ablescript/ablescript/src/value/functio.rs

114 lines
2.9 KiB
Rust

use super::ValueRef;
use crate::ast::Block;
use std::{hash::Hash, rc::Rc};
type BuiltinRc = Rc<dyn Fn(&[ValueRef]) -> Result<(), crate::error::ErrorKind>>;
/// AbleScript Function
#[derive(Debug, PartialEq, Clone, Hash)]
pub enum Functio {
/// BF instructions and a length of the type
///
/// Takes input bytes as parameters
Bf {
instructions: Vec<u8>,
tape_len: usize,
},
/// Regular AbleScript functio
///
/// Consists of parameter name mapping and AST
Able { params: Vec<String>, body: Block },
/// Builtin Rust functio
Builtin(BuiltinFunctio),
/// Chained functio pair
Chain {
functios: Box<(Functio, Functio)>,
kind: FunctioChainKind,
},
/// Code to be parsed and then executed in current scope
Eval(String),
}
impl Functio {
pub fn arity(&self) -> usize {
match self {
Functio::Bf {
instructions: _,
tape_len: _,
} => 0,
Functio::Able { params, body: _ } => params.len(),
Functio::Builtin(b) => b.arity,
Functio::Chain { functios, kind: _ } => functios.0.arity() + functios.1.arity(),
Functio::Eval(_) => 0,
}
}
}
/// Built-in Rust functio
#[derive(Clone)]
pub struct BuiltinFunctio {
pub(super) function: BuiltinRc,
pub(super) arity: usize,
}
impl BuiltinFunctio {
/// Wrap a Rust function into AbleScript's built-in functio
///
/// Arity used for functio chaining, recommend value for variadic
/// functions is the accepted minimum.
pub fn new<F>(f: F, arity: usize) -> Self
where
F: Fn(&[ValueRef]) -> Result<(), crate::error::ErrorKind> + 'static,
{
Self {
function: Rc::new(f),
arity,
}
}
pub fn call(&self, args: &[ValueRef]) -> Result<(), crate::error::ErrorKind> {
(self.function)(args)
}
pub fn fn_addr(&self) -> usize {
Rc::as_ptr(&self.function) as *const () as _
}
}
impl std::fmt::Debug for BuiltinFunctio {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("BuiltinFunctio")
.field("function", &"built-in")
.field("arity", &self.arity)
.finish()
}
}
impl PartialEq for BuiltinFunctio {
fn eq(&self, other: &Self) -> bool {
self.fn_addr() == other.fn_addr() && self.arity == other.arity
}
}
impl Hash for BuiltinFunctio {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.fn_addr().hash(state);
self.arity.hash(state);
}
}
/// A method of distributting parameters across functio chain
#[derive(Debug, PartialEq, Eq, Copy, Clone, Hash)]
pub enum FunctioChainKind {
/// All parameters are equally distributed
Equal,
/// Parameters are distributed to members of chain
/// by their arity
ByArity,
}