Pushdown Automaton
A pushdown automaton (PDA) is a theoretical model of computation that extends a finite automaton with a stack memory, allowing it to recognize context-free languages. It consists of a finite set of states, an input tape, a stack, and transition rules that depend on the current state, input symbol, and top of the stack. PDAs are fundamental in formal language theory and compiler design for parsing nested structures like arithmetic expressions or programming language syntax.
Developers should learn about pushdown automata when studying formal language theory, compiler construction, or parsing algorithms, as they provide the theoretical basis for context-free grammars used in programming language design. It is essential for understanding how parsers in compilers and interpreters handle recursive structures, such as matching parentheses or nested statements in code. Knowledge of PDAs helps in designing and analyzing parsing tools like LR parsers or recursive descent parsers.