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Deterministic BNF compiler/parser

Home Page: http://bnf-parser.ajanibilby.com/

License: MIT License

TypeScript 85.87% JavaScript 14.13%

bnf parser compiler javascript typescript

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bnf-parser's Issues

Docs syntax link

The Syntax tab is broken for docs.

It should go to https://bnf-parser.ajanibilby.com/syntax but it doesn't.

+Show bnf stack trace on error

Include a list of strings within BNF_SyntaxError for the current BNF term that failed, and what terms it was "called" from. This can then be used to print out better syntax errors, allowing you to more easily debug BNFs due to the fact you can ensure that it is attempting to match the fail point with the correct term.

Cannot read properties of undefined (reading `'getReach'`) since v3.1.2

Hello!

bnf-parser 3.1.2 seems to have introduced a regression. We're getting the following crash when calling parse:

TypeError: Cannot read properties of undefined (reading 'getReach')
      at SyntaxNode.getReach (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/syntax.js:70:50)
      at Sequence.parseSingle (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/parser.js:347:32)
      at Sequence.parse (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/parser.js:271:28)
      at Sequence.parse (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/parser.js:323:25)
      at Rule.parse (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/parser.js:389:28)
      at Parser.parse (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/bnf-parser/bin/parser.js:425:29)
      at parseAttributeSyntaxInternal (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/@sequelize/core/lib/utils/attribute-syntax.js:97:34)
      at memoized (/Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/lodash/memoize.js:62:23)
      at /Users/jeffrey.fowler/development/sequelize-v7-alias-bug/node_modules/@sequelize/core/lib/dialects/abstract/where-sql-builder.js:215:88
      at Array.map (<anonymous>)

This is the BNF in question: https://github.com/sequelize/sequelize/blob/e6690cdf27980d57be1bb9f138b04124775b153b/packages/core/src/utils/attribute-syntax.ts#L56-L87
attributeParser.parse from the above code fails when we feed something like 'prop' into it.

Do you know if we're doing something incorrectly or if this is an actual bug?

Wasm-Parser: Upper case ranges not working

With the new wasm parser upper case ranges don't appear to work at all

This example will always fail

program ::= letter+ ;
letter ::= "a"->"z" | "A"->"Z" ;

snakeCase

Error with default BNF example

Hello,

Running through the homepage example, I use the following BNF:

program ::= %w* statement+ ;
block   ::= %("block" w+) ...name %(w* "{" w*) seq_stmt* %("}" w*) ;

And run:

npx bnf-compile ./syntax.bnf

And I get:

Found: ./syntax.bnf

 - Compiling syntax
   Encoding Parser
Parse Error: Unknown term name "w" (1:14) -> (1:16)

Example code is not working properly

Hex codes don't match documentation

The documentation says that hex escapes work like "\x6b" but the actually behavior is "x6b".

Not getting correct end bytes for repetitions of a select

Repetition of a select not working correctly:

# input: $abcHello $abc World
program ::= ("$abc" | !"$"+)+ ;

{
  "root": {
    "type": "program",
    "start": 0,
    "end": 0,
    "count": 1,
    "value": [
      {
        "type": "(...)+",
        "start": 0,
        "end": 0,
        "count": 4,
        "value": [
          {
            "type": "literal",
            "start": 0,
            "end": 4,
            "count": 4,
            "value": "$abc",
            "ref": {}
          }, {}, {},
          {
            "type": "literal",
            "start": 14,
            "end": 20,
            "count": 6,
            "value": " World",
            "ref": { }
          }
        ],
        "ref": {}
      }
    ],
    "ref": {},
  "reachBytes": 20,
  "reach": {
    "line": 1,
    "col": 21,
    "index": 20
  },
  "isPartial": true
}

This leads also to things being incorrectly labeled as partial, because reachBytes !== end

Repetition of sequences work correctly:

# input: $abcHello $abc World
program ::= ("$abc" !"$"+)+ ;

Unparse

Very cool project!

What would be also nice is to have reverse parse/serialize functionality.

Should be possible without ambiguity (choose fewest possible repetitions).

Version 4.0 Release Checklist

Parse error due to select option order

// OK
let result = BNF.parse(`program ::= "aa" | "a";`);
let tree = Compile(result);
let syntax = tree.parse("aa");
console.log("result", result, "syntax", syntax);

// Not OK
let result = BNF.parse(`program ::= "a" | "aa";`);
let tree = Compile(result);
let syntax = tree.parse("aa");
console.log("result", result, "syntax", syntax);

Edit by @AjaniBilby:
Answer