Node RSQL / FIQL Parser
Gratitute
Without GOD's blessing, I am not able to do anything useful!
Thanks to Prashanth Ponugoti and Kameswara Eati for their guidance, inspiration and contribution.
Overview
RSQL (RESTful Service Query Language) is an extention of FIQL (Feed Item Query Language). It is very simple and yet capable to express complex queries within a HTTP URI string. It is very well adopted as a generic query language for searching RESTful service endpoints.
Grammar and semantic
RSQL defines comparison operators and composite operators base on FIQL. Those operators can be used to build complex queries.
The following is a list of comparison operators:
| Comparison Operator | Description |
|---|---|
| == | Equal To |
| != | Not Equal To |
| =lt= or < | Less Than |
| =le= or <= | Less Or Equal To |
| =gt= or > | Greater Than |
| =ge= or >= | Greater Or Equal To |
| =in= | In |
| =out= | Not In |
The comparation unit (simpliest query) can be formed using a key, an operator and a value as follow:
comparison = key, comparison-oprator, values;
The key identifies a field (or attribute, element, …) of the resource representation to filter by. It can be any non empty Unicode string that doesn’t contain reserved characters or a white space. The specific syntax of the selector is not enforced by this parser.
The following is the list of two composite operators:
| Composite Operator | Description |
|---|---|
| ; | AND |
| , | OR |
By default, the AND operator takes precedence (meaning, it’s evaluated before any OR operators are). However, a parenthesized expression can be used to change the precedence, yielding whatever the contained expression yields.
License
This project is licensed under MIT license.