Looks like the parser is hand crafted using recursive descent method: https://github.com/pfusik/cito/blob/master/CiParser.cs https://github.com/pfusik/cito/blob

Looks like the parser is hand crafted using recursive descent method: https://github.com/pfusik/cito/blob/master/CiParser.cs https://github.com/pfusik/cito/blob/master/CiParser.cs I did not look closely but writing parser without any tooling is asking for troubles, from parsers that enter infinite loops to not handling parse errors properly. ANTLR is way better for writing parsers for simple languages.