inigo-selwood / pimlico

A simple parser generator toolchain

Pimlico

A parser generator tool for C/C++

Installation

Install the latest version of Python

user:~$ sudo apt update
user:~$ sudo apt install python3.9

While this tool generates parsers for C/C++, the build tool itself uses Python

Install invoke

user:~$ pip3 install invoke

Invoke provides tidy Makefile-like functionality with clearer syntax, and is used to build the shared C library.

Install clang and clang-format

user:~$ sudo apt install clang clang-format

For Windows users, you'll want to install a similar C/C++ compiler like MinGW or Cygwin.

If you're a Windoes user, or for whatever reason you don't want to use clang, the only thing you'll have to change is the compiler used in our "Makefile". The parser will still work without clang-format, but any inconsistent indentation in your grammar files will be carried through to the header file output.

Clone or download the Pimlico repo

user:~$ git clone [e-mail]:inigo-selwood/Pimlico.git && cd Pimlico

Build the shared C library

user:Pimlico$ (cd library && invoke build)

The Python compiler uses ctypes to call C functions from the shared library, and can't work without them.

Quickstart Guide

Create grammar.peg:

.include(iostream)

term := 'say hello' {{
        std::cout << "hello world\n";
    }}

Here you've created a single rule term. This term matches the string constant "say hello", and binds it to an expression that prints "hello world" to stdout. When the constant is encountered, the expression is executed.

Build the grammar

user:Pimlico$ python3 source/main.py build grammar.peg --name hello_world

This creates the header file hello_world.h which you can include in your source.

Create main.c:

#include "hello_world.h"

int main() {
    pimlicoParse("say hello");
    return 0;
}

We're including the header file created in the last step, and invoking the parser we created

Build main.c:

user:Pimlico$ clang main.c -o hello_world

Run the executable:

user:Pimlico$ ./hello_world
hello world

Congratulations, you've just built you first Pimlico parser in fewer than a dozen lines.