fun, return, do

crates/codegen/src/cpp.rs

@@ -2,6 +2,12 @@ use std::fmt::Display;
 
 use hir::{IR, IRKind, Value};
 
+const MODULE_INCLUDES: [&str; 3] = [
+    "<stdbool.h>",
+    "<iostream>",
+    "<string>",
+];
+
 pub struct Codegen {
     pub emitted: String,
 }
@@ -16,14 +22,12 @@ impl Codegen {
     }
 
     pub fn gen(&mut self, irs: Vec<IR>) {
-        self.emit("#include <stdbool.h>\n");
-        self.emit("#include <iostream>\n");
-        self.emit("#include <string>\n");
-        self.emit("int main() {\n");
+        for module in MODULE_INCLUDES {
+            self.emit(format!("#include {}\n", module));
+        }
         for ir in irs {
             self.emit(&self.gen_ir(&ir.kind));
         }
-        self.emit("}");
     }
     
     fn gen_ir(&self, ir: &IRKind) -> String {
@@ -38,6 +42,21 @@ impl Codegen {
                     _ => format!("{}({});\n", name, args.iter().map(|arg| self.gen_ir(arg)).collect::<Vec<_>>().join(", ")),
                 }
             },
+            IRKind::Fun { name, return_type_hint, args, body } => {
+                let args = args.iter().map(|arg| format!("{} {}", arg.1, arg.0)).collect::<Vec<_>>().join(", ");
+                format!("{} {}({}) {{\n{}}}\n", return_type_hint, name, args, self.gen_ir(body))
+            },
+            IRKind::Return { value } => {
+                format!("return {};\n", self.gen_ir(value))
+            },
+            IRKind::Do { body } => {
+                let mut out = String::new();
+                for expr in body {
+                    out.push_str(&self.gen_ir(&expr));
+                }
+                out
+            }
+
             IRKind::Value { value } => {
                 match value {
                     Value::Int(value)     => format!("{}", value),

crates/hir/src/lib.rs

@@ -9,10 +9,11 @@ pub enum IRKind {
     Define { name: String, type_hint: String, value: Box<Self> },
     Fun { name: String, return_type_hint: String, args: Vec<(String, String)>, body: Box<Self> },
     Call { name: String, args: Vec<Self> },
-    Do { body: Box<Self> },
+    Do { body: Vec<Self> },
     If { cond: Box<Self>, body: Box<Self>, else_body: Box<Self> },
     Value { value: Value },
     Binary { op: String, left: Box<Self>, right: Box<Self> },
+    Return { value: Box<Self> },
 }
 
 #[derive(Debug)]
@@ -51,6 +52,19 @@ pub fn expr_to_ir(expr: &Expr) -> IRKind {
             let args = args.0.iter().map(|arg| expr_to_ir(&arg.0)).collect::<Vec<_>>();
             IRKind::Call { name, args }
         },
+        Expr::Fun { name, type_hint, args, body } => {
+            let args = args.0.iter().map(|arg| (arg.0.0.clone(), gen_type_hint(&arg.1.0))).collect::<Vec<_>>();
+            let body = expr_to_ir(&body.0);
+            IRKind::Fun { name: name.to_string(), return_type_hint: gen_type_hint(type_hint), args, body: Box::new(body) }
+        },
+        Expr::Return { expr } => {
+            let expr = expr_to_ir(&expr.0);
+            IRKind::Return { value: Box::new(expr) }
+        },
+        Expr::Do { body } => {
+            let body = body.iter().map(|expr| expr_to_ir(&expr.0)).collect::<Vec<_>>();
+            IRKind::Do { body }
+        },
 
         Expr::Int(value)        => IRKind::Value { value: Value::Int(*value) },
         Expr::Boolean(value)    => IRKind::Value { value: Value::Boolean(*value) },

example/ex.hades

@@ -1,4 +1,4 @@
-let foo: int = 1;
-let baz: bool = true;
-let qux: string = "Hello, World";
-write(qux);
+fun main: int = do
+    write("Hello, World!\n");
+    return 0;
+end;