[[wikipedia:Abstract_syntax_tree|AST]] stands for [[AST|Abstract Syntax Tree]] and is used in compilers (like [[JavaC]]) to represent structure of the program before final (in this case [[ByteCode]]) form is emitted.

[[wikipedia:Abstract_syntax_tree|AST]] stands for [[AST|Abstract Syntax Tree]] and is used in compilers (like [[JavaC]]) to represent structure of the program before final (in this case [[ByteCode]]) form is emitted. The [[AST]] can also be used directly in an interpreter - which is usually slow, unless one uses [[Truffle]] [[AST]] [[API]] - which observes your interpreter for a while and then turns the program into damn fast compiled machine code automatically!