|
|
|
"use strict";
|
|
|
|
|
|
|
|
let asts = require("../asts");
|
|
|
|
let js = require("../js");
|
|
|
|
let op = require("../opcodes");
|
Code generator rewrite
This is a complete rewrite of the PEG.js code generator. Its goals are:
1. Allow optimizing the generated parser code for code size as well as
for parsing speed.
2. Prepare ground for future optimizations and big features (like
incremental parsing).
2. Replace the old template-based code-generation system with
something more lightweight and flexible.
4. General code cleanup (structure, style, variable names, ...).
New Architecture
----------------
The new code generator consists of two steps:
* Bytecode generator -- produces bytecode for an abstract virtual
machine
* JavaScript generator -- produces JavaScript code based on the
bytecode
The abstract virtual machine is stack-based. Originally I wanted to make
it register-based, but it turned out that all the code related to it
would be more complex and the bytecode itself would be longer (because
of explicit register specifications in instructions). The only downsides
of the stack-based approach seem to be few small inefficiencies (see
e.g. the |NIP| instruction), which seem to be insignificant.
The new generator allows optimizing for parsing speed or code size (you
can choose using the |optimize| option of the |PEG.buildParser| method
or the --optimize/-o option on the command-line).
When optimizing for size, the JavaScript generator emits the bytecode
together with its constant table and a generic bytecode interpreter.
Because the interpreter is small and the bytecode and constant table
grow only slowly with size of the grammar, the resulting parser is also
small.
When optimizing for speed, the JavaScript generator just compiles the
bytecode into JavaScript. The generated code is relatively efficient, so
the resulting parser is fast.
Internal Identifiers
--------------------
As a small bonus, all internal identifiers visible to user code in the
initializer, actions and predicates are prefixed by |peg$|. This lowers
the chance that identifiers in user code will conflict with the ones
from PEG.js. It also makes using any internals in user code ugly, which
is a good thing. This solves GH-92.
Performance
-----------
The new code generator improved parsing speed and parser code size
significantly. The generated parsers are now:
* 39% faster when optimizing for speed
* 69% smaller when optimizing for size (without minification)
* 31% smaller when optimizing for size (with minification)
(Parsing speed was measured using the |benchmark/run| script. Code size
was measured by generating parsers for examples in the |examples|
directory and adding up the file sizes. Minification was done by |uglify
--ascii| in version 1.3.4.)
Final Note
----------
This is just a beginning! The new code generator lays a foundation upon
which many optimizations and improvements can (and will) be made.
Stay tuned :-)
12 years ago
|
|
|
|
|
|
|
// Generates parser JavaScript code.
|
|
|
|
function generateJS(ast, options) {
|
|
|
|
// These only indent non-empty lines to avoid trailing whitespace.
|
|
|
|
function indent2(code) { return code.replace(/^(.+)$/gm, " $1"); }
|
|
|
|
function indent10(code) { return code.replace(/^(.+)$/gm, " $1"); }
|
|
|
|
|
|
|
|
function generateTables() {
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
return [
|
|
|
|
"var peg$consts = [",
|
|
|
|
indent2(ast.consts.join(",\n")),
|
|
|
|
"];",
|
|
|
|
"",
|
|
|
|
"var peg$bytecode = [",
|
|
|
|
indent2(ast.rules.map(rule =>
|
|
|
|
"peg$decode(\""
|
|
|
|
+ js.stringEscape(rule.bytecode.map(
|
|
|
|
b => String.fromCharCode(b + 32)
|
|
|
|
).join(""))
|
|
|
|
+ "\")"
|
|
|
|
).join(",\n")),
|
|
|
|
"];"
|
|
|
|
].join("\n");
|
|
|
|
} else {
|
|
|
|
return ast.consts.map((c, i) => "var peg$c" + i + " = " + c + ";").join("\n");
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateRuleHeader(ruleNameCode, ruleIndexCode) {
|
|
|
|
let parts = [];
|
|
|
|
|
|
|
|
parts.push("");
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push([
|
|
|
|
"peg$tracer.trace({",
|
|
|
|
" type: \"rule.enter\",",
|
|
|
|
" rule: " + ruleNameCode + ",",
|
|
|
|
" location: peg$computeLocation(startPos, startPos)",
|
|
|
|
"});",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
if (options.cache) {
|
|
|
|
parts.push([
|
|
|
|
"var key = peg$currPos * " + ast.rules.length + " + " + ruleIndexCode + ";",
|
|
|
|
"var cached = peg$resultsCache[key];",
|
|
|
|
"",
|
|
|
|
"if (cached) {",
|
|
|
|
" peg$currPos = cached.nextPos;",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push([
|
|
|
|
"if (cached.result !== peg$FAILED) {",
|
|
|
|
" peg$tracer.trace({",
|
|
|
|
" type: \"rule.match\",",
|
|
|
|
" rule: " + ruleNameCode + ",",
|
|
|
|
" result: cached.result,",
|
|
|
|
" location: peg$computeLocation(startPos, peg$currPos)",
|
|
|
|
" });",
|
|
|
|
"} else {",
|
|
|
|
" peg$tracer.trace({",
|
|
|
|
" type: \"rule.fail\",",
|
|
|
|
" rule: " + ruleNameCode + ",",
|
|
|
|
" location: peg$computeLocation(startPos, startPos)",
|
|
|
|
" });",
|
|
|
|
"}",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" return cached.result;",
|
|
|
|
"}",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateRuleFooter(ruleNameCode, resultCode) {
|
|
|
|
let parts = [];
|
|
|
|
|
|
|
|
if (options.cache) {
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
"peg$resultsCache[key] = { nextPos: peg$currPos, result: " + resultCode + " };"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
"if (" + resultCode + " !== peg$FAILED) {",
|
|
|
|
" peg$tracer.trace({",
|
|
|
|
" type: \"rule.match\",",
|
|
|
|
" rule: " + ruleNameCode + ",",
|
|
|
|
" result: " + resultCode + ",",
|
|
|
|
" location: peg$computeLocation(startPos, peg$currPos)",
|
|
|
|
" });",
|
|
|
|
"} else {",
|
|
|
|
" peg$tracer.trace({",
|
|
|
|
" type: \"rule.fail\",",
|
|
|
|
" rule: " + ruleNameCode + ",",
|
|
|
|
" location: peg$computeLocation(startPos, startPos)",
|
|
|
|
" });",
|
|
|
|
"}"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
"return " + resultCode + ";"
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateInterpreter() {
|
|
|
|
let parts = [];
|
|
|
|
|
|
|
|
function generateCondition(cond, argsLength) {
|
|
|
|
let baseLength = argsLength + 3;
|
|
|
|
let thenLengthCode = "bc[ip + " + (baseLength - 2) + "]";
|
|
|
|
let elseLengthCode = "bc[ip + " + (baseLength - 1) + "]";
|
|
|
|
|
|
|
|
return [
|
|
|
|
"ends.push(end);",
|
|
|
|
"ips.push(ip + " + baseLength + " + " + thenLengthCode + " + " + elseLengthCode + ");",
|
|
|
|
"",
|
|
|
|
"if (" + cond + ") {",
|
|
|
|
" end = ip + " + baseLength + " + " + thenLengthCode + ";",
|
|
|
|
" ip += " + baseLength + ";",
|
|
|
|
"} else {",
|
|
|
|
" end = ip + " + baseLength + " + " + thenLengthCode + " + " + elseLengthCode + ";",
|
|
|
|
" ip += " + baseLength + " + " + thenLengthCode + ";",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"break;"
|
|
|
|
].join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateLoop(cond) {
|
|
|
|
let baseLength = 2;
|
|
|
|
let bodyLengthCode = "bc[ip + " + (baseLength - 1) + "]";
|
|
|
|
|
|
|
|
return [
|
|
|
|
"if (" + cond + ") {",
|
|
|
|
" ends.push(end);",
|
|
|
|
" ips.push(ip);",
|
|
|
|
"",
|
|
|
|
" end = ip + " + baseLength + " + " + bodyLengthCode + ";",
|
|
|
|
" ip += " + baseLength + ";",
|
|
|
|
"} else {",
|
|
|
|
" ip += " + baseLength + " + " + bodyLengthCode + ";",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"break;"
|
|
|
|
].join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateCall() {
|
|
|
|
let baseLength = 4;
|
|
|
|
let paramsLengthCode = "bc[ip + " + (baseLength - 1) + "]";
|
|
|
|
|
|
|
|
return [
|
|
|
|
"params = bc.slice(ip + " + baseLength + ", ip + " + baseLength + " + " + paramsLengthCode + ")",
|
|
|
|
" .map(function(p) { return stack[stack.length - 1 - p]; });",
|
|
|
|
"",
|
|
|
|
"stack.splice(",
|
|
|
|
" stack.length - bc[ip + 2],",
|
|
|
|
" bc[ip + 2],",
|
|
|
|
" peg$consts[bc[ip + 1]].apply(null, params)",
|
|
|
|
");",
|
|
|
|
"",
|
|
|
|
"ip += " + baseLength + " + " + paramsLengthCode + ";",
|
|
|
|
"break;"
|
|
|
|
].join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"function peg$decode(s) {",
|
|
|
|
" return s.split(\"\").map(function(ch) { return ch.charCodeAt(0) - 32; });",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"function peg$parseRule(index) {"
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push([
|
|
|
|
" var bc = peg$bytecode[index];",
|
|
|
|
" var ip = 0;",
|
|
|
|
" var ips = [];",
|
|
|
|
" var end = bc.length;",
|
|
|
|
" var ends = [];",
|
|
|
|
" var stack = [];",
|
|
|
|
" var startPos = peg$currPos;",
|
|
|
|
" var params;"
|
|
|
|
].join("\n"));
|
|
|
|
} else {
|
|
|
|
parts.push([
|
|
|
|
" var bc = peg$bytecode[index];",
|
|
|
|
" var ip = 0;",
|
|
|
|
" var ips = [];",
|
|
|
|
" var end = bc.length;",
|
|
|
|
" var ends = [];",
|
|
|
|
" var stack = [];",
|
|
|
|
" var params;"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push(indent2(generateRuleHeader("peg$ruleNames[index]", "index")));
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
// The point of the outer loop and the |ips| & |ends| stacks is to avoid
|
|
|
|
// recursive calls for interpreting parts of bytecode. In other words, we
|
|
|
|
// implement the |interpret| operation of the abstract machine without
|
|
|
|
// function calls. Such calls would likely slow the parser down and more
|
|
|
|
// importantly cause stack overflows for complex grammars.
|
|
|
|
" while (true) {",
|
|
|
|
" while (ip < end) {",
|
|
|
|
" switch (bc[ip]) {",
|
|
|
|
" case " + op.PUSH + ":", // PUSH c
|
|
|
|
" stack.push(peg$consts[bc[ip + 1]]);",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.PUSH_UNDEFINED + ":", // PUSH_UNDEFINED
|
|
|
|
" stack.push(undefined);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.PUSH_NULL + ":", // PUSH_NULL
|
|
|
|
" stack.push(null);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.PUSH_FAILED + ":", // PUSH_FAILED
|
|
|
|
" stack.push(peg$FAILED);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.PUSH_EMPTY_ARRAY + ":", // PUSH_EMPTY_ARRAY
|
|
|
|
" stack.push([]);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.PUSH_CURR_POS + ":", // PUSH_CURR_POS
|
|
|
|
" stack.push(peg$currPos);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.POP + ":", // POP
|
|
|
|
" stack.pop();",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.POP_CURR_POS + ":", // POP_CURR_POS
|
|
|
|
" peg$currPos = stack.pop();",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.POP_N + ":", // POP_N n
|
|
|
|
" stack.length -= bc[ip + 1];",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.NIP + ":", // NIP
|
|
|
|
" stack.splice(-2, 1);",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.APPEND + ":", // APPEND
|
|
|
|
" stack[stack.length - 2].push(stack.pop());",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.WRAP + ":", // WRAP n
|
|
|
|
" stack.push(stack.splice(stack.length - bc[ip + 1], bc[ip + 1]));",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.TEXT + ":", // TEXT
|
|
|
|
" stack.push(input.substring(stack.pop(), peg$currPos));",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.IF + ":", // IF t, f
|
|
|
|
indent10(generateCondition("stack[stack.length - 1]", 0)),
|
|
|
|
"",
|
|
|
|
" case " + op.IF_ERROR + ":", // IF_ERROR t, f
|
|
|
|
indent10(generateCondition(
|
|
|
|
"stack[stack.length - 1] === peg$FAILED",
|
|
|
|
0
|
|
|
|
)),
|
|
|
|
"",
|
|
|
|
" case " + op.IF_NOT_ERROR + ":", // IF_NOT_ERROR t, f
|
|
|
|
indent10(
|
|
|
|
generateCondition("stack[stack.length - 1] !== peg$FAILED",
|
|
|
|
0
|
|
|
|
)),
|
|
|
|
"",
|
|
|
|
" case " + op.WHILE_NOT_ERROR + ":", // WHILE_NOT_ERROR b
|
|
|
|
indent10(generateLoop("stack[stack.length - 1] !== peg$FAILED")),
|
|
|
|
"",
|
|
|
|
" case " + op.MATCH_ANY + ":", // MATCH_ANY a, f, ...
|
|
|
|
indent10(generateCondition("input.length > peg$currPos", 0)),
|
|
|
|
"",
|
|
|
|
" case " + op.MATCH_STRING + ":", // MATCH_STRING s, a, f, ...
|
|
|
|
indent10(generateCondition(
|
|
|
|
"input.substr(peg$currPos, peg$consts[bc[ip + 1]].length) === peg$consts[bc[ip + 1]]",
|
|
|
|
1
|
|
|
|
)),
|
|
|
|
"",
|
|
|
|
" case " + op.MATCH_STRING_IC + ":", // MATCH_STRING_IC s, a, f, ...
|
|
|
|
indent10(generateCondition(
|
|
|
|
"input.substr(peg$currPos, peg$consts[bc[ip + 1]].length).toLowerCase() === peg$consts[bc[ip + 1]]",
|
|
|
|
1
|
|
|
|
)),
|
|
|
|
"",
|
|
|
|
" case " + op.MATCH_REGEXP + ":", // MATCH_REGEXP r, a, f, ...
|
|
|
|
indent10(generateCondition(
|
|
|
|
"peg$consts[bc[ip + 1]].test(input.charAt(peg$currPos))",
|
|
|
|
1
|
|
|
|
)),
|
|
|
|
"",
|
|
|
|
" case " + op.ACCEPT_N + ":", // ACCEPT_N n
|
|
|
|
" stack.push(input.substr(peg$currPos, bc[ip + 1]));",
|
|
|
|
" peg$currPos += bc[ip + 1];",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.ACCEPT_STRING + ":", // ACCEPT_STRING s
|
|
|
|
" stack.push(peg$consts[bc[ip + 1]]);",
|
|
|
|
" peg$currPos += peg$consts[bc[ip + 1]].length;",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.FAIL + ":", // FAIL e
|
|
|
|
" stack.push(peg$FAILED);",
|
|
|
|
" if (peg$silentFails === 0) {",
|
|
|
|
" peg$fail(peg$consts[bc[ip + 1]]);",
|
|
|
|
" }",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.LOAD_SAVED_POS + ":", // LOAD_SAVED_POS p
|
|
|
|
" peg$savedPos = stack[stack.length - 1 - bc[ip + 1]];",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.UPDATE_SAVED_POS + ":", // UPDATE_SAVED_POS
|
|
|
|
" peg$savedPos = peg$currPos;",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.CALL + ":", // CALL f, n, pc, p1, p2, ..., pN
|
|
|
|
indent10(generateCall()),
|
|
|
|
"",
|
|
|
|
" case " + op.RULE + ":", // RULE r
|
|
|
|
" stack.push(peg$parseRule(bc[ip + 1]));",
|
|
|
|
" ip += 2;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.SILENT_FAILS_ON + ":", // SILENT_FAILS_ON
|
|
|
|
" peg$silentFails++;",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case " + op.SILENT_FAILS_OFF + ":", // SILENT_FAILS_OFF
|
|
|
|
" peg$silentFails--;",
|
|
|
|
" ip++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" default:",
|
|
|
|
" throw new Error(\"Invalid opcode: \" + bc[ip] + \".\");",
|
|
|
|
" }",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" if (ends.length > 0) {",
|
|
|
|
" end = ends.pop();",
|
|
|
|
" ip = ips.pop();",
|
|
|
|
" } else {",
|
|
|
|
" break;",
|
|
|
|
" }",
|
|
|
|
" }"
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
parts.push(indent2(generateRuleFooter("peg$ruleNames[index]", "stack[0]")));
|
|
|
|
parts.push("}");
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateRuleFunction(rule) {
|
|
|
|
let parts = [];
|
|
|
|
let stackVars = [];
|
|
|
|
let code;
|
|
|
|
|
|
|
|
function c(i) { return "peg$c" + i; } // |consts[i]| of the abstract machine
|
|
|
|
function s(i) { return "s" + i; } // |stack[i]| of the abstract machine
|
|
|
|
|
|
|
|
let stack = {
|
|
|
|
sp: -1,
|
|
|
|
maxSp: -1,
|
|
|
|
|
|
|
|
push(exprCode) {
|
|
|
|
let code = s(++this.sp) + " = " + exprCode + ";";
|
|
|
|
|
|
|
|
if (this.sp > this.maxSp) { this.maxSp = this.sp; }
|
|
|
|
|
|
|
|
return code;
|
|
|
|
},
|
|
|
|
|
|
|
|
pop(n) {
|
|
|
|
if (n === undefined) {
|
|
|
|
return s(this.sp--);
|
|
|
|
} else {
|
|
|
|
let values = Array(n);
|
|
|
|
|
|
|
|
for (let i = 0; i < n; i++) {
|
|
|
|
values[i] = s(this.sp - n + 1 + i);
|
|
|
|
}
|
|
|
|
|
|
|
|
this.sp -= n;
|
|
|
|
|
|
|
|
return values;
|
|
|
|
}
|
|
|
|
},
|
|
|
|
|
|
|
|
top() {
|
|
|
|
return s(this.sp);
|
|
|
|
},
|
|
|
|
|
|
|
|
index(i) {
|
|
|
|
return s(this.sp - i);
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
function compile(bc) {
|
|
|
|
let ip = 0;
|
|
|
|
let end = bc.length;
|
|
|
|
let parts = [];
|
|
|
|
let value;
|
|
|
|
|
|
|
|
function compileCondition(cond, argCount) {
|
|
|
|
let baseLength = argCount + 3;
|
|
|
|
let thenLength = bc[ip + baseLength - 2];
|
|
|
|
let elseLength = bc[ip + baseLength - 1];
|
|
|
|
let baseSp = stack.sp;
|
|
|
|
let thenCode, elseCode, thenSp, elseSp;
|
|
|
|
|
|
|
|
ip += baseLength;
|
|
|
|
thenCode = compile(bc.slice(ip, ip + thenLength));
|
|
|
|
thenSp = stack.sp;
|
|
|
|
ip += thenLength;
|
|
|
|
|
|
|
|
if (elseLength > 0) {
|
|
|
|
stack.sp = baseSp;
|
|
|
|
elseCode = compile(bc.slice(ip, ip + elseLength));
|
|
|
|
elseSp = stack.sp;
|
|
|
|
ip += elseLength;
|
|
|
|
|
|
|
|
if (thenSp !== elseSp) {
|
|
|
|
throw new Error(
|
|
|
|
"Branches of a condition must move the stack pointer in the same way."
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push("if (" + cond + ") {");
|
|
|
|
parts.push(indent2(thenCode));
|
|
|
|
if (elseLength > 0) {
|
|
|
|
parts.push("} else {");
|
|
|
|
parts.push(indent2(elseCode));
|
|
|
|
}
|
|
|
|
parts.push("}");
|
|
|
|
}
|
|
|
|
|
|
|
|
function compileLoop(cond) {
|
|
|
|
let baseLength = 2;
|
|
|
|
let bodyLength = bc[ip + baseLength - 1];
|
|
|
|
let baseSp = stack.sp;
|
|
|
|
let bodyCode, bodySp;
|
|
|
|
|
|
|
|
ip += baseLength;
|
|
|
|
bodyCode = compile(bc.slice(ip, ip + bodyLength));
|
|
|
|
bodySp = stack.sp;
|
|
|
|
ip += bodyLength;
|
|
|
|
|
|
|
|
if (bodySp !== baseSp) {
|
|
|
|
throw new Error("Body of a loop can't move the stack pointer.");
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push("while (" + cond + ") {");
|
|
|
|
parts.push(indent2(bodyCode));
|
|
|
|
parts.push("}");
|
|
|
|
}
|
|
|
|
|
|
|
|
function compileCall() {
|
|
|
|
let baseLength = 4;
|
|
|
|
let paramsLength = bc[ip + baseLength - 1];
|
|
|
|
|
|
|
|
let value = c(bc[ip + 1]) + "("
|
|
|
|
+ bc.slice(ip + baseLength, ip + baseLength + paramsLength).map(
|
|
|
|
p => stack.index(p)
|
|
|
|
).join(", ")
|
|
|
|
+ ")";
|
|
|
|
stack.pop(bc[ip + 2]);
|
|
|
|
parts.push(stack.push(value));
|
|
|
|
ip += baseLength + paramsLength;
|
|
|
|
}
|
|
|
|
|
|
|
|
while (ip < end) {
|
|
|
|
switch (bc[ip]) {
|
|
|
|
case op.PUSH: // PUSH c
|
|
|
|
parts.push(stack.push(c(bc[ip + 1])));
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.PUSH_CURR_POS: // PUSH_CURR_POS
|
|
|
|
parts.push(stack.push("peg$currPos"));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.PUSH_UNDEFINED: // PUSH_UNDEFINED
|
|
|
|
parts.push(stack.push("undefined"));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.PUSH_NULL: // PUSH_NULL
|
|
|
|
parts.push(stack.push("null"));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.PUSH_FAILED: // PUSH_FAILED
|
|
|
|
parts.push(stack.push("peg$FAILED"));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.PUSH_EMPTY_ARRAY: // PUSH_EMPTY_ARRAY
|
|
|
|
parts.push(stack.push("[]"));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.POP: // POP
|
|
|
|
stack.pop();
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.POP_CURR_POS: // POP_CURR_POS
|
|
|
|
parts.push("peg$currPos = " + stack.pop() + ";");
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.POP_N: // POP_N n
|
|
|
|
stack.pop(bc[ip + 1]);
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.NIP: // NIP
|
|
|
|
value = stack.pop();
|
|
|
|
stack.pop();
|
|
|
|
parts.push(stack.push(value));
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.APPEND: // APPEND
|
|
|
|
value = stack.pop();
|
|
|
|
parts.push(stack.top() + ".push(" + value + ");");
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.WRAP: // WRAP n
|
|
|
|
parts.push(
|
|
|
|
stack.push("[" + stack.pop(bc[ip + 1]).join(", ") + "]")
|
|
|
|
);
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.TEXT: // TEXT
|
|
|
|
parts.push(
|
|
|
|
stack.push("input.substring(" + stack.pop() + ", peg$currPos)")
|
|
|
|
);
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.IF: // IF t, f
|
|
|
|
compileCondition(stack.top(), 0);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.IF_ERROR: // IF_ERROR t, f
|
|
|
|
compileCondition(stack.top() + " === peg$FAILED", 0);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.IF_NOT_ERROR: // IF_NOT_ERROR t, f
|
|
|
|
compileCondition(stack.top() + " !== peg$FAILED", 0);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.WHILE_NOT_ERROR: // WHILE_NOT_ERROR b
|
|
|
|
compileLoop(stack.top() + " !== peg$FAILED", 0);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.MATCH_ANY: // MATCH_ANY a, f, ...
|
|
|
|
compileCondition("input.length > peg$currPos", 0);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.MATCH_STRING: // MATCH_STRING s, a, f, ...
|
|
|
|
compileCondition(
|
|
|
|
eval(ast.consts[bc[ip + 1]]).length > 1
|
|
|
|
? "input.substr(peg$currPos, "
|
Code generator rewrite
This is a complete rewrite of the PEG.js code generator. Its goals are:
1. Allow optimizing the generated parser code for code size as well as
for parsing speed.
2. Prepare ground for future optimizations and big features (like
incremental parsing).
2. Replace the old template-based code-generation system with
something more lightweight and flexible.
4. General code cleanup (structure, style, variable names, ...).
New Architecture
----------------
The new code generator consists of two steps:
* Bytecode generator -- produces bytecode for an abstract virtual
machine
* JavaScript generator -- produces JavaScript code based on the
bytecode
The abstract virtual machine is stack-based. Originally I wanted to make
it register-based, but it turned out that all the code related to it
would be more complex and the bytecode itself would be longer (because
of explicit register specifications in instructions). The only downsides
of the stack-based approach seem to be few small inefficiencies (see
e.g. the |NIP| instruction), which seem to be insignificant.
The new generator allows optimizing for parsing speed or code size (you
can choose using the |optimize| option of the |PEG.buildParser| method
or the --optimize/-o option on the command-line).
When optimizing for size, the JavaScript generator emits the bytecode
together with its constant table and a generic bytecode interpreter.
Because the interpreter is small and the bytecode and constant table
grow only slowly with size of the grammar, the resulting parser is also
small.
When optimizing for speed, the JavaScript generator just compiles the
bytecode into JavaScript. The generated code is relatively efficient, so
the resulting parser is fast.
Internal Identifiers
--------------------
As a small bonus, all internal identifiers visible to user code in the
initializer, actions and predicates are prefixed by |peg$|. This lowers
the chance that identifiers in user code will conflict with the ones
from PEG.js. It also makes using any internals in user code ugly, which
is a good thing. This solves GH-92.
Performance
-----------
The new code generator improved parsing speed and parser code size
significantly. The generated parsers are now:
* 39% faster when optimizing for speed
* 69% smaller when optimizing for size (without minification)
* 31% smaller when optimizing for size (with minification)
(Parsing speed was measured using the |benchmark/run| script. Code size
was measured by generating parsers for examples in the |examples|
directory and adding up the file sizes. Minification was done by |uglify
--ascii| in version 1.3.4.)
Final Note
----------
This is just a beginning! The new code generator lays a foundation upon
which many optimizations and improvements can (and will) be made.
Stay tuned :-)
12 years ago
|
|
|
+ eval(ast.consts[bc[ip + 1]]).length
|
|
|
|
+ ") === "
|
Code generator rewrite
This is a complete rewrite of the PEG.js code generator. Its goals are:
1. Allow optimizing the generated parser code for code size as well as
for parsing speed.
2. Prepare ground for future optimizations and big features (like
incremental parsing).
2. Replace the old template-based code-generation system with
something more lightweight and flexible.
4. General code cleanup (structure, style, variable names, ...).
New Architecture
----------------
The new code generator consists of two steps:
* Bytecode generator -- produces bytecode for an abstract virtual
machine
* JavaScript generator -- produces JavaScript code based on the
bytecode
The abstract virtual machine is stack-based. Originally I wanted to make
it register-based, but it turned out that all the code related to it
would be more complex and the bytecode itself would be longer (because
of explicit register specifications in instructions). The only downsides
of the stack-based approach seem to be few small inefficiencies (see
e.g. the |NIP| instruction), which seem to be insignificant.
The new generator allows optimizing for parsing speed or code size (you
can choose using the |optimize| option of the |PEG.buildParser| method
or the --optimize/-o option on the command-line).
When optimizing for size, the JavaScript generator emits the bytecode
together with its constant table and a generic bytecode interpreter.
Because the interpreter is small and the bytecode and constant table
grow only slowly with size of the grammar, the resulting parser is also
small.
When optimizing for speed, the JavaScript generator just compiles the
bytecode into JavaScript. The generated code is relatively efficient, so
the resulting parser is fast.
Internal Identifiers
--------------------
As a small bonus, all internal identifiers visible to user code in the
initializer, actions and predicates are prefixed by |peg$|. This lowers
the chance that identifiers in user code will conflict with the ones
from PEG.js. It also makes using any internals in user code ugly, which
is a good thing. This solves GH-92.
Performance
-----------
The new code generator improved parsing speed and parser code size
significantly. The generated parsers are now:
* 39% faster when optimizing for speed
* 69% smaller when optimizing for size (without minification)
* 31% smaller when optimizing for size (with minification)
(Parsing speed was measured using the |benchmark/run| script. Code size
was measured by generating parsers for examples in the |examples|
directory and adding up the file sizes. Minification was done by |uglify
--ascii| in version 1.3.4.)
Final Note
----------
This is just a beginning! The new code generator lays a foundation upon
which many optimizations and improvements can (and will) be made.
Stay tuned :-)
12 years ago
|
|
|
+ c(bc[ip + 1])
|
|
|
|
: "input.charCodeAt(peg$currPos) === "
|
Code generator rewrite
This is a complete rewrite of the PEG.js code generator. Its goals are:
1. Allow optimizing the generated parser code for code size as well as
for parsing speed.
2. Prepare ground for future optimizations and big features (like
incremental parsing).
2. Replace the old template-based code-generation system with
something more lightweight and flexible.
4. General code cleanup (structure, style, variable names, ...).
New Architecture
----------------
The new code generator consists of two steps:
* Bytecode generator -- produces bytecode for an abstract virtual
machine
* JavaScript generator -- produces JavaScript code based on the
bytecode
The abstract virtual machine is stack-based. Originally I wanted to make
it register-based, but it turned out that all the code related to it
would be more complex and the bytecode itself would be longer (because
of explicit register specifications in instructions). The only downsides
of the stack-based approach seem to be few small inefficiencies (see
e.g. the |NIP| instruction), which seem to be insignificant.
The new generator allows optimizing for parsing speed or code size (you
can choose using the |optimize| option of the |PEG.buildParser| method
or the --optimize/-o option on the command-line).
When optimizing for size, the JavaScript generator emits the bytecode
together with its constant table and a generic bytecode interpreter.
Because the interpreter is small and the bytecode and constant table
grow only slowly with size of the grammar, the resulting parser is also
small.
When optimizing for speed, the JavaScript generator just compiles the
bytecode into JavaScript. The generated code is relatively efficient, so
the resulting parser is fast.
Internal Identifiers
--------------------
As a small bonus, all internal identifiers visible to user code in the
initializer, actions and predicates are prefixed by |peg$|. This lowers
the chance that identifiers in user code will conflict with the ones
from PEG.js. It also makes using any internals in user code ugly, which
is a good thing. This solves GH-92.
Performance
-----------
The new code generator improved parsing speed and parser code size
significantly. The generated parsers are now:
* 39% faster when optimizing for speed
* 69% smaller when optimizing for size (without minification)
* 31% smaller when optimizing for size (with minification)
(Parsing speed was measured using the |benchmark/run| script. Code size
was measured by generating parsers for examples in the |examples|
directory and adding up the file sizes. Minification was done by |uglify
--ascii| in version 1.3.4.)
Final Note
----------
This is just a beginning! The new code generator lays a foundation upon
which many optimizations and improvements can (and will) be made.
Stay tuned :-)
12 years ago
|
|
|
+ eval(ast.consts[bc[ip + 1]]).charCodeAt(0),
|
|
|
|
1
|
|
|
|
);
|
|
|
|
break;
|
Code generator rewrite
This is a complete rewrite of the PEG.js code generator. Its goals are:
1. Allow optimizing the generated parser code for code size as well as
for parsing speed.
2. Prepare ground for future optimizations and big features (like
incremental parsing).
2. Replace the old template-based code-generation system with
something more lightweight and flexible.
4. General code cleanup (structure, style, variable names, ...).
New Architecture
----------------
The new code generator consists of two steps:
* Bytecode generator -- produces bytecode for an abstract virtual
machine
* JavaScript generator -- produces JavaScript code based on the
bytecode
The abstract virtual machine is stack-based. Originally I wanted to make
it register-based, but it turned out that all the code related to it
would be more complex and the bytecode itself would be longer (because
of explicit register specifications in instructions). The only downsides
of the stack-based approach seem to be few small inefficiencies (see
e.g. the |NIP| instruction), which seem to be insignificant.
The new generator allows optimizing for parsing speed or code size (you
can choose using the |optimize| option of the |PEG.buildParser| method
or the --optimize/-o option on the command-line).
When optimizing for size, the JavaScript generator emits the bytecode
together with its constant table and a generic bytecode interpreter.
Because the interpreter is small and the bytecode and constant table
grow only slowly with size of the grammar, the resulting parser is also
small.
When optimizing for speed, the JavaScript generator just compiles the
bytecode into JavaScript. The generated code is relatively efficient, so
the resulting parser is fast.
Internal Identifiers
--------------------
As a small bonus, all internal identifiers visible to user code in the
initializer, actions and predicates are prefixed by |peg$|. This lowers
the chance that identifiers in user code will conflict with the ones
from PEG.js. It also makes using any internals in user code ugly, which
is a good thing. This solves GH-92.
Performance
-----------
The new code generator improved parsing speed and parser code size
significantly. The generated parsers are now:
* 39% faster when optimizing for speed
* 69% smaller when optimizing for size (without minification)
* 31% smaller when optimizing for size (with minification)
(Parsing speed was measured using the |benchmark/run| script. Code size
was measured by generating parsers for examples in the |examples|
directory and adding up the file sizes. Minification was done by |uglify
--ascii| in version 1.3.4.)
Final Note
----------
This is just a beginning! The new code generator lays a foundation upon
which many optimizations and improvements can (and will) be made.
Stay tuned :-)
12 years ago
|
|
|
|
|
|
|
case op.MATCH_STRING_IC: // MATCH_STRING_IC s, a, f, ...
|
|
|
|
compileCondition(
|
|
|
|
"input.substr(peg$currPos, "
|
|
|
|
+ eval(ast.consts[bc[ip + 1]]).length
|
|
|
|
+ ").toLowerCase() === "
|
|
|
|
+ c(bc[ip + 1]),
|
|
|
|
1
|
|
|
|
);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.MATCH_REGEXP: // MATCH_REGEXP r, a, f, ...
|
|
|
|
compileCondition(
|
|
|
|
c(bc[ip + 1]) + ".test(input.charAt(peg$currPos))",
|
|
|
|
1
|
|
|
|
);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.ACCEPT_N: // ACCEPT_N n
|
|
|
|
parts.push(stack.push(
|
|
|
|
bc[ip + 1] > 1
|
|
|
|
? "input.substr(peg$currPos, " + bc[ip + 1] + ")"
|
|
|
|
: "input.charAt(peg$currPos)"
|
|
|
|
));
|
|
|
|
parts.push(
|
|
|
|
bc[ip + 1] > 1
|
|
|
|
? "peg$currPos += " + bc[ip + 1] + ";"
|
|
|
|
: "peg$currPos++;"
|
|
|
|
);
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.ACCEPT_STRING: // ACCEPT_STRING s
|
|
|
|
parts.push(stack.push(c(bc[ip + 1])));
|
|
|
|
parts.push(
|
|
|
|
eval(ast.consts[bc[ip + 1]]).length > 1
|
|
|
|
? "peg$currPos += " + eval(ast.consts[bc[ip + 1]]).length + ";"
|
|
|
|
: "peg$currPos++;"
|
|
|
|
);
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.FAIL: // FAIL e
|
|
|
|
parts.push(stack.push("peg$FAILED"));
|
|
|
|
parts.push("if (peg$silentFails === 0) { peg$fail(" + c(bc[ip + 1]) + "); }");
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.LOAD_SAVED_POS: // LOAD_SAVED_POS p
|
|
|
|
parts.push("peg$savedPos = " + stack.index(bc[ip + 1]) + ";");
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.UPDATE_SAVED_POS: // UPDATE_SAVED_POS
|
|
|
|
parts.push("peg$savedPos = peg$currPos;");
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.CALL: // CALL f, n, pc, p1, p2, ..., pN
|
|
|
|
compileCall();
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.RULE: // RULE r
|
|
|
|
parts.push(stack.push("peg$parse" + ast.rules[bc[ip + 1]].name + "()"));
|
|
|
|
ip += 2;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.SILENT_FAILS_ON: // SILENT_FAILS_ON
|
|
|
|
parts.push("peg$silentFails++;");
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case op.SILENT_FAILS_OFF: // SILENT_FAILS_OFF
|
|
|
|
parts.push("peg$silentFails--;");
|
|
|
|
ip++;
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
throw new Error("Invalid opcode: " + bc[ip] + ".");
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
code = compile(rule.bytecode);
|
|
|
|
|
|
|
|
parts.push("function peg$parse" + rule.name + "() {");
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push(" var startPos = peg$currPos;");
|
|
|
|
}
|
|
|
|
|
|
|
|
for (let i = 0; i <= stack.maxSp; i++) {
|
|
|
|
stackVars[i] = s(i);
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push(" var " + stackVars.join(", ") + ";");
|
|
|
|
|
|
|
|
parts.push(indent2(generateRuleHeader(
|
|
|
|
"\"" + js.stringEscape(rule.name) + "\"",
|
|
|
|
asts.indexOfRule(ast, rule.name)
|
|
|
|
)));
|
|
|
|
parts.push(indent2(code));
|
|
|
|
parts.push(indent2(generateRuleFooter(
|
|
|
|
"\"" + js.stringEscape(rule.name) + "\"",
|
|
|
|
s(0)
|
|
|
|
)));
|
|
|
|
|
|
|
|
parts.push("}");
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateToplevel() {
|
|
|
|
let parts = [];
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"function peg$subclass(child, parent) {",
|
|
|
|
" function C() { this.constructor = child; }",
|
|
|
|
" C.prototype = parent.prototype;",
|
|
|
|
" child.prototype = new C();",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"function peg$SyntaxError(message, expected, found, location) {",
|
|
|
|
" this.message = message;",
|
|
|
|
" this.expected = expected;",
|
|
|
|
" this.found = found;",
|
|
|
|
" this.location = location;",
|
|
|
|
" this.name = \"SyntaxError\";",
|
|
|
|
"",
|
|
|
|
" if (typeof Error.captureStackTrace === \"function\") {",
|
|
|
|
" Error.captureStackTrace(this, peg$SyntaxError);",
|
|
|
|
" }",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"peg$subclass(peg$SyntaxError, Error);",
|
|
|
|
"",
|
|
|
|
"peg$SyntaxError.buildMessage = function(expected, found) {",
|
|
|
|
" var DESCRIBE_EXPECTATION_FNS = {",
|
|
|
|
" literal: function(expectation) {",
|
|
|
|
" return \"\\\"\" + literalEscape(expectation.text) + \"\\\"\";",
|
|
|
|
" },",
|
|
|
|
"",
|
|
|
|
" class: function(expectation) {",
|
|
|
|
" var escapedParts = expectation.parts.map(function(part) {",
|
|
|
|
" return Array.isArray(part)",
|
|
|
|
" ? classEscape(part[0]) + \"-\" + classEscape(part[1])",
|
|
|
|
" : classEscape(part);",
|
|
|
|
" });",
|
|
|
|
"",
|
|
|
|
" return \"[\" + (expectation.inverted ? \"^\" : \"\") + escapedParts + \"]\";",
|
|
|
|
" },",
|
|
|
|
"",
|
|
|
|
" any: function() {",
|
|
|
|
" return \"any character\";",
|
|
|
|
" },",
|
|
|
|
"",
|
|
|
|
" end: function() {",
|
|
|
|
" return \"end of input\";",
|
|
|
|
" },",
|
|
|
|
"",
|
|
|
|
" other: function(expectation) {",
|
|
|
|
" return expectation.description;",
|
|
|
|
" }",
|
|
|
|
" };",
|
|
|
|
"",
|
|
|
|
" function hex(ch) {",
|
|
|
|
" return ch.charCodeAt(0).toString(16).toUpperCase();",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function literalEscape(s) {",
|
|
|
|
" return s",
|
|
|
|
" .replace(/\\\\/g, \"\\\\\\\\\")", // backslash
|
|
|
|
" .replace(/\"/g, \"\\\\\\\"\")", // closing double quote
|
|
|
|
" .replace(/\\0/g, \"\\\\0\")", // null
|
|
|
|
" .replace(/\\t/g, \"\\\\t\")", // horizontal tab
|
|
|
|
" .replace(/\\n/g, \"\\\\n\")", // line feed
|
|
|
|
" .replace(/\\r/g, \"\\\\r\")", // carriage return
|
|
|
|
" .replace(/[\\x00-\\x0F]/g, function(ch) { return \"\\\\x0\" + hex(ch); })",
|
|
|
|
" .replace(/[\\x10-\\x1F\\x7F-\\x9F]/g, function(ch) { return \"\\\\x\" + hex(ch); });",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function classEscape(s) {",
|
|
|
|
" return s",
|
|
|
|
" .replace(/\\\\/g, \"\\\\\\\\\")", // backslash
|
|
|
|
" .replace(/\\]/g, \"\\\\]\")", // closing bracket
|
|
|
|
" .replace(/\\^/g, \"\\\\^\")", // caret
|
|
|
|
" .replace(/-/g, \"\\\\-\")", // dash
|
|
|
|
" .replace(/\\0/g, \"\\\\0\")", // null
|
|
|
|
" .replace(/\\t/g, \"\\\\t\")", // horizontal tab
|
|
|
|
" .replace(/\\n/g, \"\\\\n\")", // line feed
|
|
|
|
" .replace(/\\r/g, \"\\\\r\")", // carriage return
|
|
|
|
" .replace(/[\\x00-\\x0F]/g, function(ch) { return \"\\\\x0\" + hex(ch); })",
|
|
|
|
" .replace(/[\\x10-\\x1F\\x7F-\\x9F]/g, function(ch) { return \"\\\\x\" + hex(ch); });",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function describeExpectation(expectation) {",
|
|
|
|
" return DESCRIBE_EXPECTATION_FNS[expectation.type](expectation);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function describeExpected(expected) {",
|
|
|
|
" var descriptions = expected.map(describeExpectation);",
|
|
|
|
" var i, j;",
|
|
|
|
"",
|
|
|
|
" descriptions.sort();",
|
|
|
|
"",
|
|
|
|
" if (descriptions.length > 0) {",
|
|
|
|
" for (i = 1, j = 1; i < descriptions.length; i++) {",
|
|
|
|
" if (descriptions[i - 1] !== descriptions[i]) {",
|
|
|
|
" descriptions[j] = descriptions[i];",
|
|
|
|
" j++;",
|
|
|
|
" }",
|
|
|
|
" }",
|
|
|
|
" descriptions.length = j;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" switch (descriptions.length) {",
|
|
|
|
" case 1:",
|
|
|
|
" return descriptions[0];",
|
|
|
|
"",
|
|
|
|
" case 2:",
|
|
|
|
" return descriptions[0] + \" or \" + descriptions[1];",
|
|
|
|
"",
|
|
|
|
" default:",
|
|
|
|
" return descriptions.slice(0, -1).join(\", \")",
|
|
|
|
" + \", or \"",
|
|
|
|
" + descriptions[descriptions.length - 1];",
|
|
|
|
" }",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function describeFound(found) {",
|
|
|
|
" return found ? \"\\\"\" + literalEscape(found) + \"\\\"\" : \"end of input\";",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" return \"Expected \" + describeExpected(expected) + \" but \" + describeFound(found) + \" found.\";",
|
|
|
|
"};",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
parts.push([
|
|
|
|
"function peg$DefaultTracer() {",
|
|
|
|
" this.indentLevel = 0;",
|
|
|
|
"}",
|
|
|
|
"",
|
|
|
|
"peg$DefaultTracer.prototype.trace = function(event) {",
|
|
|
|
" var that = this;",
|
|
|
|
"",
|
|
|
|
" function log(event) {",
|
|
|
|
" function repeat(string, n) {",
|
|
|
|
" var result = \"\", i;",
|
|
|
|
"",
|
|
|
|
" for (i = 0; i < n; i++) {",
|
|
|
|
" result += string;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" return result;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function pad(string, length) {",
|
|
|
|
" return string + repeat(\" \", length - string.length);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" if (typeof console === \"object\") {", // IE 8-10
|
|
|
|
" console.log(",
|
|
|
|
" event.location.start.line + \":\" + event.location.start.column + \"-\"",
|
|
|
|
" + event.location.end.line + \":\" + event.location.end.column + \" \"",
|
|
|
|
" + pad(event.type, 10) + \" \"",
|
|
|
|
" + repeat(\" \", that.indentLevel) + event.rule",
|
|
|
|
" );",
|
|
|
|
" }",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" switch (event.type) {",
|
|
|
|
" case \"rule.enter\":",
|
|
|
|
" log(event);",
|
|
|
|
" this.indentLevel++;",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case \"rule.match\":",
|
|
|
|
" this.indentLevel--;",
|
|
|
|
" log(event);",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" case \"rule.fail\":",
|
|
|
|
" this.indentLevel--;",
|
|
|
|
" log(event);",
|
|
|
|
" break;",
|
|
|
|
"",
|
|
|
|
" default:",
|
|
|
|
" throw new Error(\"Invalid event type: \" + event.type + \".\");",
|
|
|
|
" }",
|
|
|
|
"};",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"function peg$parse(input, options) {",
|
|
|
|
" options = options !== undefined ? options : {};",
|
|
|
|
"",
|
|
|
|
" var peg$FAILED = {};",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
let startRuleIndices = "{ "
|
|
|
|
+ options.allowedStartRules.map(
|
|
|
|
r => r + ": " + asts.indexOfRule(ast, r)
|
|
|
|
).join(", ")
|
|
|
|
+ " }";
|
|
|
|
let startRuleIndex = asts.indexOfRule(ast, options.allowedStartRules[0]);
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" var peg$startRuleIndices = " + startRuleIndices + ";",
|
|
|
|
" var peg$startRuleIndex = " + startRuleIndex + ";"
|
|
|
|
].join("\n"));
|
|
|
|
} else {
|
|
|
|
let startRuleFunctions = "{ "
|
|
|
|
+ options.allowedStartRules.map(
|
|
|
|
r => r + ": peg$parse" + r
|
|
|
|
).join(", ")
|
|
|
|
+ " }";
|
|
|
|
let startRuleFunction = "peg$parse" + options.allowedStartRules[0];
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" var peg$startRuleFunctions = " + startRuleFunctions + ";",
|
|
|
|
" var peg$startRuleFunction = " + startRuleFunction + ";"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push("");
|
|
|
|
|
|
|
|
parts.push(indent2(generateTables()));
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
" var peg$currPos = 0;",
|
|
|
|
" var peg$savedPos = 0;",
|
|
|
|
" var peg$posDetailsCache = [{ line: 1, column: 1 }];",
|
|
|
|
" var peg$maxFailPos = 0;",
|
|
|
|
" var peg$maxFailExpected = [];",
|
|
|
|
" var peg$silentFails = 0;", // 0 = report failures, > 0 = silence failures
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.cache) {
|
|
|
|
parts.push([
|
|
|
|
" var peg$resultsCache = {};",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
if (options.trace) {
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
let ruleNames = "["
|
|
|
|
+ ast.rules.map(
|
|
|
|
r => "\"" + js.stringEscape(r.name) + "\""
|
|
|
|
).join(", ")
|
|
|
|
+ "]";
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" var peg$ruleNames = " + ruleNames + ";",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" var peg$tracer = \"tracer\" in options ? options.tracer : new peg$DefaultTracer();",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" var peg$result;",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
parts.push([
|
|
|
|
" if (\"startRule\" in options) {",
|
|
|
|
" if (!(options.startRule in peg$startRuleIndices)) {",
|
|
|
|
" throw new Error(\"Can't start parsing from rule \\\"\" + options.startRule + \"\\\".\");",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" peg$startRuleIndex = peg$startRuleIndices[options.startRule];",
|
|
|
|
" }"
|
|
|
|
].join("\n"));
|
|
|
|
} else {
|
|
|
|
parts.push([
|
|
|
|
" if (\"startRule\" in options) {",
|
|
|
|
" if (!(options.startRule in peg$startRuleFunctions)) {",
|
|
|
|
" throw new Error(\"Can't start parsing from rule \\\"\" + options.startRule + \"\\\".\");",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" peg$startRuleFunction = peg$startRuleFunctions[options.startRule];",
|
|
|
|
" }"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
" function text() {",
|
|
|
|
" return input.substring(peg$savedPos, peg$currPos);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function location() {",
|
|
|
|
" return peg$computeLocation(peg$savedPos, peg$currPos);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function expected(description, location) {",
|
|
|
|
" location = location !== undefined",
|
|
|
|
" ? location",
|
|
|
|
" : peg$computeLocation(peg$savedPos, peg$currPos);",
|
|
|
|
"",
|
|
|
|
" throw peg$buildStructuredError(",
|
|
|
|
" [peg$otherExpectation(description)],",
|
|
|
|
" input.substring(peg$savedPos, peg$currPos),",
|
|
|
|
" location",
|
|
|
|
" );",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function error(message, location) {",
|
|
|
|
" location = location !== undefined",
|
|
|
|
" ? location",
|
|
|
|
" : peg$computeLocation(peg$savedPos, peg$currPos);",
|
|
|
|
"",
|
|
|
|
" throw peg$buildSimpleError(message, location);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$literalExpectation(text, ignoreCase) {",
|
|
|
|
" return { type: \"literal\", text: text, ignoreCase: ignoreCase };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$classExpectation(parts, inverted, ignoreCase) {",
|
|
|
|
" return { type: \"class\", parts: parts, inverted: inverted, ignoreCase: ignoreCase };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$anyExpectation() {",
|
|
|
|
" return { type: \"any\" };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$endExpectation() {",
|
|
|
|
" return { type: \"end\" };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$otherExpectation(description) {",
|
|
|
|
" return { type: \"other\", description: description };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$computePosDetails(pos) {",
|
|
|
|
" var details = peg$posDetailsCache[pos];",
|
|
|
|
" var p;",
|
|
|
|
"",
|
|
|
|
" if (details) {",
|
|
|
|
" return details;",
|
|
|
|
" } else {",
|
|
|
|
" p = pos - 1;",
|
|
|
|
" while (!peg$posDetailsCache[p]) {",
|
|
|
|
" p--;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" details = peg$posDetailsCache[p];",
|
|
|
|
" details = {",
|
|
|
|
" line: details.line,",
|
|
|
|
" column: details.column",
|
|
|
|
" };",
|
|
|
|
"",
|
|
|
|
" while (p < pos) {",
|
|
|
|
" if (input.charCodeAt(p) === 10) {",
|
|
|
|
" details.line++;",
|
|
|
|
" details.column = 1;",
|
|
|
|
" } else {",
|
|
|
|
" details.column++;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" p++;",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" peg$posDetailsCache[pos] = details;",
|
|
|
|
"",
|
|
|
|
" return details;",
|
|
|
|
" }",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$computeLocation(startPos, endPos) {",
|
|
|
|
" var startPosDetails = peg$computePosDetails(startPos);",
|
|
|
|
" var endPosDetails = peg$computePosDetails(endPos);",
|
|
|
|
"",
|
|
|
|
" return {",
|
|
|
|
" start: {",
|
|
|
|
" offset: startPos,",
|
|
|
|
" line: startPosDetails.line,",
|
|
|
|
" column: startPosDetails.column",
|
|
|
|
" },",
|
|
|
|
" end: {",
|
|
|
|
" offset: endPos,",
|
|
|
|
" line: endPosDetails.line,",
|
|
|
|
" column: endPosDetails.column",
|
|
|
|
" }",
|
|
|
|
" };",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$fail(expected) {",
|
|
|
|
" if (peg$currPos < peg$maxFailPos) { return; }",
|
|
|
|
"",
|
|
|
|
" if (peg$currPos > peg$maxFailPos) {",
|
|
|
|
" peg$maxFailPos = peg$currPos;",
|
|
|
|
" peg$maxFailExpected = [];",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" peg$maxFailExpected.push(expected);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$buildSimpleError(message, location) {",
|
|
|
|
" return new peg$SyntaxError(message, null, null, location);",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" function peg$buildStructuredError(expected, found, location) {",
|
|
|
|
" return new peg$SyntaxError(",
|
|
|
|
" peg$SyntaxError.buildMessage(expected, found),",
|
|
|
|
" expected,",
|
|
|
|
" found,",
|
|
|
|
" location",
|
|
|
|
" );",
|
|
|
|
" }",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
parts.push(indent2(generateInterpreter()));
|
|
|
|
parts.push("");
|
|
|
|
} else {
|
|
|
|
ast.rules.forEach(rule => {
|
|
|
|
parts.push(indent2(generateRuleFunction(rule)));
|
|
|
|
parts.push("");
|
|
|
|
});
|
|
|
|
}
|
|
|
|
|
|
|
|
if (ast.initializer) {
|
|
|
|
parts.push(indent2(ast.initializer.code));
|
|
|
|
parts.push("");
|
|
|
|
}
|
|
|
|
|
|
|
|
if (options.optimize === "size") {
|
|
|
|
parts.push(" peg$result = peg$parseRule(peg$startRuleIndex);");
|
|
|
|
} else {
|
|
|
|
parts.push(" peg$result = peg$startRuleFunction();");
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
"",
|
|
|
|
" if (peg$result !== peg$FAILED && peg$currPos === input.length) {",
|
|
|
|
" return peg$result;",
|
|
|
|
" } else {",
|
|
|
|
" if (peg$result !== peg$FAILED && peg$currPos < input.length) {",
|
|
|
|
" peg$fail(peg$endExpectation());",
|
|
|
|
" }",
|
|
|
|
"",
|
|
|
|
" throw peg$buildStructuredError(",
|
|
|
|
" peg$maxFailExpected,",
|
|
|
|
" peg$maxFailPos < input.length ? input.charAt(peg$maxFailPos) : null,",
|
|
|
|
" peg$maxFailPos < input.length",
|
|
|
|
" ? peg$computeLocation(peg$maxFailPos, peg$maxFailPos + 1)",
|
|
|
|
" : peg$computeLocation(peg$maxFailPos, peg$maxFailPos)",
|
|
|
|
" );",
|
|
|
|
" }",
|
|
|
|
"}"
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateWrapper(toplevelCode) {
|
|
|
|
function generateGeneratedByComment() {
|
|
|
|
return [
|
|
|
|
`// Generated by PEG.js ${require("../../../package.json").version}.`,
|
|
|
|
"//",
|
|
|
|
"// https://pegjs.org/"
|
|
|
|
].join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
function generateParserObject() {
|
|
|
|
return options.trace
|
|
|
|
? [
|
|
|
|
"{",
|
|
|
|
" SyntaxError: peg$SyntaxError,",
|
|
|
|
" DefaultTracer: peg$DefaultTracer,",
|
|
|
|
" parse: peg$parse",
|
|
|
|
"}"
|
|
|
|
].join("\n")
|
|
|
|
: [
|
|
|
|
"{",
|
|
|
|
" SyntaxError: peg$SyntaxError,",
|
|
|
|
" parse: peg$parse",
|
|
|
|
"}"
|
|
|
|
].join("\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
let generators = {
|
|
|
|
bare() {
|
|
|
|
return [
|
|
|
|
generateGeneratedByComment(),
|
|
|
|
"(function() {",
|
|
|
|
" \"use strict\";",
|
|
|
|
"",
|
|
|
|
indent2(toplevelCode),
|
|
|
|
"",
|
|
|
|
indent2("return " + generateParserObject() + ";"),
|
|
|
|
"})()"
|
|
|
|
].join("\n");
|
|
|
|
},
|
|
|
|
|
|
|
|
commonjs() {
|
|
|
|
let parts = [];
|
|
|
|
let dependencyVars = Object.keys(options.dependencies);
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
generateGeneratedByComment(),
|
|
|
|
"",
|
|
|
|
"\"use strict\";",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (dependencyVars.length > 0) {
|
|
|
|
dependencyVars.forEach(variable => {
|
|
|
|
parts.push("var " + variable
|
|
|
|
+ " = require(\""
|
|
|
|
+ js.stringEscape(options.dependencies[variable])
|
|
|
|
+ "\");"
|
|
|
|
);
|
|
|
|
});
|
|
|
|
parts.push("");
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
toplevelCode,
|
|
|
|
"",
|
|
|
|
"module.exports = " + generateParserObject() + ";",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
},
|
|
|
|
|
|
|
|
amd() {
|
|
|
|
let dependencyVars = Object.keys(options.dependencies);
|
|
|
|
let dependencyIds = dependencyVars.map(v => options.dependencies[v]);
|
|
|
|
let dependencies = "["
|
|
|
|
+ dependencyIds.map(
|
|
|
|
id => "\"" + js.stringEscape(id) + "\""
|
|
|
|
).join(", ")
|
|
|
|
+ "]";
|
|
|
|
let params = dependencyVars.join(", ");
|
|
|
|
|
|
|
|
return [
|
|
|
|
generateGeneratedByComment(),
|
|
|
|
"define(" + dependencies + ", function(" + params + ") {",
|
|
|
|
" \"use strict\";",
|
|
|
|
"",
|
|
|
|
indent2(toplevelCode),
|
|
|
|
"",
|
|
|
|
indent2("return " + generateParserObject() + ";"),
|
|
|
|
"});",
|
|
|
|
""
|
|
|
|
].join("\n");
|
|
|
|
},
|
|
|
|
|
|
|
|
globals() {
|
|
|
|
return [
|
|
|
|
generateGeneratedByComment(),
|
|
|
|
"(function(root) {",
|
|
|
|
" \"use strict\";",
|
|
|
|
"",
|
|
|
|
indent2(toplevelCode),
|
|
|
|
"",
|
|
|
|
indent2("root." + options.exportVar + " = " + generateParserObject() + ";"),
|
|
|
|
"})(this);",
|
|
|
|
""
|
|
|
|
].join("\n");
|
|
|
|
},
|
|
|
|
|
|
|
|
umd() {
|
|
|
|
let parts = [];
|
|
|
|
let dependencyVars = Object.keys(options.dependencies);
|
|
|
|
let dependencyIds = dependencyVars.map(v => options.dependencies[v]);
|
|
|
|
let dependencies = "["
|
|
|
|
+ dependencyIds.map(
|
|
|
|
id => "\"" + js.stringEscape(id) + "\""
|
|
|
|
).join(", ")
|
|
|
|
+ "]";
|
|
|
|
let requires = dependencyIds.map(
|
|
|
|
id => "require(\"" + js.stringEscape(id) + "\")"
|
|
|
|
).join(", ");
|
|
|
|
let params = dependencyVars.join(", ");
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
generateGeneratedByComment(),
|
|
|
|
"(function(root, factory) {",
|
|
|
|
" if (typeof define === \"function\" && define.amd) {",
|
|
|
|
" define(" + dependencies + ", factory);",
|
|
|
|
" } else if (typeof module === \"object\" && module.exports) {",
|
|
|
|
" module.exports = factory(" + requires + ");"
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
if (options.exportVar !== null) {
|
|
|
|
parts.push([
|
|
|
|
" } else {",
|
|
|
|
" root." + options.exportVar + " = factory();"
|
|
|
|
].join("\n"));
|
|
|
|
}
|
|
|
|
|
|
|
|
parts.push([
|
|
|
|
" }",
|
|
|
|
"})(this, function(" + params + ") {",
|
|
|
|
" \"use strict\";",
|
|
|
|
"",
|
|
|
|
indent2(toplevelCode),
|
|
|
|
"",
|
|
|
|
indent2("return " + generateParserObject() + ";"),
|
|
|
|
"});",
|
|
|
|
""
|
|
|
|
].join("\n"));
|
|
|
|
|
|
|
|
return parts.join("\n");
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
return generators[options.format]();
|
|
|
|
}
|
|
|
|
|
|
|
|
ast.code = generateWrapper(generateToplevel());
|
|
|
|
}
|
|
|
|
|
|
|
|
module.exports = generateJS;
|