Tiny Language Parser

A parser and interpreter for a tiny programming language implemented in Rust using Pest.

Description

This project implements a complete parser and interpreter for a simple language that supports variable assignments and basic arithmetic operations. The parser generates AST which can then be executed by the interpreter.

Technical Description

Parsing Process

The parsing process follows these stages:

1. Lexical Analysis: The input string is tokenized using Pest grammar rules
2. Syntax Analysis: Tokens are parsed into an Abstract Syntax Tree (AST)
3. Semantic Analysis: The AST is executed by the interpreter

Grammar Rules

The language supports four main grammar rules:

1. Program: Root rule containing zero or more statements
2. Statement: Basic execution units (assignments or expressions)
3. Assignment: Variable assignments (identifier = expression)
4. Expression: Arithmetic expressions with operator precedence

Grammar Diagram

program = { statement* } statement = { (assignment | expression) ";" } assignment = { identifier "=" expression } expression = { term (add_op term)* } term = { factor (mul_op factor)* } factor = { number | identifier | "(" expression ")" } add_op = { "+" | "-" } mul_op = { "*" | "/" } number = { ASCII_DIGIT+ } identifier = { (ASCII_ALPHA_LOWER | "_")+ }

Features

• Parser: Converts source code to AST using Pest
• Interpreter: Executes AST with variable storage
• Error Handling: Error types for parsing and evaluation
• CLI: CLI for file parsing
• Testing: Complete test coverage for all grammar rules