README.md

Cycle 3 — p13: Recursive Descent Parsers

Files:

• p13.c - Simple recursive descent parser for i+i sequences
• recursive_descent.c - Full recursive descent parser for arithmetic expressions

Brief description:

This directory contains two implementations of recursive descent parsers:

1. Simple Parser (p13.c):

   • Parses expressions of form "i+i+i..." (identifier sequences)
   • Uses two simple productions: E → iZ and Z → +iZ | ε
   • Demonstrates basic recursive descent concepts

2. Arithmetic Expression Parser (recursive_descent.c):

   • Implements a complete parser for arithmetic expressions
   • Grammar productions:
     • E → TE'
     • E' → +TE' | -TE' | ε
     • T → FT'
     • T' → *FT' | /FT' | ε
     • F → (E) | identifier
   • Features:
     • Proper operator precedence
     • Nested expressions with parentheses
     • Error handling
     • Left recursion removed

Usage: Run either program and enter an expression matching its grammar. The parser will indicate whether the input is accepted or rejected.