parsning

Parsning is the process of analyzing a sequence of symbols to determine its grammatical structure according to a formal grammar. In computing, parsning converts text into a structured representation that a program can manipulate, such as a parse tree or an abstract syntax tree. The term is closely related to parsing; parsning is often a misspelling or variant spelling found in some sources.

Input typically begins with lexical analysis (tokenization) to produce tokens, followed by syntactic analysis that uses a grammar to assemble tokens into hierarchical structures. Outputs include parse trees, which show all linguistic constituents, and abstract syntax trees, which abstract away syntactic detail to emphasize the program’s semantic structure.

Common domains include programming languages, where parsning turns source code into ASTs used by compilers and interpreters; data formats like JSON, XML, or CSV, where parsning yields data objects; and natural language processing, where parsning reveals sentence structure or semantic roles.

Techniques vary: top-down parsers (such as recursive-descent) and bottom-up parsers (LR, LALR, SLR); parser generators like Yacc/Bison or ANTLR automate parser construction; chart parsers handle ambiguity; Earley parser handles broader grammars.

Challenges include ambiguity, error reporting, and performance. Robust parsning relies on well-defined grammars, unambiguous rules, and appropriate error recovery strategies.

See also grammar, context-free grammar, formal language, parser, compiler, interpreter.