () {
var rgb;
if (input.charAt(i) === '#' && (rgb = $re(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/))) {
return new(tree.Color)(rgb[1]);
}
},
//
// A Dimension, that is, a number and a unit
//
// 0.5em 95%
//
dimension: function () {
var value, c = input.charCodeAt(i);
//Is the first char of the dimension 0-9, '.', '+' or '-'
if ((c > 57 || c < 43) || c === 47 || c == 44) {
return;
}
if (value = $re(/^([+-]?\d*\.?\d+)(%|[a-z]+)?/)) {
return new(tree.Dimension)(value[1], value[2]);
}
},
//
// A unicode descriptor, as is used in unicode-range
//
// U+0?? or U+00A1-00A9
//
unicodeDescriptor: function () {
var ud;
if (ud = $re(/^U\+[0-9a-fA-F?]+(\-[0-9a-fA-F?]+)?/)) {
return new(tree.UnicodeDescriptor)(ud[0]);
}
},
//
// JavaScript code to be evaluated
//
// `window.location.href`
//
javascript: function () {
var str, j = i, e;
if (input.charAt(j) === '~') { j++; e = true; } // Escaped strings
if (input.charAt(j) !== '`') { return; }
if (env.javascriptEnabled !== undefined && !env.javascriptEnabled) {
error("You are using JavaScript, which has been disabled.");
}
if (e) { $char('~'); }
if (str = $re(/^`([^`]*)`/)) {
return new(tree.JavaScript)(str[1], i, e);
}
}
},
//
// The variable part of a variable definition. Used in the `rule` parser
//
// @fink:
//
variable: function () {
var name;
if (input.charAt(i) === '@' && (name = $re(/^(@[\w-]+)\s*:/))) { return name[1]; }
},
//
// extend syntax - used to extend selectors
//
extend: function(isRule) {
var elements, e, index = i, option, extendList, extend;
if (!(isRule ? $re(/^&:extend\(/) : $re(/^:extend\(/))) { return; }
do {
option = null;
elements = null;
while (! (option = $re(/^(all)(?=\s*(\)|,))/))) {
e = this.element();
if (!e) { break; }
if (elements) { elements.push(e); } else { elements = [ e ]; }
}
option = option && option[1];
extend = new(tree.Extend)(new(tree.Selector)(elements), option, index);
if (extendList) { extendList.push(extend); } else { extendList = [ extend ]; }
} while($char(","));
expect(/^\)/);
if (isRule) {
expect(/^;/);
}
return extendList;
},
//
// extendRule - used in a rule to extend all the parent selectors
//
extendRule: function() {
return this.extend(true);
},
//
// Mixins
//
mixin: {
//
// A Mixin call, with an optional argument list
//
// #mixins > .square(#fff);
// .rounded(4px, black);
// .button;
//
// The `while` loop is there because mixins can be
// namespaced, but we only support the child and descendant
// selector for now.
//
call: function () {
var s = input.charAt(i), important = false, index = i,
elements, elem, e, c, args;
if (s !== '.' && s !== '#') { return; }
save(); // stop us absorbing part of an invalid selector
while (e = $re(/^[#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/)) {
elem = new(tree.Element)(c, e, i, env.currentFileInfo);
if (elements) { elements.push(elem); } else { elements = [ elem ]; }
c = $char('>');
}
if ($char('(')) {
args = this.args(true).args;
expectChar(')');
}
if (parsers.important()) {
important = true;
}
if (elements && ($char(';') || peekChar('}'))) {
return new(tree.mixin.Call)(elements, args, index, env.currentFileInfo, important);
}
restore();
},
args: function (isCall) {
var parsers = parser.parsers, entities = parsers.entities,
returner = { args:null, variadic: false },
expressions = [], argsSemiColon = [], argsComma = [],
isSemiColonSeperated, expressionContainsNamed, name, nameLoop, value, arg;
while (true) {
if (isCall) {
arg = parsers.expression();
} else {
parsers.comments();
if (input.charAt(i) === '.' && $re(/^\.{3}/)) {
returner.variadic = true;
if ($char(";") && !isSemiColonSeperated) {
isSemiColonSeperated = true;
}
(isSemiColonSeperated ? argsSemiColon : argsComma)
.push({ variadic: true });
break;
}
arg = entities.variable() || entities.literal() || entities.keyword();
}
if (!arg) {
break;
}
nameLoop = null;
if (arg.throwAwayComments) {
arg.throwAwayComments();
}
value = arg;
var val = null;
if (isCall) {
// Variable
if (arg.value.length == 1) {
val = arg.value[0];
}
} else {
val = arg;
}
if (val && val instanceof tree.Variable) {
if ($char(':')) {
if (expressions.length > 0) {
if (isSemiColonSeperated) {
error("Cannot mix ; and , as delimiter types");
}
expressionContainsNamed = true;
}
value = expect(parsers.expression);
nameLoop = (name = val.name);
} else if (!isCall && $re(/^\.{3}/)) {
returner.variadic = true;
if ($char(";") && !isSemiColonSeperated) {
isSemiColonSeperated = true;
}
(isSemiColonSeperated ? argsSemiColon : argsComma)
.push({ name: arg.name, variadic: true });
break;
} else if (!isCall) {
name = nameLoop = val.name;
value = null;
}
}
if (value) {
expressions.push(value);
}
argsComma.push({ name:nameLoop, value:value });
if ($char(',')) {
continue;
}
if ($char(';') || isSemiColonSeperated) {
if (expressionContainsNamed) {
error("Cannot mix ; and , as delimiter types");
}
isSemiColonSeperated = true;
if (expressions.length > 1) {
value = new(tree.Value)(expressions);
}
argsSemiColon.push({ name:name, value:value });
name = null;
expressions = [];
expressionContainsNamed = false;
}
}
returner.args = isSemiColonSeperated ? argsSemiColon : argsComma;
return returner;
},
//
// A Mixin definition, with a list of parameters
//
// .rounded (@radius: 2px, @color) {
// ...
// }
//
// Until we have a finer grained state-machine, we have to
// do a look-ahead, to make sure we don't have a mixin call.
// See the `rule` function for more information.
//
// We start by matching `.rounded (`, and then proceed on to
// the argument list, which has optional default values.
// We store the parameters in `params`, with a `value` key,
// if there is a value, such as in the case of `@radius`.
//
// Once we've got our params list, and a closing `)`, we parse
// the `{...}` block.
//
definition: function () {
var name, params = [], match, ruleset, cond, variadic = false;
if ((input.charAt(i) !== '.' && input.charAt(i) !== '#') ||
peek(/^[^{]*\}/)) {
return;
}
save();
if (match = $re(/^([#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+)\s*\(/)) {
name = match[1];
var argInfo = this.args(false);
params = argInfo.args;
variadic = argInfo.variadic;
// .mixincall("@{a}");
// looks a bit like a mixin definition.. so we have to be nice and restore
if (!$char(')')) {
furthest = i;
restore();
}
parsers.comments();
if ($re(/^when/)) { // Guard
cond = expect(parsers.conditions, 'expected condition');
}
ruleset = parsers.block();
if (ruleset) {
return new(tree.mixin.Definition)(name, params, ruleset, cond, variadic);
} else {
restore();
}
}
}
},
//
// Entities are the smallest recognized token,
// and can be found inside a rule's value.
//
entity: function () {
var entities = this.entities;
return entities.literal() || entities.variable() || entities.url() ||
entities.call() || entities.keyword() || entities.javascript() ||
this.comment();
},
//
// A Rule terminator. Note that we use `peek()` to check for '}',
// because the `block` rule will be expecting it, but we still need to make sure
// it's there, if ';' was ommitted.
//
end: function () {
return $char(';') || peekChar('}');
},
//
// IE's alpha function
//
// alpha(opacity=88)
//
alpha: function () {
var value;
if (! $re(/^\(opacity=/i)) { return; }
if (value = $re(/^\d+/) || this.entities.variable()) {
expectChar(')');
return new(tree.Alpha)(value);
}
},
//
// A Selector Element
//
// div
// + h1
// #socks
// input[type="text"]
//
// Elements are the building blocks for Selectors,
// they are made out of a `Combinator` (see combinator rule),
// and an element name, such as a tag a class, or `*`.
//
element: function () {
var e, c, v;
c = this.combinator();
e = $re(/^(?:\d+\.\d+|\d+)%/) || $re(/^(?:[.#]?|:*)(?:[\w-]|[^\x00-\x9f]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/) ||
$char('*') || $char('&') || this.attribute() || $re(/^\([^()@]+\)/) || $re(/^[\.#](?=@)/) ||
this.entities.variableCurly();
if (! e) {
if ($char('(')) {
if ((v = this.selector()) && $char(')')) {
e = new(tree.Paren)(v);
}
}
}
if (e) { return new(tree.Element)(c, e, i, env.currentFileInfo); }
},
//
// Combinators combine elements together, in a Selector.
//
// Because our parser isn't white-space sensitive, special care
// has to be taken, when parsing the descendant combinator, ` `,
// as it's an empty space. We have to check the previous character
// in the input, to see if it's a ` ` character. More info on how
// we deal with this in *combinator.js*.
//
combinator: function () {
var c = input.charAt(i);
if (c === '>' || c === '+' || c === '~' || c === '|') {
i++;
while (isWhitespace(input, i)) { i++; }
return new(tree.Combinator)(c);
} else if (isWhitespace(input, i - 1)) {
return new(tree.Combinator)(" ");
} else {
return new(tree.Combinator)(null);
}
},
//
// A CSS selector (see selector below)
// with less extensions e.g. the ability to extend and guard
//
lessSelector: function () {
return this.selector(true);
},
//
// A CSS Selector
//
// .class > div + h1
// li a:hover
//
// Selectors are made out of one or more Elements, see above.
//
selector: function (isLess) {
var $re = _$re, elements, extendList, c, e, extend, when, condition;
while ((isLess && (extend = this.extend())) || (isLess && (when = $re(/^when/))) || (e = this.element())) {
if (when) {
condition = expect(this.conditions, 'expected condition');
} else if (condition) {
error("CSS guard can only be used at the end of selector");
} else if (extend) {
if (extendList) { extendList.push(extend); } else { extendList = [ extend ]; }
} else {
if (extendList) { error("Extend can only be used at the end of selector"); }
c = input.charAt(i);
if (elements) { elements.push(e); } else { elements = [ e ]; }
e = null;
}
if (c === '{' || c === '}' || c === ';' || c === ',' || c === ')') {
break;
}
}
if (elements) { return new(tree.Selector)(elements, extendList, condition, i, env.currentFileInfo); }
if (extendList) { error("Extend must be used to extend a selector, it cannot be used on its own"); }
},
attribute: function () {
if (! $char('[')) { return; }
var entities = this.entities,
key, val, op;
if (!(key = entities.variableCurly())) {
key = expect(/^(?:[_A-Za-z0-9-\*]*\|)?(?:[_A-Za-z0-9-]|\\.)+/);
}
if (op = $re(/^[|~*$^]?=/)) {
val = entities.quoted() || $re(/^[0-9]+%/) || $re(/^[\w-]+/) || entities.variableCurly();
}
expectChar(']');
return new(tree.Attribute)(key, op, val);
},
//
// The `block` rule is used by `ruleset` and `mixin.definition`.
// It's a wrapper around the `primary` rule, with added `{}`.
//
block: function () {
var content;
if ($char('{') && (content = this.primary()) && $char('}')) {
return content;
}
},
//
// div, .class, body > p {...}
//
ruleset: function () {
var selectors, s, rules, debugInfo;
save();
if (env.dumpLineNumbers) {
debugInfo = getDebugInfo(i, input, env);
}
while (s = this.lessSelector()) {
if (selectors) { selectors.push(s); } else { selectors = [ s ]; }
this.comments();
if (! $char(',')) { break; }
if (s.condition) {
error("Guards are only currently allowed on a single selector.");
}
this.comments();
}
if (selectors && (rules = this.block())) {
var ruleset = new(tree.Ruleset)(selectors, rules, env.strictImports);
if (env.dumpLineNumbers) {
ruleset.debugInfo = debugInfo;
}
return ruleset;
} else {
// Backtrack
furthest = i;
restore();
}
},
rule: function (tryAnonymous) {
var name, value, c = input.charAt(i), important, merge = false;
save();
if (c === '.' || c === '#' || c === '&') { return; }
if (name = this.variable() || this.ruleProperty()) {
// prefer to try to parse first if its a variable or we are compressing
// but always fallback on the other one
value = !tryAnonymous && (env.compress || (name.charAt(0) === '@')) ?
(this.value() || this.anonymousValue()) :
(this.anonymousValue() || this.value());
important = this.important();
if (name[name.length-1] === "+") {
merge = true;
name = name.substr(0, name.length - 1);
}
if (value && this.end()) {
return new (tree.Rule)(name, value, important, merge, memo, env.currentFileInfo);
} else {
furthest = i;
restore();
if (value && !tryAnonymous) {
return this.rule(true);
}
}
}
},
anonymousValue: function () {
var match;
if (match = /^([^@+\/'"*`(;{}-]*);/.exec(current)) {
i += match[0].length - 1;
return new(tree.Anonymous)(match[1]);
}
},
//
// An @import directive
//
// @import "lib";
//
// Depending on our environemnt, importing is done differently:
// In the browser, it's an XHR request, in Node, it would be a
// file-system operation. The function used for importing is
// stored in `import`, which we pass to the Import constructor.
//
"import": function () {
var path, features, index = i;
save();
var dir = $re(/^@import?\s+/);
var options = (dir ? this.importOptions() : null) || {};
if (dir && (path = this.entities.quoted() || this.entities.url())) {
features = this.mediaFeatures();
if ($char(';')) {
features = features && new(tree.Value)(features);
return new(tree.Import)(path, features, options, index, env.currentFileInfo);
}
}
restore();
},
importOptions: function() {
var o, options = {}, optionName, value;
// list of options, surrounded by parens
if (! $char('(')) { return null; }
do {
if (o = this.importOption()) {
optionName = o;
value = true;
switch(optionName) {
case "css":
optionName = "less";
value = false;
break;
case "once":
optionName = "multiple";
value = false;
break;
}
options[optionName] = value;
if (! $char(',')) { break; }
}
} while (o);
expectChar(')');
return options;
},
importOption: function() {
var opt = $re(/^(less|css|multiple|once|inline|reference)/);
if (opt) {
return opt[1];
}
},
mediaFeature: function () {
var entities = this.entities, nodes = [], e, p;
do {
if (e = entities.keyword() || entities.variable()) {
nodes.push(e);
} else if ($char('(')) {
p = this.property();
e = this.value();
if ($char(')')) {
if (p && e) {
nodes.push(new(tree.Paren)(new(tree.Rule)(p, e, null, null, i, env.currentFileInfo, true)));
} else if (e) {
nodes.push(new(tree.Paren)(e));
} else {
return null;
}
} else { return null; }
}
} while (e);
if (nodes.length > 0) {
return new(tree.Expression)(nodes);
}
},
mediaFeatures: function () {
var entities = this.entities, features = [], e;
do {
if (e = this.mediaFeature()) {
features.push(e);
if (! $char(',')) { break; }
} else if (e = entities.variable()) {
features.push(e);
if (! $char(',')) { break; }
}
} while (e);
return features.length > 0 ? features : null;
},
media: function () {
var features, rules, media, debugInfo;
if (env.dumpLineNumbers) {
debugInfo = getDebugInfo(i, input, env);
}
if ($re(/^@media/)) {
features = this.mediaFeatures();
if (rules = this.block()) {
media = new(tree.Media)(rules, features, i, env.currentFileInfo);
if (env.dumpLineNumbers) {
media.debugInfo = debugInfo;
}
return media;
}
}
},
//
// A CSS Directive
//
// @charset "utf-8";
//
directive: function () {
var name, value, rules, nonVendorSpecificName,
hasBlock, hasIdentifier, hasExpression, identifier;
if (input.charAt(i) !== '@') { return; }
if (value = this['import']() || this.media()) {
return value;
}
save();
name = $re(/^@[a-z-]+/);
if (!name) { return; }
nonVendorSpecificName = name;
if (name.charAt(1) == '-' && name.indexOf('-', 2) > 0) {
nonVendorSpecificName = "@" + name.slice(name.indexOf('-', 2) + 1);
}
switch(nonVendorSpecificName) {
case "@font-face":
hasBlock = true;
break;
case "@viewport":
case "@top-left":
case "@top-left-corner":
case "@top-center":
case "@top-right":
case "@top-right-corner":
case "@bottom-left":
case "@bottom-left-corner":
case "@bottom-center":
case "@bottom-right":
case "@bottom-right-corner":
case "@left-top":
case "@left-middle":
case "@left-bottom":
case "@right-top":
case "@right-middle":
case "@right-bottom":
hasBlock = true;
break;
case "@host":
case "@page":
case "@document":
case "@supports":
case "@keyframes":
hasBlock = true;
hasIdentifier = true;
break;
case "@namespace":
hasExpression = true;
break;
}
if (hasIdentifier) {
identifier = ($re(/^[^{]+/) || '').trim();
if (identifier) {
name += " " + identifier;
}
}
if (hasBlock) {
if (rules = this.block()) {
return new(tree.Directive)(name, rules, i, env.currentFileInfo);
}
} else {
if ((value = hasExpression ? this.expression() : this.entity()) && $char(';')) {
var directive = new(tree.Directive)(name, value, i, env.currentFileInfo);
if (env.dumpLineNumbers) {
directive.debugInfo = getDebugInfo(i, input, env);
}
return directive;
}
}
restore();
},
//
// A Value is a comma-delimited list of Expressions
//
// font-family: Baskerville, Georgia, serif;
//
// In a Rule, a Value represents everything after the `:`,
// and before the `;`.
//
value: function () {
var e, expressions = [];
while (e = this.expression()) {
expressions.push(e);
if (! $char(',')) { break; }
}
if (expressions.length > 0) {
return new(tree.Value)(expressions);
}
},
important: function () {
if (input.charAt(i) === '!') {
return $re(/^! *important/);
}
},
sub: function () {
var a, e;
if ($char('(')) {
if (a = this.addition()) {
e = new(tree.Expression)([a]);
expectChar(')');
e.parens = true;
return e;
}
}
},
multiplication: function () {
var m, a, op, operation, isSpaced;
if (m = this.operand()) {
isSpaced = isWhitespace(input, i - 1);
while (!peek(/^\/[*\/]/) && (op = ($char('/') || $char('*')))) {
if (a = this.operand()) {
m.parensInOp = true;
a.parensInOp = true;
operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
isSpaced = isWhitespace(input, i - 1);
} else {
break;
}
}
return operation || m;
}
},
addition: function () {
var m, a, op, operation, isSpaced;
if (m = this.multiplication()) {
isSpaced = isWhitespace(input, i - 1);
while ((op = $re(/^[-+]\s+/) || (!isSpaced && ($char('+') || $char('-')))) &&
(a = this.multiplication())) {
m.parensInOp = true;
a.parensInOp = true;
operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
isSpaced = isWhitespace(input, i - 1);
}
return operation || m;
}
},
conditions: function () {
var a, b, index = i, condition;
if (a = this.condition()) {
while (peek(/^,\s*(not\s*)?\(/) && $char(',') && (b = this.condition())) {
condition = new(tree.Condition)('or', condition || a, b, index);
}
return condition || a;
}
},
condition: function () {
var entities = this.entities, index = i, negate = false,
a, b, c, op;
if ($re(/^not/)) { negate = true; }
expectChar('(');
if (a = this.addition() || entities.keyword() || entities.quoted()) {
if (op = $re(/^(?:>=|<=|=<|[<=>])/)) {
if (b = this.addition() || entities.keyword() || entities.quoted()) {
c = new(tree.Condition)(op, a, b, index, negate);
} else {
error('expected expression');
}
} else {
c = new(tree.Condition)('=', a, new(tree.Keyword)('true'), index, negate);
}
expectChar(')');
return $re(/^and/) ? new(tree.Condition)('and', c, this.condition()) : c;
}
},
//
// An operand is anything that can be part of an operation,
// such as a Color, or a Variable
//
operand: function () {
var entities = this.entities,
p = input.charAt(i + 1), negate;
if (input.charAt(i) === '-' && (p === '@' || p === '(')) { negate = $char('-'); }
var o = this.sub() || entities.dimension() ||
entities.color() || entities.variable() ||
entities.call();
if (negate) {
o.parensInOp = true;
o = new(tree.Negative)(o);
}
return o;
},
//
// Expressions either represent mathematical operations,
// or white-space delimited Entities.
//
// 1px solid black
// @var * 2
//
expression: function () {
var entities = [], e, delim;
while (e = this.addition() || this.entity()) {
entities.push(e);
// operations do not allow keyword "/" dimension (e.g. small/20px) so we support that here
if (!peek(/^\/[\/*]/) && (delim = $char('/'))) {
entities.push(new(tree.Anonymous)(delim));
}
}
if (entities.length > 0) {
return new(tree.Expression)(entities);
}
},
property: function () {
var name;
if (name = $re(/^(\*?-?[_a-zA-Z0-9-]+)\s*:/)) {
return name[1];
}
},
ruleProperty: function () {
var name;
if (name = $re(/^(\*?-?[_a-zA-Z0-9-]+)\s*(\+?)\s*:/)) {
return name[1] + (name[2] || "");
}
}
}
};
};