Support ! in symbols provided to host

crates/compiler/mono/src/layout.rs

@@ -4647,20 +4647,20 @@ impl LayoutId {
     // Returns something like "#UserApp_foo_1" when given a symbol that interns to "foo"
     // and a LayoutId of 1.
     pub fn to_symbol_string(self, symbol: Symbol, interns: &Interns) -> String {
-        let ident_string = symbol.as_str(interns);
+        let ident_string = symbol.as_str(interns).trim_end_matches('!');
         let module_string = interns.module_ids.get_name(symbol.module_id()).unwrap();
         format!("{}_{}_{}", module_string, ident_string, self.0)
     }
 
     // Returns something like "roc__foo_1_exposed" when given a symbol that interns to "foo"
     // and a LayoutId of 1.
     pub fn to_exposed_symbol_string(self, symbol: Symbol, interns: &Interns) -> String {
-        let ident_string = symbol.as_str(interns);
+        let ident_string = symbol.as_str(interns).trim_end_matches('!');
         format!("roc__{}_{}_exposed", ident_string, self.0)
     }
 
     pub fn to_exposed_generic_symbol_string(self, symbol: Symbol, interns: &Interns) -> String {
-        let ident_string = symbol.as_str(interns);
+        let ident_string = symbol.as_str(interns).trim_end_matches('!');
         format!("roc__{}_{}_exposed_generic", ident_string, self.0)
     }
 }

examples/cli/effects-platform/main.roc

@@ -1,9 +1,9 @@
 platform "effects"
-    requires {} { main : {} => {} }
+    requires {} { main! : {} => {} }
     exposes []
     packages {}
     imports []
-    provides [mainForHost]
+    provides [mainForHost!]
 
-mainForHost : {} => {}
-mainForHost = \{} -> main {}
+mainForHost! : {} => {}
+mainForHost! = \{} -> main! {}

examples/cli/effects.roc

@@ -1,9 +1,9 @@
-app [main] { pf: platform "effects-platform/main.roc" }
+app [main!] { pf: platform "effects-platform/main.roc" }
 
 import pf.Effect
 
-main : {} => {}
-main = \{} ->
+main! : {} => {}
+main! = \{} ->
     line = Effect.getLine! {}
 
     if line == "secret" then