switch callable to interning too

src/frontend.rs

@@ -4,7 +4,7 @@ use std::fmt::Write;
 
 use super::parser;
 use crate::rtlil;
-pub use callable::Callable;
+pub use callable::{Callable, CallableId};
 pub use types::{Type, TypeStruct, TypingContext};
 
 mod callable;
@@ -64,7 +64,8 @@ impl Signal {
 
 pub struct Context {
     /// map callable name to callable
-    callables: BTreeMap<String, Callable>,
+    callable_names: BTreeMap<String, CallableId>,
+    callables: BTreeMap<CallableId, Callable>,
     /// type names
     typenames: BTreeMap<String, Type>,
     types: TypingContext,
@@ -92,6 +93,7 @@ impl Context {
         let tcx = TypingContext::new();
         Context {
             callables: BTreeMap::new(),
+            callable_names: BTreeMap::new(),
             signals: BTreeMap::new(),
             types: TypingContext::new(),
             typenames: [
@@ -115,8 +117,8 @@ impl Context {
         })
     }
 
-    fn try_get_callable(&self, callname: &str) -> Result<&Callable, CompileError> {
+    fn try_get_callable(&self, callname: &str) -> Result<CallableId, CompileError> {
-        self.callables.get(callname).ok_or_else(|| {
+        self.callable_names.get(callname).copied().ok_or_else(|| {
             CompileError::new(CompileErrorKind::UndefinedReference(callname.to_owned()))
         })
     }

src/frontend/callable.rs

@@ -1,5 +1,8 @@
 use super::types::Type;
 
+#[derive(Copy, Clone, PartialEq)]
+pub struct CallableId(u32);
+
 pub struct Callable {
     pub name: String,
     pub args: Vec<(Option<String>, Type)>,