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ast: Allow type specifier in let statement

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John 2024-02-26 15:49:55 -06:00
parent 490d320633
commit ffa313eea8
4 changed files with 15 additions and 9 deletions
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1
libconlang/src/ast.rs
View File

@ -241,6 +241,7 @@ pub enum StmtKind {
pub struct Let {
pub mutable: Mutability,
pub name: Identifier,
pub ty: Option<Box<Ty>>,
pub init: Option<Box<Expr>>,
}

5
libconlang/src/ast/ast_impl.rs
View File

@ -252,8 +252,11 @@ mod display {
}
impl Display for Let {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let Self { mutable, name, init } = self;
let Self { mutable, name, ty, init } = self;
write!(f, "let {mutable}{name}")?;
if let Some(value) = ty {
write!(f, ": {value}")?;
}
if let Some(value) = init {
write!(f, " = {value}")?;
}

10
libconlang/src/interpreter.rs
View File

@ -398,13 +398,9 @@ pub mod interpret {
}
impl Interpret for Let {
fn interpret(&self, env: &mut Environment) -> IResult<ConValue> {
let Let { mutable: _, name: Identifier(name), init } = self;
if let Some(init) = init {
let init = init.interpret(env)?;
env.insert(name, Some(init));
} else {
env.insert(name, None);
}
let Let { mutable: _, name: Identifier(name), ty: _, init } = self;
let init = init.as_ref().map(|i| i.interpret(env)).transpose()?;
env.insert(name, init);
Ok(ConValue::Empty)
}
}

8
libconlang/src/parser.rs
View File

@ -785,7 +785,13 @@ impl<'t> Parser<'t> {
Ok(Let {
mutable: self.mutability()?,
name: self.identifier()?,
init: if Type::Eq == self.peek_type(Parsing::Let)? {
ty: if Ok(Type::Colon) == self.peek_type(Parsing::Let) {
self.consume_peeked();
Some(self.ty()?.into())
} else {
None
},
init: if Ok(Type::Eq) == self.peek_type(Parsing::Let) {
self.consume_peeked();
Some(self.expr()?.into())
} else {