azur
/
bobbylisp
mirror of https://github.com/azur1s/bobbylisp.git
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We are so back

tc
azur 2023-04-14 11:50:07 +07:00
parent 0c79321826
commit 50ae682203
16 changed files with 812 additions and 201 deletions
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33
Cargo.lock generated
View File

@ -23,6 +23,16 @@ dependencies = [
"yansi",
]
[[package]]
name = "bin"
version = "0.1.0"
dependencies = [
"ariadne",
"chumsky",
"syntax",
"typing",
]
[[package]]
name = "cc"
version = "1.0.79"
@ -54,14 +64,6 @@ dependencies = [
"ahash",
]
[[package]]
name = "holymer"
version = "0.1.0"
dependencies = [
"ariadne",
"chumsky",
]
[[package]]
name = "libc"
version = "0.2.140"
@ -96,6 +98,21 @@ dependencies = [
"winapi",
]
[[package]]
name = "syntax"
version = "0.1.0"
dependencies = [
"chumsky",
]
[[package]]
name = "typing"
version = "0.1.0"
dependencies = [
"chumsky",
"syntax",
]
[[package]]
name = "unicode-width"
version = "0.1.10"

13
Cargo.toml
View File

@ -1,8 +1,7 @@
[package]
name = "holymer"
version = "0.1.0"
edition = "2021"
[workspace]
[dependencies]
ariadne = "0.2.0"
chumsky = "1.0.0-alpha.3"
members = [
"bin",
"syntax",
"typing",
]

10
bin/Cargo.toml Normal file
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@ -0,0 +1,10 @@
[package]
name = "bin"
version = "0.1.0"
edition = "2021"
[dependencies]
ariadne = "0.2.0"
chumsky = "1.0.0-alpha.3"
syntax = { path = "../syntax" }
typing = { path = "../typing" }

14
src/main.rs → bin/src/main.rs
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@ -1,9 +1,7 @@
use ariadne::{sources, Color, Label, Report, ReportKind};
use chumsky::{Parser, prelude::Input};
use self::{parse::parser::{lexer, exprs_parser}};
pub mod parse;
pub mod typing;
use syntax::parser::{lexer, exprs_parser};
use typing::infer::infer_exprs;
fn main() {
let src = "
@ -26,7 +24,13 @@ fn main() {
.into_output_errors();
if let Some(ast) = ast.filter(|_| errs.len() + parse_errs.len() == 0) {
println!("{:?}", ast);
let (ast, e) = infer_exprs(ast.0);
if !e.is_empty() {
println!("{:?}", e);
}
if !ast.is_empty() {
println!("{:?}", ast);
}
}
parse_errs

26
sketch.hlm
View File

@ -1,25 +1 @@
mut ret_ty: Option<Ty>
if type_check(expr) = Return {
if ret_ty.is_some() && ret_ty != this_ty {
error
} else {
ret_ty = this_ty
}
}
=====
{
if true {
return 1;
}
if false {
return "Hello";
}
do_something();
return 4;
}
let add = \x : num, y : num -> num = x + y;

2
src/typing/mod.rs
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@ -1,2 +0,0 @@
pub mod ty;
pub mod typed;

7
syntax/Cargo.toml Normal file
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@ -0,0 +1,7 @@
[package]
name = "syntax"
version = "0.1.0"
edition = "2021"
[dependencies]
chumsky = "1.0.0-alpha.3"

134
syntax/src/expr.rs Normal file
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@ -0,0 +1,134 @@
use std::fmt::{ Display, Formatter, self };
use chumsky::span::SimpleSpan;
use super::ty::Type;
#[derive(Clone, Debug, PartialEq)]
pub enum Delim { Paren, Brack, Brace }
// The tokens of the language.
// 'src is the lifetime of the source code string.
#[derive(Clone, Debug, PartialEq)]
pub enum Token<'src> {
Unit, Bool(bool), Num(f64), Str(&'src str),
Ident(&'src str),
Add, Sub, Mul, Div, Rem,
Eq, Ne, Lt, Gt, Le, Ge,
And, Or, Not,
Assign, Comma, Colon, Semicolon,
Open(Delim), Close(Delim),
Lambda, Arrow,
Let, In, Func, Return, If, Then, Else,
}
impl<'src> Display for Token<'src> {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
match self {
Token::Unit => write!(f, "()"),
Token::Bool(b) => write!(f, "{}", b),
Token::Num(n) => write!(f, "{}", n),
Token::Str(s) => write!(f, "\"{}\"", s),
Token::Ident(s) => write!(f, "{}", s),
Token::Add => write!(f, "+"),
Token::Sub => write!(f, "-"),
Token::Mul => write!(f, "*"),
Token::Div => write!(f, "/"),
Token::Rem => write!(f, "%"),
Token::Eq => write!(f, "=="),
Token::Ne => write!(f, "!="),
Token::Lt => write!(f, "<"),
Token::Gt => write!(f, ">"),
Token::Le => write!(f, "<="),
Token::Ge => write!(f, ">="),
Token::And => write!(f, "&&"),
Token::Or => write!(f, "||"),
Token::Not => write!(f, "!"),
Token::Assign => write!(f, "="),
Token::Comma => write!(f, ","),
Token::Colon => write!(f, ":"),
Token::Semicolon => write!(f, ";"),
Token::Open(d) => write!(f, "{}", match d {
Delim::Paren => "(",
Delim::Brack => "[",
Delim::Brace => "{",
}),
Token::Close(d) => write!(f, "{}", match d {
Delim::Paren => ")",
Delim::Brack => "]",
Delim::Brace => "}",
}),
Token::Lambda => write!(f, "\\"),
Token::Arrow => write!(f, "->"),
Token::Let => write!(f, "let"),
Token::In => write!(f, "in"),
Token::Func => write!(f, "func"),
Token::Return => write!(f, "return"),
Token::If => write!(f, "if"),
Token::Then => write!(f, "then"),
Token::Else => write!(f, "else"),
}
}
}
pub type Span = SimpleSpan<usize>;
#[derive(Clone, Debug, PartialEq)]
pub enum Lit<'src> {
Unit,
Bool(bool),
Num(f64),
Str(&'src str),
}
#[derive(Clone, Debug)]
pub enum UnaryOp { Neg, Not }
#[derive(Clone, Debug)]
pub enum BinaryOp {
Add, Sub, Mul, Div, Rem,
And, Or,
Eq, Ne, Lt, Le, Gt, Ge,
}
pub type Spanned<T> = (T, Span);
// Clone is needed for type checking since the type checking
// algorithm is recursive and sometimes consume the AST.
#[derive(Clone, Debug)]
pub enum Expr<'src> {
Lit(Lit<'src>),
Ident(&'src str),
Unary(UnaryOp, Spanned<Box<Self>>),
Binary(BinaryOp, Spanned<Box<Self>>, Spanned<Box<Self>>),
Lambda(Vec<(&'src str, Option<Type>)>, Option<Type>, Spanned<Box<Self>>),
Call(Spanned<Box<Self>>, Vec<Spanned<Self>>),
If {
cond: Spanned<Box<Self>>,
t: Spanned<Box<Self>>,
f: Spanned<Box<Self>>,
},
Let {
name: &'src str,
ty: Option<Type>,
value: Spanned<Box<Self>>,
body: Spanned<Box<Self>>,
},
Define {
name: &'src str,
ty: Option<Type>,
value: Spanned<Box<Self>>,
},
Block {
exprs: Vec<Spanned<Box<Self>>>,
void: bool, // True if last expression is discarded (ends with semicolon).
},
}

4
src/parse/mod.rs → syntax/src/lib.rs
View File

@ -1,9 +1,11 @@
pub mod expr;
pub mod parser;
pub mod ty;
#[cfg(test)]
mod tests {
use chumsky::prelude::*;
use super::parser::*;
use super::{ expr::*, parser::* };
#[test]
fn simple() {

159
src/parse/parser.rs → syntax/src/parser.rs
View File

@ -1,85 +1,6 @@
use std::fmt::{
Display,
Formatter,
self,
};
use chumsky::prelude::*;
use crate::typing::ty::Type;
#[derive(Clone, Debug, PartialEq)]
pub enum Delim { Paren, Brack, Brace }
// The tokens of the language.
// 'src is the lifetime of the source code string.
#[derive(Clone, Debug, PartialEq)]
pub enum Token<'src> {
Unit, Bool(bool), Num(f64), Str(&'src str),
Ident(&'src str),
Add, Sub, Mul, Div, Rem,
Eq, Ne, Lt, Gt, Le, Ge,
And, Or, Not,
Assign, Comma, Colon, Semicolon,
Open(Delim), Close(Delim),
Lambda, Arrow,
Let, In, Func, Return, If, Then, Else,
}
impl<'src> Display for Token<'src> {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
match self {
Token::Unit => write!(f, "()"),
Token::Bool(b) => write!(f, "{}", b),
Token::Num(n) => write!(f, "{}", n),
Token::Str(s) => write!(f, "\"{}\"", s),
Token::Ident(s) => write!(f, "{}", s),
Token::Add => write!(f, "+"),
Token::Sub => write!(f, "-"),
Token::Mul => write!(f, "*"),
Token::Div => write!(f, "/"),
Token::Rem => write!(f, "%"),
Token::Eq => write!(f, "=="),
Token::Ne => write!(f, "!="),
Token::Lt => write!(f, "<"),
Token::Gt => write!(f, ">"),
Token::Le => write!(f, "<="),
Token::Ge => write!(f, ">="),
Token::And => write!(f, "&&"),
Token::Or => write!(f, "||"),
Token::Not => write!(f, "!"),
Token::Assign => write!(f, "="),
Token::Comma => write!(f, ","),
Token::Colon => write!(f, ":"),
Token::Semicolon => write!(f, ";"),
Token::Open(d) => write!(f, "{}", match d {
Delim::Paren => "(",
Delim::Brack => "[",
Delim::Brace => "{",
}),
Token::Close(d) => write!(f, "{}", match d {
Delim::Paren => ")",
Delim::Brack => "]",
Delim::Brace => "}",
}),
Token::Lambda => write!(f, "\\"),
Token::Arrow => write!(f, "->"),
Token::Let => write!(f, "let"),
Token::In => write!(f, "in"),
Token::Func => write!(f, "func"),
Token::Return => write!(f, "return"),
Token::If => write!(f, "if"),
Token::Then => write!(f, "then"),
Token::Else => write!(f, "else"),
}
}
}
pub type Span = SimpleSpan<usize>;
use super::{ expr::*, ty::Type };
pub fn lexer<'src>() -> impl Parser<'src, &'src str, Vec<(Token<'src>, Span)>, extra::Err<Rich<'src, char, Span>>> {
let num = text::int(10)
@ -159,61 +80,6 @@ pub fn lexer<'src>() -> impl Parser<'src, &'src str, Vec<(Token<'src>, Span)>, e
.collect()
}
#[derive(Clone, Debug, PartialEq)]
pub enum Lit<'src> {
Unit,
Bool(bool),
Num(f64),
Str(&'src str),
}
#[derive(Clone, Debug)]
pub enum UnaryOp { Neg, Not }
#[derive(Clone, Debug)]
pub enum BinaryOp {
Add, Sub, Mul, Div, Rem,
And, Or,
Eq, Ne, Lt, Le, Gt, Ge,
}
pub type Spanned<T> = (T, Span);
// Clone is needed for type checking since the type checking
// algorithm is recursive and sometimes consume the AST.
#[derive(Clone, Debug)]
pub enum Expr<'src> {
Lit(Lit<'src>),
Ident(&'src str),
Unary(UnaryOp, Spanned<Box<Self>>),
Binary(BinaryOp, Spanned<Box<Self>>, Spanned<Box<Self>>),
Lambda(Vec<(&'src str, Option<Type>)>, Spanned<Box<Self>>),
Call(Spanned<Box<Self>>, Vec<Spanned<Self>>),
If {
cond: Spanned<Box<Self>>,
t: Spanned<Box<Self>>,
f: Spanned<Box<Self>>,
},
Let {
name: &'src str,
ty: Option<Type>,
value: Spanned<Box<Self>>,
body: Spanned<Box<Self>>,
},
Define {
name: &'src str,
ty: Option<Type>,
value: Spanned<Box<Self>>,
},
Block {
exprs: Vec<Spanned<Box<Self>>>,
void: bool, // True if last expression is discarded (ends with semicolon).
},
}
// (a, s) -> (Box::new(a), s)
fn boxspan<T>(a: Spanned<T>) -> Spanned<Box<T>> {
(Box::new(a.0), a.1)
@ -255,22 +121,26 @@ pub fn expr_parser<'tokens, 'src: 'tokens>() -> impl Parser<
)
.map(|e: Spanned<Expr>| e.0);
// \x : t, y : t -> rt = e
let lambda = just(Token::Lambda)
.ignore_then(
(
symbol
.then(
just(Token::Colon)
.ignore_then(type_parser())
.or_not())
)
.separated_by(just(Token::Comma))
symbol.then(
just(Token::Colon)
.ignore_then(type_parser())
.or_not())
).separated_by(just(Token::Comma))
.allow_trailing()
.collect::<Vec<_>>()
)
.then_ignore(just(Token::Arrow))
.then(
just(Token::Arrow)
.ignore_then(type_parser())
.or_not()
)
.then_ignore(just(Token::Assign))
.then(expr.clone())
.map(|(args, body)| Expr::Lambda(args, boxspan(body)));
.map(|((args, ret), body)| Expr::Lambda(args, ret, boxspan(body)));
// ident (: type)?
let bind = symbol
@ -444,7 +314,6 @@ pub fn type_parser<'tokens, 'src: 'tokens>() -> impl Parser<
Token::Ident("num") => Type::Num,
Token::Ident("str") => Type::Str,
Token::Unit => Type::Unit,
Token::Ident(s) => Type::Var(s.to_string()),
};
let tys_paren = ty.clone()

17
src/typing/ty.rs → syntax/src/ty.rs
View File

@ -4,10 +4,10 @@ use std::fmt::{self, Display, Formatter};
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum Type {
Unit, Bool, Num, Str,
Var(usize), // This type is only used during type inference.
Func(Vec<Type>, Box<Type>),
Tuple(Vec<Type>),
Array(Box<Type>),
Var(String),
}
impl Display for Type {
@ -17,6 +17,7 @@ impl Display for Type {
Type::Bool => write!(f, "Bool"),
Type::Num => write!(f, "Num"),
Type::Str => write!(f, "Str"),
Type::Var(id) => write!(f, "{}", itoa(id)),
Type::Func(ref args, ref ret) => {
write!(f, "({}", args[0])?;
for arg in &args[1..] {
@ -32,7 +33,19 @@ impl Display for Type {
write!(f, ")")
}
Type::Array(ref ty) => write!(f, "[{}]", ty),
Type::Var(ref id) => write!(f, "{}", id),
}
}
}
/// Convert a number to a string of lowercase letters
pub fn itoa(i: usize) -> String {
let mut s = String::new();
let mut i = i;
while i >= 26 {
s.push((b'a' + (i % 26) as u8) as char);
i /= 26;
}
s.push((b'a' + i as u8) as char);
s
}

8
typing/Cargo.toml Normal file
View File

@ -0,0 +1,8 @@
[package]
name = "typing"
version = "0.1.0"
edition = "2021"
[dependencies]
chumsky = "1.0.0-alpha.3"
syntax = { path = "../syntax" }

569
typing/src/infer.rs Normal file
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@ -0,0 +1,569 @@
use std::collections::HashMap;
use chumsky::span::SimpleSpan;
use syntax::{
expr::{
Lit, UnaryOp, BinaryOp,
Expr,
},
ty::*,
};
use super::typed::TExpr;
#[derive(Clone, Debug)]
struct Infer<'src> {
env: HashMap<&'src str, Type>,
subst: Vec<Type>,
constraints: Vec<(Type, Type)>,
}
impl<'src> Infer<'src> {
fn new() -> Self {
Infer {
env: HashMap::new(),
subst: Vec::new(),
constraints: Vec::new(),
}
}
/// Generate a fresh type variable
fn fresh(&mut self) -> Type {
let i = self.subst.len();
self.subst.push(Type::Var(i));
Type::Var(i)
}
/// Get a substitution for a type variable
fn subst(&self, i: usize) -> Option<Type> {
self.subst.get(i).cloned()
}
/// Check if a type variable occurs in a type
fn occurs(&self, i: usize, t: Type) -> bool {
use Type::*;
match t {
Unit | Bool | Num | Str => false,
Var(j) => {
if let Some(t) = self.subst(j) {
if t != Var(j) {
return self.occurs(i, t);
}
}
i == j
},
Func(args, ret) => {
args.into_iter().any(|t| self.occurs(i, t)) || self.occurs(i, *ret)
},
Tuple(tys) => tys.into_iter().any(|t| self.occurs(i, t)),
Array(ty) => self.occurs(i, *ty),
}
}
/// Unify two types
fn unify(&mut self, t1: Type, t2: Type) -> Result<(), String> {
use Type::*;
match (t1, t2) {
// Literal types
(Unit, Unit)
| (Bool, Bool)
| (Num, Num)
| (Str, Str) => Ok(()),
// Variable
(Var(i), Var(j)) if i == j => Ok(()), // Same variables can be unified
(Var(i), t2) => {
// If the substitution is not the variable itself,
// unify the substitution with t2
if let Some(t) = self.subst(i) {
if t != Var(i) {
return self.unify(t, t2);
}
}
// If the variable occurs in t2
if self.occurs(i, t2.clone()) {
return Err(format!("Infinite type: '{} = {}", itoa(i), t2));
}
// Set the substitution
self.subst[i] = t2;
Ok(())
},
(t1, Var(i)) => {
if let Some(t) = self.subst(i) {
if t != Var(i) {
return self.unify(t1, t);
}
}
if self.occurs(i, t1.clone()) {
return Err(format!("Infinite type: '{} = {}", itoa(i), t1));
}
self.subst[i] = t1;
Ok(())
},
// Function
(Func(a1, r1), Func(a2, r2)) => {
// Check the number of arguments
if a1.len() != a2.len() {
return Err(format!("Function argument mismatch: {} != {}", a1.len(), a2.len()));
}
// Unify the arguments
for (a1, a2) in a1.into_iter().zip(a2.into_iter()) {
self.unify(a1, a2)?;
}
// Unify the return types
self.unify(*r1, *r2)
},
// Tuple
(Tuple(t1), Tuple(t2)) => {
// Check the number of elements
if t1.len() != t2.len() {
return Err(format!("Tuple element mismatch: {} != {}", t1.len(), t2.len()));
}
// Unify the elements
for (t1, t2) in t1.into_iter().zip(t2.into_iter()) {
self.unify(t1, t2)?;
}
Ok(())
},
// Array
(Array(t1), Array(t2)) => self.unify(*t1, *t2),
// The rest will be type mismatch
(t1, t2) => Err(format!("Type mismatch: {} != {}", t1, t2)),
}
}
/// Solve the constraints by unifying them
fn solve(&mut self) -> Result<(), String> {
for (t1, t2) in self.constraints.clone().into_iter() {
self.unify(t1, t2)?;
}
Ok(())
}
/// Substitute the type variables with the substitutions
fn substitute(&mut self, t: Type) -> Type {
use Type::*;
match t {
// Only match any type that can contain type variables
Var(i) => {
if let Some(t) = self.subst(i) {
if t != Var(i) {
return self.substitute(t);
}
}
Var(i)
},
Func(args, ret) => {
Func(
args.into_iter().map(|t| self.substitute(t)).collect(),
Box::new(self.substitute(*ret)),
)
},
Tuple(tys) => Tuple(tys.into_iter().map(|t| self.substitute(t)).collect()),
Array(ty) => Array(Box::new(self.substitute(*ty))),
// The rest will be returned as is
_ => t,
}
}
/// Find a type variable in (typed) expression and substitute them
fn substitute_texp(&mut self, e: TExpr<'src>) -> TExpr<'src> {
use TExpr::*;
match e {
Lit(_) | Ident(_) => e,
Unary { op, expr: (e, lspan), ret_ty } => {
Unary {
op,
expr: (Box::new(self.substitute_texp(*e)), lspan),
ret_ty,
}
},
Binary { op, lhs: (lhs, lspan), rhs: (rhs, rspan), ret_ty } => {
let lhst = self.substitute_texp(*lhs);
let rhst = self.substitute_texp(*rhs);
Binary {
op,
lhs: (Box::new(lhst), lspan),
rhs: (Box::new(rhst), rspan),
ret_ty: self.substitute(ret_ty),
}
},
Lambda { params, body: (body, bspan), ret_ty } => {
let bodyt = self.substitute_texp(*body);
let paramst = params.into_iter()
.map(|(name, ty)| (name, self.substitute(ty)))
.collect::<Vec<_>>();
Lambda {
params: paramst,
body: (Box::new(bodyt), bspan),
ret_ty: self.substitute(ret_ty),
}
},
Call { func: (func, fspan), args } => {
let funct = self.substitute_texp(*func);
let argst = args.into_iter()
.map(|(arg, span)| (self.substitute_texp(arg), span))
.collect::<Vec<_>>();
Call {
func: (Box::new(funct), fspan),
args: argst,
}
},
If { cond: (cond, cspan), t: (t, tspan), f: (f, fspan), br_ty } => {
let condt = self.substitute_texp(*cond);
let tt = self.substitute_texp(*t);
let ft = self.substitute_texp(*f);
If {
cond: (Box::new(condt), cspan),
t: (Box::new(tt), tspan),
f: (Box::new(ft), fspan),
br_ty,
}
},
Let { name, ty, value: (v, vspan), body: (b, bspan) } => {
let vt = self.substitute_texp(*v);
let bt = self.substitute_texp(*b);
Let {
name,
ty: self.substitute(ty),
value: (Box::new(vt), vspan),
body: (Box::new(bt), bspan),
}
},
Define { name, ty, value: (v, vspan) } => {
let vt = self.substitute_texp(*v);
Define {
name,
ty: self.substitute(ty),
value: (Box::new(vt), vspan),
}
},
Block { exprs, void, ret_ty } => {
let exprst = exprs.into_iter()
.map(|(e, span)| (self.substitute_texp(e), span))
.collect::<Vec<_>>();
Block {
exprs: exprst,
void,
ret_ty,
}
},
}
}
/// Infer the type of an expression
fn infer(&mut self, e: Expr<'src>, expected: Type) -> Result<TExpr<'src>, String> {
match e {
// Literal values
// Push the constraint (expected type to be the literal type) and
// return the typed expression
Expr::Lit(l) => {
let t = match l {
Lit::Unit => Type::Unit,
Lit::Bool(_) => Type::Bool,
Lit::Num(_) => Type::Num,
Lit::Str(_) => Type::Str,
};
self.constraints.push((expected, t));
Ok(TExpr::Lit(l))
},
// Identifiers
// The same as literals but the type is looked up in the environment
Expr::Ident(ref x) => {
let t = self.env.get(x)
.ok_or(format!("Unbound variable: {}", x))?;
self.constraints.push((expected, t.clone()));
Ok(TExpr::Ident(x.clone()))
}
// Unary & binary operators
// The type of the left and right hand side are inferred and
// the expected type is determined by the operator
Expr::Unary(op, (expr, espan)) => match op {
// Numeric operators (Num -> Num)
UnaryOp::Neg => {
let et = self.infer(*expr, Type::Num)?;
self.constraints.push((expected, Type::Num));
Ok(TExpr::Unary {
op,
expr: (Box::new(et), espan),
ret_ty: Type::Num,
})
},
// Boolean operators (Bool -> Bool)
UnaryOp::Not => {
let et = self.infer(*expr, Type::Bool)?;
self.constraints.push((expected, Type::Bool));
Ok(TExpr::Unary {
op,
expr: (Box::new(et), espan),
ret_ty: Type::Bool,
})
},
}
Expr::Binary(op, (lhs, lspan), (rhs, rspan)) => match op {
// Numeric operators (Num -> Num -> Num)
BinaryOp::Add
| BinaryOp::Sub
| BinaryOp::Mul
| BinaryOp::Div
| BinaryOp::Rem
=> {
let lt = self.infer(*lhs, Type::Num)?;
let rt = self.infer(*rhs, Type::Num)?;
self.constraints.push((expected, Type::Num));
Ok(TExpr::Binary {
op,
lhs: (Box::new(lt), lspan),
rhs: (Box::new(rt), rspan),
ret_ty: Type::Num,
})
},
// Boolean operators (Bool -> Bool -> Bool)
BinaryOp::And
| BinaryOp::Or
=> {
let lt = self.infer(*lhs, Type::Bool)?;
let rt = self.infer(*rhs, Type::Bool)?;
self.constraints.push((expected, Type::Bool));
Ok(TExpr::Binary {
op,
lhs: (Box::new(lt), lspan),
rhs: (Box::new(rt), rspan),
ret_ty: Type::Bool,
})
},
// Comparison operators ('a -> 'a -> Bool)
BinaryOp::Eq
| BinaryOp::Ne
| BinaryOp::Lt
| BinaryOp::Le
| BinaryOp::Gt
| BinaryOp::Ge
=> {
// Create a fresh type variable and then use it as the
// expected type for both the left and right hand side
// so the type on both side have to be the same
let t = self.fresh();
let lt = self.infer(*lhs, t.clone())?;
let rt = self.infer(*rhs, t)?;
self.constraints.push((expected, Type::Bool));
Ok(TExpr::Binary {
op,
lhs: (Box::new(lt), lspan),
rhs: (Box::new(rt), rspan),
ret_ty: Type::Bool,
})
},
}
// Lambda
Expr::Lambda(args, ret, (b, bspan)) => {
// Get the return type or create a fresh type variable
let rt = ret.unwrap_or(self.fresh());
// Fill in the type of the arguments with a fresh type
let xs = args.into_iter()
.map(|(x, t)| (x, t.unwrap_or(self.fresh())))
.collect::<Vec<_>>();
// Create a new environment, and add the arguments to it
// and use the new environment to infer the body
let mut env = self.env.clone();
xs.clone().into_iter().for_each(|(x, t)| { env.insert(x, t); });
let mut inf = self.clone();
inf.env = env;
let bt = inf.infer(*b, rt.clone())?;
// Add the substitutions & constraints from the body
// if it doesn't already exist
for s in inf.subst {
if !self.subst.contains(&s) {
self.subst.push(s);
}
}
for c in inf.constraints {
if !self.constraints.contains(&c) {
self.constraints.push(c);
}
}
// Push the constraints
self.constraints.push((expected, Type::Func(
xs.clone().into_iter()
.map(|x| x.1)
.collect(),
Box::new(rt.clone()),
)));
Ok(TExpr::Lambda {
params: xs,
body: (Box::new(bt), bspan),
ret_ty: rt,
})
},
// Call
Expr::Call((f, fspan), args) => {
// Generate fresh types for the arguments
let freshes = args.clone().into_iter()
.map(|_| self.fresh())
.collect::<Vec<Type>>();
// Create a function type
let fsig = Type::Func(
freshes.clone(),
Box::new(expected),
);
// Expect the function to have the function type
let ft = self.infer(*f, fsig)?;
// Infer the arguments
let xs = args.into_iter()
.zip(freshes.into_iter())
.map(|((x, xspan), t)| {
let xt = self.infer(x, t)?;
Ok((xt, xspan))
})
.collect::<Result<Vec<_>, String>>()?;
Ok(TExpr::Call {
func: (Box::new(ft), fspan),
args: xs,
})
},
// If
Expr::If { cond: (c, cspan), t: (t, tspan), f: (f, fspan) } => {
// Condition has to be a boolean
let ct = self.infer(*c, Type::Bool)?;
// The type of the if expression is the same as the
// expected type
let tt = self.infer(*t, expected.clone())?;
let et = self.infer(*f, expected.clone())?;
Ok(TExpr::If {
cond: (Box::new(ct), cspan),
t: (Box::new(tt), tspan),
f: (Box::new(et), fspan),
br_ty: expected,
})
},
// Let & define
Expr::Let { name, ty, value: (v, vspan), body: (b, bspan) } => {
// Infer the type of the value
let ty = ty.unwrap_or(self.fresh());
let vt = self.infer(*v, ty.clone())?;
// Create a new environment and add the binding to it
// and then use the new environment to infer the body
let mut env = self.env.clone();
env.insert(name.clone(), ty.clone());
let mut inf = Infer::new();
inf.env = env;
let bt = inf.infer(*b, expected)?;
Ok(TExpr::Let {
name, ty,
value: (Box::new(vt), vspan),
body: (Box::new(bt), bspan),
})
},
Expr::Define { name, ty, value: (v, vspan) } => {
let ty = ty.unwrap_or(self.fresh());
let vt = self.infer(*v, ty.clone())?;
self.env.insert(name.clone(), ty.clone());
// Define always returns unit
self.constraints.push((expected, Type::Unit));
Ok(TExpr::Define {
name, ty,
value: (Box::new(vt), vspan),
})
},
// Block
Expr::Block { exprs, void } => {
// Infer the type of each expression
let xs = exprs.into_iter()
.map(|(x, xspan)| {
let xt = self.infer(*x, expected.clone())?;
Ok((xt, xspan))
})
.collect::<Result<Vec<_>, String>>()?;
let ret_ty = if void {
Type::Unit
} else {
expected
};
Ok(TExpr::Block {
exprs: xs,
void, ret_ty,
})
},
}
}
}
/// Infer a list of expressions
pub fn infer_exprs(es: Vec<(Expr, SimpleSpan)>) -> (Vec<(TExpr, SimpleSpan)>, String) {
let mut inf = Infer::new();
// Typed expressions
let mut tes = vec![];
// Typed expressions without substitutions
let mut tes_nosub = vec![];
// Errors
let mut errs = vec![];
for e in es {
let f = inf.fresh();
let t = inf.infer(e.0, f).unwrap();
tes.push(Some((t.clone(), e.1)));
tes_nosub.push((t, e.1));
match inf.solve() {
Ok(_) => {
// Substitute the type variables for the solved expressions
tes = tes.into_iter()
.map(|te| match te {
Some((t, s)) => {
Some((inf.substitute_texp(t), s))
},
None => None,
})
.collect();
},
Err(e) => {
errs.push(e);
// Replace the expression with None
tes.pop();
tes.push(None);
},
}
}
// Union typed expressions, replacing None with the typed expression without substitutions
// None means that the expression has an error
let mut tes_union = vec![];
for (te, te_nosub) in tes.into_iter().zip(tes_nosub.into_iter()) {
match te {
Some(t) => {
tes_union.push(t);
},
None => {
tes_union.push(te_nosub);
},
}
}
(
// Renamer::new().process(tes_union),
tes_union,
errs.join("\n")
)
}

3
typing/src/lib.rs Normal file
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@ -0,0 +1,3 @@
pub mod infer;
pub mod rename;
pub mod typed;

0
typing/src/rename.rs Normal file
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14
src/typing/typed.rs → typing/src/typed.rs
View File

@ -1,9 +1,11 @@
use super::ty::Type;
use crate::parse::parser::{
BinaryOp,
UnaryOp,
Lit,
Spanned,
use syntax::{
expr::{
BinaryOp,
UnaryOp,
Lit,
Spanned,
},
ty::Type,
};
// Typed version of the expression.