RQL parser

This is a RQL parsing library written in PHP.

This library consists of the following parts:

• lexer for tokenization RQL code
• parser for creating abstract syntax tree

Installation

The preferred way to install library is through composer.

Either run

composer require graviton/rql-parser

or add

"graviton/rql-parser": "*",

to the require section of your composer.json.

Basic usage

<?php
require 'vendor/autoload.php';

// default lexer supports all RQL rules
$lexer = new Graviton\RqlParser\Lexer();

// default parser contains all parsing strategies
$parser = new Graviton\RqlParser\Parser();

// RQL code
$rql = '(eq(a,string:1)|lt(b,2)|(c<>3&d>=string:4&e=eq=boolean:1))&u!=5&not(or(u=6,ge(i,10)))&z=1&(a==2|b<-3|in(c,(2,float:3)))&select(a,b)&sort(+a,-b)&limit(1,2)';

// tokenize RQL
$tokens = $lexer->tokenize($rql);

// parsing
var_dump($parser->parse($tokens));

See also rql-command library. This is a console application to debug RQL lexing and parsing.

Advanced usage

See examples:

• Enable only FIQL operators
• Add new query operators
• Add support for aggregate functions
• Convert RQL to SQL
• Add date support
• Use scalars in array nodes
• Add timestamp caster
• Wrap strings with quotes

Current state

Operators

Basic syntax

• scalar operators
  • eq(a,b)
  • ne(a,b)
  • lt(a,b)
  • gt(a,b)
  • le(a,b)
  • ge(a,b)
• array operators
  • in(a,(b,c))
  • out(a,(b,c))
• logic operators
  • and(eq(a,b),ne(c,d))
  • or(eq(a,b),ne(c,d))
  • not(eq(a,b))

Short logic syntax

• (eq(a,b)&ne(b,c))
• (eq(a,b)|ne(b,c))

FIQL syntax

• scalar operators
  • a=eq=b
  • a=ne=b
  • a=lt=b
  • a=gt=b
  • a=le=b
  • a=ge=b
• array operators
  • a=in=(b,c)
  • a=out=(b,c)

Simplified FIQL syntax

• a=b
• a==b
• a<>b
• a!=b
• a<b
• a>b
• a<=b
• a>=b

Other

• select(a,b,c)
• sort(+a,-b)
• limit(1,2)

All syntax variations may be used together.

Value types

• string
  • abc
  • abc%20def
• integer
  • 1, +1, -1
• float
  • 1., +1., -1.
  • 0.1, +0.1, -0.1,
  • 0.1e5, +0.1e+5, -0.1e-5
  • .1, +.1, -.1
  • .1e5, +.1e+5, -.1e-5
• boolean
  • true()
  • false()
• null
  • null()
• empty
  • empty()
• date
  • 2015-06-02T20:00:00Z
• glob
  • abc*
  • ?abc
  • abc*def?

Type casting

• string:1
• boolean:0
• integer:a
• float:1

Encoding rules

String values

In string values all non-alphanumeric characters must be encoded with a percent (%) sign followed by two hex digits.

Examples:

eq(string,2015%2D05%2D30T15%3A10%3A00Z)
in(string,(%2B1%2E5,%2D1%2E5))
in(string,(null%28%29,empty%28%29,true%28%29,false%28%29))

String encoding in PHP:

function encodeString($value)
{
    return strtr(rawurlencode($value), [
        '-' => '%2D',
        '_' => '%5F',
        '.' => '%2E',
        '~' => '%7E',
    ]);
}

String encoding in JavaScript:

function encodeString(value) {
    return encodeURIComponent(value).replace(/[\-_\.~!\\'\*\(\)]/g, function (char) {
        return '%' + char.charCodeAt(0).toString(16).toUpperCase();
    });
}

Other values

Date, number and const-function values must not be encoded.

Examples:

eq(date,2015-05-30T15:10:00Z)
in(number,(+1.5,-1.5))
in(const,(null(),empty(),true(),false()))

Resources

• RQL Rules
• RQL documentation