SyntaxSage: The EEL Expression Interpreter

Overview

The EEL (Extended Expression Language) Interpreter is a C implementation of an interpreter for a custom expression language developed as part of the CS 429 course. This project provides a command-line interface (CI) that allows users to evaluate expressions written in the EEL language.

Project Structure

• Core Components:

  • Lexer: Tokenizes input strings into lexemes (lex.c)
  • Parser: Builds abstract syntax trees from tokens (parse.c)
  • Evaluator: Evaluates parsed expressions (eval.c)
  • Variable Management: Handles variable definitions and lookups (variable.c)
  • Error Handler: Provides robust error handling (err_handler.c)

• Support Files:

  • ci.h: Main header file with function declarations and shared variables
  • token.h: Token definitions for the lexer
  • node.h: Node structure for the abstract syntax tree
  • value.h & type.h: Value and type system definitions
  • Makefile: Build configuration

Features

• Arithmetic operations
• String manipulation
• Comparison operators
• Ternary conditional expressions
• Variable assignment and retrieval
• Robust error handling

Language Elements

The EEL language supports various operations including:

• String operations (concatenation, repetition, comparison)
• Numeric operations (addition, subtraction, multiplication, division)
• Type conversion
• Boolean operations

Building & Running

To build the interpreter:

make ci

To run the interpreter:

./ci

To run tests:

make test

To check for memory leaks:

make memtest

Testing

The tests/ directory contains various test files to verify different aspects of the interpreter:

• test_string.txt: String operations
• test_binary.txt: Binary operations
• test_ternary.txt: Ternary conditional expressions
• test_variable.txt: Variable assignment and usage
• test_unary.txt: Unary operations

License

Copyright (c) 2021. S. Chatterjee, X. Shen, T. Byrd. All rights reserved. May not be used, modified, or copied without permission.