YACC is a parser generator that translates context-free grammar specifications into C programs capable of parsing the defined language. Developed in the early 1970s by Stephen C. Johnson at Bell Labs, YACC has been instrumental in compiler and interpreter development, enabling the creation of parsers that interpret or compile code written in various programming languages. Key Features and Functionality: - Grammar Specification: YACC accepts context-free grammars, typically written in Backus-Naur Form , to define the syntax rules of a language. - Parser Generation: It generates efficient LALR parsers in C, facilitating the parsing of input text according to the specified grammar. - Semantic Actions: YACC allows embedding C code within grammar rules, enabling actions such as constructing abstract syntax trees, generating intermediate code, or handling errors during parsing. - Integration with Lex: Often used alongside Lex, a lexical analyzer generator, YACC processes tokens produced by Lex to perform syntactic analysis, streamlining the development of language processors. Primary Value and Problem Solving: YACC simplifies the development of language parsers by automating the conversion of formal grammar specifications into executable parsing programs. This automation reduces the complexity and potential errors associated with manual parser development. By providing a systematic approach to parser generation, YACC has been pivotal in the creation of compilers and interpreters for various programming languages, thereby advancing software development and language design.