feat: add Type methods: as_tuple, as_slice, as_array, `as_con…

…stant`, `is_bool` (#5678)

# Description

## Problem

Part of #5668

## Summary

I'm leaving `as_struct` for a next PR.

## Additional Context

None.

## Documentation

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

compiler/noirc_frontend/src/hir/comptime/interpreter/builtin.rs

@@ -57,8 +57,13 @@ impl<'local, 'context> Interpreter<'local, 'context> {
             "trait_def_hash" => trait_def_hash(interner, arguments, location),
             "quoted_as_trait_constraint" => quoted_as_trait_constraint(self, arguments, location),
             "quoted_as_type" => quoted_as_type(self, arguments, location),
+            "type_as_array" => type_as_array(arguments, return_type, location),
+            "type_as_constant" => type_as_constant(arguments, return_type, location),
             "type_as_integer" => type_as_integer(arguments, return_type, location),
+            "type_as_slice" => type_as_slice(arguments, return_type, location),
+            "type_as_tuple" => type_as_tuple(arguments, return_type, location),
             "type_eq" => type_eq(arguments, location),
+            "type_is_bool" => type_is_bool(arguments, location),
             "type_is_field" => type_is_field(arguments, location),
             "type_of" => type_of(arguments, location),
             "zeroed" => zeroed(return_type),
@@ -485,20 +490,101 @@ fn quoted_as_type(
     Ok(Value::Type(typ))
 }
 
+// fn as_array(self) -> Option<(Type, Type)>
+fn type_as_array(
+    arguments: Vec<(Value, Location)>,
+    return_type: Type,
+    location: Location,
+) -> IResult<Value> {
+    type_as(arguments, return_type, location, |typ| {
+        if let Type::Array(length, array_type) = typ {
+            Some(Value::Tuple(vec![Value::Type(*array_type), Value::Type(*length)]))
+        } else {
+            None
+        }
+    })
+}
+
+// fn as_constant(self) -> Option<u32>
+fn type_as_constant(
+    arguments: Vec<(Value, Location)>,
+    return_type: Type,
+    location: Location,
+) -> IResult<Value> {
+    type_as(arguments, return_type, location, |typ| {
+        if let Type::Constant(n) = typ {
+            Some(Value::U32(n))
+        } else {
+            None
+        }
+    })
+}
+
 // fn as_integer(self) -> Option<(bool, u8)>
 fn type_as_integer(
     arguments: Vec<(Value, Location)>,
     return_type: Type,
     location: Location,
 ) -> IResult<Value> {
+    type_as(arguments, return_type, location, |typ| {
+        if let Type::Integer(sign, bits) = typ {
+            Some(Value::Tuple(vec![Value::Bool(sign.is_signed()), Value::U8(bits.bit_size())]))
+        } else {
+            None
+        }
+    })
+}
+
+// fn as_slice(self) -> Option<Type>
+fn type_as_slice(
+    arguments: Vec<(Value, Location)>,
+    return_type: Type,
+    location: Location,
+) -> IResult<Value> {
+    type_as(arguments, return_type, location, |typ| {
+        if let Type::Slice(slice_type) = typ {
+            Some(Value::Type(*slice_type))
+        } else {
+            None
+        }
+    })
+}
+
+// fn as_tuple(self) -> Option<[Type]>
+fn type_as_tuple(
+    arguments: Vec<(Value, Location)>,
+    return_type: Type,
+    location: Location,
+) -> IResult<Value> {
+    type_as(arguments, return_type.clone(), location, |typ| {
+        if let Type::Tuple(types) = typ {
+            let t = extract_option_generic_type(return_type);
+
+            let Type::Slice(slice_type) = t else {
+                panic!("Expected T to be a slice");
+            };
+
+            Some(Value::Slice(types.into_iter().map(Value::Type).collect(), *slice_type))
+        } else {
+            None
+        }
+    })
+}
+
+// Helper function for implementing the `type_as_...` functions.
+fn type_as<F>(
+    arguments: Vec<(Value, Location)>,
+    return_type: Type,
+    location: Location,
+    f: F,
+) -> IResult<Value>
+where
+    F: FnOnce(Type) -> Option<Value>,
+{
     let value = check_one_argument(arguments, location)?;
     let typ = get_type(value, location)?;
 
-    let option_value = if let Type::Integer(sign, bits) = typ {
-        Some(Value::Tuple(vec![Value::Bool(sign.is_signed()), Value::U8(bits.bit_size())]))
-    } else {
-        None
-    };
+    let option_value = f(typ);
 
     option(return_type, option_value)
 }
@@ -510,6 +596,14 @@ fn type_eq(arguments: Vec<(Value, Location)>, location: Location) -> IResult<Val
     Ok(Value::Bool(self_type == other_type))
 }
 
+// fn is_bool(self) -> bool
+fn type_is_bool(arguments: Vec<(Value, Location)>, location: Location) -> IResult<Value> {
+    let value = check_one_argument(arguments, location)?;
+    let typ = get_type(value, location)?;
+
+    Ok(Value::Bool(matches!(typ, Type::Bool)))
+}
+
 // fn is_field(self) -> bool
 fn type_is_field(arguments: Vec<(Value, Location)>, location: Location) -> IResult<Value> {
     let value = check_one_argument(arguments, location)?;
@@ -751,14 +845,7 @@ fn trait_def_as_trait_constraint(
 /// Creates a value that holds an `Option`.
 /// `option_type` must be a Type referencing the `Option` type.
 pub(crate) fn option(option_type: Type, value: Option<Value>) -> IResult<Value> {
-    let Type::Struct(shared_option_type, mut generics) = option_type.clone() else {
-        panic!("Expected type to be a struct");
-    };
-
-    let shared_option_type = shared_option_type.borrow();
-    assert_eq!(shared_option_type.name.0.contents, "Option");
-
-    let t = generics.pop().expect("Expected Option to have a T generic type");
+    let t = extract_option_generic_type(option_type.clone());
 
     let (is_some, value) = match value {
         Some(value) => (Value::Bool(true), value),
@@ -770,3 +857,15 @@ pub(crate) fn option(option_type: Type, value: Option<Value>) -> IResult<Value>
     fields.insert(Rc::new("_value".to_string()), value);
     Ok(Value::Struct(fields, option_type))
 }
+
+/// Given a type, assert that it's an Option<T> and return the Type for T
+pub(crate) fn extract_option_generic_type(typ: Type) -> Type {
+    let Type::Struct(struct_type, mut generics) = typ else {
+        panic!("Expected type to be a struct");
+    };
+
+    let struct_type = struct_type.borrow();
+    assert_eq!(struct_type.name.0.contents, "Option");
+
+    generics.pop().expect("Expected Option to have a T generic type")
+}

noir_stdlib/src/meta/typ.nr

@@ -2,9 +2,24 @@ use crate::cmp::Eq;
 use crate::option::Option;
 
 impl Type {
+    #[builtin(type_as_array)]
+    fn as_array(self) -> Option<(Type, Type)> {}
+
+    #[builtin(type_as_constant)]
+    fn as_constant(self) -> Option<u32> {}
+
     #[builtin(type_as_integer)]
     fn as_integer(self) -> Option<(bool, u8)> {}
 
+    #[builtin(type_as_slice)]
+    fn as_slice(self) -> Option<Type> {}
+
+    #[builtin(type_as_tuple)]
+    fn as_tuple(self) -> Option<[Type]> {}
+
+    #[builtin(type_is_bool)]
+    fn is_bool(self) -> bool {}
+
     #[builtin(type_is_field)]
     fn is_field(self) -> bool {}
 }

test_programs/compile_success_empty/comptime_type/src/main.nr

@@ -29,5 +29,42 @@ fn main() {
         let (signed, bits) = u8_type.as_integer().unwrap();
         assert(!signed);
         assert_eq(bits, 8);
+
+        // Check Type::as_tuple
+        assert(u8_type.as_tuple().is_none());
+
+        let tuple = (an_i32, a_u8);
+        let tuple_type = type_of(tuple);
+        let tuple_types = tuple_type.as_tuple().unwrap();
+        assert_eq(tuple_types.len(), 2);
+        assert_eq(tuple_types[0], i32_type);
+        assert_eq(tuple_types[1], u8_type);
+
+        // Check Type::as_slice
+        assert(u8_type.as_slice().is_none());
+
+        let slice = &[1];
+        let slice_type = type_of(slice);
+        let slice_type_element_type = slice_type.as_slice().unwrap();
+        assert_eq(slice_type_element_type, field_type_1);
+
+        // Check Type::as_array
+        assert(u8_type.as_array().is_none());
+
+        let array = [1, 2, 3];
+        let array_type = type_of(array);
+        let (array_type_element_type , array_length) = array_type.as_array().unwrap();
+        assert_eq(array_type_element_type, field_type_1);
+
+        // Check Type::as_constant
+        assert(u8_type.as_constant().is_none());
+        assert_eq(array_length.as_constant().unwrap(), 3);
+
+        // Check Type::is_bool
+        assert(!u8_type.is_bool());
+
+        let yes = true;
+        let bool_type = type_of(yes);
+        assert(bool_type.is_bool());
     }
 }