conlang: Introduce ..rest Patterns, refactor Ranges

This commit is contained in:
John 2025-02-23 02:41:41 -06:00
parent cc6168b55e
commit 7d3f189100
12 changed files with 162 additions and 73 deletions

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@ -413,6 +413,7 @@ pub struct Let {
pub enum Pattern {
Name(Sym),
Literal(Literal),
Rest(Option<Box<Pattern>>),
Ref(Mutability, Box<Pattern>),
Tuple(Vec<Pattern>),
Array(Vec<Pattern>),
@ -505,6 +506,8 @@ pub enum UnaryKind {
Deref,
Neg,
Not,
RangeInc,
RangeExc,
/// A Loop expression: `loop` [`Block`]
Loop,
/// Unused

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@ -463,6 +463,8 @@ mod display {
match self {
Pattern::Name(sym) => sym.fmt(f),
Pattern::Literal(literal) => literal.fmt(f),
Pattern::Rest(Some(name)) => write!(f, "..{name}"),
Pattern::Rest(None) => "..".fmt(f),
Pattern::Ref(mutability, pattern) => write!(f, "&{mutability}{pattern}"),
Pattern::Tuple(patterns) => separate(patterns, ", ")(f.delimit(INLINE_PARENS)),
Pattern::Array(patterns) => separate(patterns, ", ")(f.delimit(INLINE_SQUARE)),
@ -590,6 +592,8 @@ mod display {
UnaryKind::Deref => "*",
UnaryKind::Neg => "-",
UnaryKind::Not => "!",
UnaryKind::RangeExc => "..",
UnaryKind::RangeInc => "..=",
UnaryKind::At => "@",
UnaryKind::Tilde => "~",
}
@ -894,6 +898,9 @@ mod convert {
};
Pattern::TupleStruct(path, args)
}
ExprKind::Unary(Unary { kind: UnaryKind::RangeExc, tail }) => {
Pattern::Rest(Some(Pattern::try_from(*tail)?.into()))
}
ExprKind::Structor(Structor { to, init }) => {
let fields = init
.into_iter()
@ -934,9 +941,9 @@ mod path {
}
/// Checks whether this path ends in the given [Sym]
pub fn ends_with(&self, name: &Sym) -> bool {
pub fn ends_with(&self, name: &str) -> bool {
match self.parts.as_slice() {
[.., PathPart::Ident(last)] => name == last,
[.., PathPart::Ident(last)] => name == &**last,
_ => false,
}
}

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@ -246,6 +246,8 @@ pub trait Fold {
match p {
Pattern::Name(sym) => Pattern::Name(self.fold_sym(sym)),
Pattern::Literal(literal) => Pattern::Literal(self.fold_literal(literal)),
Pattern::Rest(Some(name)) => Pattern::Rest(Some(self.fold_pattern(*name).into())),
Pattern::Rest(None) => Pattern::Rest(None),
Pattern::Ref(mutability, pattern) => Pattern::Ref(
self.fold_mutability(mutability),
Box::new(self.fold_pattern(*pattern)),

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@ -211,6 +211,8 @@ pub trait Visit<'a>: Sized {
match p {
Pattern::Name(name) => self.visit_sym(name),
Pattern::Literal(literal) => self.visit_literal(literal),
Pattern::Rest(Some(name)) => self.visit_pattern(name),
Pattern::Rest(None) => {}
Pattern::Ref(mutability, pattern) => {
self.visit_mutability(mutability);
self.visit_pattern(pattern);

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@ -167,8 +167,6 @@ pub const Builtins: &[Builtin] = &builtins![
ConValue::Ref(r) => return len(env, slice::from_ref(r.as_ref())),
ConValue::Array(t) => t.len() as _,
ConValue::Tuple(t) => t.len() as _,
ConValue::RangeExc(start, end) => (end - start) as _,
ConValue::RangeInc(start, end) => (end - start + 1) as _,
_ => Err(Error::TypeError)?,
})
}
@ -279,20 +277,25 @@ pub const Math: &[Builtin] = &builtins![
})
}
/// Exclusive Range `a..b`
fn range_exc(from, to) {
let (&ConValue::Int(from), &ConValue::Int(to)) = (from, to) else {
Err(Error::TypeError)?
};
Ok(ConValue::RangeExc(from, to))
#[allow(non_snake_case)]
fn RangeExc(start, end) {
Ok(ConValue::TupleStruct(Box::new((
"RangeExc", Box::new([start.clone(), end.clone()])
))))
}
/// Inclusive Range `a..=b`
fn range_inc(from, to) {
let (&ConValue::Int(from), &ConValue::Int(to)) = (from, to) else {
Err(Error::TypeError)?
};
Ok(ConValue::RangeInc(from, to))
#[allow(non_snake_case)]
fn RangeInc(start, end) {
Ok(ConValue::TupleStruct(Box::new((
"RangeInc", Box::new([start.clone(), end.clone()])
))))
}
#[allow(non_snake_case)]
fn RangeTo(end) {
Ok(ConValue::TupleStruct(Box::new((
"RangeInc", Box::new([end.clone()])
))))
}
/// Negates the ConValue

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@ -35,14 +35,10 @@ pub enum ConValue {
Array(Box<[ConValue]>),
/// A tuple
Tuple(Box<[ConValue]>),
/// An exclusive range
RangeExc(Integer, Integer),
/// An inclusive range
RangeInc(Integer, Integer),
/// A value of a product type
Struct(Box<(Sym, HashMap<Sym, ConValue>)>),
/// A value of a product type with anonymous members
TupleStruct(Box<(Sym, Box<[ConValue]>)>),
TupleStruct(Box<(&'static str, Box<[ConValue]>)>),
/// An entire namespace
Module(Box<HashMap<Sym, Option<ConValue>>>),
/// A quoted expression
@ -61,18 +57,6 @@ impl ConValue {
_ => Err(Error::TypeError)?,
}
}
pub fn range_exc(self, other: Self) -> IResult<Self> {
let (Self::Int(a), Self::Int(b)) = (self, other) else {
Err(Error::TypeError)?
};
Ok(Self::RangeExc(a, b))
}
pub fn range_inc(self, other: Self) -> IResult<Self> {
let (Self::Int(a), Self::Int(b)) = (self, other) else {
Err(Error::TypeError)?
};
Ok(Self::RangeInc(a, b))
}
pub fn index(&self, index: &Self) -> IResult<ConValue> {
let Self::Int(index) = index else {
Err(Error::TypeError)?
@ -289,8 +273,6 @@ impl std::fmt::Display for ConValue {
}
']'.fmt(f)
}
ConValue::RangeExc(a, b) => write!(f, "{a}..{}", b + 1),
ConValue::RangeInc(a, b) => write!(f, "{a}..={b}"),
ConValue::Tuple(tuple) => {
'('.fmt(f)?;
for (idx, element) in tuple.iter().enumerate() {

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@ -59,7 +59,7 @@ impl Callable for Function {
return Err(Error::ArgNumber { want: bind.len(), got: args.len() });
}
if self.is_constructor {
return Ok(ConValue::TupleStruct(Box::new((*name, args.into()))));
return Ok(ConValue::TupleStruct(Box::new((Sym::to_ref(name), args.into()))));
}
let Some(body) = body else {
return Err(Error::NotDefined(*name));

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@ -107,6 +107,10 @@ impl<'a> Visit<'a> for CollectUpvars<'_> {
self.bind_name(name);
}
Pattern::Literal(literal) => self.visit_literal(literal),
Pattern::Rest(Some(name)) => {
self.visit_pattern(name);
}
Pattern::Rest(None) => {}
Pattern::Ref(mutability, pattern) => {
self.visit_mutability(mutability);
self.visit_pattern(pattern);

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@ -542,8 +542,8 @@ impl Interpret for Binary {
BinaryKind::NotEq => head.neq(&tail),
BinaryKind::GtEq => head.gt_eq(&tail),
BinaryKind::Gt => head.gt(&tail),
BinaryKind::RangeExc => head.range_exc(tail),
BinaryKind::RangeInc => head.range_inc(tail),
BinaryKind::RangeExc => env.call("RangeExc".into(), &[head, tail]),
BinaryKind::RangeInc => env.call("RangeInc".into(), &[head, tail]),
BinaryKind::BitAnd => head & tail,
BinaryKind::BitOr => head | tail,
BinaryKind::BitXor => head ^ tail,
@ -617,6 +617,14 @@ impl Interpret for Unary {
let operand = tail.interpret(env)?;
env.call("not".into(), &[operand])
}
UnaryKind::RangeExc => {
let operand = tail.interpret(env)?;
env.call("RangeTo".into(), &[operand])
}
UnaryKind::RangeInc => {
let operand = tail.interpret(env)?;
env.call("RangeToInc".into(), &[operand])
}
UnaryKind::At => {
let operand = tail.interpret(env)?;
println!("{operand}");
@ -855,8 +863,21 @@ impl Interpret for For {
let cond = cond.interpret(env)?;
// TODO: A better iterator model
let mut bounds: Box<dyn Iterator<Item = ConValue>> = match &cond {
&ConValue::RangeExc(a, b) => Box::new((a..b).map(ConValue::Int)),
&ConValue::RangeInc(a, b) => Box::new((a..=b).map(ConValue::Int)),
ConValue::TupleStruct(inner) => match &**inner {
("RangeExc", values) => match **values {
[ConValue::Int(from), ConValue::Int(to)] => {
Box::new((from..to).map(ConValue::Int))
}
_ => Err(Error::NotIterable)?,
},
("RangeInc", values) => match **values {
[ConValue::Int(from), ConValue::Int(to)] => {
Box::new((from..=to).map(ConValue::Int))
}
_ => Err(Error::NotIterable)?,
},
_ => Err(Error::NotIterable)?,
},
ConValue::Array(a) => Box::new(a.iter().cloned()),
ConValue::String(s) => Box::new(s.chars().map(ConValue::Char)),
_ => Err(Error::TypeError)?,

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@ -8,7 +8,10 @@ use crate::{
error::{Error, IResult},
};
use cl_ast::{Literal, Pattern, Sym};
use std::{collections::HashMap, rc::Rc};
use std::{
collections::{HashMap, VecDeque},
rc::Rc,
};
/// Gets the path variables in the given Pattern
pub fn variables(pat: &Pattern) -> Vec<&Sym> {
@ -17,6 +20,8 @@ pub fn variables(pat: &Pattern) -> Vec<&Sym> {
Pattern::Name(name) if &**name == "_" => {}
Pattern::Name(name) => set.push(name),
Pattern::Literal(_) => {}
Pattern::Rest(Some(pattern)) => patvars(set, pattern),
Pattern::Rest(None) => {}
Pattern::Ref(_, pattern) => patvars(set, pattern),
Pattern::Tuple(patterns) | Pattern::Array(patterns) => {
patterns.iter().for_each(|pat| patvars(set, pat))
@ -37,6 +42,41 @@ pub fn variables(pat: &Pattern) -> Vec<&Sym> {
set
}
fn rest_binding<'pat>(
sub: &mut HashMap<&'pat Sym, ConValue>,
mut patterns: &'pat [Pattern],
mut values: VecDeque<ConValue>,
) -> IResult<Option<(&'pat Pattern, VecDeque<ConValue>)>> {
// Bind the head of the list
while let [pattern, tail @ ..] = patterns {
if matches!(pattern, Pattern::Rest(_)) {
break;
}
let value = values
.pop_front()
.ok_or_else(|| Error::PatFailed(Box::new(pattern.clone())))?;
append_sub(sub, pattern, value)?;
patterns = tail;
}
// Bind the tail of the list
while let [head @ .., pattern] = patterns {
if matches!(pattern, Pattern::Rest(_)) {
break;
}
let value = values
.pop_back()
.ok_or_else(|| Error::PatFailed(Box::new(pattern.clone())))?;
append_sub(sub, pattern, value)?;
patterns = head;
}
// Bind the ..rest of the list
match patterns {
[] | [Pattern::Rest(None)] => Ok(None),
[Pattern::Rest(Some(pattern))] => Ok(Some((pattern.as_ref(), values))),
_ => Err(Error::PatFailed(Box::new(Pattern::Array(patterns.into())))),
}
}
/// Appends a substitution to the provided table
pub fn append_sub<'pat>(
sub: &mut HashMap<&'pat Sym, ConValue>,
@ -44,18 +84,6 @@ pub fn append_sub<'pat>(
value: ConValue,
) -> IResult<()> {
match (pat, value) {
(Pattern::Array(patterns), ConValue::Array(values))
| (Pattern::Tuple(patterns), ConValue::Tuple(values)) => {
if patterns.len() != values.len() {
Err(Error::ArgNumber { want: patterns.len(), got: values.len() })?
}
for (pat, value) in patterns.iter().zip(Vec::from(values).into_iter()) {
append_sub(sub, pat, value)?;
}
Ok(())
}
(Pattern::Tuple(patterns), ConValue::Empty) if patterns.is_empty() => Ok(()),
(Pattern::Literal(Literal::Bool(a)), ConValue::Bool(b)) => {
(*a == b).then_some(()).ok_or(Error::NotAssignable)
}
@ -73,6 +101,25 @@ pub fn append_sub<'pat>(
}
(Pattern::Literal(_), _) => Err(Error::NotAssignable),
(Pattern::Rest(Some(pat)), value) => match (pat.as_ref(), value) {
(Pattern::Literal(Literal::Int(a)), ConValue::Int(b)) => {
(b < *a as _).then_some(()).ok_or(Error::NotAssignable)
}
(Pattern::Literal(Literal::Char(a)), ConValue::Char(b)) => {
(b < *a as _).then_some(()).ok_or(Error::NotAssignable)
}
(Pattern::Literal(Literal::Bool(a)), ConValue::Bool(b)) => {
(!b & *a).then_some(()).ok_or(Error::NotAssignable)
}
(Pattern::Literal(Literal::Float(a)), ConValue::Float(b)) => {
(b < *a as _).then_some(()).ok_or(Error::NotAssignable)
}
(Pattern::Literal(Literal::String(a)), ConValue::String(b)) => {
(&*b < a).then_some(()).ok_or(Error::NotAssignable)
}
_ => Err(Error::NotAssignable)
},
(Pattern::Name(name), _) if "_".eq(&**name) => Ok(()),
(Pattern::Name(name), value) => {
sub.insert(name, value);
@ -81,14 +128,43 @@ pub fn append_sub<'pat>(
(Pattern::Ref(_, pat), ConValue::Ref(r)) => append_sub(sub, pat, Rc::unwrap_or_clone(r)),
(Pattern::Array(patterns), ConValue::Array(values)) => {
match rest_binding(sub, patterns, values.into_vec().into())? {
Some((pattern, values)) => {
append_sub(sub, pattern, ConValue::Array(Vec::from(values).into()))
}
_ => Ok(()),
}
}
(Pattern::Tuple(patterns), ConValue::Empty) if patterns.is_empty() => Ok(()),
(Pattern::Tuple(patterns), ConValue::Tuple(values)) => {
match rest_binding(sub, patterns, values.into_vec().into())? {
Some((pattern, values)) => {
append_sub(sub, pattern, ConValue::Tuple(Vec::from(values).into()))
}
_ => Ok(()),
}
}
(Pattern::TupleStruct(path, patterns), ConValue::TupleStruct(parts)) => {
let (name, values) = *parts;
if !path.ends_with(name) {
Err(Error::TypeError)?
}
match rest_binding(sub, patterns, values.into_vec().into())? {
Some((pattern, values)) => {
append_sub(sub, pattern, ConValue::Tuple(Vec::from(values).into()))
}
_ => Ok(()),
}
}
(Pattern::Struct(path, patterns), ConValue::Struct(parts)) => {
let (name, mut values) = *parts;
if !path.ends_with(&name) {
Err(Error::TypeError)?
}
if patterns.len() != values.len() {
return Err(Error::ArgNumber { want: patterns.len(), got: values.len() });
}
for (name, pat) in patterns {
let value = values.remove(name).ok_or(Error::TypeError)?;
match pat {
@ -101,23 +177,9 @@ pub fn append_sub<'pat>(
Ok(())
}
(Pattern::TupleStruct(path, patterns), ConValue::TupleStruct(parts)) => {
let (name, values) = *parts;
if !path.ends_with(&name) {
Err(Error::TypeError)?
}
if patterns.len() != values.len() {
Err(Error::ArgNumber { want: patterns.len(), got: values.len() })?
}
for (pat, value) in patterns.iter().zip(Vec::from(values).into_iter()) {
append_sub(sub, pat, value)?;
}
Ok(())
}
(pat, value) => {
eprintln!("Could not match pattern `{pat}` with value `{value}`!");
Err(Error::NotAssignable)
Ok(())
}
}
}

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@ -330,7 +330,7 @@ impl From<UnaryKind> for Precedence {
use UnaryKind as Op;
match value {
Op::Loop => Precedence::Assign,
Op::Deref | Op::Neg | Op::Not | Op::At | Op::Tilde => Precedence::Unary,
_ => Precedence::Unary,
}
}
}
@ -351,6 +351,8 @@ operator! {
Star => Deref,
Minus => Neg,
Bang => Not,
DotDot => RangeExc,
DotDotEq => RangeInc,
At => At,
Tilde => Tilde,
};

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@ -430,6 +430,7 @@ pub mod yamlify {
match self {
Pattern::Name(name) => y.value(name),
Pattern::Literal(literal) => y.value(literal),
Pattern::Rest(name) => y.pair("Rest", name),
Pattern::Ref(mutability, pattern) => {
y.pair("mutability", mutability).pair("subpattern", pattern)
}