traits

mist-test/src/logger.mist

@@ -1,6 +1,6 @@
 use <std::fmt>;
 
-public trait TestLogging: Display {}
+public trait TestLogging<T: fmt::Display>: fmt::Display {}
 
 public enum LogLevel {
     Info,

parser/src/ast.rs

@@ -80,7 +80,7 @@ pub enum TopLevelKind {
         name: Identifier,
         generics: Generics,
         requirements: Vec<TypeExpr>,
-        items: Vec<TraitItem>,
+        items: Vec<FunctionDecl>,
     },
     EnumDecl {
         visibility: Visibility,
@@ -105,12 +105,6 @@ pub enum TopLevelKind {
     },
 }
 
-#[derive(Debug, Clone, Serialize)]
-pub enum TraitItem {
-    WithBody(FunctionDecl),
-    NoBody(FunctionDecl),
-}
-
 #[derive(Debug, Clone, Serialize)]
 pub enum ClassItem {
     Method(FunctionDecl),
@@ -158,7 +152,7 @@ pub struct FunctionDecl {
     pub generics: Generics,
     pub params: ParamList,
     pub return_type: TypeExpr,
-    pub body: Block,
+    pub body: Option<Block>,
 }
 
 #[derive(Debug, Clone, Serialize)]

parser/src/lib.rs

@@ -314,7 +314,7 @@ impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {
                 requirements: consume_rule(&mut inner, Rule::trait_requirements)
                     .map(|pair| pair.into_inner().map(TypeExpr::from).collect())
                     .unwrap_or_default(),
-                items: inner.map(TraitItem::from).collect(),
+                items: inner.map(FunctionDecl::from).collect(),
             },
 
             _ => unimplemented!("{rule:#?}"),
@@ -322,19 +322,6 @@ impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {
     }
 }
 
-impl From<pest::iterators::Pair<'_, Rule>> for TraitItem {
-    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
-        let rule = pair.as_rule();
-
-        match rule {
-            Rule::method => TraitItem::WithBody(FunctionDecl::from(pair)),
-            Rule::method_no_body => TraitItem::NoBody(FunctionDecl::from(pair)),
-
-            _ => unimplemented!("{rule:#?}"),
-        }
-    }
-}
-
 impl From<pest::iterators::Pair<'_, Rule>> for ClassItem {
     fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
         let rule = pair.as_rule();
@@ -789,7 +776,7 @@ impl From<pest::iterators::Pair<'_, Rule>> for FunctionDecl {
             })
             .unwrap_or_else(|| ParamList(self_param.into_iter().collect()));
 
-        let body = Block::from(inner.next().unwrap());
+        let body = inner.next().map(Block::from);
 
         Self {
             visibility,

src/codegen.rs

@@ -358,6 +358,38 @@ impl ToRust for TopLevelKind {
                 cg.indent -= 1;
                 cg.addln("}\n");
             }
+            Self::TraitDecl {
+                visibility,
+                name,
+                generics,
+                requirements,
+                items,
+            } => {
+                cg.addln(&format!(
+                    "{}trait {}{}{} {{",
+                    visibility.get_rust(),
+                    name.get_rust(),
+                    generics.get_rust(),
+                    if requirements.len() != 0 {
+                        String::from(": ")
+                            + &requirements
+                                .iter()
+                                .map(TypeExpr::get_rust)
+                                .collect::<Vec<_>>()
+                                .join("+")
+                    } else {
+                        String::new()
+                    },
+                ));
+                cg.indent += 1;
+
+                for item in items {
+                    item.to_rust(cg);
+                }
+
+                cg.indent -= 1;
+                cg.addln("}\n");
+            }
             Self::ClassDecl {
                 visibility,
                 name,
@@ -627,9 +659,13 @@ impl ToRust for FunctionDecl {
             params_str,
             self.return_type.get_rust()
         ));
-        cg.indent += 1;
-        self.body.to_rust(cg);
-        cg.indent -= 1;
+        if let Some(body) = &self.body {
+            cg.indent += 1;
+            body.to_rust(cg);
+            cg.indent -= 1;
+        } else {
+            cg.add(";");
+        }
         cg.add_indentedln("}\n");
     }
 }