PCASTL

The PCASTL (an acronym for by Parent and Childset Accessible Syntax Tree Language) is an interpreted high-level programming language. It was created in 2008 by Philippe Choquette. The PCASTL is designed to ease the writing of self-modifying code. The language has reserved words parent and childset to access the nodes of the syntax tree of the currently written code. The "Hello world program" is quite simple: or will do the same. The syntax of PCASTL is derived from programming languages C and R. The source of R version 2.5.1 has been studied to write the grammar and the lexer used in the PCASTL interpreter. Like in R, statements can, but do not have to, be separated by semicolons. Like in R, a variable can change type in a session. Like...