Implement int and float subtraction

compiler/gen/src/crane/build.rs

@@ -559,13 +559,20 @@ fn call_by_name<'a, B: Backend>(
 
             builder.ins().fadd(a, b)
         }
-        Symbol::NUM_SUB => {
+        Symbol::INT_SUB | Symbol::NUM_SUB => {
             debug_assert!(args.len() == 2);
             let a = build_arg(&args[0], env, scope, module, builder, procs);
             let b = build_arg(&args[1], env, scope, module, builder, procs);
 
             builder.ins().isub(a, b)
         }
+        Symbol::FLOAT_SUB => {
+            debug_assert!(args.len() == 2);
+            let a = build_arg(&args[0], env, scope, module, builder, procs);
+            let b = build_arg(&args[1], env, scope, module, builder, procs);
+
+            builder.ins().fsub(a, b)
+        }
         Symbol::NUM_MUL => {
             debug_assert!(args.len() == 2);
             let a = build_arg(&args[0], env, scope, module, builder, procs);

compiler/gen/src/llvm/build.rs

@@ -558,7 +558,7 @@ fn call_with_args<'a, 'ctx, 'env>(
 
             BasicValueEnum::FloatValue(float_val)
         }
-        Symbol::NUM_SUB => {
+        Symbol::INT_SUB | Symbol::NUM_SUB => {
             debug_assert!(args.len() == 2);
 
             let int_val = env.builder.build_int_sub(
@@ -569,6 +569,17 @@ fn call_with_args<'a, 'ctx, 'env>(
 
             BasicValueEnum::IntValue(int_val)
         }
+        Symbol::FLOAT_SUB => {
+            debug_assert!(args.len() == 2);
+
+            let float_val = env.builder.build_float_sub(
+                args[0].into_float_value(),
+                args[1].into_float_value(),
+                "sub_f64",
+            );
+
+            BasicValueEnum::FloatValue(float_val)
+        }
         Symbol::NUM_MUL => {
             debug_assert!(args.len() == 2);
 

compiler/gen/tests/test_gen.rs

@@ -826,6 +826,19 @@ mod test_gen {
         );
     }
 
+    #[test]
+    fn gen_sub_f64() {
+        assert_evals_to!(
+            indoc!(
+                r#"
+                    1.5 - 2.4 - 3
+                "#
+            ),
+            -3.9,
+            f64
+        );
+    }
+
     #[test]
     fn gen_sub_i64() {
         assert_evals_to!(

compiler/module/src/symbol.rs

@@ -576,6 +576,7 @@ define_builtins! {
         5 INT_HIGHEST: "highest"
         6 INT_LOWEST: "lowest"
         7 INT_ADD: "#add"
+        8 INT_SUB: "#sub"
     }
     3 FLOAT: "Float" => {
         0 FLOAT_FLOAT: "Float" imported // the Float.Float type alias
@@ -587,6 +588,7 @@ define_builtins! {
         6 FLOAT_HIGHEST: "highest"
         7 FLOAT_LOWEST: "lowest"
         8 FLOAT_ADD: "#add"
+        9 FLOAT_SUB: "#sub"
     }
     4 BOOL: "Bool" => {
         0 BOOL_BOOL: "Bool" imported // the Bool.Bool type alias

compiler/mono/src/expr.rs

@@ -345,6 +345,10 @@ fn from_can<'a>(
                         FloatType => Symbol::FLOAT_ADD,
                         IntType => Symbol::INT_ADD,
                     },
+                    Symbol::NUM_SUB => match to_int_or_float(subs, ret_var) {
+                        FloatType => Symbol::FLOAT_SUB,
+                        IntType => Symbol::INT_SUB,
+                    },
                     _ => symbol,
                 }
             };