Add ++ and -- for float/double

compiler/builders/ast_to_builder.jou

@@ -225,6 +225,8 @@ class AstToBuilder:
         match t->kind:
             case TypeKind.SignedInteger | TypeKind.UnsignedInteger:
                 new_value = self->builder->add(old_value, self->builder->integer(t, diff))
+            case TypeKind.FloatingPoint:
+                new_value = self->builder->add(old_value, self->builder->cast(self->builder->integer(intType, diff), t))
             case TypeKind.Pointer:
                 idx = self->builder->integer(longType, diff)
                 new_value = self->builder->indexed_pointer(old_value, idx)

compiler/typecheck/step3_function_and_method_bodies.jou

@@ -489,7 +489,7 @@ def check_increment_or_decrement(state: State*, expr: AstExpression*) -> Type*:
             assert False
 
     t = typecheck_expression_not_void(state, &expr->operands[0])
-    if not t->is_integer_type() and t->kind != TypeKind.Pointer:
+    if not t->is_number_type() and t->kind != TypeKind.Pointer:
         msg: byte[500]
         snprintf(msg, sizeof(msg), bad_type_fmt, t->name)
         fail(expr->location, msg)

tests/should_succeed/plusplus_minusminus.jou

@@ -32,4 +32,18 @@ def main() -> int:
     n = 0
     printf("%d %d\n", n, ++n)  # Output: 0 1
 
+    # float
+    f = 1.23f
+    printf("%.2f f=%.2f\n", f++, f)  # Output: 1.23 f=2.23
+    printf("%.2f f=%.2f\n", f--, f)  # Output: 2.23 f=1.23
+    printf("%.2f f=%.2f\n", ++f, f)  # Output: 2.23 f=2.23
+    printf("%.2f f=%.2f\n", --f, f)  # Output: 1.23 f=1.23
+
+    # double
+    d = 1.23
+    printf("%.2f d=%.2f\n", d++, d)  # Output: 1.23 d=2.23
+    printf("%.2f d=%.2f\n", d--, d)  # Output: 2.23 d=1.23
+    printf("%.2f d=%.2f\n", ++d, d)  # Output: 2.23 d=2.23
+    printf("%.2f d=%.2f\n", --d, d)  # Output: 1.23 d=1.23
+
     return 0