VERY basic implementation of LALR(1) parser for final course assignment
The code generates the parsing table for the given CFG (grammar.txt) and then
parses the given string (input.txt)
If the string belongs to the grammar, the rightmost derivation that produces that string will be printed to the terminal
Doesn't accept left recursive grammars nor grammars that have empty string productions (ε-productions)
Modify grammar.txt and input.txt to your liking then
run using python: python3 ./main.py
The CFG goes in grammar.txt
Every CFG must have a starting S0 rule
All rules must conform to this format:
A : B | c D | E f | g H i | j
A is the nonterminal that originates the rule and the symbols in each production
MUST be separated by whitespace
The input string goes in string.txt
All whitespaces will be ignored by the parser, so the input:
1 2 3 * 4 5 6 + 9
Would be parsed as:
123*456+90
Examples of grammar and input strings are available in the folder examples/