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This commit is contained in:
Adam Wick
2024-04-22 20:49:44 -07:00
parent c8d6719eb7
commit 52d5c9252b
15 changed files with 1528 additions and 1358 deletions
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10
examples/basic/function0004.ngr Normal file
View File

@@ -0,0 +1,10 @@
function make_adder(x)
function (y)
x + y;
add1 = make_adder(1);
add2 = make_adder(2);
one_plus_one = add1(1);
one_plus_three = add1(3);
print one_plus_one;
print one_plus_three;

2
src/ir/ast.rs
View File

@@ -74,6 +74,8 @@ impl Arbitrary for Program<Type> {
#[derive(Clone, Debug)]
pub enum TopLevel<Type> {
Statement(Expression<Type>),
// FIXME: Is the return type actually necessary, given we can infer it from
// the expression type?
Function(Variable, Vec<(Variable, Type)>, Type, Expression<Type>),
}

20
src/syntax/ast.rs
View File

@@ -27,12 +27,6 @@ pub struct Program {
#[derive(Clone, Debug, PartialEq)]
pub enum TopLevel {
Expression(Expression),
Function(
Option<Name>,
Vec<(Name, Option<Type>)>,
Option<Type>,
Expression,
),
Structure(Location, Name, Vec<(Name, Type)>),
}
@@ -103,6 +97,13 @@ pub enum Expression {
Call(Location, Box<Expression>, Vec<Expression>),
Block(Location, Vec<Expression>),
Binding(Location, Name, Box<Expression>),
Function(
Location,
Option<Name>,
Vec<(Name, Option<Type>)>,
Option<Type>,
Box<Expression>,
),
}
impl Expression {
@@ -157,6 +158,12 @@ impl PartialEq for Expression {
Expression::Binding(_, name2, expr2) => name1 == name2 && expr1 == expr2,
_ => false,
},
Expression::Function(_, mname1, args1, mret1, body1) => match other {
Expression::Function(_, mname2, args2, mret2, body2) => {
mname1 == mname2 && args1 == args2 && mret1 == mret2 && body1 == body2
}
_ => false,
},
}
}
}
@@ -174,6 +181,7 @@ impl Expression {
Expression::Call(loc, _, _) => loc,
Expression::Block(loc, _) => loc,
Expression::Binding(loc, _, _) => loc,
Expression::Function(loc, _, _, _, _) => loc,
}
}
}

35
src/syntax/eval.rs
View File

@@ -24,22 +24,6 @@ impl Program {
for stmt in self.items.iter() {
match stmt {
TopLevel::Function(name, arg_names, _, body) => {
last_result = Value::Closure(
name.clone().map(Name::intern),
env.clone(),
arg_names
.iter()
.cloned()
.map(|(x, _)| Name::intern(x))
.collect(),
body.clone(),
);
if let Some(name) = name {
env.insert(name.clone().intern(), last_result.clone());
}
}
TopLevel::Expression(expr) => last_result = expr.eval(&mut stdout, &mut env)?,
TopLevel::Structure(_, _, _) => {
@@ -191,6 +175,25 @@ impl Expression {
env.insert(name.clone().intern(), actual_value.clone());
Ok(actual_value)
}
Expression::Function(_, name, arg_names, _, body) => {
let result = Value::Closure(
name.clone().map(Name::intern),
env.clone(),
arg_names
.iter()
.cloned()
.map(|(x, _)| Name::intern(x))
.collect(),
*body.clone(),
);
if let Some(name) = name {
env.insert(name.clone().intern(), result.clone());
}
Ok(result)
}
}
}
}

13
src/syntax/parser.lalrpop
View File

@@ -79,16 +79,10 @@ ProgramTopLevel: Vec<TopLevel> = {
}
pub TopLevel: TopLevel = {
<f:Function> => f,
<s:Structure> => s,
<s:Expression> ";" => TopLevel::Expression(s),
}
Function: TopLevel = {
"function" <opt_name:Name?> "(" <args:Comma<Argument>> ")" <ret:("->" Type)?> <exp:Expression> ";" =>
TopLevel::Function(opt_name, args, ret.map(|x| x.1), exp),
}
Argument: (Name, Option<Type>) = {
<name_start: @L> <v:"<var>"> <name_end: @L> <t:(":" Type)?> =>
(Name::new(v, Location::new(file_idx, name_start..name_end)), t.map(|v| v.1)),
@@ -170,6 +164,13 @@ BindingExpression: Expression = {
Box::new(e),
),
FunctionExpression,
}
FunctionExpression: Expression = {
<s:@L> "function" <opt_name:Name?> "(" <args:Comma<Argument>> ")" <ret:("->" Type)?> <exp:Expression> <e:@L> =>
Expression::Function(Location::new(file_idx, s..e), opt_name, args, ret.map(|x| x.1), Box::new(exp)),
PrintExpression,
}

82
src/syntax/pretty.rs
View File

@@ -21,47 +21,6 @@ impl TopLevel {
pub fn pretty<'a>(&self, allocator: &'a Allocator<'a>) -> DocBuilder<'a, Allocator<'a>> {
match self {
TopLevel::Expression(expr) => expr.pretty(allocator),
TopLevel::Function(name, args, rettype, body) => allocator
.text("function")
.append(allocator.space())
.append(
name.as_ref()
.map(|x| allocator.text(x.to_string()))
.unwrap_or_else(|| allocator.nil()),
)
.append(
allocator
.intersperse(
args.iter().map(|(x, t)| {
allocator.text(x.to_string()).append(
t.as_ref()
.map(|t| {
allocator
.text(":")
.append(allocator.space())
.append(t.pretty(allocator))
})
.unwrap_or_else(|| allocator.nil()),
)
}),
allocator.text(","),
)
.parens(),
)
.append(
rettype
.as_ref()
.map(|rettype| {
allocator
.space()
.append(allocator.text("->"))
.append(allocator.space())
.append(rettype.pretty(allocator))
})
.unwrap_or_else(|| allocator.nil()),
)
.append(allocator.space())
.append(body.pretty(allocator)),
TopLevel::Structure(_, name, fields) => allocator
.text("struct")
.append(allocator.space())
@@ -148,6 +107,47 @@ impl Expression {
.append(allocator.text("="))
.append(allocator.space())
.append(expr.pretty(allocator)),
Expression::Function(_, name, args, rettype, body) => allocator
.text("function")
.append(allocator.space())
.append(
name.as_ref()
.map(|x| allocator.text(x.to_string()))
.unwrap_or_else(|| allocator.nil()),
)
.append(
allocator
.intersperse(
args.iter().map(|(x, t)| {
allocator.text(x.to_string()).append(
t.as_ref()
.map(|t| {
allocator
.text(":")
.append(allocator.space())
.append(t.pretty(allocator))
})
.unwrap_or_else(|| allocator.nil()),
)
}),
allocator.text(","),
)
.parens(),
)
.append(
rettype
.as_ref()
.map(|rettype| {
allocator
.space()
.append(allocator.text("->"))
.append(allocator.space())
.append(rettype.pretty(allocator))
})
.unwrap_or_else(|| allocator.nil()),
)
.append(allocator.space())
.append(body.pretty(allocator)),
}
}
}

27
src/syntax/validate.rs
View File

@@ -84,9 +84,6 @@ impl Program {
let mut warnings = vec![];
for stmt in self.items.iter() {
if let TopLevel::Function(Some(name), _, _, _) = stmt {
bound_variables.insert(name.to_string(), name.location.clone());
}
let (mut new_errors, mut new_warnings) = stmt.validate_with_bindings(bound_variables);
errors.append(&mut new_errors);
warnings.append(&mut new_warnings);
@@ -119,18 +116,6 @@ impl TopLevel {
bound_variables: &mut ScopedMap<String, Location>,
) -> (Vec<Error>, Vec<Warning>) {
match self {
TopLevel::Function(name, arguments, _, body) => {
bound_variables.new_scope();
if let Some(name) = name {
bound_variables.insert(name.name.clone(), name.location.clone());
}
for (arg, _) in arguments.iter() {
bound_variables.insert(arg.name.clone(), arg.location.clone());
}
let result = body.validate(bound_variables);
bound_variables.release_scope();
result
}
TopLevel::Expression(expr) => expr.validate(bound_variables),
TopLevel::Structure(_, _, _) => (vec![], vec![]),
}
@@ -214,6 +199,18 @@ impl Expression {
(errors, warnings)
}
Expression::Function(_, name, arguments, _, body) => {
if let Some(name) = name {
variable_map.insert(name.name.clone(), name.location.clone());
}
variable_map.new_scope();
for (arg, _) in arguments.iter() {
variable_map.insert(arg.name.clone(), arg.location.clone());
}
let result = body.validate(variable_map);
variable_map.release_scope();
result
}
}
}
}

62
src/type_infer.rs
View File

@@ -10,20 +10,43 @@
//! all the constraints we've generated. If that's successful, in the final phase, we
//! do the final conversion to the IR AST, filling in any type information we've learned
//! along the way.
mod constraint;
mod convert;
mod error;
mod finalize;
mod result;
mod solve;
mod warning;
use self::convert::convert_program;
use self::finalize::finalize_program;
use self::solve::solve_constraints;
pub use self::solve::{TypeInferenceError, TypeInferenceResult, TypeInferenceWarning};
use self::constraint::Constraint;
use self::error::TypeInferenceError;
pub use self::result::TypeInferenceResult;
use self::warning::TypeInferenceWarning;
use crate::ir::ast as ir;
use crate::syntax;
#[cfg(test)]
use crate::syntax::arbitrary::GenerationEnvironment;
use internment::ArcIntern;
#[cfg(test)]
use proptest::prelude::Arbitrary;
use std::collections::HashMap;
#[derive(Default)]
struct InferenceEngine {
constraints: Vec<Constraint>,
type_definitions: HashMap<ArcIntern<String>, ir::TypeOrVar>,
variable_types: HashMap<ArcIntern<String>, ir::TypeOrVar>,
functions: HashMap<
ArcIntern<String>,
(
Vec<(ArcIntern<String>, ir::TypeOrVar)>,
ir::Expression<ir::TypeOrVar>,
),
>,
statements: Vec<ir::Expression<ir::TypeOrVar>>,
errors: Vec<TypeInferenceError>,
warnings: Vec<TypeInferenceWarning>,
}
impl syntax::Program {
/// Infer the types for the syntactic AST, returning either a type-checked program in
@@ -32,10 +55,35 @@ impl syntax::Program {
/// You really should have made sure that this program was validated before running
/// this method, otherwise you may experience panics during operation.
pub fn type_infer(self) -> TypeInferenceResult<ir::Program<ir::Type>> {
let (program, constraint_db) = convert_program(self);
let inference_result = solve_constraints(&program.type_definitions, constraint_db);
let mut engine = InferenceEngine::default();
engine.injest_program(self);
engine.solve_constraints();
inference_result.map(|resolutions| finalize_program(program, &resolutions))
if engine.errors.is_empty() {
let resolutions = std::mem::take(&mut engine.constraints)
.into_iter()
.map(|constraint| match constraint {
Constraint::Equivalent(_, ir::TypeOrVar::Variable(_, name), result) => {
match result.try_into() {
Err(e) => panic!("Ended up with complex type {}", e),
Ok(v) => (name, v),
}
}
_ => panic!("Had something that wasn't an equivalence left at the end!"),
})
.collect();
let warnings = std::mem::take(&mut engine.warnings);
TypeInferenceResult::Success {
result: engine.finalize_program(resolutions),
warnings,
}
} else {
TypeInferenceResult::Failure {
errors: engine.errors,
warnings: engine.warnings,
}
}
}
}

79
src/type_infer/constraint.rs Normal file
View File

@@ -0,0 +1,79 @@
use crate::ir::TypeOrVar;
use crate::syntax::Location;
use internment::ArcIntern;
use std::fmt;
/// A type inference constraint that we're going to need to solve.
#[derive(Debug)]
pub enum Constraint {
/// The given type must be printable using the `print` built-in
Printable(Location, TypeOrVar),
/// The provided numeric value fits in the given constant type
FitsInNumType(Location, TypeOrVar, u64),
/// The given type can be casted to the target type safely
CanCastTo(Location, TypeOrVar, TypeOrVar),
/// The given type has the given field in it, and the type of that field
/// is as given.
TypeHasField(Location, TypeOrVar, ArcIntern<String>, TypeOrVar),
/// The given type must be some numeric type, but this is not a constant
/// value, so don't try to default it if we can't figure it out
NumericType(Location, TypeOrVar),
/// The given type is attached to a constant and must be some numeric type.
/// If we can't figure it out, we should warn the user and then just use a
/// default.
ConstantNumericType(Location, TypeOrVar),
/// The two types should be equivalent
Equivalent(Location, TypeOrVar, TypeOrVar),
/// The given type can be resolved to something
IsSomething(Location, TypeOrVar),
/// The given type can be negated
IsSigned(Location, TypeOrVar),
/// Checks to see if the given named type is equivalent to the provided one.
NamedTypeIs(Location, ArcIntern<String>, TypeOrVar),
}
impl fmt::Display for Constraint {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Constraint::Printable(_, ty) => write!(f, "PRINTABLE {}", ty),
Constraint::FitsInNumType(_, ty, num) => write!(f, "FITS_IN {} {}", num, ty),
Constraint::CanCastTo(_, ty, ty2) => write!(f, "CAST {} -> {}", ty, ty2),
Constraint::TypeHasField(_, ty1, field, ty2) => {
write!(f, "FIELD {}.{} -> {}", ty1, field, ty2)
}
Constraint::NumericType(_, ty) => write!(f, "NUMERIC {}", ty),
Constraint::ConstantNumericType(_, ty) => write!(f, "CONST_NUMERIC {}", ty),
Constraint::Equivalent(_, ty, ty2) => write!(f, "EQUIVALENT {} => {}", ty, ty2),
Constraint::IsSomething(_, ty) => write!(f, "SOMETHING {}", ty),
Constraint::IsSigned(_, ty) => write!(f, "SIGNED {}", ty),
Constraint::NamedTypeIs(_, name, ty) => write!(f, "TYPE_EQUIV {} == {}", name, ty),
}
}
}
impl Constraint {
/// Replace all instances of the name (anywhere! including on the left hand side of equivalences!)
/// with the given type.
///
/// Returns whether or not anything was changed in the constraint.
pub fn replace(&mut self, name: &ArcIntern<String>, replace_with: &TypeOrVar) -> bool {
match self {
Constraint::Printable(_, ty) => ty.replace(name, replace_with),
Constraint::FitsInNumType(_, ty, _) => ty.replace(name, replace_with),
Constraint::CanCastTo(_, ty1, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::TypeHasField(_, ty1, _, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::ConstantNumericType(_, ty) => ty.replace(name, replace_with),
Constraint::Equivalent(_, ty1, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::IsSigned(_, ty) => ty.replace(name, replace_with),
Constraint::IsSomething(_, ty) => ty.replace(name, replace_with),
Constraint::NumericType(_, ty) => ty.replace(name, replace_with),
Constraint::NamedTypeIs(_, name, ty) => ty.replace(name, replace_with),
}
}
}

467
src/type_infer/convert.rs
View File

@@ -1,17 +1,32 @@
use super::constraint::Constraint;
use super::InferenceEngine;
use crate::eval::PrimitiveType;
use crate::ir;
use crate::syntax::{self, ConstantType};
use crate::type_infer::solve::Constraint;
use crate::util::scoped_map::ScopedMap;
use internment::ArcIntern;
use std::collections::HashMap;
use std::collections::{HashMap, HashSet};
use std::str::FromStr;
enum TopLevelItem {
Type(ArcIntern<String>, ir::TypeOrVar),
Value(ir::TopLevel<ir::TypeOrVar>),
struct ExpressionInfo {
expression: ir::Expression<ir::TypeOrVar>,
result_type: ir::TypeOrVar,
free_variables: HashSet<ArcIntern<String>>,
bound_variables: HashSet<ArcIntern<String>>,
}
impl ExpressionInfo {
fn simple(expression: ir::Expression<ir::TypeOrVar>, result_type: ir::TypeOrVar) -> Self {
ExpressionInfo {
expression,
result_type,
free_variables: HashSet::new(),
bound_variables: HashSet::new(),
}
}
}
impl InferenceEngine {
/// This function takes a syntactic program and converts it into the IR version of the
/// program, with appropriate type variables introduced and their constraints added to
/// the given database.
@@ -19,144 +34,37 @@ enum TopLevelItem {
/// If the input function has been validated (which it should be), then this should run
/// into no error conditions. However, if you failed to validate the input, then this
/// function can panic.
pub fn convert_program(
mut program: syntax::Program,
) -> (ir::Program<ir::TypeOrVar>, Vec<Constraint>) {
let mut constraint_db = Vec::new();
let mut items = Vec::new();
pub fn injest_program(&mut self, program: syntax::Program) {
let mut renames = ScopedMap::new();
let mut bindings = HashMap::new();
let mut type_definitions = HashMap::new();
for item in program.items.drain(..) {
let tli = convert_top_level(item, &mut constraint_db, &mut renames, &mut bindings);
match tli {
TopLevelItem::Value(item) => items.push(item),
TopLevelItem::Type(name, decl) => {
let _ = type_definitions.insert(name, decl);
for item in program.items.into_iter() {
self.convert_top_level(item, &mut renames);
}
}
}
(
ir::Program {
items,
type_definitions,
},
constraint_db,
)
}
/// This function takes a top-level item and converts it into the IR version of the
/// program, with all the appropriate type variables introduced and their constraints
/// added to the given database.
fn convert_top_level(
&mut self,
top_level: syntax::TopLevel,
constraint_db: &mut Vec<Constraint>,
renames: &mut ScopedMap<ArcIntern<String>, ArcIntern<String>>,
bindings: &mut HashMap<ArcIntern<String>, ir::TypeOrVar>,
) -> TopLevelItem {
) {
match top_level {
syntax::TopLevel::Function(name, args, _, expr) => {
// First, at some point we're going to want to know a location for this function,
// which should either be the name if we have one, or the body if we don't.
let function_location = match name {
None => expr.location().clone(),
Some(ref name) => name.location.clone(),
};
// Next, let us figure out what we're going to name this function. If the user
// didn't provide one, we'll just call it "function:<something>" for them. (We'll
// want a name for this function, eventually, so we might as well do it now.)
//
// If they did provide a name, see if we're shadowed. IF we are, then we'll have
// to specialize the name a bit. Otherwise we'll stick with their name.
let function_name = match name {
None => ir::gensym("function"),
Some(unbound) => finalize_name(bindings, renames, unbound),
};
// This function is going to have a type. We don't know what it is, but it'll have
// one.
let function_type = ir::TypeOrVar::new();
bindings.insert(function_name.clone(), function_type.clone());
// Then, let's figure out what to do with the argument names, which similarly
// may need to be renamed. We'll also generate some new type variables to associate
// with all of them.
//
// Note that we want to do all this in a new renaming scope, so that we shadow
// appropriately.
renames.new_scope();
let arginfo = args
.into_iter()
.map(|(name, mut declared_type)| {
let new_type = ir::TypeOrVar::new();
constraint_db.push(Constraint::IsSomething(
name.location.clone(),
new_type.clone(),
));
let new_name = finalize_name(bindings, renames, name.clone());
bindings.insert(new_name.clone(), new_type.clone());
if let Some(declared_type) = declared_type.take() {
let declared_type = convert_type(declared_type, constraint_db);
constraint_db.push(Constraint::Equivalent(
name.location.clone(),
new_type.clone(),
declared_type,
));
syntax::TopLevel::Expression(expr) => {
let expr_info = self.convert_expression(expr, renames);
self.statements.push(expr_info.expression);
}
(new_name, new_type)
})
.collect::<Vec<_>>();
// Now we manufacture types for the outputs and then a type for the function itself.
// We're not going to make any claims on these types, yet; they're all just unknown
// type variables we need to work out.
let rettype = ir::TypeOrVar::new();
let actual_function_type = ir::TypeOrVar::Function(
arginfo.iter().map(|x| x.1.clone()).collect(),
Box::new(rettype.clone()),
);
constraint_db.push(Constraint::Equivalent(
function_location,
function_type,
actual_function_type,
));
// Now let's convert the body over to the new IR.
let (expr, ty) = convert_expression(expr, constraint_db, renames, bindings);
constraint_db.push(Constraint::Equivalent(
expr.location().clone(),
rettype.clone(),
ty,
));
// Remember to exit this scoping level!
renames.release_scope();
TopLevelItem::Value(ir::TopLevel::Function(
function_name,
arginfo,
rettype,
expr,
))
}
syntax::TopLevel::Expression(expr) => TopLevelItem::Value(ir::TopLevel::Statement(
convert_expression(expr, constraint_db, renames, bindings).0,
)),
syntax::TopLevel::Structure(_loc, name, fields) => {
let mut updated_fields = ir::Fields::default();
for (name, field_type) in fields.into_iter() {
updated_fields.insert(name.intern(), convert_type(field_type, constraint_db));
updated_fields.insert(name.intern(), self.convert_type(field_type));
}
TopLevelItem::Type(name.intern(), ir::TypeOrVar::Structure(updated_fields))
self.type_definitions
.insert(name.intern(), ir::TypeOrVar::Structure(updated_fields));
}
}
}
@@ -173,11 +81,10 @@ fn convert_top_level(
/// you have run [`Statement::validate`], and will trigger panics in error
/// conditions if you have run that and had it come back clean.
fn convert_expression(
&mut self,
expression: syntax::Expression,
constraint_db: &mut Vec<Constraint>,
renames: &mut ScopedMap<ArcIntern<String>, ArcIntern<String>>,
bindings: &mut HashMap<ArcIntern<String>, ir::TypeOrVar>,
) -> (ir::Expression<ir::TypeOrVar>, ir::TypeOrVar) {
) -> ExpressionInfo {
match expression {
// converting values is mostly tedious, because there's so many cases
// involved
@@ -188,7 +95,7 @@ fn convert_expression(
let newtype = ir::TypeOrVar::new();
let newval = ir::Value::U64(base, value);
constraint_db.push(Constraint::ConstantNumericType(
self.constraints.push(Constraint::ConstantNumericType(
loc.clone(),
newtype.clone(),
));
@@ -232,12 +139,13 @@ fn convert_expression(
),
};
constraint_db.push(Constraint::FitsInNumType(
self.constraints.push(Constraint::FitsInNumType(
loc.clone(),
newtype.clone(),
value,
));
(
ExpressionInfo::simple(
ir::Expression::Atomic(ir::ValueOrRef::Value(loc, newtype.clone(), newval)),
newtype,
)
@@ -248,75 +156,107 @@ fn convert_expression(
let mut result_fields = HashMap::new();
let mut type_fields = ir::Fields::default();
let mut prereqs = vec![];
let mut free_variables = HashSet::new();
let mut bound_variables = HashSet::new();
for (name, syntax_expr) in fields.into_iter() {
let (ir_expr, expr_type) =
convert_expression(syntax_expr, constraint_db, renames, bindings);
type_fields.insert(name.clone().intern(), expr_type);
let (prereq, value) = simplify_expr(ir_expr);
let field_expr_info = self.convert_expression(syntax_expr, renames);
type_fields.insert(name.clone().intern(), field_expr_info.result_type);
let (prereq, value) = simplify_expr(field_expr_info.expression);
result_fields.insert(name.clone().intern(), value);
merge_prereq(&mut prereqs, prereq);
free_variables.extend(field_expr_info.free_variables);
bound_variables.extend(field_expr_info.bound_variables);
}
let result_type = ir::TypeOrVar::Structure(type_fields);
constraint_db.push(Constraint::NamedTypeIs(
self.constraints.push(Constraint::NamedTypeIs(
loc.clone(),
name.clone().intern(),
result_type.clone(),
));
let result =
ir::Expression::Construct(loc, result_type.clone(), name.intern(), result_fields);
let expression = ir::Expression::Construct(
loc,
result_type.clone(),
name.intern(),
result_fields,
);
(finalize_expressions(prereqs, result), result_type)
ExpressionInfo {
expression,
result_type,
free_variables,
bound_variables,
}
}
syntax::Expression::Reference(loc, name) => {
let iname = ArcIntern::new(name);
let final_name = renames.get(&iname).cloned().unwrap_or(iname);
let rtype = bindings
let result_type = self
.variable_types
.get(&final_name)
.cloned()
.expect("variable bound before use");
let refexp =
ir::Expression::Atomic(ir::ValueOrRef::Ref(loc, rtype.clone(), final_name));
let expression = ir::Expression::Atomic(ir::ValueOrRef::Ref(
loc,
result_type.clone(),
final_name.clone(),
));
let free_variables = HashSet::from([final_name]);
(refexp, rtype)
ExpressionInfo {
expression,
result_type,
free_variables,
bound_variables: HashSet::new(),
}
}
syntax::Expression::FieldRef(loc, expr, field) => {
let (nexpr, etype) = convert_expression(*expr, constraint_db, renames, bindings);
let (prereqs, val_or_ref) = simplify_expr(nexpr);
let mut expr_info = self.convert_expression(*expr, renames);
let (prereqs, val_or_ref) = simplify_expr(expr_info.expression);
let result_type = ir::TypeOrVar::new();
let result = ir::Expression::FieldRef(
loc.clone(),
result_type.clone(),
etype.clone(),
expr_info.result_type.clone(),
val_or_ref,
field.clone().intern(),
);
constraint_db.push(Constraint::TypeHasField(
self.constraints.push(Constraint::TypeHasField(
loc,
etype,
expr_info.result_type.clone(),
field.intern(),
result_type.clone(),
));
(finalize_expression(prereqs, result), result_type)
expr_info.expression = finalize_expression(prereqs, result);
expr_info.result_type = result_type;
expr_info
}
syntax::Expression::Cast(loc, target, expr) => {
let (nexpr, etype) = convert_expression(*expr, constraint_db, renames, bindings);
let (prereqs, val_or_ref) = simplify_expr(nexpr);
let mut expr_info = self.convert_expression(*expr, renames);
let (prereqs, val_or_ref) = simplify_expr(expr_info.expression);
let target_type: ir::TypeOrVar = PrimitiveType::from_str(&target)
.expect("valid type for cast")
.into();
let res = ir::Expression::Cast(loc.clone(), target_type.clone(), val_or_ref);
constraint_db.push(Constraint::CanCastTo(loc, etype, target_type.clone()));
self.constraints.push(Constraint::CanCastTo(
loc,
expr_info.result_type.clone(),
target_type.clone(),
));
(finalize_expression(prereqs, res), target_type)
expr_info.expression = finalize_expression(prereqs, res);
expr_info.result_type = target_type;
expr_info
}
syntax::Expression::Primitive(loc, name) => {
@@ -325,45 +265,50 @@ fn convert_expression(
match primop {
ir::Primitive::Plus | ir::Primitive::Times | ir::Primitive::Divide => {
let numeric_type = ir::TypeOrVar::new_located(loc.clone());
constraint_db.push(Constraint::NumericType(loc.clone(), numeric_type.clone()));
self.constraints
.push(Constraint::NumericType(loc.clone(), numeric_type.clone()));
let funtype = ir::TypeOrVar::Function(
vec![numeric_type.clone(), numeric_type.clone()],
Box::new(numeric_type.clone()),
);
let result_value = ir::ValueOrRef::Primitive(loc, funtype.clone(), primop);
(ir::Expression::Atomic(result_value), funtype)
ExpressionInfo::simple(ir::Expression::Atomic(result_value), funtype)
}
ir::Primitive::Minus => {
let numeric_type = ir::TypeOrVar::new_located(loc.clone());
constraint_db.push(Constraint::NumericType(loc.clone(), numeric_type.clone()));
self.constraints
.push(Constraint::NumericType(loc.clone(), numeric_type.clone()));
let funtype = ir::TypeOrVar::Function(
vec![numeric_type.clone(), numeric_type.clone()],
Box::new(numeric_type.clone()),
);
let result_value = ir::ValueOrRef::Primitive(loc, funtype.clone(), primop);
(ir::Expression::Atomic(result_value), funtype)
ExpressionInfo::simple(ir::Expression::Atomic(result_value), funtype)
}
ir::Primitive::Print => {
let arg_type = ir::TypeOrVar::new_located(loc.clone());
constraint_db.push(Constraint::Printable(loc.clone(), arg_type.clone()));
self.constraints
.push(Constraint::Printable(loc.clone(), arg_type.clone()));
let funtype = ir::TypeOrVar::Function(
vec![arg_type],
Box::new(ir::TypeOrVar::Primitive(PrimitiveType::Void)),
);
let result_value = ir::ValueOrRef::Primitive(loc, funtype.clone(), primop);
(ir::Expression::Atomic(result_value), funtype)
ExpressionInfo::simple(ir::Expression::Atomic(result_value), funtype)
}
ir::Primitive::Negate => {
let arg_type = ir::TypeOrVar::new_located(loc.clone());
constraint_db.push(Constraint::NumericType(loc.clone(), arg_type.clone()));
constraint_db.push(Constraint::IsSigned(loc.clone(), arg_type.clone()));
self.constraints
.push(Constraint::NumericType(loc.clone(), arg_type.clone()));
self.constraints
.push(Constraint::IsSigned(loc.clone(), arg_type.clone()));
let funtype =
ir::TypeOrVar::Function(vec![arg_type.clone()], Box::new(arg_type));
let result_value = ir::ValueOrRef::Primitive(loc, funtype.clone(), primop);
(ir::Expression::Atomic(result_value), funtype)
ExpressionInfo::simple(ir::Expression::Atomic(result_value), funtype)
}
}
}
@@ -375,79 +320,185 @@ fn convert_expression(
.map(|_| ir::TypeOrVar::new())
.collect::<Vec<_>>();
let (new_fun, new_fun_type) =
convert_expression(*fun, constraint_db, renames, bindings);
let mut expr_info = self.convert_expression(*fun, renames);
let target_fun_type =
ir::TypeOrVar::Function(arg_types.clone(), Box::new(return_type.clone()));
constraint_db.push(Constraint::Equivalent(
self.constraints.push(Constraint::Equivalent(
loc.clone(),
new_fun_type,
expr_info.result_type,
target_fun_type,
));
let mut prereqs = vec![];
let (fun_prereqs, fun) = simplify_expr(new_fun);
let (fun_prereqs, fun) = simplify_expr(expr_info.expression);
merge_prereq(&mut prereqs, fun_prereqs);
let new_args = args
.into_iter()
.zip(arg_types)
.map(|(arg, target_type)| {
let (new_arg, inferred_type) =
convert_expression(arg, constraint_db, renames, bindings);
let location = new_arg.location().clone();
let (arg_prereq, new_valref) = simplify_expr(new_arg);
let arg_info = self.convert_expression(arg, renames);
let location = arg_info.expression.location().clone();
let (arg_prereq, new_valref) = simplify_expr(arg_info.expression);
merge_prereq(&mut prereqs, arg_prereq);
constraint_db.push(Constraint::Equivalent(
self.constraints.push(Constraint::Equivalent(
location,
inferred_type,
arg_info.result_type,
target_type,
));
expr_info.free_variables.extend(arg_info.free_variables);
expr_info.bound_variables.extend(arg_info.bound_variables);
new_valref
})
.collect();
let last_call = ir::Expression::Call(loc.clone(), return_type.clone(), fun, new_args);
let last_call =
ir::Expression::Call(loc.clone(), return_type.clone(), fun, new_args);
(finalize_expressions(prereqs, last_call), return_type)
expr_info.expression = finalize_expressions(prereqs, last_call);
expr_info.result_type = return_type;
expr_info
}
syntax::Expression::Block(loc, stmts) => {
let mut ret_type = ir::TypeOrVar::Primitive(PrimitiveType::Void);
let mut result_type = ir::TypeOrVar::Primitive(PrimitiveType::Void);
let mut exprs = vec![];
let mut free_variables = HashSet::new();
let mut bound_variables = HashSet::new();
for xpr in stmts.into_iter() {
let (expr, expr_type) = convert_expression(xpr, constraint_db, renames, bindings);
ret_type = expr_type;
exprs.push(expr);
let expr_info = self.convert_expression(xpr, renames);
result_type = expr_info.result_type;
exprs.push(expr_info.expression);
free_variables.extend(
expr_info
.free_variables
.difference(&bound_variables)
.cloned()
.collect::<Vec<_>>(),
);
bound_variables.extend(expr_info.bound_variables);
}
(
ir::Expression::Block(loc, ret_type.clone(), exprs),
ret_type,
)
ExpressionInfo {
expression: ir::Expression::Block(loc, result_type.clone(), exprs),
result_type,
free_variables,
bound_variables,
}
}
syntax::Expression::Binding(loc, name, expr) => {
let (expr, ty) = convert_expression(*expr, constraint_db, renames, bindings);
let final_name = finalize_name(bindings, renames, name);
bindings.insert(final_name.clone(), ty.clone());
let mut expr_info = self.convert_expression(*expr, renames);
let final_name = self.finalize_name(renames, name);
self.variable_types
.insert(final_name.clone(), expr_info.result_type.clone());
expr_info.expression = ir::Expression::Bind(
loc,
final_name.clone(),
expr_info.result_type.clone(),
Box::new(expr_info.expression),
);
expr_info.bound_variables.insert(final_name);
expr_info
}
(
ir::Expression::Bind(loc, final_name, ty.clone(), Box::new(expr)),
ty,
)
syntax::Expression::Function(_, name, args, _, expr) => {
// First, at some point we're going to want to know a location for this function,
// which should either be the name if we have one, or the body if we don't.
let function_location = match name {
None => expr.location().clone(),
Some(ref name) => name.location.clone(),
};
// Next, let us figure out what we're going to name this function. If the user
// didn't provide one, we'll just call it "function:<something>" for them. (We'll
// want a name for this function, eventually, so we might as well do it now.)
//
// If they did provide a name, see if we're shadowed. IF we are, then we'll have
// to specialize the name a bit. Otherwise we'll stick with their name.
let function_name = match name {
None => ir::gensym("function"),
Some(unbound) => self.finalize_name(renames, unbound),
};
// This function is going to have a type. We don't know what it is, but it'll have
// one.
let function_type = ir::TypeOrVar::new();
self.variable_types
.insert(function_name.clone(), function_type.clone());
// Then, let's figure out what to do with the argument names, which similarly
// may need to be renamed. We'll also generate some new type variables to associate
// with all of them.
//
// Note that we want to do all this in a new renaming scope, so that we shadow
// appropriately.
renames.new_scope();
let arginfo = args
.into_iter()
.map(|(name, mut declared_type)| {
let new_type = ir::TypeOrVar::new();
self.constraints.push(Constraint::IsSomething(
name.location.clone(),
new_type.clone(),
));
let new_name = self.finalize_name(renames, name.clone());
self.variable_types
.insert(new_name.clone(), new_type.clone());
if let Some(declared_type) = declared_type.take() {
let declared_type = self.convert_type(declared_type);
self.constraints.push(Constraint::Equivalent(
name.location.clone(),
new_type.clone(),
declared_type,
));
}
(new_name, new_type)
})
.collect::<Vec<_>>();
// Now we manufacture types for the outputs and then a type for the function itself.
// We're not going to make any claims on these types, yet; they're all just unknown
// type variables we need to work out.
let rettype = ir::TypeOrVar::new();
let actual_function_type = ir::TypeOrVar::Function(
arginfo.iter().map(|x| x.1.clone()).collect(),
Box::new(rettype.clone()),
);
self.constraints.push(Constraint::Equivalent(
function_location,
function_type,
actual_function_type,
));
// Now let's convert the body over to the new IR.
let expr_info = self.convert_expression(*expr, renames);
self.constraints.push(Constraint::Equivalent(
expr_info.expression.location().clone(),
rettype.clone(),
expr_info.result_type.clone(),
));
// Remember to exit this scoping level!
renames.release_scope();
self.functions
.insert(function_name, (arginfo, expr_info.expression.clone()));
unimplemented!()
}
}
}
fn convert_type(ty: syntax::Type, constraint_db: &mut Vec<Constraint>) -> ir::TypeOrVar {
fn convert_type(&mut self, ty: syntax::Type) -> ir::TypeOrVar {
match ty {
syntax::Type::Named(x) => match PrimitiveType::from_str(x.name.as_str()) {
Err(_) => {
let retval = ir::TypeOrVar::new_located(x.location.clone());
constraint_db.push(Constraint::NamedTypeIs(
self.constraints.push(Constraint::NamedTypeIs(
x.location.clone(),
x.intern(),
retval.clone(),
@@ -461,7 +512,7 @@ fn convert_type(ty: syntax::Type, constraint_db: &mut Vec<Constraint>) -> ir::Ty
for (name, field_type) in fields.into_iter() {
let new_field_type = field_type
.map(|x| convert_type(x, constraint_db))
.map(|x| self.convert_type(x))
.unwrap_or_else(ir::TypeOrVar::new);
new_fields.insert(name.intern(), new_field_type);
}
@@ -471,6 +522,24 @@ fn convert_type(ty: syntax::Type, constraint_db: &mut Vec<Constraint>) -> ir::Ty
}
}
fn finalize_name(
&mut self,
renames: &mut ScopedMap<ArcIntern<String>, ArcIntern<String>>,
name: syntax::Name,
) -> ArcIntern<String> {
if self
.variable_types
.contains_key(&ArcIntern::new(name.name.clone()))
{
let new_name = ir::gensym(&name.name);
renames.insert(ArcIntern::new(name.name.to_string()), new_name.clone());
new_name
} else {
ArcIntern::new(name.to_string())
}
}
}
fn simplify_expr(
expr: ir::Expression<ir::TypeOrVar>,
) -> (
@@ -520,20 +589,6 @@ fn finalize_expressions(
}
}
fn finalize_name(
bindings: &HashMap<ArcIntern<String>, ir::TypeOrVar>,
renames: &mut ScopedMap<ArcIntern<String>, ArcIntern<String>>,
name: syntax::Name,
) -> ArcIntern<String> {
if bindings.contains_key(&ArcIntern::new(name.name.clone())) {
let new_name = ir::gensym(&name.name);
renames.insert(ArcIntern::new(name.name.to_string()), new_name.clone());
new_name
} else {
ArcIntern::new(name.to_string())
}
}
fn merge_prereq<T>(left: &mut Vec<T>, prereq: Option<T>) {
if let Some(item) = prereq {
left.push(item)

146
src/type_infer/error.rs Normal file
View File

@@ -0,0 +1,146 @@
use super::constraint::Constraint;
use crate::eval::PrimitiveType;
use crate::ir::{Primitive, TypeOrVar};
use crate::syntax::Location;
use codespan_reporting::diagnostic::Diagnostic;
use internment::ArcIntern;
/// The various kinds of errors that can occur while doing type inference.
pub enum TypeInferenceError {
/// The user provide a constant that is too large for its inferred type.
ConstantTooLarge(Location, PrimitiveType, u64),
/// Somehow we're trying to use a non-number as a number
NotANumber(Location, PrimitiveType),
/// The two types needed to be equivalent, but weren't.
NotEquivalent(Location, TypeOrVar, TypeOrVar),
/// We cannot safely cast the first type to the second type.
CannotSafelyCast(Location, PrimitiveType, PrimitiveType),
/// The primitive invocation provided the wrong number of arguments.
WrongPrimitiveArity(Location, Primitive, usize, usize, usize),
/// We cannot cast between the type types, for any number of reasons
CannotCast(Location, TypeOrVar, TypeOrVar),
/// We cannot turn a number into a function.
CannotMakeNumberAFunction(Location, TypeOrVar, Option<u64>),
/// We cannot turn a number into a Structure.
CannotMakeNumberAStructure(Location, TypeOrVar, Option<u64>),
/// We had a constraint we just couldn't solve.
CouldNotSolve(Constraint),
/// Functions are not printable.
FunctionsAreNotPrintable(Location),
/// The given type isn't signed, and can't be negated
IsNotSigned(Location, TypeOrVar),
/// The given type doesn't have the given field.
NoFieldForType(Location, ArcIntern<String>, TypeOrVar),
/// There is no type with the given name.
UnknownTypeName(Location, ArcIntern<String>),
}
impl From<TypeInferenceError> for Diagnostic<usize> {
fn from(value: TypeInferenceError) -> Self {
match value {
TypeInferenceError::ConstantTooLarge(loc, primty, value) => loc
.labelled_error("constant too large for type")
.with_message(format!(
"Type {} has a max value of {}, which is smaller than {}",
primty,
primty.max_value().expect("constant type has max value"),
value
)),
TypeInferenceError::NotANumber(loc, primty) => loc
.labelled_error("not a numeric type")
.with_message(format!(
"For some reason, we're trying to use {} as a numeric type",
primty,
)),
TypeInferenceError::NotEquivalent(loc, ty1, ty2) => loc
.labelled_error("type inference error")
.with_message(format!("Expected type {}, received type {}", ty1, ty2)),
TypeInferenceError::CannotSafelyCast(loc, ty1, ty2) => loc
.labelled_error("unsafe type cast")
.with_message(format!("Cannot safely cast {} to {}", ty1, ty2)),
TypeInferenceError::WrongPrimitiveArity(loc, prim, lower, upper, observed) => loc
.labelled_error("wrong number of arguments")
.with_message(format!(
"expected {} for {}, received {}",
if lower == upper && lower > 1 {
format!("{} arguments", lower)
} else if lower == upper {
format!("{} argument", lower)
} else {
format!("{}-{} arguments", lower, upper)
},
prim,
observed
)),
TypeInferenceError::CannotCast(loc, t1, t2) => loc
.labelled_error("cannot cast between types")
.with_message(format!(
"tried to cast from {} to {}",
t1, t2,
)),
TypeInferenceError::CannotMakeNumberAFunction(loc, t, val) => loc
.labelled_error(if let Some(val) = val {
format!("cannot turn {} into a function", val)
} else {
"cannot use a constant as a function type".to_string()
})
.with_message(format!("function type was {}", t)),
TypeInferenceError::CannotMakeNumberAStructure(loc, t, val) => loc
.labelled_error(if let Some(val) = val {
format!("cannot turn {} into a function", val)
} else {
"cannot use a constant as a function type".to_string()
})
.with_message(format!("function type was {}", t)),
TypeInferenceError::FunctionsAreNotPrintable(loc) => loc
.labelled_error("cannot print function values"),
TypeInferenceError::IsNotSigned(loc, pt) => loc
.labelled_error(format!("type {} is not signed", pt))
.with_message("and so it cannot be negated"),
TypeInferenceError::NoFieldForType(loc, field, t) => loc
.labelled_error(format!("no field {} available for type {}", field, t)),
TypeInferenceError::UnknownTypeName(loc , name) => loc
.labelled_error(format!("unknown type named {}", name)),
TypeInferenceError::CouldNotSolve(Constraint::CanCastTo(loc, a, b)) => {
loc.labelled_error("internal error").with_message(format!(
"could not determine if it was safe to cast from {} to {}",
a, b
))
}
TypeInferenceError::CouldNotSolve(Constraint::TypeHasField(loc, a, field, _)) => {
loc.labelled_error("internal error")
.with_message(format!("fould not determine if type {} has field {}", a, field))
}
TypeInferenceError::CouldNotSolve(Constraint::Equivalent(loc, a, b)) => {
loc.labelled_error("internal error").with_message(format!(
"could not determine if {} and {} were equivalent",
a, b
))
}
TypeInferenceError::CouldNotSolve(Constraint::FitsInNumType(loc, ty, val)) => {
loc.labelled_error("internal error").with_message(format!(
"Could not determine if {} could fit in {}",
val, ty
))
}
TypeInferenceError::CouldNotSolve(Constraint::NumericType(loc, ty)) => loc
.labelled_error("internal error")
.with_message(format!("Could not determine if {} was a numeric type", ty)),
TypeInferenceError::CouldNotSolve(Constraint::ConstantNumericType(loc, ty)) =>
panic!("What? Constants should always eventually be solved, even by default; {:?} and type {:?}", loc, ty),
TypeInferenceError::CouldNotSolve(Constraint::Printable(loc, ty)) => loc
.labelled_error("internal error")
.with_message(format!("Could not determine if type {} was printable", ty)),
TypeInferenceError::CouldNotSolve(Constraint::IsSomething(loc, _)) => {
loc.labelled_error("could not infer type")
.with_message("Could not find *any* type information; is this an unused function argument?")
}
TypeInferenceError::CouldNotSolve(Constraint::IsSigned(loc, t)) => loc
.labelled_error("internal error")
.with_message(format!("could not infer that type {} was signed", t)),
TypeInferenceError::CouldNotSolve(Constraint::NamedTypeIs(loc, name, ty)) => loc
.labelled_error("internal error")
.with_message(format!("could not infer that the name {} refers to {}", name, ty)),
}
}
}

76
src/type_infer/finalize.rs
View File

@@ -1,41 +1,61 @@
use super::solve::TypeResolutions;
use crate::eval::PrimitiveType;
use crate::ir::{Expression, Program, TopLevel, Type, TypeOrVar, Value, ValueOrRef};
use crate::ir::{Expression, Program, TopLevel, Type, TypeOrVar, TypeWithVoid, Value, ValueOrRef};
use crate::syntax::Location;
use internment::ArcIntern;
use std::collections::HashMap;
pub fn finalize_program(
program: Program<TypeOrVar>,
resolutions: &TypeResolutions,
) -> Program<Type> {
pub type TypeResolutions = HashMap<ArcIntern<String>, Type>;
impl super::InferenceEngine {
pub fn finalize_program(self, resolutions: TypeResolutions) -> Program<Type> {
for (name, ty) in resolutions.iter() {
tracing::debug!(name = %name, resolved_type = %ty, "resolved type variable");
}
Program {
items: program
.items
.into_iter()
.map(|x| finalize_top_level(x, resolutions))
.collect(),
let mut type_definitions = HashMap::new();
let mut items = Vec::new();
type_definitions: program
.type_definitions
.into_iter()
.map(|(n, t)| (n, finalize_type(t, resolutions)))
.collect(),
}
for (name, def) in self.type_definitions.into_iter() {
type_definitions.insert(name, finalize_type(def, &resolutions));
}
fn finalize_top_level(item: TopLevel<TypeOrVar>, resolutions: &TypeResolutions) -> TopLevel<Type> {
match item {
TopLevel::Function(name, args, rettype, expr) => TopLevel::Function(
for (name, (arguments, body)) in self.functions.into_iter() {
let new_body = finalize_expression(body, &resolutions);
let arguments = arguments
.into_iter()
.map(|(name, t)| (name, finalize_type(t, &resolutions)))
.collect();
items.push(TopLevel::Function(
name,
args.into_iter()
.map(|(name, t)| (name, finalize_type(t, resolutions)))
.collect(),
finalize_type(rettype, resolutions),
finalize_expression(expr, resolutions),
),
TopLevel::Statement(expr) => TopLevel::Statement(finalize_expression(expr, resolutions)),
arguments,
new_body.type_of(),
new_body,
));
}
let mut body = vec![];
let mut last_type = Type::void();
let mut location = None;
for expr in self.statements.into_iter() {
let next = finalize_expression(expr, &resolutions);
location = location
.map(|x: Location| x.merge(next.location()))
.unwrap_or_else(|| Some(next.location().clone()));
last_type = next.type_of();
body.push(next);
}
items.push(TopLevel::Statement(Expression::Block(
location.unwrap_or_else(Location::manufactured),
last_type,
body,
)));
Program {
items,
type_definitions,
}
}
}

50
src/type_infer/result.rs Normal file
View File

@@ -0,0 +1,50 @@
use super::error::TypeInferenceError;
use super::warning::TypeInferenceWarning;
/// The results of type inference; like [`Result`], but with a bit more information.
///
/// This result is parameterized, because sometimes it's handy to return slightly
/// different things; there's a [`TypeInferenceResult::map`] function for performing
/// those sorts of conversions.
pub enum TypeInferenceResult<Result> {
Success {
result: Result,
warnings: Vec<TypeInferenceWarning>,
},
Failure {
errors: Vec<TypeInferenceError>,
warnings: Vec<TypeInferenceWarning>,
},
}
impl<R> TypeInferenceResult<R> {
// If this was a successful type inference, run the function over the result to
// create a new result.
//
// This is the moral equivalent of [`Result::map`], but for type inference results.
pub fn map<U, F>(self, f: F) -> TypeInferenceResult<U>
where
F: FnOnce(R) -> U,
{
match self {
TypeInferenceResult::Success { result, warnings } => TypeInferenceResult::Success {
result: f(result),
warnings,
},
TypeInferenceResult::Failure { errors, warnings } => {
TypeInferenceResult::Failure { errors, warnings }
}
}
}
// Return the final result, or panic if it's not a success
pub fn expect(self, msg: &str) -> R {
match self {
TypeInferenceResult::Success { result, .. } => result,
TypeInferenceResult::Failure { .. } => {
panic!("tried to get value from failed type inference: {}", msg)
}
}
}
}

422
src/type_infer/solve.rs
View File

@@ -1,293 +1,11 @@
use super::constraint::Constraint;
use super::error::TypeInferenceError;
use super::warning::TypeInferenceWarning;
use crate::eval::PrimitiveType;
use crate::ir::{Primitive, Type, TypeOrVar};
use crate::syntax::Location;
use codespan_reporting::diagnostic::Diagnostic;
use crate::ir::TypeOrVar;
use internment::ArcIntern;
use std::{collections::HashMap, fmt};
/// A type inference constraint that we're going to need to solve.
#[derive(Debug)]
pub enum Constraint {
/// The given type must be printable using the `print` built-in
Printable(Location, TypeOrVar),
/// The provided numeric value fits in the given constant type
FitsInNumType(Location, TypeOrVar, u64),
/// The given type can be casted to the target type safely
CanCastTo(Location, TypeOrVar, TypeOrVar),
/// The given type has the given field in it, and the type of that field
/// is as given.
TypeHasField(Location, TypeOrVar, ArcIntern<String>, TypeOrVar),
/// The given type must be some numeric type, but this is not a constant
/// value, so don't try to default it if we can't figure it out
NumericType(Location, TypeOrVar),
/// The given type is attached to a constant and must be some numeric type.
/// If we can't figure it out, we should warn the user and then just use a
/// default.
ConstantNumericType(Location, TypeOrVar),
/// The two types should be equivalent
Equivalent(Location, TypeOrVar, TypeOrVar),
/// The given type can be resolved to something
IsSomething(Location, TypeOrVar),
/// The given type can be negated
IsSigned(Location, TypeOrVar),
/// Checks to see if the given named type is equivalent to the provided one.
NamedTypeIs(Location, ArcIntern<String>, TypeOrVar),
}
impl fmt::Display for Constraint {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Constraint::Printable(_, ty) => write!(f, "PRINTABLE {}", ty),
Constraint::FitsInNumType(_, ty, num) => write!(f, "FITS_IN {} {}", num, ty),
Constraint::CanCastTo(_, ty, ty2) => write!(f, "CAST {} -> {}", ty, ty2),
Constraint::TypeHasField(_, ty1, field, ty2) => {
write!(f, "FIELD {}.{} -> {}", ty1, field, ty2)
}
Constraint::NumericType(_, ty) => write!(f, "NUMERIC {}", ty),
Constraint::ConstantNumericType(_, ty) => write!(f, "CONST_NUMERIC {}", ty),
Constraint::Equivalent(_, ty, ty2) => write!(f, "EQUIVALENT {} => {}", ty, ty2),
Constraint::IsSomething(_, ty) => write!(f, "SOMETHING {}", ty),
Constraint::IsSigned(_, ty) => write!(f, "SIGNED {}", ty),
Constraint::NamedTypeIs(_, name, ty) => write!(f, "TYPE_EQUIV {} == {}", name, ty),
}
}
}
impl Constraint {
/// Replace all instances of the name (anywhere! including on the left hand side of equivalences!)
/// with the given type.
///
/// Returns whether or not anything was changed in the constraint.
fn replace(&mut self, name: &ArcIntern<String>, replace_with: &TypeOrVar) -> bool {
match self {
Constraint::Printable(_, ty) => ty.replace(name, replace_with),
Constraint::FitsInNumType(_, ty, _) => ty.replace(name, replace_with),
Constraint::CanCastTo(_, ty1, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::TypeHasField(_, ty1, _, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::ConstantNumericType(_, ty) => ty.replace(name, replace_with),
Constraint::Equivalent(_, ty1, ty2) => {
ty1.replace(name, replace_with) || ty2.replace(name, replace_with)
}
Constraint::IsSigned(_, ty) => ty.replace(name, replace_with),
Constraint::IsSomething(_, ty) => ty.replace(name, replace_with),
Constraint::NumericType(_, ty) => ty.replace(name, replace_with),
Constraint::NamedTypeIs(_, name, ty) => ty.replace(name, replace_with),
}
}
}
pub type TypeResolutions = HashMap<ArcIntern<String>, Type>;
/// The results of type inference; like [`Result`], but with a bit more information.
///
/// This result is parameterized, because sometimes it's handy to return slightly
/// different things; there's a [`TypeInferenceResult::map`] function for performing
/// those sorts of conversions.
pub enum TypeInferenceResult<Result> {
Success {
result: Result,
warnings: Vec<TypeInferenceWarning>,
},
Failure {
errors: Vec<TypeInferenceError>,
warnings: Vec<TypeInferenceWarning>,
},
}
impl<R> TypeInferenceResult<R> {
// If this was a successful type inference, run the function over the result to
// create a new result.
//
// This is the moral equivalent of [`Result::map`], but for type inference results.
pub fn map<U, F>(self, f: F) -> TypeInferenceResult<U>
where
F: FnOnce(R) -> U,
{
match self {
TypeInferenceResult::Success { result, warnings } => TypeInferenceResult::Success {
result: f(result),
warnings,
},
TypeInferenceResult::Failure { errors, warnings } => {
TypeInferenceResult::Failure { errors, warnings }
}
}
}
// Return the final result, or panic if it's not a success
pub fn expect(self, msg: &str) -> R {
match self {
TypeInferenceResult::Success { result, .. } => result,
TypeInferenceResult::Failure { .. } => {
panic!("tried to get value from failed type inference: {}", msg)
}
}
}
}
/// The various kinds of errors that can occur while doing type inference.
pub enum TypeInferenceError {
/// The user provide a constant that is too large for its inferred type.
ConstantTooLarge(Location, PrimitiveType, u64),
/// Somehow we're trying to use a non-number as a number
NotANumber(Location, PrimitiveType),
/// The two types needed to be equivalent, but weren't.
NotEquivalent(Location, TypeOrVar, TypeOrVar),
/// We cannot safely cast the first type to the second type.
CannotSafelyCast(Location, PrimitiveType, PrimitiveType),
/// The primitive invocation provided the wrong number of arguments.
WrongPrimitiveArity(Location, Primitive, usize, usize, usize),
/// We cannot cast between the type types, for any number of reasons
CannotCast(Location, TypeOrVar, TypeOrVar),
/// We cannot turn a number into a function.
CannotMakeNumberAFunction(Location, TypeOrVar, Option<u64>),
/// We cannot turn a number into a Structure.
CannotMakeNumberAStructure(Location, TypeOrVar, Option<u64>),
/// We had a constraint we just couldn't solve.
CouldNotSolve(Constraint),
/// Functions are not printable.
FunctionsAreNotPrintable(Location),
/// The given type isn't signed, and can't be negated
IsNotSigned(Location, TypeOrVar),
/// The given type doesn't have the given field.
NoFieldForType(Location, ArcIntern<String>, TypeOrVar),
/// There is no type with the given name.
UnknownTypeName(Location, ArcIntern<String>),
}
impl From<TypeInferenceError> for Diagnostic<usize> {
fn from(value: TypeInferenceError) -> Self {
match value {
TypeInferenceError::ConstantTooLarge(loc, primty, value) => loc
.labelled_error("constant too large for type")
.with_message(format!(
"Type {} has a max value of {}, which is smaller than {}",
primty,
primty.max_value().expect("constant type has max value"),
value
)),
TypeInferenceError::NotANumber(loc, primty) => loc
.labelled_error("not a numeric type")
.with_message(format!(
"For some reason, we're trying to use {} as a numeric type",
primty,
)),
TypeInferenceError::NotEquivalent(loc, ty1, ty2) => loc
.labelled_error("type inference error")
.with_message(format!("Expected type {}, received type {}", ty1, ty2)),
TypeInferenceError::CannotSafelyCast(loc, ty1, ty2) => loc
.labelled_error("unsafe type cast")
.with_message(format!("Cannot safely cast {} to {}", ty1, ty2)),
TypeInferenceError::WrongPrimitiveArity(loc, prim, lower, upper, observed) => loc
.labelled_error("wrong number of arguments")
.with_message(format!(
"expected {} for {}, received {}",
if lower == upper && lower > 1 {
format!("{} arguments", lower)
} else if lower == upper {
format!("{} argument", lower)
} else {
format!("{}-{} arguments", lower, upper)
},
prim,
observed
)),
TypeInferenceError::CannotCast(loc, t1, t2) => loc
.labelled_error("cannot cast between types")
.with_message(format!(
"tried to cast from {} to {}",
t1, t2,
)),
TypeInferenceError::CannotMakeNumberAFunction(loc, t, val) => loc
.labelled_error(if let Some(val) = val {
format!("cannot turn {} into a function", val)
} else {
"cannot use a constant as a function type".to_string()
})
.with_message(format!("function type was {}", t)),
TypeInferenceError::CannotMakeNumberAStructure(loc, t, val) => loc
.labelled_error(if let Some(val) = val {
format!("cannot turn {} into a function", val)
} else {
"cannot use a constant as a function type".to_string()
})
.with_message(format!("function type was {}", t)),
TypeInferenceError::FunctionsAreNotPrintable(loc) => loc
.labelled_error("cannot print function values"),
TypeInferenceError::IsNotSigned(loc, pt) => loc
.labelled_error(format!("type {} is not signed", pt))
.with_message("and so it cannot be negated"),
TypeInferenceError::NoFieldForType(loc, field, t) => loc
.labelled_error(format!("no field {} available for type {}", field, t)),
TypeInferenceError::UnknownTypeName(loc , name) => loc
.labelled_error(format!("unknown type named {}", name)),
TypeInferenceError::CouldNotSolve(Constraint::CanCastTo(loc, a, b)) => {
loc.labelled_error("internal error").with_message(format!(
"could not determine if it was safe to cast from {} to {}",
a, b
))
}
TypeInferenceError::CouldNotSolve(Constraint::TypeHasField(loc, a, field, _)) => {
loc.labelled_error("internal error")
.with_message(format!("fould not determine if type {} has field {}", a, field))
}
TypeInferenceError::CouldNotSolve(Constraint::Equivalent(loc, a, b)) => {
loc.labelled_error("internal error").with_message(format!(
"could not determine if {} and {} were equivalent",
a, b
))
}
TypeInferenceError::CouldNotSolve(Constraint::FitsInNumType(loc, ty, val)) => {
loc.labelled_error("internal error").with_message(format!(
"Could not determine if {} could fit in {}",
val, ty
))
}
TypeInferenceError::CouldNotSolve(Constraint::NumericType(loc, ty)) => loc
.labelled_error("internal error")
.with_message(format!("Could not determine if {} was a numeric type", ty)),
TypeInferenceError::CouldNotSolve(Constraint::ConstantNumericType(loc, ty)) =>
panic!("What? Constants should always eventually be solved, even by default; {:?} and type {:?}", loc, ty),
TypeInferenceError::CouldNotSolve(Constraint::Printable(loc, ty)) => loc
.labelled_error("internal error")
.with_message(format!("Could not determine if type {} was printable", ty)),
TypeInferenceError::CouldNotSolve(Constraint::IsSomething(loc, _)) => {
loc.labelled_error("could not infer type")
.with_message("Could not find *any* type information; is this an unused function argument?")
}
TypeInferenceError::CouldNotSolve(Constraint::IsSigned(loc, t)) => loc
.labelled_error("internal error")
.with_message(format!("could not infer that type {} was signed", t)),
TypeInferenceError::CouldNotSolve(Constraint::NamedTypeIs(loc, name, ty)) => loc
.labelled_error("internal error")
.with_message(format!("could not infer that the name {} refers to {}", name, ty)),
}
}
}
/// Warnings that we might want to tell the user about.
///
/// These are fine, probably, but could indicate some behavior the user might not
/// expect, and so they might want to do something about them.
pub enum TypeInferenceWarning {
DefaultedTo(Location, TypeOrVar),
}
impl From<TypeInferenceWarning> for Diagnostic<usize> {
fn from(value: TypeInferenceWarning) -> Self {
match value {
TypeInferenceWarning::DefaultedTo(loc, ty) => Diagnostic::warning()
.with_labels(vec![loc.primary_label().with_message("unknown type")])
.with_message(format!("Defaulted unknown type to {}", ty)),
}
}
}
impl super::InferenceEngine {
/// Solve all the constraints in the provided database.
///
/// This process can take a bit, so you might not want to do it multiple times. Basically,
@@ -298,12 +16,7 @@ impl From<TypeInferenceWarning> for Diagnostic<usize> {
/// The return value is a type inference result, which pairs some warnings with either a
/// successful set of type resolutions (mappings from type variables to their values), or
/// a series of inference errors.
pub fn solve_constraints(
known_types: &HashMap<ArcIntern<String>, TypeOrVar>,
mut constraint_db: Vec<Constraint>,
) -> TypeInferenceResult<TypeResolutions> {
let mut errors = vec![];
let mut warnings = vec![];
pub fn solve_constraints(&mut self) {
let mut iteration = 0u64;
loop {
@@ -312,12 +25,12 @@ pub fn solve_constraints(
let mut new_constraints = vec![];
tracing::debug!(iteration, "Restarting constraint solving loop");
for constraint in constraint_db.iter() {
for constraint in self.constraints.iter() {
tracing::debug!(%constraint, "remaining constraint");
}
iteration += 1;
while let Some(constraint) = constraint_db.pop() {
while let Some(constraint) = self.constraints.pop() {
match constraint {
// The basic philosophy of this match block is that, for each constraint, we're
// going to start seeing if we can just solve (or abandon) the constraint. Then,
@@ -330,7 +43,7 @@ pub fn solve_constraints(
TypeOrVar::Primitive(to_type),
) => {
if !from_type.can_cast_to(&to_type) {
errors.push(TypeInferenceError::CannotSafelyCast(
self.errors.push(TypeInferenceError::CannotSafelyCast(
loc, from_type, to_type,
));
}
@@ -346,11 +59,15 @@ pub fn solve_constraints(
if args1.len() == args2.len() {
new_constraints.push(Constraint::Equivalent(loc.clone(), *ret1, *ret2));
for (arg1, arg2) in args1.into_iter().zip(args2) {
new_constraints.push(Constraint::Equivalent(loc.clone(), arg1, arg2))
new_constraints.push(Constraint::Equivalent(
loc.clone(),
arg1,
arg2,
))
}
all_constraints_solved = false;
} else {
errors.push(TypeInferenceError::CannotCast(
self.errors.push(TypeInferenceError::CannotCast(
loc,
TypeOrVar::Function(args1, ret1),
TypeOrVar::Function(args2, ret2),
@@ -380,7 +97,8 @@ pub fn solve_constraints(
ot @ TypeOrVar::Primitive(_) | ot @ TypeOrVar::Structure(_),
) => {
tracing::trace!(function_type = %ft, other_type = %ot, "we can't cast a function type to a primitive or structure type");
errors.push(TypeInferenceError::CannotCast(loc, ft, ot));
self.errors
.push(TypeInferenceError::CannotCast(loc, ft, ot));
changed_something = true;
}
@@ -390,7 +108,8 @@ pub fn solve_constraints(
ot @ TypeOrVar::Function(_, _) | ot @ TypeOrVar::Structure(_),
) => {
tracing::trace!(other_type = %ot, primitive_type = %pt, "we can't cast a primitive type to a function or structure type");
errors.push(TypeInferenceError::CannotCast(loc, pt, ot));
self.errors
.push(TypeInferenceError::CannotCast(loc, pt, ot));
changed_something = true;
}
@@ -400,14 +119,17 @@ pub fn solve_constraints(
ot @ TypeOrVar::Primitive(_) | ot @ TypeOrVar::Function(_, _),
) => {
tracing::trace!(structure_type = %st, other_type = %ot, "we can't cast a structure type to a function or primitive type");
errors.push(TypeInferenceError::CannotCast(loc, st, ot));
self.errors
.push(TypeInferenceError::CannotCast(loc, st, ot));
changed_something = true;
}
Constraint::NamedTypeIs(loc, name, ty) => match known_types.get(&name) {
Constraint::NamedTypeIs(loc, name, ty) => {
match self.type_definitions.get(&name) {
None => {
tracing::trace!(type_name = %name, "we don't know a type named name");
errors.push(TypeInferenceError::UnknownTypeName(loc, name));
self.errors
.push(TypeInferenceError::UnknownTypeName(loc, name));
changed_something = true;
}
@@ -420,7 +142,8 @@ pub fn solve_constraints(
));
changed_something = true;
}
},
}
}
Constraint::TypeHasField(
loc,
@@ -431,7 +154,7 @@ pub fn solve_constraints(
None => {
let reconstituted = TypeOrVar::Structure(fields);
tracing::trace!(structure_type = %reconstituted, %field, "no field found in type");
errors.push(TypeInferenceError::NoFieldForType(
self.errors.push(TypeInferenceError::NoFieldForType(
loc,
field,
reconstituted,
@@ -457,7 +180,8 @@ pub fn solve_constraints(
_,
) => {
tracing::trace!(other_type = %ot, %field, "can't get field from primitive or function type");
errors.push(TypeInferenceError::NoFieldForType(loc, field, ot));
self.errors
.push(TypeInferenceError::NoFieldForType(loc, field, ot));
changed_something = true;
}
@@ -465,7 +189,7 @@ pub fn solve_constraints(
Constraint::ConstantNumericType(loc, TypeOrVar::Primitive(pt)) => {
tracing::trace!(primitive_type = %pt, "its easy to tell if a constant number can be a primitive type");
if pt.max_value().is_none() {
errors.push(TypeInferenceError::NotANumber(loc, pt))
self.errors.push(TypeInferenceError::NotANumber(loc, pt))
}
changed_something = true;
}
@@ -473,24 +197,27 @@ pub fn solve_constraints(
// if we're testing if a function type is numeric, then throw a useful warning
Constraint::ConstantNumericType(loc, t @ TypeOrVar::Function(_, _)) => {
tracing::trace!(function_type = %t, "functions can't be constant numbers");
errors.push(TypeInferenceError::CannotMakeNumberAFunction(loc, t, None));
self.errors
.push(TypeInferenceError::CannotMakeNumberAFunction(loc, t, None));
changed_something = true;
}
// if we're testing if a function type is numeric, then throw a useful warning
Constraint::ConstantNumericType(loc, t @ TypeOrVar::Structure(_)) => {
tracing::trace!(structure_type = %t, "structures can't be constant numbers");
errors.push(TypeInferenceError::CannotMakeNumberAStructure(loc, t, None));
self.errors
.push(TypeInferenceError::CannotMakeNumberAStructure(loc, t, None));
changed_something = true;
}
// if we're testing if a number can fit into a numeric type, we can just do that!
Constraint::FitsInNumType(loc, TypeOrVar::Primitive(ctype), val) => {
match ctype.max_value() {
None => errors.push(TypeInferenceError::NotANumber(loc, ctype)),
None => self.errors.push(TypeInferenceError::NotANumber(loc, ctype)),
Some(max_value) if max_value < val => {
errors.push(TypeInferenceError::ConstantTooLarge(loc, ctype, val));
self.errors
.push(TypeInferenceError::ConstantTooLarge(loc, ctype, val));
}
Some(_) => {}
@@ -502,7 +229,8 @@ pub fn solve_constraints(
// if we're testing if a function type can fit into a numeric type, that's a problem
Constraint::FitsInNumType(loc, t @ TypeOrVar::Function(_, _), val) => {
tracing::trace!(function_type = %t, "values don't fit in function types");
errors.push(TypeInferenceError::CannotMakeNumberAFunction(
self.errors
.push(TypeInferenceError::CannotMakeNumberAFunction(
loc,
t,
Some(val),
@@ -513,7 +241,8 @@ pub fn solve_constraints(
// if we're testing if a function type can fit into a numeric type, that's a problem
Constraint::FitsInNumType(loc, t @ TypeOrVar::Structure(_), val) => {
tracing::trace!(function_type = %t, "values don't fit in structure types");
errors.push(TypeInferenceError::CannotMakeNumberAStructure(
self.errors
.push(TypeInferenceError::CannotMakeNumberAStructure(
loc,
t,
Some(val),
@@ -533,7 +262,7 @@ pub fn solve_constraints(
Constraint::IsSigned(loc, TypeOrVar::Primitive(pt)) => {
tracing::trace!(primitive_type = %pt, "we can check if a primitive is signed");
if !pt.valid_operators().contains(&("-", 1)) {
errors.push(TypeInferenceError::IsNotSigned(
self.errors.push(TypeInferenceError::IsNotSigned(
loc,
TypeOrVar::Primitive(pt),
));
@@ -544,14 +273,14 @@ pub fn solve_constraints(
// again with the functions and the numbers
Constraint::IsSigned(loc, t @ TypeOrVar::Function(_, _)) => {
tracing::trace!(function_type = %t, "functions are not signed");
errors.push(TypeInferenceError::IsNotSigned(loc, t));
self.errors.push(TypeInferenceError::IsNotSigned(loc, t));
changed_something = true;
}
// again with the functions and the numbers
Constraint::IsSigned(loc, t @ TypeOrVar::Structure(_)) => {
tracing::trace!(structure_type = %t, "structures are not signed");
errors.push(TypeInferenceError::IsNotSigned(loc, t));
self.errors.push(TypeInferenceError::IsNotSigned(loc, t));
changed_something = true;
}
@@ -559,7 +288,7 @@ pub fn solve_constraints(
Constraint::NumericType(loc, TypeOrVar::Primitive(pt)) => {
tracing::trace!(primitive_type = %pt, "its easy to tell if a primitive type is numeric");
if pt.max_value().is_none() {
errors.push(TypeInferenceError::NotANumber(loc, pt))
self.errors.push(TypeInferenceError::NotANumber(loc, pt))
}
changed_something = true;
}
@@ -567,14 +296,16 @@ pub fn solve_constraints(
// if we're testing if a function type is numeric, then throw a useful warning
Constraint::NumericType(loc, t @ TypeOrVar::Function(_, _)) => {
tracing::trace!(function_type = %t, "function types aren't numeric");
errors.push(TypeInferenceError::CannotMakeNumberAFunction(loc, t, None));
self.errors
.push(TypeInferenceError::CannotMakeNumberAFunction(loc, t, None));
changed_something = true;
}
// if we're testing if a structure type is numeric, then throw a useful warning
Constraint::NumericType(loc, t @ TypeOrVar::Structure(_)) => {
tracing::trace!(structure_type = %t, "structure types aren't numeric");
errors.push(TypeInferenceError::CannotMakeNumberAStructure(loc, t, None));
self.errors
.push(TypeInferenceError::CannotMakeNumberAStructure(loc, t, None));
changed_something = true;
}
@@ -587,7 +318,8 @@ pub fn solve_constraints(
// function types are definitely not printable
Constraint::Printable(loc, ft @ TypeOrVar::Function(_, _)) => {
tracing::trace!(function_type = %ft, "function types are not printable");
errors.push(TypeInferenceError::FunctionsAreNotPrintable(loc));
self.errors
.push(TypeInferenceError::FunctionsAreNotPrintable(loc));
changed_something = true;
}
@@ -609,7 +341,7 @@ pub fn solve_constraints(
TypeOrVar::Primitive(pt2),
) => {
if pt1 != pt2 {
errors.push(TypeInferenceError::NotEquivalent(
self.errors.push(TypeInferenceError::NotEquivalent(
loc,
TypeOrVar::Primitive(pt1),
TypeOrVar::Primitive(pt2),
@@ -630,7 +362,8 @@ pub fn solve_constraints(
pt @ TypeOrVar::Primitive(_),
) => {
tracing::trace!(primitive_type = %pt, function_type = %ft, "function and primitive types cannot be equivalent");
errors.push(TypeInferenceError::NotEquivalent(loc, pt, ft));
self.errors
.push(TypeInferenceError::NotEquivalent(loc, pt, ft));
changed_something = true;
}
@@ -645,7 +378,8 @@ pub fn solve_constraints(
pt @ TypeOrVar::Primitive(_),
) => {
tracing::trace!(primitive_type = %pt, structure_type = %st, "structure and primitive types cannot be equivalent");
errors.push(TypeInferenceError::NotEquivalent(loc, pt, st));
self.errors
.push(TypeInferenceError::NotEquivalent(loc, pt, st));
changed_something = true;
}
@@ -660,7 +394,8 @@ pub fn solve_constraints(
st @ TypeOrVar::Structure(_),
) => {
tracing::trace!(structure_type = %st, function_type = %ft, "structure and primitive types cannot be equivalent");
errors.push(TypeInferenceError::NotEquivalent(loc, st, ft));
self.errors
.push(TypeInferenceError::NotEquivalent(loc, st, ft));
changed_something = true;
}
@@ -681,10 +416,15 @@ pub fn solve_constraints(
if args1.len() != args2.len() {
let t1 = TypeOrVar::Function(args1, ret1);
let t2 = TypeOrVar::Function(args2, ret2);
errors.push(TypeInferenceError::NotEquivalent(loc, t1, t2));
self.errors
.push(TypeInferenceError::NotEquivalent(loc, t1, t2));
} else {
for (left, right) in args1.into_iter().zip(args2) {
new_constraints.push(Constraint::Equivalent(loc.clone(), left, right));
new_constraints.push(Constraint::Equivalent(
loc.clone(),
left,
right,
));
}
new_constraints.push(Constraint::Equivalent(loc, *ret1, *ret2));
all_constraints_solved = false;
@@ -713,7 +453,7 @@ pub fn solve_constraints(
));
}
} else {
errors.push(TypeInferenceError::NotEquivalent(
self.errors.push(TypeInferenceError::NotEquivalent(
loc,
TypeOrVar::Structure(fields1),
TypeOrVar::Structure(fields2),
@@ -724,7 +464,7 @@ pub fn solve_constraints(
}
Constraint::Equivalent(_, TypeOrVar::Variable(_, ref name), ref rhs) => {
changed_something |= replace_variable(&mut constraint_db, name, rhs);
changed_something |= replace_variable(&mut self.constraints, name, rhs);
changed_something |= replace_variable(&mut new_constraints, name, rhs);
all_constraints_solved &= rhs.is_resolved();
if changed_something {
@@ -756,19 +496,7 @@ pub fn solve_constraints(
}
if all_constraints_solved {
let result = new_constraints
.into_iter()
.map(|constraint| match constraint {
Constraint::Equivalent(_, TypeOrVar::Variable(_, name), result) => {
match result.try_into() {
Err(e) => panic!("Ended up with complex type {}", e),
Ok(v) => (name, v),
}
}
_ => panic!("Had something that wasn't an equivalence left at the end!"),
})
.collect();
return TypeInferenceResult::Success { result, warnings };
return;
}
if !changed_something {
@@ -782,7 +510,8 @@ pub fn solve_constraints(
$t.clone(),
resty.clone(),
));
warnings.push(TypeInferenceWarning::DefaultedTo($loc.clone(), resty));
self.warnings
.push(TypeInferenceWarning::DefaultedTo($loc.clone(), resty));
tracing::trace!("Adding number equivalence");
};
}
@@ -808,19 +537,20 @@ pub fn solve_constraints(
}
if addendums.is_empty() {
if errors.is_empty() {
errors = new_constraints
if self.errors.is_empty() {
self.errors = new_constraints
.into_iter()
.map(TypeInferenceError::CouldNotSolve)
.collect();
}
return TypeInferenceResult::Failure { errors, warnings };
return;
}
new_constraints.append(&mut addendums);
}
constraint_db = new_constraints;
self.constraints = new_constraints;
}
}
}

21
src/type_infer/warning.rs Normal file
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use crate::ir::TypeOrVar;
use crate::syntax::Location;
use codespan_reporting::diagnostic::Diagnostic;
/// Warnings that we might want to tell the user about.
///
/// These are fine, probably, but could indicate some behavior the user might not
/// expect, and so they might want to do something about them.
pub enum TypeInferenceWarning {
DefaultedTo(Location, TypeOrVar),
}
impl From<TypeInferenceWarning> for Diagnostic<usize> {
fn from(value: TypeInferenceWarning) -> Self {
match value {
TypeInferenceWarning::DefaultedTo(loc, ty) => Diagnostic::warning()
.with_labels(vec![loc.primary_label().with_message("unknown type")])
.with_message(format!("Defaulted unknown type to {}", ty)),
}
}
}