446 lines
14 KiB
Rust

//! Values in the dynamically typed AST interpreter.
//!
//! The most permanent fix is a temporary one.
use cl_ast::{Expr, Sym, format::FmtAdapter};
use crate::{closure::Closure, constructor::Constructor};
use super::{
Callable, Environment,
builtin::Builtin,
error::{Error, IResult},
function::Function,
};
use std::{collections::HashMap, ops::*, rc::Rc};
/*
A Value can be:
- A Primitive (Empty, isize, etc.)
- A Record (Array, Tuple, Struct)
- A Variant (discriminant, Value) pair
array [
10, // 0
20, // 1
]
tuple (
10, // 0
20, // 1
)
struct {
x: 10, // x => 0
y: 20, // y => 1
}
*/
type Integer = isize;
/// A Conlang value stores data in the interpreter
#[derive(Clone, Debug, Default)]
pub enum ConValue {
/// The empty/unit `()` type
#[default]
Empty,
/// An integer
Int(Integer),
/// A floating point number
Float(f64),
/// A boolean
Bool(bool),
/// A unicode character
Char(char),
/// A string
String(Sym),
/// A reference
Ref(usize),
/// A reference to an array
Slice(usize, usize),
/// An Array
Array(Box<[ConValue]>),
/// A tuple
Tuple(Box<[ConValue]>),
/// A value of a product type
Struct(Box<(&'static str, HashMap<Sym, ConValue>)>),
/// A value of a product type with anonymous members
TupleStruct(Box<(&'static str, Box<[ConValue]>)>),
/// An entire namespace
Module(Box<HashMap<Sym, ConValue>>),
/// A namespace, sans storage
Module2(HashMap<Sym, usize>),
/// A quoted expression
Quote(Box<Expr>),
/// A callable thing
Function(Rc<Function>),
/// A tuple constructor
TupleConstructor(Constructor),
/// A closure, capturing by reference
Closure(Rc<Closure>),
/// A built-in function
Builtin(&'static Builtin),
}
impl ConValue {
/// Gets whether the current value is true or false
pub fn truthy(&self) -> IResult<bool> {
match self {
ConValue::Bool(v) => Ok(*v),
_ => Err(Error::TypeError())?,
}
}
pub fn typename(&self) -> IResult<&'static str> {
Ok(match self {
ConValue::Empty => "Empty",
ConValue::Int(_) => "i64",
ConValue::Float(_) => "f64",
ConValue::Bool(_) => "bool",
ConValue::Char(_) => "char",
ConValue::String(_) => "String",
ConValue::Ref(_) => "Ref",
ConValue::Slice(_, _) => "Slice",
ConValue::Array(_) => "Array",
ConValue::Tuple(_) => "Tuple",
ConValue::Struct(_) => "Struct",
ConValue::TupleStruct(_) => "TupleStruct",
ConValue::Module(_) => "",
ConValue::Module2(_) => "",
ConValue::Quote(_) => "Quote",
ConValue::Function(_) => "Fn",
ConValue::TupleConstructor(_) => "Fn",
ConValue::Closure(_) => "Fn",
ConValue::Builtin(_) => "Fn",
})
}
#[allow(non_snake_case)]
pub fn TupleStruct(id: Sym, values: Box<[ConValue]>) -> Self {
Self::TupleStruct(Box::new((id.to_ref(), values)))
}
#[allow(non_snake_case)]
pub fn Struct(id: Sym, values: HashMap<Sym, ConValue>) -> Self {
Self::Struct(Box::new((id.to_ref(), values)))
}
pub fn index(&self, index: &Self, _env: &Environment) -> IResult<ConValue> {
let &Self::Int(index) = index else {
Err(Error::TypeError())?
};
match self {
ConValue::String(string) => string
.chars()
.nth(index as _)
.map(ConValue::Char)
.ok_or(Error::OobIndex(index as usize, string.chars().count())),
ConValue::Array(arr) => arr
.get(index as usize)
.cloned()
.ok_or(Error::OobIndex(index as usize, arr.len())),
&ConValue::Slice(id, len) => {
let index = if index < 0 {
len.wrapping_add_signed(index)
} else {
index as usize
};
if index < len {
Ok(ConValue::Ref(id + index))
} else {
Err(Error::OobIndex(index, len))
}
}
_ => Err(Error::TypeError()),
}
}
cmp! {
lt: false, <;
lt_eq: true, <=;
eq: true, ==;
neq: false, !=;
gt_eq: true, >=;
gt: false, >;
}
assign! {
add_assign: +;
bitand_assign: &;
bitor_assign: |;
bitxor_assign: ^;
div_assign: /;
mul_assign: *;
rem_assign: %;
shl_assign: <<;
shr_assign: >>;
sub_assign: -;
}
}
impl Callable for ConValue {
fn name(&self) -> Sym {
match self {
ConValue::Function(func) => func.name(),
ConValue::Closure(func) => func.name(),
ConValue::Builtin(func) => func.name(),
_ => "".into(),
}
}
fn call(&self, env: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
match self {
Self::Function(func) => func.call(env, args),
Self::TupleConstructor(func) => func.call(env, args),
Self::Closure(func) => func.call(env, args),
Self::Builtin(func) => func.call(env, args),
Self::Module(m) => {
if let Some(func) = m.get(&"call".into()) {
func.call(env, args)
} else {
Err(Error::NotCallable(self.clone()))
}
}
&Self::Ref(ptr) => {
// Move onto stack, and call
let func = env.get_id(ptr).ok_or(Error::StackOverflow(ptr))?.clone();
func.call(env, args)
}
_ => Err(Error::NotCallable(self.clone())),
}
}
}
/// Templates comparison functions for [ConValue]
macro cmp ($($fn:ident: $empty:literal, $op:tt);*$(;)?) {$(
/// TODO: Remove when functions are implemented:
/// Desugar into function calls
pub fn $fn(&self, other: &Self) -> IResult<Self> {
match (self, other) {
(Self::Empty, Self::Empty) => Ok(Self::Bool($empty)),
(Self::Int(a), Self::Int(b)) => Ok(Self::Bool(a $op b)),
(Self::Float(a), Self::Float(b)) => Ok(Self::Bool(a $op b)),
(Self::Bool(a), Self::Bool(b)) => Ok(Self::Bool(a $op b)),
(Self::Char(a), Self::Char(b)) => Ok(Self::Bool(a $op b)),
(Self::String(a), Self::String(b)) => Ok(Self::Bool(&**a $op &**b)),
_ => Err(Error::TypeError())
}
}
)*}
macro assign($( $fn: ident: $op: tt );*$(;)?) {$(
pub fn $fn(&mut self, other: Self) -> IResult<()> {
*self = (std::mem::take(self) $op other)?;
Ok(())
}
)*}
/// Implements [From] for an enum with 1-tuple variants
macro from ($($T:ty => $v:expr),*$(,)?) {
$(impl From<$T> for ConValue {
fn from(value: $T) -> Self { $v(value.into()) }
})*
}
impl From<&Sym> for ConValue {
fn from(value: &Sym) -> Self {
ConValue::String(*value)
}
}
from! {
Integer => ConValue::Int,
f64 => ConValue::Float,
bool => ConValue::Bool,
char => ConValue::Char,
Sym => ConValue::String,
&str => ConValue::String,
Expr => ConValue::Quote,
String => ConValue::String,
Rc<str> => ConValue::String,
Function => ConValue::Function,
Vec<ConValue> => ConValue::Tuple,
&'static Builtin => ConValue::Builtin,
}
impl From<()> for ConValue {
fn from(_: ()) -> Self {
Self::Empty
}
}
impl From<&[ConValue]> for ConValue {
fn from(value: &[ConValue]) -> Self {
match value {
[] => Self::Empty,
[value] => value.clone(),
_ => Self::Tuple(value.into()),
}
}
}
/// Implements binary [std::ops] traits for [ConValue]
///
/// TODO: Desugar operators into function calls
macro ops($($trait:ty: $fn:ident = [$($match:tt)*])*) {
$(impl $trait for ConValue {
type Output = IResult<Self>;
/// TODO: Desugar operators into function calls
fn $fn(self, rhs: Self) -> Self::Output {Ok(match (self, rhs) {$($match)*})}
})*
}
ops! {
Add: add = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_add(b)),
(ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a + b),
(ConValue::String(a), ConValue::String(b)) => (a.to_string() + &*b).into(),
(ConValue::String(s), ConValue::Char(c)) => { let mut s = s.to_string(); s.push(c); s.into() }
(ConValue::Char(a), ConValue::Char(b)) => {
ConValue::String([a, b].into_iter().collect::<String>().into())
}
_ => Err(Error::TypeError())?
]
BitAnd: bitand = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a & b),
(ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a & b),
_ => Err(Error::TypeError())?
]
BitOr: bitor = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a | b),
(ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a | b),
_ => Err(Error::TypeError())?
]
BitXor: bitxor = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a ^ b),
(ConValue::Bool(a), ConValue::Bool(b)) => ConValue::Bool(a ^ b),
_ => Err(Error::TypeError())?
]
Div: div = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_div(b).unwrap_or_else(|| {
eprintln!("Warning: Divide by zero in {a} / {b}"); a
})),
(ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a / b),
_ => Err(Error::TypeError())?
]
Mul: mul = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_mul(b)),
(ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a * b),
_ => Err(Error::TypeError())?
]
Rem: rem = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_rem(b).unwrap_or_else(|| {
println!("Warning: Divide by zero in {a} % {b}"); a
})),
(ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a % b),
_ => Err(Error::TypeError())?
]
Shl: shl = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shl(b as _)),
_ => Err(Error::TypeError())?
]
Shr: shr = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_shr(b as _)),
_ => Err(Error::TypeError())?
]
Sub: sub = [
(ConValue::Empty, ConValue::Empty) => ConValue::Empty,
(ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_sub(b)),
(ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a - b),
_ => Err(Error::TypeError())?
]
}
impl std::fmt::Display for ConValue {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
ConValue::Empty => "Empty".fmt(f),
ConValue::Int(v) => v.fmt(f),
ConValue::Float(v) => v.fmt(f),
ConValue::Bool(v) => v.fmt(f),
ConValue::Char(v) => v.fmt(f),
ConValue::String(v) => v.fmt(f),
ConValue::Ref(v) => write!(f, "&<{}>", v),
ConValue::Slice(id, len) => write!(f, "&<{id}>[{len}..]"),
ConValue::Array(array) => {
'['.fmt(f)?;
for (idx, element) in array.iter().enumerate() {
if idx > 0 {
", ".fmt(f)?
}
element.fmt(f)?
}
']'.fmt(f)
}
ConValue::Tuple(tuple) => {
'('.fmt(f)?;
for (idx, element) in tuple.iter().enumerate() {
if idx > 0 {
", ".fmt(f)?
}
element.fmt(f)?
}
')'.fmt(f)
}
ConValue::TupleStruct(parts) => {
let (id, tuple) = parts.as_ref();
write!(f, "{id}")?;
'('.fmt(f)?;
for (idx, element) in tuple.iter().enumerate() {
if idx > 0 {
", ".fmt(f)?
}
element.fmt(f)?
}
')'.fmt(f)
}
ConValue::Struct(parts) => {
let (id, map) = parts.as_ref();
use std::fmt::Write;
write!(f, "{id} ")?;
let mut f = f.delimit_with("{", "\n}");
for (k, v) in map.iter() {
write!(f, "\n{k}: {v},")?;
}
Ok(())
}
ConValue::Module(module) => {
use std::fmt::Write;
let mut f = f.delimit_with("{", "\n}");
for (k, v) in module.iter() {
write!(f, "\n{k}: {v},")?;
}
Ok(())
}
ConValue::Module2(module) => {
use std::fmt::Write;
let mut f = f.delimit_with("{", "\n}");
for (k, v) in module.iter() {
write!(f, "\n{k}: <{v}>,")?;
}
Ok(())
}
ConValue::Quote(q) => {
write!(f, "`{q}`")
}
ConValue::Function(func) => {
write!(f, "{}", func.decl())
}
ConValue::TupleConstructor(Constructor { name: index, arity }) => {
write!(f, "{index}(..{arity})")
}
ConValue::Closure(func) => {
write!(f, "{}", func.as_ref())
}
ConValue::Builtin(func) => {
write!(f, "{}", func.description())
}
}
}
}
pub macro cvstruct (
$Name:ident {
$($member:ident : $expr:expr),*
}
) {{
let mut members = HashMap::new();
$(members.insert(stringify!($member).into(), ($expr).into());)*
ConValue::Struct(Box::new((stringify!($Name).into(), members)))
}}