parser definition language
or program to determine the syntactic structure of ("parse") a sentence
or string of symbols in some language. A parser normally takes as input a sequence of tokens
output by a lexical analyser
. It may produce some kind of abstract syntax tree
as output. A parser may be produced automatically from a grammar by a parser generators such as yacc
A parser is normally part of some larger program, like a compiler
, which takes the output of the parser and attempts to extract meaning from it in some way, e.g. translating it into another language.