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Add some limited type information
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@crummy
crummy committed Dec 11, 2024
1 parent 7366d17 commit c7843d0
Showing 1 changed file with 132 additions and 39 deletions.
171 changes: 132 additions & 39 deletions pPEG.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,7 @@ function ID(exp, env) { // [ID, idx, name]
if (name[0] === '_') { // no results required..
if (env.tree.length > stack) { // nested rule results...
env.tree = env.tree.slice(0, stack); // deleted
}
}
if (env.trace) trace_result(exp, env, true, start);
return true;
}
Expand Down Expand Up @@ -141,7 +141,7 @@ function ALT(exp, env) { // [ALT, [...exp], [...guards]]
}
const arg = exp[1][i];
const result = arg[0](arg, env);
if (result) return true;
if (result) return true;
if (env.tree.length > stack) {
env.tree = env.tree.slice(0, stack);
}
Expand All @@ -164,12 +164,12 @@ function SEQ(exp, env) { // [SEQ, min, max, [...exp]]
env.pos = start;
if (env.tree.length > stack) {
env.tree = env.tree.slice(0, stack);
}
}
return true;
}
if (env.pos > start && env.pos > env.fault_pos) {
env.fault_pos = env.pos;
env.fault_tree = env.tree.slice(0);
env.fault_tree = env.tree.slice(0);
env.fault_rule = env.rule_names[env.depth];
env.fault_exp = exp[3][i];
}
Expand Down Expand Up @@ -241,7 +241,7 @@ function SQ(exp, env) { // [SQ, icase, "..."]
let pos = env.pos;
for (let i=0; i < len; i+=1) {
let char = input[pos]; // undefined if pos >= input.length
if (icase && pos < input.length) char = char.toUpperCase();
if (icase && pos < input.length) char = char.toUpperCase();
if (str[i] !== char) {
env.pos = start;
if (env.trace) trace_chars_fail(exp, env);
Expand Down Expand Up @@ -287,7 +287,7 @@ function CHS(exp, env) { // [CHS, neg, min, max, str]
env.pos = pos;
if (pos > env.peak) env.peak = pos;
if (env.trace) trace_chars_match(exp, env, start);
return true;
return true;
}

function EXTN(exp, env) { // [EXTN, "<xxx>"]
Expand All @@ -302,7 +302,7 @@ function EXTN(exp, env) { // [EXTN, "<xxx>"]
if (!fn) {
if (env.pos > env.fault_pos) {
env.fault_pos = env.pos;
env.fault_tree = env.tree.slice(0);
env.fault_tree = env.tree.slice(0);
env.fault_rule = env.rule_names[env.depth];
env.fault_exp = "missing extension: "+exp[1];;
}
Expand Down Expand Up @@ -342,7 +342,7 @@ function dump_trace(exp, env) {
let report = "<?> at line: "+line_number(env.input, env.pos)+"\n";
for (let i=0; i<env.tree.length; i+=1) {
report += show_tree(env.tree[i])+"\n";
}
}
report += line_report(env.input, env.pos);
console.log(report);
return true;
Expand All @@ -355,14 +355,14 @@ function infix(exp, env) {
if (env.tree.length - stack < 3) return true
let next = stack-1; // tree stack index
env.tree[stack] = pratt(0);
env.tree.length = stack+1;
env.tree.length = stack+1;
return true;

function pratt(lbp) {
let result = env.tree[next+=1];
while (true) {
const op = env.tree[next+=1];
let rbp = op? 0 : -1,
let rbp = op? 0 : -1,
sfx = op? op[0].slice(-3) : undefined;
if (sfx && sfx[0] === '_') { // _xL or _xR
let x = sfx.charCodeAt(1);
Expand Down Expand Up @@ -402,7 +402,7 @@ function same_match(exp, env) { // <eq name>, deprecate <@name>
if (env.input.startsWith(prior, env.pos)) {
env.pos += prior.length;
return true;
}
}
return false;
}

Expand Down Expand Up @@ -503,7 +503,7 @@ function lines_before(str, ln, i, j, n) {
n -= 1;
if (i === 0 || n === 0) return before;
ln -= 1;
if (i>0 && str[i-1] === "\n") i -= 1;
if (i>0 && str[i-1] === "\n") i -= 1;
if (i>0 && str[i-1] === "\r") i -= 1;
j = i;
while (i > 0 && str[i-1] !== "\n" && str[i-1] !== "\r") i-=1;
Expand All @@ -515,7 +515,7 @@ function lines_after(str, ln, i, n) {
while (n>0 && i < str.length) {
ln += 1;
let j = i;
if (str[j] === "\n") j += 1;
if (str[j] === "\n") j += 1;
if (j < str.length && str[j] === "\r") j += 1;
let k = j;
while (k < str.length && str[k] !== "\n" && str[k] !== "\r") k+=1;
Expand Down Expand Up @@ -573,7 +573,7 @@ function trace_rep(exp, env) {

function trace_chars_match(exp, env, start) {
if (env.trace_depth === -1) return; // not active
trace_report(indent(env)+exp_show(exp)+" == "+
trace_report(indent(env)+exp_show(exp)+" == "+
show_input(env, start, env.pos));
}

Expand Down Expand Up @@ -670,28 +670,32 @@ function str_esc(s) {
let n = c.charCodeAt(0);
let xxxx = n.toString(16);
while (xxxx.length < 4) xxxx = '0'+xxxx;
r += "\\u"+xxxx;
r += "\\u"+xxxx;
}
}
return r;
}

// compiler -- ptree rules => instruction code ----------------------------

function compiler(rules) { // -> {rules, names, code, start}
/**
* @param {Array} rules
* @returns {Codex} codex
*/
function compiler(rules) {
let names = {}, first;
for (let i=0; i<rules.length; i+=1) {
const [_rule, [[_id, name], _exp]] = rules[i];
if (i==0) first = name;
names[name] = i;
names[name] = i;
}
let start = [ID, 0, first]; // start rule
let code = [];
for (const rule of rules) {
const [_rule, [[_id, name], exp]] = rule;
code.push(emit(exp));
}
for (let i=0; i<code.length; i+=1) {
for (let i=0; i<code.length; i+=1) {
optimize(code[i], code);
}
// let space, sp = names["_space_"];
Expand All @@ -704,7 +708,7 @@ function compiler(rules) { // -> {rules, names, code, start}
const name = exp[1],
index = names[name];
if (index === undefined) throw "Undefined rule: "+name;
return [ID, index, name];
return [ID, index, name];
}
case "alt": return [ALT, exp[1].map(emit)];
case "seq": return [SEQ, 1, 1, exp[1].map(emit)];
Expand All @@ -730,7 +734,7 @@ function compiler(rules) { // -> {rules, names, code, start}
return [CHS, false, min, max, str];
}
}
return [REP, min, max, expr];
return [REP, min, max, expr];
};
case "pre": {
const [[_pfx, pfx], term] = exp[1];
Expand All @@ -744,11 +748,11 @@ function compiler(rules) { // -> {rules, names, code, start}
if (!neg) return [CHS, true, min, max, str];
}
}
return [PRE, pfx, expr];
return [PRE, pfx, expr];
};
// case "sq": return sq_dq(SQ, exp[1]);
// case "dq": return sq_dq(DQ, exp[1]);

case "sq": {
const txt = exp[1];
const icase = txt.slice(-1) === "i";
Expand All @@ -763,7 +767,7 @@ function compiler(rules) { // -> {rules, names, code, start}
str = escape_codes(str);
return [CHS, false, 1, 1, str];
};

case "extn": return [EXTN, exp[1]];

default: throw "Undefined ptree node: " + exp;
Expand All @@ -777,7 +781,7 @@ function compiler(rules) { // -> {rules, names, code, start}
if (suffix === "sfx") {
if (sfx === "+") { min = 1; }
else if (sfx === "?") { max = 1; }
} else if (suffix === "num") {
} else if (suffix === "num") {
min = parseInt(sfx, 10); max = min;
} else if (suffix === "range") { // *N..M
// ["range", [[num, min],["dots", ".."]]]
Expand Down Expand Up @@ -811,7 +815,7 @@ function compiler(rules) { // -> {rules, names, code, start}
default: return;
}
}

function first_char(exp, code) {
switch (exp[0]) { // TODO empty sq return undefined...
case ID: {
Expand Down Expand Up @@ -865,6 +869,11 @@ function escape_codes(str) {

// -- pretty print ptree ----------------------------------------------

/**
* @param {Array} ptree
* @param {boolean=false} json
* @returns {string}
*/
function show_tree(ptree, json=false) {
if (!ptree) return "";
if (json) return show_json(ptree);
Expand Down Expand Up @@ -895,6 +904,9 @@ function show_ptree(ptree, inset, last) {
}
}

/**
* @returns {string}
*/
function show_json(ptree, inset='') {
if (!ptree) return "";
// if (!inset) inset = '';
Expand Down Expand Up @@ -925,6 +937,52 @@ function trace_report(report) {
console.log(report); // TODO output in env ?
}

/**
* @typedef {Object} Codex
* @property {Object} names
* @property {Array} code
* @property {((function(*, *): (boolean))|*|number)[]} start
* @property rules
*/

/**
* @typedef {Object} ParseSuccess
* @property {true} ok
* @property {() => string} show_err
* @property {(boolean: false) => string} show_ptree
* @property {0} err
* @property {Object} ptree
*/

/**
* @typedef {Object} ParseFailure
* @property {false} ok
* @property {() => string} show_err
* @property {number} err
* @property {Object} env
*/

/**
* @typedef {Object} Options
* @property {boolean} trace
* @property {boolean} short
*/

/**
* Environment configuration object
* @typedef {Object} Env
* @property {boolean} trace
* @property {boolean} short
* @property {Options} options
*/

/**
* @param {Object} codex
* @param {Object} input
* @param {Object} extend
* @param {Options} options
* @return { ParseSuccess | ParseFailure }
*/
function parse(codex, input, extend, options) {
let env = {
codex, // {rules, names, code, start}
Expand Down Expand Up @@ -977,13 +1035,17 @@ function parse(codex, input, extend, options) {
if (err > 0) { // returns env for show_err to sort out later
env.result = result;
return {
ok:false, env, err,
ok: false,
env,
err,
show_err: () => err_report(env)
}
}

return {
ok: true, err: 0, ptree: env.tree[0],
ok: true,
err: 0,
ptree: env.tree[0],
show_ptree: (json=false) => show_tree(env.tree[0], json),
show_err: () => "No errors to report...\n"
}
Expand All @@ -1002,34 +1064,65 @@ function err_report(env) {
report += "in rule: "+env.fault_rule+
", expected: "+exp_show(env.fault_exp)+", ";
}
report += "at line: "+line_number(env.input, env.peak)+"\n";
report += "at line: "+line_number(env.input, env.peak)+"\n";
}
report += line_report(env.input, env.peak);
return report;
}


/**
* @typedef CompileSuccess
* @extends ParseSuccess
* @property {boolean} ok
* @property {(input: any, options?: any) => any} parse
*/

/**
* @typedef CompileFailure
* @extends ParseFailure
* @param {String} panic
* @param {() => any} parse
*/

/**
*
* @param {String} grammar
* @param {Object?} extend
* @param {Object?} options
* @returns {(CompileSuccess|CompileFailure)}
*/
function compile(grammar, extend, options) {
const peg = parse(pPEG_codex, grammar, {}, options);
// console.log(JSON.stringify(peg));
if (!peg.ok) {
peg.panic = "grammar error\n"+peg.panic;
peg.parse = () => peg;
return peg;
return {
show_err: peg.show_err,
env: peg.env,
err: peg.err,
ok: false,
panic: "grammar error\n"+peg.panic,
parse: () => peg
}
}
try {
peg.codex = compiler(peg.ptree[1]);
// console.log("codex\n",JSON.stringify(peg.codex));
} catch(err) {
peg.ok = false;
peg.parse = () => peg;
peg.show_err = () => "grammar compile error\n"+err;
return peg;
return {
err: 1,
ok: false,
parse: () => peg,
show_err: () => "grammar compile error\n"+err,
}
}
peg.parse = function parser(input, options) {
return parse(peg.codex, input, extend, options);
return {
err: 0,
show_ptree: peg.show_ptree,
ok: true,
parse: (input, options) => parse(peg.codex, input, extend, options),
show_err: () => "No grammar errors ...",
}
peg.show_err = () => "No grammar errors ...";
return peg;
}

const peg = { compile, show_tree };
Expand Down

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