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//! # Passerine //! This repository contains the core of the Passerine Programming Language, //! including the compiler, VM, and various utilities. //! If you're looking for the documentation for Passerine's CLI, Aspen, //! you're not in the right place. //! //! ## Running Passerine //! Passerine is primarily run through Aspen, //! Passerine's package manager. //! Simply install Aspen, then: //! ```bash //! $ aspen new first-package //! $ cd first-package //! $ aspen run //! ``` //! Aspen is the idiomatic way to create and run Passerine packages. //! The documentation that follows is about the core compiler itself. //! This is only useful if you're trying to embed Passerine in your Rust project //! or developing the core Passerine compiler and VM. //! If that's the case, read on! //! //! > NOTE: Write `aspen` install script. //! > TODO: direct users to the installation location. //! //! ## Embedding Passerine in Rust //! > TODO: Clean up crate visibility, create `run` function. //! //! Add passerine to your `Cargo.toml`: //! ```toml //! # make sure this is the latest version //! passerine = 0.7 //! ``` //! Then simply: //! ```ignore //! // DISCLAIMER: The `run` function used here has not been implemented yet, //! // although the underlying interface is mostly stable. //! //! use passerine; //! //! fn main() { //! passerine::run("print \"Hello from Passerine!\""); //! } //! ``` //! > NOTE: print statements are not yet implemented. //! > They'll be implemented by version 0.11, once the FFI is solidified //! //! ## Overview of the compilation process //! > NOTE: For a more detail, read through the documentation //! for any of the components mentioned. //! //! Within the compiler pipeline, source code is represented as a `Source` object. //! A source is a reference to some code, with an associated path //! telling which file it came from. //! //! Regions of source code can be marked with `Span`s, //! Which are like `&strs` but with a reference-counted reference to the original `Source`, //! methods for combining them, and so on. //! Spans are used throughout the compiler when reporting errors. //! Compiler Datastructures can be `Spanned` to indicate where they originated. //! //! ### Compilation //! Compilation steps can raise `Err(Syntax)`, //! indicating that an error occured. //! `Syntax` is just a `Span` and a message, //! which can be pretty-printed. //! //! The first phase of compilation is lexing. //! The `Lexer` reads through a source, and produces a stream of `Spanned<Token>`s. //! The `Lexer` is super simple - it greedily looks for the longest next token, //! Then consumes it and advances by the token's length. //! To lex a file, use the `compiler::lex::lex` function. //! //! The next phase of compilation is parsing. //! The parser takes a spanned token stream, //! and builts a spanned Abstract Syntax Tree (AST). //! The parser used is a modified Pratt parser. //! (It's modified to handle the special function-call syntax used.) //! To parse a token stream, use the `compiler::parse::parse` function. //! //! After constructing the AST, bytecode is generated. //! Bytecode is just a vector of u8s, interlaced with split numbers. //! All the opcodes are defined in `common::opcode`, //! And implemented in `compiler::vm::vm`. //! A bytecode object is a called a `Lambda`. //! The bytecode generator works by walking the AST, //! Recursively nesting itself when a new scope is encountered. //! To generate bytecode for an AST, use the `compiler::gen::gen` function. //! //! ### Execution //! The VM can raise `Err(Trace)` if it encounters //! errors during execution. //! A `Trace` is similar to `Syntax`, but it keeps track of //! multiple spans representing function calls and so on. //! //! After this, raw `Lambda`s are passed to the `VM` to be run. //! before being run by the `VM`, `Lambdas` are wrapped in `Closure`s, //! which hold some extra context. //! To run some bytecode: //! //! ``` //! # use passerine::common::{closure::Closure, source::Source}; //! # use passerine::compiler::{lex, parse, gen}; //! # use passerine::vm::vm::VM; //! # //! # fn main() { //! # let source = Source::source("pi = 3.14"); //! # let bytecode = Closure::wrap(gen(parse(lex(source).unwrap()).unwrap()).unwrap()); //! // Initialize the VM: //! let mut vm = VM::init(); //! // Run some bytecode: //! vm.run(bytecode); //! # } //! ``` //! //! The `VM` is just a simple light stack-based VM. pub mod common; pub mod compiler; pub mod vm;