Implement literal types (#978)

I got something that *compiles* and parses literals into the AST. Lots
of `todo!()`s left.
<!-- ELLIPSIS_HIDDEN -->

----

> [!IMPORTANT]
> Implement literal types in the codebase, including coercion,
validation, and code generation updates for Python, Ruby, and
TypeScript.
> 
>   - **Behavior**:
>     - Implement literal types in `FieldType` and `LiteralValue` enums.
>     - Add coercion logic for literals in `coerce_literal.rs`.
>     - Update `to_baml_arg.rs` to handle literal values.
>     - Modify `json_schema.rs` to support literal types in JSON schema.
>     - Update `repr.rs` to include literal types in representation.
>   - **Validation**:
>     - Add validation for literal types in `types.rs`.
>     - Introduce tests for literals in `test_literals.rs`.
>   - **Code Generation**:
> - Update Python, Ruby, and TypeScript code generation to support
literals.
>     - Modify OpenAPI generation to include literal types.
>   - **Misc**:
>     - Add new test files for validation of literal types.
>     - Update existing test files to include literal type scenarios.
> 
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=BoundaryML%2Fbaml&utm_source=github&utm_medium=referral)<sup>
for a14b308. It will automatically
update as commits are pushed.</sup>

<!-- ELLIPSIS_HIDDEN -->

---------

Co-authored-by: Greg Hale <imalsogreg@gmail.com>
Co-authored-by: Vaibhav Gupta <vbv@boundaryml.com>

engine/baml-lib/baml-core/src/ir/ir_helpers/to_baml_arg.rs

@@ -1,4 +1,4 @@
-use baml_types::{BamlMap, BamlMediaType, BamlValue, FieldType, TypeValue};
+use baml_types::{BamlMap, BamlMediaType, BamlValue, FieldType, LiteralValue, TypeValue};
 use core::result::Result;
 use std::path::PathBuf;
 
@@ -198,6 +198,17 @@ impl ArgCoercer {
                     Err(())
                 }
             },
+            FieldType::Literal(literal) => Ok(match (literal, value) {
+                (LiteralValue::Int(lit), BamlValue::Int(baml)) if lit == baml => value.clone(),
+                (LiteralValue::String(lit), BamlValue::String(baml)) if lit == baml => {
+                    value.clone()
+                }
+                (LiteralValue::Bool(lit), BamlValue::Bool(baml)) if lit == baml => value.clone(),
+                _ => {
+                    scope.push_error(format!("Expected literal {:?}, got `{}`", literal, value));
+                    return Err(());
+                }
+            }),
             FieldType::Class(name) => match value {
                 BamlValue::Class(n, _) if n == name => return Ok(value.clone()),
                 BamlValue::Class(_, obj) | BamlValue::Map(obj) => match ir.find_class(name) {

engine/baml-lib/baml-core/src/ir/json_schema.rs

@@ -159,6 +159,9 @@ impl<'db> WithJsonSchema for FieldType {
             FieldType::Class(name) | FieldType::Enum(name) => json!({
                 "$ref": format!("#/definitions/{}", name),
             }),
+            FieldType::Literal(v) => json!({
+                "const": v.to_string(),
+            }),
             FieldType::Primitive(t) => match t {
                 TypeValue::String => json!({
                     "type": "string",

engine/baml-lib/baml-core/src/ir/repr.rs

@@ -288,6 +288,14 @@ impl WithRepr<FieldType> for ast::FieldType {
                     repr
                 }
             }
+            ast::FieldType::Literal(arity, literal_value, ..) => {
+                let repr = FieldType::Literal(literal_value.clone());
+                if arity.is_optional() {
+                    FieldType::Optional(Box::new(repr))
+                } else {
+                    repr
+                }
+            }
             ast::FieldType::Symbol(arity, idn, ..) => type_with_arity(
                 match db.find_type(idn) {
                     Some(Either::Left(class_walker)) => {

engine/baml-lib/baml-core/src/validate/validation_pipeline/validations/types.rs

@@ -66,6 +66,7 @@ fn validate_type_allowed(ctx: &mut Context<'_>, field_type: &FieldType) {
         }
 
         FieldType::Primitive(..) => {}
+        FieldType::Literal(..) => {}
         FieldType::Symbol(..) => {}
 
         FieldType::List(arity, field_type, ..) => {

engine/baml-lib/baml-types/src/field_type/mod.rs

@@ -40,11 +40,40 @@ impl std::fmt::Display for TypeValue {
     }
 }
 
+/// Subset of [`crate::BamlValue`] allowed for literal type definitions.
+#[derive(serde::Serialize, Debug, Clone, PartialOrd, Ord, PartialEq, Eq)]
+pub enum LiteralValue {
+    String(String),
+    Int(i64),
+    Bool(bool),
+}
+
+impl LiteralValue {
+    pub fn literal_base_type(&self) -> FieldType {
+        match self {
+            Self::String(_) => FieldType::string(),
+            Self::Int(_) => FieldType::int(),
+            Self::Bool(_) => FieldType::bool(),
+        }
+    }
+}
+
+impl std::fmt::Display for LiteralValue {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            LiteralValue::String(str) => write!(f, "\"{str}\""),
+            LiteralValue::Int(int) => write!(f, "{int}"),
+            LiteralValue::Bool(bool) => write!(f, "{bool}"),
+        }
+    }
+}
+
 /// FieldType represents the type of either a class field or a function arg.
 #[derive(serde::Serialize, Debug, Clone)]
 pub enum FieldType {
     Primitive(TypeValue),
     Enum(String),
+    Literal(LiteralValue),
     Class(String),
     List(Box<FieldType>),
     Map(Box<FieldType>, Box<FieldType>),
@@ -61,6 +90,7 @@ impl std::fmt::Display for FieldType {
                 write!(f, "{}", name)
             }
             FieldType::Primitive(t) => write!(f, "{}", t),
+            FieldType::Literal(v) => write!(f, "{}", v),
             FieldType::Union(choices) => {
                 write!(
                     f,

engine/baml-lib/baml-types/src/lib.rs

@@ -8,7 +8,7 @@ mod field_type;
 mod generator;
 
 pub use baml_value::BamlValue;
-pub use field_type::{FieldType, TypeValue};
+pub use field_type::{FieldType, LiteralValue, TypeValue};
 pub use generator::{GeneratorDefaultClientMode, GeneratorOutputType};
 pub use map::Map as BamlMap;
 pub use media::{BamlMedia, BamlMediaContent, BamlMediaType, MediaBase64, MediaUrl};

engine/baml-lib/baml/tests/validation_files/class/literal_types.baml

@@ -0,0 +1,9 @@
+class TestLiterals {
+  a "SingleLiteral"
+  b "Field" | "With" | "Multiple" | "Literals"
+  c "Field" | "With" | "Some" @description("Description")
+  d 2 | 3
+  e "Optional"?
+  f 2 | "SomeString"
+  g "boolean" | true | false
+}

engine/baml-lib/baml/tests/validation_files/class/misspeled_boolean_literals.baml

@@ -0,0 +1,17 @@
+class TestLiterals {
+  a "SingleLiteral"
+  b "boolean" | True | False
+}
+
+// error: Type `True` does not exist. Did you mean one of these: `true`, `string`, `int`, `bool`, `false`, `float`, `TestLiterals`?
+//   -->  class/misspeled_boolean_literals.baml:3
+//    | 
+//  2 |   a "SingleLiteral"
+//  3 |   b "boolean" | True | False
+//    | 
+// error: Type `False` does not exist. Did you mean one of these: `false`, `float`, `true`, `int`, `bool`, `string`, `TestLiterals`?
+//   -->  class/misspeled_boolean_literals.baml:3
+//    | 
+//  2 |   a "SingleLiteral"
+//  3 |   b "boolean" | True | False
+//    | 

engine/baml-lib/baml/tests/validation_files/class/secure_types.baml

@@ -19,7 +19,7 @@ class ComplexTypes {
   q map<string, string>?
 }
 
-// error: Type `apple_pie` does not exist. Did you mean one of these: `ComplexTypes`, `float`, `bool`, `string`, `int`?
+// error: Type `apple_pie` does not exist. Did you mean one of these: `false`, `ComplexTypes`, `float`, `bool`, `true`, `string`, `int`?
 //   -->  class/secure_types.baml:3
 //    | 
 //  2 | class ComplexTypes {
@@ -31,13 +31,13 @@ class ComplexTypes {
 //  2 | class ComplexTypes {
 //  3 |   a map<string[], (int | bool[]) | apple_pie[][]>
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:4
 //    | 
 //  3 |   a map<string[], (int | bool[]) | apple_pie[][]>
 //  4 |   b (int, map<bool, string?>, (char | float)[][] | long_word_123.foobar[])
 //    | 
-// error: Type `long_word_123.foobar` does not exist. Did you mean one of these: `float`, `bool`, `ComplexTypes`, `string`, `int`?
+// error: Type `long_word_123.foobar` does not exist. Did you mean one of these: `float`, `bool`, `ComplexTypes`, `string`, `int`, `true`, `false`?
 //   -->  class/secure_types.baml:4
 //    | 
 //  3 |   a map<string[], (int | bool[]) | apple_pie[][]>
@@ -49,25 +49,25 @@ class ComplexTypes {
 //  3 |   a map<string[], (int | bool[]) | apple_pie[][]>
 //  4 |   b (int, map<bool, string?>, (char | float)[][] | long_word_123.foobar[])
 //    | 
-// error: Type `apple123_456_pie` does not exist. Did you mean one of these: `ComplexTypes`, `float`, `bool`, `string`, `int`?
+// error: Type `apple123_456_pie` does not exist. Did you mean one of these: `ComplexTypes`, `false`, `float`, `bool`, `true`, `string`, `int`?
 //   -->  class/secure_types.baml:5
 //    | 
 //  4 |   b (int, map<bool, string?>, (char | float)[][] | long_word_123.foobar[])
 //  5 |   c apple123_456_pie | (stringer, bool[], (int | char))[]
 //    | 
-// error: Type `stringer` does not exist. Did you mean one of these: `string`, `int`, `float`, `bool`, `ComplexTypes`?
+// error: Type `stringer` does not exist. Did you mean one of these: `string`, `true`, `int`, `false`, `float`, `bool`, `ComplexTypes`?
 //   -->  class/secure_types.baml:5
 //    | 
 //  4 |   b (int, map<bool, string?>, (char | float)[][] | long_word_123.foobar[])
 //  5 |   c apple123_456_pie | (stringer, bool[], (int | char))[]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:5
 //    | 
 //  4 |   b (int, map<bool, string?>, (char | float)[][] | long_word_123.foobar[])
 //  5 |   c apple123_456_pie | (stringer, bool[], (int | char))[]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:6
 //    | 
 //  5 |   c apple123_456_pie | (stringer, bool[], (int | char))[]
@@ -79,19 +79,19 @@ class ComplexTypes {
 //  5 |   c apple123_456_pie | (stringer, bool[], (int | char))[]
 //  6 |   d map<int[][], ((int | float) | char[])>
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:7
 //    | 
 //  6 |   d map<int[][], ((int | float) | char[])>
 //  7 |   e ((int, string | char) | ((float, double) | long[], bool)[][][])
 //    | 
-// error: Type `double` does not exist. Did you mean one of these: `bool`, `string`, `int`, `float`, `ComplexTypes`?
+// error: Type `double` does not exist. Did you mean one of these: `bool`, `true`, `false`, `string`, `int`, `float`, `ComplexTypes`?
 //   -->  class/secure_types.baml:7
 //    | 
 //  6 |   d map<int[][], ((int | float) | char[])>
 //  7 |   e ((int, string | char) | ((float, double) | long[], bool)[][][])
 //    | 
-// error: Type `long` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `long` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `true`, `false`, `ComplexTypes`?
 //   -->  class/secure_types.baml:7
 //    | 
 //  6 |   d map<int[][], ((int | float) | char[])>
@@ -103,19 +103,19 @@ class ComplexTypes {
 //  7 |   e ((int, string | char) | ((float, double) | long[], bool)[][][])
 //  8 |   f VeryLongWord_With_123_Numbers[][][][]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:9
 //    | 
 //  8 |   f VeryLongWord_With_123_Numbers[][][][]
 //  9 |   g (int, (float, char, bool), string[]) | tuple_inside_tuple[]
 //    | 
-// error: Type `tuple_inside_tuple` does not exist. Did you mean one of these: `ComplexTypes`, `int`, `string`, `float`, `bool`?
+// error: Type `tuple_inside_tuple` does not exist. Did you mean one of these: `ComplexTypes`, `int`, `true`, `false`, `string`, `float`, `bool`?
 //   -->  class/secure_types.baml:9
 //    | 
 //  8 |   f VeryLongWord_With_123_Numbers[][][][]
 //  9 |   g (int, (float, char, bool), string[]) | tuple_inside_tuple[]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:10
 //    | 
 //  9 |   g (int, (float, char, bool), string[]) | tuple_inside_tuple[]
@@ -127,55 +127,55 @@ class ComplexTypes {
 //  9 |   g (int, (float, char, bool), string[]) | tuple_inside_tuple[]
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 //    | 
-// error: Type `apple` does not exist. Did you mean one of these: `bool`, `int`, `float`, `string`, `ComplexTypes`?
+// error: Type `apple` does not exist. Did you mean one of these: `bool`, `true`, `false`, `int`, `float`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:11
 //    | 
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 //    | 
-// error: Type `banana` does not exist. Did you mean one of these: `string`, `int`, `float`, `bool`, `ComplexTypes`?
+// error: Type `banana` does not exist. Did you mean one of these: `string`, `int`, `float`, `bool`, `false`, `true`, `ComplexTypes`?
 //   -->  class/secure_types.baml:11
 //    | 
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 //    | 
-// error: Type `cherry` does not exist. Did you mean one of these: `string`, `int`, `float`, `bool`, `ComplexTypes`?
+// error: Type `cherry` does not exist. Did you mean one of these: `true`, `string`, `int`, `float`, `bool`, `false`, `ComplexTypes`?
 //   -->  class/secure_types.baml:11
 //    | 
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 //    | 
-// error: Type `date_fruit` does not exist. Did you mean one of these: `string`, `float`, `int`, `bool`, `ComplexTypes`?
+// error: Type `date_fruit` does not exist. Did you mean one of these: `true`, `string`, `float`, `int`, `false`, `bool`, `ComplexTypes`?
 //   -->  class/secure_types.baml:11
 //    | 
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 //    | 
-// error: Type `eggplant_vegetable` does not exist. Did you mean one of these: `ComplexTypes`, `string`, `int`, `float`, `bool`?
+// error: Type `eggplant_vegetable` does not exist. Did you mean one of these: `ComplexTypes`, `string`, `int`, `float`, `true`, `false`, `bool`?
 //   -->  class/secure_types.baml:11
 //    | 
 // 10 |   h (((int | string)[]) | map<bool[][], char[]>)
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:12
 //    | 
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 // 12 |   j ((char, int[][], (bool | string[][])) | double[][][][], (float, int)[])
 //    | 
-// error: Type `double` does not exist. Did you mean one of these: `bool`, `string`, `int`, `float`, `ComplexTypes`?
+// error: Type `double` does not exist. Did you mean one of these: `bool`, `true`, `false`, `string`, `int`, `float`, `ComplexTypes`?
 //   -->  class/secure_types.baml:12
 //    | 
 // 11 |   i (apple, banana | cherry | date_fruit | eggplant_vegetable)[]
 // 12 |   j ((char, int[][], (bool | string[][])) | double[][][][], (float, int)[])
 //    | 
-// error: Type `long` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `long` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `true`, `false`, `ComplexTypes`?
 //   -->  class/secure_types.baml:13
 //    | 
 // 12 |   j ((char, int[][], (bool | string[][])) | double[][][][], (float, int)[])
 // 13 |   k map<string[], (int | long[])> | map<float[][], double[][]>
 //    | 
-// error: Type `double` does not exist. Did you mean one of these: `bool`, `string`, `int`, `float`, `ComplexTypes`?
+// error: Type `double` does not exist. Did you mean one of these: `bool`, `true`, `false`, `string`, `int`, `float`, `ComplexTypes`?
 //   -->  class/secure_types.baml:13
 //    | 
 // 12 |   j ((char, int[][], (bool | string[][])) | double[][][][], (float, int)[])
@@ -199,49 +199,49 @@ class ComplexTypes {
 // 13 |   k map<string[], (int | long[])> | map<float[][], double[][]>
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 //    | 
-// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `string`, `ComplexTypes`?
+// error: Type `char` does not exist. Did you mean one of these: `int`, `float`, `bool`, `true`, `false`, `string`, `ComplexTypes`?
 //   -->  class/secure_types.baml:14
 //    | 
 // 13 |   k map<string[], (int | long[])> | map<float[][], double[][]>
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 //    | 
-// error: Type `tuple_1` does not exist. Did you mean one of these: `float`, `bool`, `string`, `int`, `ComplexTypes`?
+// error: Type `tuple_1` does not exist. Did you mean one of these: `true`, `float`, `bool`, `false`, `string`, `int`, `ComplexTypes`?
 //   -->  class/secure_types.baml:15
 //    | 
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 //    | 
-// error: Type `tuple_2` does not exist. Did you mean one of these: `float`, `bool`, `string`, `int`, `ComplexTypes`?
+// error: Type `tuple_2` does not exist. Did you mean one of these: `true`, `float`, `bool`, `false`, `string`, `int`, `ComplexTypes`?
 //   -->  class/secure_types.baml:15
 //    | 
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 //    | 
-// error: Type `tuple_3` does not exist. Did you mean one of these: `float`, `bool`, `string`, `int`, `ComplexTypes`?
+// error: Type `tuple_3` does not exist. Did you mean one of these: `true`, `float`, `bool`, `false`, `string`, `int`, `ComplexTypes`?
 //   -->  class/secure_types.baml:15
 //    | 
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 //    | 
-// error: Type `tuple_4` does not exist. Did you mean one of these: `float`, `bool`, `string`, `int`, `ComplexTypes`?
+// error: Type `tuple_4` does not exist. Did you mean one of these: `true`, `float`, `bool`, `false`, `string`, `int`, `ComplexTypes`?
 //   -->  class/secure_types.baml:15
 //    | 
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 //    | 
-// error: Type `tuple_5` does not exist. Did you mean one of these: `float`, `bool`, `string`, `int`, `ComplexTypes`?
+// error: Type `tuple_5` does not exist. Did you mean one of these: `true`, `float`, `bool`, `false`, `string`, `int`, `ComplexTypes`?
 //   -->  class/secure_types.baml:15
 //    | 
 // 14 |   l AlphaNumeric_123_456_789 | (int, bool?) | char[]
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 //    | 
-// error: Type `another_key` does not exist. Did you mean one of these: `string`, `int`, `ComplexTypes`, `float`, `bool`?
+// error: Type `another_key` does not exist. Did you mean one of these: `true`, `string`, `int`, `ComplexTypes`, `float`, `bool`, `false`?
 //   -->  class/secure_types.baml:16
 //    | 
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 // 16 |   n map<complex_key_type[], map<another_key, (int | string[])>>
 //    | 
-// error: Type `complex_key_type` does not exist. Did you mean one of these: `ComplexTypes`, `float`, `bool`, `int`, `string`?
+// error: Type `complex_key_type` does not exist. Did you mean one of these: `ComplexTypes`, `float`, `bool`, `true`, `false`, `int`, `string`?
 //   -->  class/secure_types.baml:16
 //    | 
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
@@ -259,7 +259,7 @@ class ComplexTypes {
 // 15 |   m (tuple_1, tuple_2 | tuple_3, (tuple_4, tuple_5))[]
 // 16 |   n map<complex_key_type[], map<another_key, (int | string[])>>
 //    | 
-// error: Type `double` does not exist. Did you mean one of these: `bool`, `string`, `int`, `float`, `ComplexTypes`?
+// error: Type `double` does not exist. Did you mean one of these: `bool`, `true`, `false`, `string`, `int`, `float`, `ComplexTypes`?
 //   -->  class/secure_types.baml:17
 //    | 
 // 16 |   n map<complex_key_type[], map<another_key, (int | string[])>>