Abstract syntax is a representation of data (typically either a message passing over a communications link or a computer program being compiled) which is independent of machine-oriented structures and encodings and also of the physical representation of the data (called "concrete syntax" in the case of compilation or "transfer syntax" in communications).
A compiler's internal representation of a program will typically be specified by an abstract syntax in terms of categories such as "statement", "expression" and "identifier". This is independent of the source syntax (concrete syntax) of the language being compiled (though it will often be very similar). A parse tree is similar to an abstract syntax tree but it will typically also contain features such as parentheses which are syntactically significant but which are implicit in the structure of the abstract syntax tree.
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This article was originally based on material from the Free On_line Dictionary of Computing, which is licensed under the GFDL.
Abstractsyntax is a representation of data (typically either a message passing over a communications link or a computer program being compiled) which is independent of machine-oriented structures and encodings and also of the physical representation of the data (called "concrete syntax" in the case of compilation or "transfer syntax" in communications).
A compiler's internal representation of a program will typically be specified by an abstractsyntax in terms of categories such as "statement", "expression" and "identifier".
A parse tree is similar to an abstractsyntax tree but it will typically also contain features such as parentheses which are syntactically significant but which are implicit in the structure of the abstractsyntax tree.
In computer science, an abstractsyntax tree (AST) is a finite, labeled, directed tree, where the nodes are labeled by operators, and the edges represent the operands of the node operators.
In computing, it is used in a parser as an intermediate between a parse tree and a data structure, the latter which is often used as a compiler or interpreter's internal representation of a computer program while it is being optimized and from which code generation is performed.
The range of all possible such structures is described by the abstractsyntax.
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