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landed first version of FSM based tokenizer
fsm style taken from creationix/jsonparse support for special tags (<script> & <style>) is missing
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,349 @@ | ||
| module.exports = Parser; | ||
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| var WritableStream = require("stream").Writable, | ||
|
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| i = 0, | ||
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| TEXT = i++, | ||
| TAG_START = i++, //after < | ||
| IN_TAG_NAME = i++, | ||
| CLOSING_TAG_START = i++, | ||
| IN_CLOSING_TAG_NAME = i++, | ||
| AFTER_CLOSING_TAG_NAME = i++, | ||
|
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| //attributes | ||
| BEFORE_ATTRIBUTE_NAME = i++, | ||
| IN_ATTRIBUTE_NAME = i++, | ||
| AFTER_ATTRIBUTE_NAME = i++, | ||
| BEFORE_ATTRIBUTE_VALUE = i++, | ||
| IN_ATTRIBUTE_VALUE_DOUBLE_QUOTES = i++, // " | ||
| IN_ATTRIBUTE_VALUE_SINGLE_QUOTES = i++, // ' | ||
| IN_ATTRIBUTE_VALUE_NO_QUOTES = i++, | ||
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| //declarations | ||
| DECLARATION_START = i++, // ! | ||
| IN_DECLARATION = i++, | ||
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| //processing instructions | ||
| IN_PROCESSING_INSTRUCTION = i++, // ? | ||
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| //comments | ||
| BEFORE_COMMENT = i++, | ||
| IN_COMMENT = i++, | ||
| COMMENT_END_1 = i++, | ||
| COMMENT_END_2 = i++, | ||
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| //cdata | ||
| CDATA_1 = i++, // [ | ||
| CDATA_2 = i++, // C | ||
| CDATA_3 = i++, // D | ||
| CDATA_4 = i++, // A | ||
| CDATA_5 = i++, // T | ||
| CDATA_6 = i++, // A | ||
| IN_CDATA = i++,// [ | ||
| CDATA_END_1 = i++, // ] | ||
| CDATA_END_2 = i++; // ] | ||
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| //TODO add logic to handle special tags | ||
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| function code(c){ | ||
| return c.charCodeAt(0); | ||
| } | ||
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| function whitespace(c){ | ||
| return c === code(" ") || c === code("\t") || c === code("\r") || c === code("\n"); | ||
| } | ||
|
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| function Parser(options){ | ||
| this._state = TEXT; | ||
| this._buffer = null; | ||
| this._sectionStart = 0; | ||
| this._index = 0; | ||
| this._options = options; | ||
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| WritableStream.call(this, options); | ||
| } | ||
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| require("util").inherits(Parser, WritableStream); | ||
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| Parser.prototype._write = function(chunk, encoding, cb){ | ||
| if(this._buffer === null) this._buffer = chunk; | ||
| else this._buffer = Buffer.concat([this._buffer, chunk]); | ||
|
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| while(this._index < this._buffer.length){ | ||
| var c = this._buffer[this._index]; | ||
| if(this._state === TEXT){ | ||
| if(c === code("<")){ | ||
| this._emitIfToken("text"); | ||
| this._state = TAG_START; | ||
| } | ||
| } else if(this._state === TAG_START){ | ||
| if(c === code("!")){ | ||
| this._state = DECLARATION_START; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(c === code("?")){ | ||
| this._state = IN_PROCESSING_INSTRUCTION; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(c === code("/")){ | ||
| this._state = CLOSING_TAG_START; | ||
| } else if(!whitespace(c)){ | ||
| this._state = IN_TAG_NAME; | ||
| this._sectionStart = this._index; | ||
| } | ||
| //TODO handle ">" | ||
| } else if(this._state === IN_TAG_NAME){ | ||
| if(c === code("/")){ | ||
| this._emitToken("opentagname"); | ||
| this.emit("selfclosingtag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } else if(c === code(">")){ | ||
| this._emitToken("opentagname"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(whitespace(c)){ | ||
| this._emitToken("opentagname"); | ||
| this._state = BEFORE_ATTRIBUTE_NAME; | ||
| } | ||
| } else if(this._state === CLOSING_TAG_START){ | ||
| if(!whitespace(c)){ | ||
| this._state = IN_CLOSING_TAG_NAME; | ||
| this._sectionStart = this._index; | ||
| } | ||
| // TODO handle ">" | ||
| } else if(this._state === IN_CLOSING_TAG_NAME){ | ||
| if(c === code(">")){ | ||
| this._emitToken("closetag"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(whitespace(c)){ | ||
| this._emitToken("closetag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } | ||
| } else if(this._state === AFTER_CLOSING_TAG_NAME){ | ||
| //skip everything until ">" | ||
| if(c === code(">")){ | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } | ||
| } | ||
|
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||
| /* | ||
| * attributes | ||
| */ | ||
| else if(this._state === BEFORE_ATTRIBUTE_NAME){ | ||
| if(c === code("/")){ | ||
| this.emit("selfclosingtag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } else if(c === code(">")){ | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(!whitespace(c)){ | ||
| this._state = IN_ATTRIBUTE_NAME; | ||
| this._sectionStart = this._index; | ||
| } | ||
| } else if(this._state === IN_ATTRIBUTE_NAME){ | ||
| if(c === code("=")){ | ||
| this._emitIfToken("attribname"); | ||
| this._state = BEFORE_ATTRIBUTE_VALUE; | ||
| } else if(c === code("/")){ | ||
| this._emitIfToken("attribname"); | ||
| this.emit("selfclosingtag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } else if(c === code(">")){ | ||
| this._emitIfToken("attribname"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(whitespace(c)){ | ||
| this._emitIfToken("attribname"); | ||
| this._state = AFTER_ATTRIBUTE_NAME; | ||
| } | ||
| } else if(this._state === AFTER_ATTRIBUTE_NAME){ | ||
| if(c === code("=")){ | ||
| this._state = BEFORE_ATTRIBUTE_VALUE; | ||
| } else if(c === code("/")){ | ||
| this.emit("selfclosingtag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } else if(c === code(">")){ | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(!whitespace(c)){ | ||
| this._state = IN_ATTRIBUTE_NAME; | ||
| this._sectionStart = this._index; | ||
| } | ||
| } else if(this._state === BEFORE_ATTRIBUTE_VALUE){ | ||
| if(c === code("\"")){ | ||
| this._state = IN_ATTRIBUTE_VALUE_DOUBLE_QUOTES; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(c === code("'")){ | ||
| this._state = IN_ATTRIBUTE_VALUE_SINGLE_QUOTES; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(!whitespace(c)){ | ||
| this._state = IN_ATTRIBUTE_VALUE_NO_QUOTES; | ||
| this._sectionStart = this._index; | ||
| } | ||
| } else if(this._state === IN_ATTRIBUTE_VALUE_DOUBLE_QUOTES){ | ||
| if(c === code("\"")){ | ||
| this._emitToken("attribvalue"); | ||
| this._state = BEFORE_ATTRIBUTE_NAME; | ||
| } | ||
| } else if(this._state === IN_ATTRIBUTE_VALUE_SINGLE_QUOTES){ | ||
| if(c === code("'")){ | ||
| this._emitToken("attribvalue"); | ||
| this._state = BEFORE_ATTRIBUTE_NAME; | ||
| } | ||
| } else if(this._state === IN_ATTRIBUTE_VALUE_NO_QUOTES){ | ||
| if(c === code("/")){ | ||
| this._emitToken("attribvalue"); | ||
| this.emit("selfclosingtag"); | ||
| this._state = AFTER_CLOSING_TAG_NAME; | ||
| } else if(c === code(">")){ | ||
| this._emitToken("attribvalue"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else if(whitespace(c)){ | ||
| this._emitToken("attribvalue"); | ||
| this._state = BEFORE_ATTRIBUTE_NAME; | ||
| } | ||
| } | ||
|
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||
| /* | ||
| * declarations | ||
| */ | ||
| else if(this._state === DECLARATION_START){ | ||
| if(c === code("[")) this._state = CDATA_1; | ||
| else if(c === code("-")) this._state = BEFORE_COMMENT; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === IN_DECLARATION){ | ||
| if(c === code(">")){ | ||
| this._emitToken("declaration"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } | ||
| } | ||
|
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| /* | ||
| * processing instructions | ||
| */ | ||
| else if(this._state === IN_PROCESSING_INSTRUCTION){ | ||
| if(c === code(">")){ | ||
| this._emitToken("processinginstruction"); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } | ||
| } | ||
|
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| /* | ||
| * comments | ||
| */ | ||
| else if(this._state === BEFORE_COMMENT){ | ||
| if(c === code("-")){ | ||
| this._state = IN_COMMENT; | ||
| this._sectionStart = this._index + 1; | ||
| } else { | ||
| this._state = IN_DECLARATION; | ||
| } | ||
| } else if(this._state === IN_COMMENT){ | ||
| if(c === code("-")) this._state = COMMENT_END_1; | ||
| } else if(this._state === COMMENT_END_1){ | ||
| if(c === code("-")) this._state = COMMENT_END_2; | ||
| else this._state = IN_COMMENT; | ||
| } else if(this._state === COMMENT_END_2){ | ||
| if(c === code(">")){ | ||
| //remove 2 trailing chars | ||
| this.emit("comment", this._buffer.toString("utf8", this._sectionStart, this._index - 2)); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else { | ||
| this._state = IN_COMMENT; | ||
| } | ||
| } | ||
|
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||
| /* | ||
| * cdata | ||
| */ | ||
| else if(this._state === CDATA_1){ | ||
| if(c === code("C")) this._state = CDATA_2; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === CDATA_2){ | ||
| if(c === code("D")) this._state = CDATA_3; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === CDATA_3){ | ||
| if(c === code("A")) this._state = CDATA_4; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === CDATA_4){ | ||
| if(c === code("T")) this._state = CDATA_5; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === CDATA_5){ | ||
| if(c === code("A")) this._state = CDATA_6; | ||
| else this._state = IN_DECLARATION; | ||
| } else if(this._state === CDATA_6){ | ||
| if(c === code("[")){ | ||
| this._state = IN_CDATA; | ||
| this._sectionStart = this._index + 1; | ||
| } else { | ||
| this._state = IN_DECLARATION; | ||
| } | ||
| } else if(this._state === IN_CDATA){ | ||
| if(c === code("]")) this._state = CDATA_END_1; | ||
| } else if(this._state === CDATA_END_1){ | ||
| if(c === code("]")) this._state = CDATA_END_2; | ||
| else this._state = IN_CDATA; | ||
| } else if(this._state === CDATA_END_2){ | ||
| if(c === code(">")){ | ||
| //remove 2 trailing chars | ||
| this.emit("cdata", this._buffer.toString("utf8", this._sectionStart, this._index - 2)); | ||
| this._state = TEXT; | ||
| this._sectionStart = this._index + 1; | ||
| } else { | ||
| this._state = IN_CDATA; | ||
| } | ||
| } else { | ||
| throw Error("unknown state " + this._state); | ||
| } | ||
|
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| this._index++; | ||
| } | ||
|
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| //cleanup | ||
| if(this._sectionStart === -1){ | ||
| this._buffer = null; | ||
| } else { | ||
| this._sectionStart = 0; | ||
|
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| if(this._sectionStart === this._index - 1){ | ||
| this._buffer = null; | ||
| } else { | ||
| this._buffer = this._buffer.slice(this._sectionStart); | ||
| } | ||
| } | ||
|
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| cb(); | ||
| }; | ||
|
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| Parser.prototype._emitToken = function(name){ | ||
| this.emit(name, this._buffer.toString("utf8", this._sectionStart, this._index)); | ||
| this._sectionStart = -1; | ||
| }; | ||
|
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| Parser.prototype._emitIfToken = function(name){ | ||
| if(this._index > this._sectionStart){ | ||
| this.emit(name, this._buffer.toString("utf8", this._sectionStart, this._index)); | ||
| } | ||
| this._sectionStart = -1; | ||
| }; | ||
|
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| /* | ||
| //overwritten for better debuggability | ||
| Parser.prototype.emit = function(){ | ||
| process.stdout.write("[" + this._state + "]\t"); | ||
| console.log.apply(null, [].map.call(arguments, Function.prototype.call, String.prototype.trim)); | ||
| WritableStream.prototype.emit.apply(this, arguments); | ||
| }; | ||
| Parser.prototype.end = function(){ | ||
| WritableStream.prototype.end.apply(this, arguments); | ||
| if(this._state === TEXT) return; | ||
| console.log("the game must go on!", this._state); | ||
| }; | ||
| */ |