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diff src/nabble/view/web/util/codemirror/js/parsejavascript.js @ 0:7ecd1a4ef557
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author | Franklin Schmidt <fschmidt@gmail.com> |
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date | Thu, 21 Mar 2019 19:15:52 -0600 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/nabble/view/web/util/codemirror/js/parsejavascript.js Thu Mar 21 19:15:52 2019 -0600 @@ -0,0 +1,359 @@ +/* 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(pushlex(")"), pushcontext, commasep(funarg, ")"), poplex, 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; + } + }; +})();