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92 lines
2.7 KiB
JavaScript

"use strict";
let generateBytecode = require("./passes/generate-bytecode");
let generateJS = require("./passes/generate-js");
let removeProxyRules = require("./passes/remove-proxy-rules");
let reportDuplicateLabels = require("./passes/report-duplicate-labels");
let reportDuplicateRules = require("./passes/report-duplicate-rules");
let reportInfiniteRecursion = require("./passes/report-infinite-recursion");
let reportInfiniteRepetition = require("./passes/report-infinite-repetition");
let reportUndefinedRules = require("./passes/report-undefined-rules");
let visitor = require("./visitor");
function processOptions(options, defaults) {
let processedOptions = {};
Object.keys(options).forEach(name => {
processedOptions[name] = options[name];
});
Object.keys(defaults).forEach(name => {
if (!Object.prototype.hasOwnProperty.call(processedOptions, name)) {
processedOptions[name] = defaults[name];
}
});
return processedOptions;
}
let compiler = {
// AST node visitor builder. Useful mainly for plugins which manipulate the
// AST.
visitor: visitor,
// 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: {
reportUndefinedRules: reportUndefinedRules,
reportDuplicateRules: reportDuplicateRules,
reportDuplicateLabels: reportDuplicateLabels,
reportInfiniteRecursion: reportInfiniteRecursion,
reportInfiniteRepetition: reportInfiniteRepetition
},
transform: {
removeProxyRules: removeProxyRules
},
generate: {
generateBytecode: generateBytecode,
generateJS: generateJS
}
},
// 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(ast, passes, options) {
options = options !== undefined ? options : {};
options = processOptions(options, {
allowedStartRules: [ast.rules[0].name],
cache: false,
dependencies: {},
exportVar: null,
format: "bare",
optimize: "speed",
output: "parser",
trace: false
});
Object.keys(passes).forEach(stage => {
passes[stage].forEach(p => { p(ast, options); });
});
switch (options.output) {
case "parser":
return eval(ast.code);
case "source":
return ast.code;
default:
throw new Error("Invalid output format: " + options.output + ".");
}
}
};
module.exports = compiler;