apex-parser

apex-parser

Parser for Salesforce Apex Language. This is based on a ANTLR4 grammar (see antlr/ApexParser.g4) using antlr4ts to generate a parser/lexer in Typescript. The grammar has been extensively used for parsing with Java but not with antlr4ts.

This module just contains the Parser & Lexer and provides no further support for analysing the generated parse trees beyond what is provided by antlr4ts.

As Apex is a case-insenstive language you need to use the provided CaseInsensitiveInputStream for the parser to function correctly. You can find some minimal examples in the src/_test_ directory. Supports parsing of class & trigger files but not anonymous code snippets.

Example

To parse a class file:

let lexer = new ApexLexer(new CaseInsensitiveInputStream("public class Hello {}"))
let tokens  = new CommonTokenStream(lexer);

let parser = new ApexParser(tokens)
let context = parser.compilationUnit()

The 'context' is a CompilationUnitContext object which is the root of the parsed representation of the class. You can access the parse tree via functions on it.

Change grammar

If you change the Parser or Lexer grammar files you will need to update the parser with

npm run antlr4ts 

History

2.0.0 - Supports trigger parsing and switch statement parsing syntax was corrected
1.0.0 - Initial version

Source & Licenses

All the source code included uses a 3-clause BSD license. The only third-party component included is the Apex Antlr4 grammar originally from Tooling-force.com, although this version used is now markedly different from the original.