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60 lines
1.7 KiB
JavaScript

var utils = require("./utils");
module.exports = {
/*
* Compiler passes.
*
* Each pass is a function that is passed the AST. It can perform checks on it
* or modify it as needed. If the pass encounters a semantic error, it throws
* |PEG.GrammarError|.
*/
passes: {
check: {
reportMissingRules: require("./compiler/passes/report-missing-rules"),
reportLeftRecursion: require("./compiler/passes/report-left-recursion")
},
transform: {
removeProxyRules: require("./compiler/passes/remove-proxy-rules")
},
generate: {
generateBytecode: require("./compiler/passes/generate-bytecode"),
generateJavascript: require("./compiler/passes/generate-javascript")
}
},
/*
* Generates a parser from a specified grammar AST. Throws |PEG.GrammarError|
* if the AST contains a semantic error. Note that not all errors are detected
* during the generation and some may protrude to the generated parser and
* cause its malfunction.
*/
compile: function(ast, passes) {
var options = arguments.length > 2 ? utils.clone(arguments[2]) : {},
stage;
/*
* Extracted into a function just to silence JSHint complaining about
* creating functions in a loop.
*/
function runPass(pass) {
pass(ast, options);
}
utils.defaults(options, {
allowedStartRules: [ast.rules[0].name],
cache: false,
optimize: "speed",
output: "parser"
});
for (stage in passes) {
utils.each(passes[stage], runPass);
}
switch (options.output) {
case "parser": return eval(ast.code);
case "source": return ast.code;
}
}
};