Adam-Muyobo/LR1_Parser

LR(1) parser for CSI428 - Programming Language Translation (Assignment 2). The project tokenizes a small Setswana sentence grammar, feeds the tokens into a hand-written LR(1) driver, and reports whether the sentence is accepted, rejected, or blocked by a grammar conflict in the supplied parsing table. # LR(1) Parser LR(1) parser for **CSI428 - Programming Language Translation** (Assignment 2). The project tokenizes a small Setswana sentence grammar, feeds the tokens into a hand-written LR(1) driver, and reports whether the sentence is accepted, rejected, or blocked by a grammar conflict in the supplied parsing table. ## What this project does - Tokenizes assignment vocabulary into grammar terminals such as `x`, `n1`, `c1`, `c2`, `g`, `v`, `n`, `c3`, `c4`, and `l` - Parses the resulting token stream using the provided LR(1) `ACTION` and `GOTO` tables - Reports three failure categories clearly: lexical errors, syntax errors, and grammar conflicts - Provides both an interactive parser shell and a file-driven test runner - Includes extra code comments and a simplified `five.md` walkthrough ## Project Layout - `main.py` - interactive parser CLI; keeps running until you type `Quit` - `run_tests.py` - runs the parser on predefined statements loaded from `tests/sample_sentences.txt` - `parser/grammar.py` - productions and terminal vocabularies - `parser/lexer.py` - sentence-to-token conversion - `parser/lr1_table.py` - LR(1) `ACTION` and `GOTO` tables - `parser/parser_engine.py` - stack-based LR(1) parser driver - `parser/exceptions.py` - parser-specific exception types - `tests/sample_sentences.txt` - predefined input sentences for smoke testing - `five.md` - simpler file-by-file explanation - `LR(1) Transition Diagram.jpg` - reference diagram supplied for the assignment ## Usage Start the live parser: ```bash python main.py ``` Run the predefined parser checks: ```bash python run_tests.py ``` ## Input Notes - The parser expects sentences built from the assignment vocabulary - Tokenization is word-based and ignores common edge punctuation such as `. , ! ? ; :` - The live parser accepts input repeatedly and only exits when you type `Quit` ## Error Types - `Lexical Error` - a word is not in the parser vocabulary - `Syntax Error` - the token stream does not fit the …