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. adding xml and js parsers
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kowsik committed Nov 11, 2010
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359 changes: 359 additions & 0 deletions script/codemirror/parsejavascript.js
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/* Parse function for JavaScript. Makes use of the tokenizer from
* tokenizejavascript.js. Note that your parsers do not have to be
* this complicated -- if you don't want to recognize local variables,
* in many languages it is enough to just look for braces, semicolons,
* parentheses, etc, and know when you are inside a string or comment.
*
* See manual.html for more info about the parser interface.
*/

var JSParser = Editor.Parser = (function() {
// Token types that can be considered to be atoms.
var atomicTypes = {"atom": true, "number": true, "variable": true, "string": true, "regexp": true};
// Setting that can be used to have JSON data indent properly.
var json = false;
// Constructor for the lexical context objects.
function JSLexical(indented, column, type, align, prev, info) {
// indentation at start of this line
this.indented = indented;
// column at which this scope was opened
this.column = column;
// type of scope ('vardef', 'stat' (statement), 'form' (special form), '[', '{', or '(')
this.type = type;
// '[', '{', or '(' blocks that have any text after their opening
// character are said to be 'aligned' -- any lines below are
// indented all the way to the opening character.
if (align != null)
this.align = align;
// Parent scope, if any.
this.prev = prev;
this.info = info;
}

// My favourite JavaScript indentation rules.
function indentJS(lexical) {
return function(firstChars) {
var firstChar = firstChars && firstChars.charAt(0), type = lexical.type;
var closing = firstChar == type;
if (type == "vardef")
return lexical.indented + 4;
else if (type == "form" && firstChar == "{")
return lexical.indented;
else if (type == "stat" || type == "form")
return lexical.indented + indentUnit;
else if (lexical.info == "switch" && !closing)
return lexical.indented + (/^(?:case|default)\b/.test(firstChars) ? indentUnit : 2 * indentUnit);
else if (lexical.align)
return lexical.column - (closing ? 1 : 0);
else
return lexical.indented + (closing ? 0 : indentUnit);
};
}

// The parser-iterator-producing function itself.
function parseJS(input, basecolumn) {
// Wrap the input in a token stream
var tokens = tokenizeJavaScript(input);
// The parser state. cc is a stack of actions that have to be
// performed to finish the current statement. For example we might
// know that we still need to find a closing parenthesis and a
// semicolon. Actions at the end of the stack go first. It is
// initialized with an infinitely looping action that consumes
// whole statements.
var cc = [json ? expressions : statements];
// Context contains information about the current local scope, the
// variables defined in that, and the scopes above it.
var context = null;
// The lexical scope, used mostly for indentation.
var lexical = new JSLexical((basecolumn || 0) - indentUnit, 0, "block", false);
// Current column, and the indentation at the start of the current
// line. Used to create lexical scope objects.
var column = 0;
var indented = 0;
// Variables which are used by the mark, cont, and pass functions
// below to communicate with the driver loop in the 'next'
// function.
var consume, marked;

// The iterator object.
var parser = {next: next, copy: copy};

function next(){
// Start by performing any 'lexical' actions (adjusting the
// lexical variable), or the operations below will be working
// with the wrong lexical state.
while(cc[cc.length - 1].lex)
cc.pop()();

// Fetch a token.
var token = tokens.next();

// Adjust column and indented.
if (token.type == "whitespace" && column == 0)
indented = token.value.length;
column += token.value.length;
if (token.content == "\n"){
indented = column = 0;
// If the lexical scope's align property is still undefined at
// the end of the line, it is an un-aligned scope.
if (!("align" in lexical))
lexical.align = false;
// Newline tokens get an indentation function associated with
// them.
token.indentation = indentJS(lexical);
}
// No more processing for meaningless tokens.
if (token.type == "whitespace" || token.type == "comment")
return token;
// When a meaningful token is found and the lexical scope's
// align is undefined, it is an aligned scope.
if (!("align" in lexical))
lexical.align = true;

// Execute actions until one 'consumes' the token and we can
// return it.
while(true) {
consume = marked = false;
// Take and execute the topmost action.
cc.pop()(token.type, token.content);
if (consume){
// Marked is used to change the style of the current token.
if (marked)
token.style = marked;
// Here we differentiate between local and global variables.
else if (token.type == "variable" && inScope(token.content))
token.style = "js-localvariable";
return token;
}
}
}

// This makes a copy of the parser state. It stores all the
// stateful variables in a closure, and returns a function that
// will restore them when called with a new input stream. Note
// that the cc array has to be copied, because it is contantly
// being modified. Lexical objects are not mutated, and context
// objects are not mutated in a harmful way, so they can be shared
// between runs of the parser.
function copy(){
var _context = context, _lexical = lexical, _cc = cc.concat([]), _tokenState = tokens.state;

return function copyParser(input){
context = _context;
lexical = _lexical;
cc = _cc.concat([]); // copies the array
column = indented = 0;
tokens = tokenizeJavaScript(input, _tokenState);
return parser;
};
}

// Helper function for pushing a number of actions onto the cc
// stack in reverse order.
function push(fs){
for (var i = fs.length - 1; i >= 0; i--)
cc.push(fs[i]);
}
// cont and pass are used by the action functions to add other
// actions to the stack. cont will cause the current token to be
// consumed, pass will leave it for the next action.
function cont(){
push(arguments);
consume = true;
}
function pass(){
push(arguments);
consume = false;
}
// Used to change the style of the current token.
function mark(style){
marked = style;
}

// Push a new scope. Will automatically link the current scope.
function pushcontext(){
context = {prev: context, vars: {"this": true, "arguments": true}};
}
// Pop off the current scope.
function popcontext(){
context = context.prev;
}
// Register a variable in the current scope.
function register(varname){
if (context){
mark("js-variabledef");
context.vars[varname] = true;
}
}
// Check whether a variable is defined in the current scope.
function inScope(varname){
var cursor = context;
while (cursor) {
if (cursor.vars[varname])
return true;
cursor = cursor.prev;
}
return false;
}

// Push a new lexical context of the given type.
function pushlex(type, info) {
var result = function(){
lexical = new JSLexical(indented, column, type, null, lexical, info)
};
result.lex = true;
return result;
}
// Pop off the current lexical context.
function poplex(){
if (lexical.type == ")")
indented = lexical.indented;
lexical = lexical.prev;
}
poplex.lex = true;
// The 'lex' flag on these actions is used by the 'next' function
// to know they can (and have to) be ran before moving on to the
// next token.

// Creates an action that discards tokens until it finds one of
// the given type.
function expect(wanted){
return function expecting(type){
if (type == wanted) cont();
else if (wanted == ";") pass();
else cont(arguments.callee);
};
}

// Looks for a statement, and then calls itself.
function statements(type){
return pass(statement, statements);
}
function expressions(type){
return pass(expression, expressions);
}
// Dispatches various types of statements based on the type of the
// current token.
function statement(type){
if (type == "var") cont(pushlex("vardef"), vardef1, expect(";"), poplex);
else if (type == "keyword a") cont(pushlex("form"), expression, statement, poplex);
else if (type == "keyword b") cont(pushlex("form"), statement, poplex);
else if (type == "{") cont(pushlex("}"), block, poplex);
else if (type == ";") cont();
else if (type == "function") cont(functiondef);
else if (type == "for") cont(pushlex("form"), expect("("), pushlex(")"), forspec1, expect(")"), poplex, statement, poplex);
else if (type == "variable") cont(pushlex("stat"), maybelabel);
else if (type == "switch") cont(pushlex("form"), expression, pushlex("}", "switch"), expect("{"), block, poplex, poplex);
else if (type == "case") cont(expression, expect(":"));
else if (type == "default") cont(expect(":"));
else if (type == "catch") cont(pushlex("form"), pushcontext, expect("("), funarg, expect(")"), statement, poplex, popcontext);
else pass(pushlex("stat"), expression, expect(";"), poplex);
}
// Dispatch expression types.
function expression(type){
if (atomicTypes.hasOwnProperty(type)) cont(maybeoperator);
else if (type == "function") cont(functiondef);
else if (type == "keyword c") cont(expression);
else if (type == "(") cont(pushlex(")"), expression, expect(")"), poplex, maybeoperator);
else if (type == "operator") cont(expression);
else if (type == "[") cont(pushlex("]"), commasep(expression, "]"), poplex, maybeoperator);
else if (type == "{") cont(pushlex("}"), commasep(objprop, "}"), poplex, maybeoperator);
else cont();
}
// Called for places where operators, function calls, or
// subscripts are valid. Will skip on to the next action if none
// is found.
function maybeoperator(type, value){
if (type == "operator" && /\+\+|--/.test(value)) cont(maybeoperator);
else if (type == "operator") cont(expression);
else if (type == ";") pass();
else if (type == "(") cont(pushlex(")"), commasep(expression, ")"), poplex, maybeoperator);
else if (type == ".") cont(property, maybeoperator);
else if (type == "[") cont(pushlex("]"), expression, expect("]"), poplex, maybeoperator);
}
// When a statement starts with a variable name, it might be a
// label. If no colon follows, it's a regular statement.
function maybelabel(type){
if (type == ":") cont(poplex, statement);
else pass(maybeoperator, expect(";"), poplex);
}
// Property names need to have their style adjusted -- the
// tokenizer thinks they are variables.
function property(type){
if (type == "variable") {mark("js-property"); cont();}
}
// This parses a property and its value in an object literal.
function objprop(type){
if (type == "variable") mark("js-property");
if (atomicTypes.hasOwnProperty(type)) cont(expect(":"), expression);
}
// Parses a comma-separated list of the things that are recognized
// by the 'what' argument.
function commasep(what, end){
function proceed(type) {
if (type == ",") cont(what, proceed);
else if (type == end) cont();
else cont(expect(end));
}
return function commaSeparated(type) {
if (type == end) cont();
else pass(what, proceed);
};
}
// Look for statements until a closing brace is found.
function block(type){
if (type == "}") cont();
else pass(statement, block);
}
// Variable definitions are split into two actions -- 1 looks for
// a name or the end of the definition, 2 looks for an '=' sign or
// a comma.
function vardef1(type, value){
if (type == "variable"){register(value); cont(vardef2);}
else cont();
}
function vardef2(type, value){
if (value == "=") cont(expression, vardef2);
else if (type == ",") cont(vardef1);
}
// For loops.
function forspec1(type){
if (type == "var") cont(vardef1, forspec2);
else if (type == ";") pass(forspec2);
else if (type == "variable") cont(formaybein);
else pass(forspec2);
}
function formaybein(type, value){
if (value == "in") cont(expression);
else cont(maybeoperator, forspec2);
}
function forspec2(type, value){
if (type == ";") cont(forspec3);
else if (value == "in") cont(expression);
else cont(expression, expect(";"), forspec3);
}
function forspec3(type) {
if (type == ")") pass();
else cont(expression);
}
// A function definition creates a new context, and the variables
// in its argument list have to be added to this context.
function functiondef(type, value){
if (type == "variable"){register(value); cont(functiondef);}
else if (type == "(") cont(pushcontext, commasep(funarg, ")"), statement, popcontext);
}
function funarg(type, value){
if (type == "variable"){register(value); cont();}
}

return parser;
}

return {
make: parseJS,
electricChars: "{}:",
configure: function(obj) {
if (obj.json != null) json = obj.json;
}
};
})();
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