rebel-lang: typing: implement turning an AST Type into a runtime Type

1 files changed, 55 insertions, 1 deletions

diff --git a/crates/rebel-lang/src/typing.rs b/crates/rebel-lang/src/typing.rs
index fc3009a..2af8d33 100644
--- a/crates/rebel-lang/src/typing.rs
+++ b/crates/rebel-lang/src/typing.rs
@@ -2,7 +2,7 @@ use std::{collections::HashMap, fmt::Display};
 
 use enum_kinds::EnumKind;
 
-use rebel_parse::ast::{self, expr};
+use rebel_parse::ast::{self, expr, typ};
 
 use crate::{func::FuncType, scope::Context};
 
@@ -79,6 +79,50 @@ impl Type {
 		})
 	}
 
+	pub fn ast_type(ctx: &Context, expr: &typ::Type<'_>) -> Result<Type> {
+		use typ::Type::*;
+
+		Ok(match expr {
+			Paren(subexpr) => Self::ast_type(ctx, subexpr)?,
+			Path(path) => Self::path_type(ctx, path)?,
+			Literal(lit) => Self::literal_type(ctx, lit)?,
+		})
+	}
+
+	fn path_type(ctx: &Context, path: &ast::Path<'_>) -> Result<Type> {
+		use Type::*;
+
+		if path.components == [ast::Ident { name: "_" }] {
+			return Ok(Free);
+		}
+
+		ctx.types.lookup(&path.components).cloned().ok_or(TypeError)
+	}
+
+	fn literal_type(ctx: &Context, lit: &typ::Literal<'_>) -> Result<Type> {
+		use typ::Literal;
+		use Type::*;
+
+		Ok(match lit {
+			Literal::Unit => Unit,
+			Literal::Tuple(elems) => Tuple(
+				elems
+					.iter()
+					.map(|elem| Self::ast_type(ctx, elem))
+					.collect::<Result<_>>()?,
+			),
+			Literal::Array(typ, len) => Array(Box::new(Self::ast_type(ctx, typ)?), (*len).into()),
+			Literal::Struct(entries) => Struct(
+				entries
+					.iter()
+					.map(|typ::StructField { name, typ }| {
+						Ok(((*name).to_owned(), Self::ast_type(ctx, typ)?))
+					})
+					.collect::<Result<_>>()?,
+			),
+		})
+	}
+
 	pub fn ast_stmt_type(ctx: &Context, stmt: &ast::BodyStmt<'_>) -> Result<Type> {
 		match stmt {
 			ast::BodyStmt::Assign { dest: _, expr } => {
@@ -417,6 +461,16 @@ impl ArrayLen {
 	}
 }
 
+impl From<typ::ArrayLen> for ArrayLen {
+	fn from(value: typ::ArrayLen) -> Self {
+		match value {
+			typ::ArrayLen::Free => ArrayLen::Free,
+			typ::ArrayLen::Fixed(len) => ArrayLen::Fixed(len),
+			typ::ArrayLen::Dynamic => ArrayLen::Dynamic,
+		}
+	}
+}
+
 impl Display for ArrayLen {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		match self {