The Piper Programming Language

Goal

Piper aims to be a general purpose functional language.

This repository contains the interpreter for the piper language specification.

Setup

Prerequisites

If you plan active development on the piper parser, you'll need to ensure that your $GOBIN environment variable as well as your $PATH environment variables are setup accordingly before the installation of pigeon.

A possible setup in your .bashrc or .zshrc can look like this

# Go related
export PATH=$PATH:/usr/local/go/bin

export GOBIN=$(go env GOPATH)/bin
export GOPATH=$(go env GOPATH)

export PATH=$PATH:$GOPATH/bin

This ensures that the pigeon binary gets installed into your $GOPATH/bin directory (usually $HOME/bin) and is also loaded into the $PATH environment variable. After you restarted your terminal, the pigeon -h command should be available and ready to use.

If you installed pigeon beforehand, you'll need to rerun the following command:

go install github.com/mna/pigeon@latest

Running the interpreter

For running the interpreter, you can use the following commands (in the root folder of the project)

# Regenerate the parser from the pigeon.peg file (only necessary if you've changed the .peg file)
pigeon -support-left-recursion -o internal/parser/parser.go internal/parser/pigeon.peg

# Run the interpreter
go run .

# Run the interpreter in repl mode
go run . -repl

# Regenerate parser & running the interpreter (useful for parser development)
pigeon -support-left-recursion -o internal/parser/parser.go internal/parser/pigeon.peg && go run .