cminus-lexer-parser

Build a simply lexer and parser for C minus (subset of C), using Java.

Explore more details in this blog post.

Structure

• Lexer:
  • Input a C source file to be syntactically analyzed, output the token sequence after the lexical analysis process, and return it with Java's built-in data structure ArrayList to provide a data source for subsequent lexical analysis.
• Parser:
  • The token sequence obtained from the lexical analysis of a program in the previous experiment is input, and the move-in statute sequence from the LR(1) analysis in the bottom-up syntax analysis is output.
  • The sequence also shows the contents of the stack and contains error handling and hints. The program can automatically construct an LR(1) analysis table by entering the grammar.

Todo

• Performance improvement. Too many switch-cases, too many nested if-else.
• Complete unit tests to improve test coverage.
• Simply GUI to improve user ease of use.

Reference

• Let's Build a Compiler, by Jack Crenshaw
• The LEMON Parser Generator