[File:Abstract syntax tree for Euclidean algorithm.svg|thumb|400px|An abstract syntax tree for the following code for the
Euclidean algorithm:
]] In
computer science, an
abstract syntax tree (
AST), or just
syntax tree, is a
tree representation of the
abstract syntactic structure of
source code written in a
programming language. Each node of the tree denotes a construct occurring in the source code. The syntax is "abstract" in not representing every detail appearing in the real syntax. For instance, grouping
parentheses are implicit in the tree structure, and a syntactic construct like an if-condition-then expression may be denoted by means of a single node with three branches.