SLR(1) Parser Generator. Grammar to NFA, DFA, Table

Overview

Given a grammar in (limited) EBNF, this tool will draw the NFA and DFA used in producing a SLR(1) parser. It also generates the SLR(1) parse table in two formats: a table for people, and a JSON matrix for accommodating our robot overlords.

Feed me your delicious grammar, mortal.

Grammar Specification Requirements

Productions use the following format:

• Goal -> A
• A -> ( A ) | Two
• Two -> a
• Two -> b

• "->" separates the non-terminal on the left-hand-side from what it produces.
• x -> y | z is EBNF short-hand for
  • x -> y
  • x -> z

Be certain to place spaces between things you don't want read as one symbol. ( A ) ≠ (A)

About This Tool

Intended Audience

Computer science students & autodidacts studying compilers or parsing.

Purpose

This tool provides rapid feedback loop for learning about grammars. How?

• Rapid visualization of grammars enables convenient tweaking. Botched a production? No problem; tweak it and everything's spit back out.
• Ability to dump LR(0) and SLR(1) tables. Helps with manual parse tracing and hand-writing parsers.
• Assisting with coursework.

Underlying Theory

How to draw NFAs for SLR(0) and LR(1) grammars. Want to learn how it works or how to do it by hand? Read that.