refactor: reduce coupling

evaluator/nixjit_macros/src/ir.rs

@@ -0,0 +1,54 @@
+use syn::{
+    FieldsNamed, Ident, Token, Type, parenthesized,
+    parse::{Parse, ParseStream, Result},
+    punctuated::Punctuated,
+    token,
+};
+
+pub enum VariantInput {
+    Unit(Ident),
+    Tuple(Ident, Type),
+    Struct(Ident, FieldsNamed),
+}
+
+pub struct MacroInput {
+    pub base_name: Ident,
+    pub variants: Punctuated<VariantInput, Token![,]>,
+}
+
+impl Parse for VariantInput {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let name: Ident = input.parse()?;
+
+        if input.peek(token::Paren) {
+            let content;
+            parenthesized!(content in input);
+            let ty: Type = content.parse()?;
+
+            if !content.is_empty() {
+                return Err(content.error("Expected a single type inside parentheses"));
+            }
+
+            Ok(VariantInput::Tuple(name, ty))
+        } else if input.peek(token::Brace) {
+            let fields: FieldsNamed = input.parse()?;
+
+            Ok(VariantInput::Struct(name, fields))
+        } else {
+            Ok(VariantInput::Unit(name))
+        }
+    }
+}
+
+impl Parse for MacroInput {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let base_name = input.parse()?;
+        input.parse::<Token![,]>()?;
+        let variants = Punctuated::parse_terminated(input)?;
+
+        Ok(MacroInput {
+            base_name,
+            variants,
+        })
+    }
+}