08-27-周三_17-09-29

node_modules/CSSselect/lib/compile.js

@@ -0,0 +1,84 @@
+/*
+	compiles a selector to an executable function
+*/
+
+module.exports = compile;
+module.exports.compileUnsafe = compileUnsafe;
+
+var parse       = require("CSSwhat"),
+    DomUtils    = require("domutils"),
+    isTag       = DomUtils.isTag,
+    Rules       = require("./general.js"),
+    sortRules   = require("./sort.js"),
+    BaseFuncs   = require("./basefunctions.js"),
+    trueFunc    = BaseFuncs.trueFunc,
+    falseFunc   = BaseFuncs.falseFunc;
+
+function compile(selector, options){
+	var next = compileUnsafe(selector, options);
+
+	return function base(elem){
+		return isTag(elem) && next(elem);
+	};
+}
+
+function compileUnsafe(selector, options){
+	return parse(selector, options)
+		.map(compileRules)
+		.reduce(reduceRules, falseFunc);
+}
+
+function compileRules(arr){
+	if(arr.length === 0) return falseFunc;
+	return sortRules(arr).reduce(function(func, rule){
+		if(func === falseFunc) return func;
+		return Rules[rule.type](func, rule);
+	}, trueFunc);
+}
+
+function reduceRules(a, b){
+	if(b === falseFunc || a === trueFunc){
+		return a;
+	}
+	if(a === falseFunc || b === trueFunc){
+		return b;
+	}
+
+	return function combine(elem){
+		return a(elem) || b(elem);
+	};	
+}
+
+//:not and :has have to compile selectors
+//doing this in lib/pseudos.js would lead to circular dependencies,
+//so we add them here
+
+var Pseudos     = require("./pseudos.js"),
+    filters     = Pseudos.filters,
+    isParent    = Pseudos.pseudos.parent,
+    existsOne   = DomUtils.existsOne,
+    getChildren = DomUtils.getChildren;
+
+filters.not = function(next, select){
+	var func = compileUnsafe(select);
+
+	if(func === falseFunc) return next;
+	if(func === trueFunc)  return falseFunc;
+
+	return function(elem){
+		return !func(elem) && next(elem);
+	};
+};
+
+filters.has = function(next, selector){
+	var func = compile(selector);
+
+	if(func === falseFunc) return falseFunc;
+	if(func === trueFunc)  return function(elem){
+			return isParent(elem) && next(elem);
+		};
+
+	return function has(elem){
+		return next(elem) && existsOne(func, getChildren(elem));
+	};
+};