ylyxa / Conjunctive-GLR

GLR interpreter generator for Okhotin conjunctive grammars

Interpreter generation

Installation

1. Clone the repository: git clone https://github.com/ylyxa/Conjunctive-GLR.git
2. Install pygraphviz
3. Install other packages: pip install -r requirements.txt

Using premade examples

1. Navigate to /examples/ and then to the example's folder
2. Run generate_and_run.sh inside the folder

Generating custom interpreters

Defining the grammar

Grammar syntax:

Grammar → ((Rule ∨ TermRule)\n)+

Rule → Nterm ::= (ConjRHS ∨ DisjRHS);Semantic

ConjRHS → (Str & Str ∨ (Str & ConjRHS));Semantic

DisjRHS → (Str ∨ (Str | DisjRHS));Semantic

Str → (Nterm ∨ Term ∨ _)+

TermRule → Regex

Semantic → FunctionName

Nterm → [A-Z][a-zA-Z0-9]*

Term → [a-z][a-zA-Z0-9]*

Here Regex means a python regular expression, FunctionName - name of a function from semantic.py

Defining semantic actions

Semantic functions are defined as Python functions that accept one argument (a list of lower-level semantic results) and return a single value (which is then passed up the graph). Note: there must be a function pass_through defined like this:

def pass_through(x):
return x[0]

Note: Semantic results are undetermined if the grammar is ambiguous or contains conjunctive rules. File must be named semantic.py

Defining reconfiguration

Must be defined as a function reconfigure in reconfigure.py. Function accepts one argument (semantic result for the graph root) and returns a string (to be used in the next step of the interpretation loop)

Running

1. Generate the interpreter: place semantic.py and reconfigure.py in the same directory as generator.py and run generator.py grammar
2. Run the interpreter: navigate to /generated/ generated by the program and run main.py grammar input where grammar is the generated grammar and input is the file with the input string