2643f72a9d
Reviewers: xymostech Reviewed By: xymostech Differential Revision: http://phabricator.benalpert.com/D42
76 lines
1.7 KiB
JavaScript
76 lines
1.7 KiB
JavaScript
function Lexer() {
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};
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var normals = [
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[/^[/|a-zA-Z0-9.]/, 'ORD'],
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[/^[*+-]/, 'BIN'],
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[/^\^/, '^'],
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[/^_/, '_'],
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[/^{/, '{'],
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[/^}/, '}'],
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[/^[(\[]/, 'OPEN'],
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[/^[)\]]/, 'CLOSE']
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];
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var funcs = [
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'cdot', 'frac', 'lvert', 'rvert', 'pm', 'div'
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];
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var anyFunc = new RegExp("^\\\\(" + funcs.join("|") + ")(?![a-zA-Z])");
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Lexer.prototype.doMatch = function(match) {
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this.yytext = match;
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this.yyleng = match.length;
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this.yylloc.first_column = this._pos;
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this.yylloc.last_column = this._pos + match.length;
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this._pos += match.length;
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this._input = this._input.slice(match.length);
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};
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Lexer.prototype.lex = function() {
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// Get rid of whitespace
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var whitespace = this._input.match(/^\s*/)[0];
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this._pos += whitespace.length;
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this._input = this._input.slice(whitespace.length);
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if (this._input.length === 0) {
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return 'EOF';
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}
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var match;
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if ((match = this._input.match(anyFunc))) {
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this.doMatch(match[0]);
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return match[1];
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} else {
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for (var i = 0; i < normals.length; i++) {
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var normal = normals[i];
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if ((match = this._input.match(normal[0]))) {
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this.doMatch(match[0]);
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return normal[1];
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}
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}
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}
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throw "Unexpected character: '" + toMatch[0] + "' at position " + this._pos;
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};
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Lexer.prototype.setInput = function(input) {
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this._input = input;
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this._pos = 0;
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this.yyleng = 0;
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this.yytext = "";
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this.yylineno = 0;
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this.yylloc = {
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first_line: 1,
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first_column: 0,
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last_line: 1,
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last_column: 0
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};
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};
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module.exports = new Lexer();
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