From d4af7352072e0bff9d803f2ad9fa45b3e48609a3 Mon Sep 17 00:00:00 2001
From: mtardy <mahe5397@hotmail.fr>
Date: Wed, 2 Sep 2020 09:04:22 +0200
Subject: [PATCH 1/2] Add TYPESIG and CASE macros to switch between types
 combinations more elegantly

---
 object.c  |  4 ++++
 parse.leg | 37 +++++++++++++++++++++----------------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/object.c b/object.c
index 66a97d8..ad4c1d5 100644
--- a/object.c
+++ b/object.c
@@ -77,6 +77,10 @@ typedef enum {
     Map
 } type_t;
 
+#define NTYPES (Map + 1)
+#define TYPESIG(L, R) L*NTYPES+R
+#define CASE(L, R) case TYPESIG(L, R)
+
 union object;
 typedef union object *oop;
 
diff --git a/parse.leg b/parse.leg
index 018850b..c4f7061 100644
--- a/parse.leg
+++ b/parse.leg
@@ -991,28 +991,33 @@ void runtimeError(char *msg)
 
 oop addOperation(oop ast, oop lhs, oop rhs)
 {
-    if (getType(lhs) == Integer && getType(rhs) == Integer) {
-        return makeInteger(getInteger(lhs) + getInteger(rhs));
-    } else if (getType(lhs) == String && getType(rhs) == String) {
-        return string_concat(lhs, rhs);
-    } else {
-        runtimeError("addition between two incompatible types");
-        assert(0); // to prevent: control may reach end of non-void function
+    switch (TYPESIG(getType(lhs), getType(rhs))) {
+        CASE(Integer, Integer): {
+            return makeInteger(getInteger(lhs) + getInteger(rhs));
+        }
+        CASE(String, String): {
+            return string_concat(lhs, rhs);
+        }
     }
+    runtimeError("addition between two incompatible types");
+    assert(0); // to prevent: control may reach end of non-void function
 }
 
 oop mulOperation(oop ast, oop lhs, oop rhs)
 {
-    if (getType(lhs) == Integer && getType(rhs) == Integer) {
-        return makeInteger(getInteger(lhs) * getInteger(rhs));
-    } else if (getType(lhs) == String && getType(rhs) == Integer) {
-        return string_mul(lhs, rhs);
-    } else if (getType(lhs) == Integer && getType(rhs) == String) {
-        return string_mul(rhs, lhs);
-    } else {
-        runtimeError("multiplication between two incompatible types");
-        assert(0);
+    switch (TYPESIG(getType(lhs), getType(rhs))) {
+        CASE(Integer, Integer): {
+            return makeInteger(getInteger(lhs) * getInteger(rhs));
+        }
+        CASE(String, Integer): {
+            return string_mul(lhs, rhs);
+        }
+        CASE(Integer, String): {
+            return string_mul(rhs, lhs);
+        }
     }
+    runtimeError("multiplication between two incompatible types");
+    assert(0);
 }
 
 oop expandUnquotes(oop scope, oop obj)

From 530e71426be4470faf2a6a5ca42028fdcb8568a2 Mon Sep 17 00:00:00 2001
From: mtardy <mahe5397@hotmail.fr>
Date: Wed, 2 Sep 2020 11:06:13 +0200
Subject: [PATCH 2/2] Move TYPESIG and CASE macros and undef them

---
 object.c  | 2 --
 parse.leg | 6 ++++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/object.c b/object.c
index ad4c1d5..85e3dff 100644
--- a/object.c
+++ b/object.c
@@ -78,8 +78,6 @@ typedef enum {
 } type_t;
 
 #define NTYPES (Map + 1)
-#define TYPESIG(L, R) L*NTYPES+R
-#define CASE(L, R) case TYPESIG(L, R)
 
 union object;
 typedef union object *oop;
diff --git a/parse.leg b/parse.leg
index c4f7061..78b0412 100644
--- a/parse.leg
+++ b/parse.leg
@@ -989,6 +989,9 @@ void runtimeError(char *msg)
     exit(1);
 }
 
+#define TYPESIG(L, R) L*NTYPES+R
+#define CASE(L, R) case TYPESIG(L, R)
+
 oop addOperation(oop ast, oop lhs, oop rhs)
 {
     switch (TYPESIG(getType(lhs), getType(rhs))) {
@@ -1020,6 +1023,9 @@ oop mulOperation(oop ast, oop lhs, oop rhs)
     assert(0);
 }
 
+#undef TYPESIG
+#undef CASE
+
 oop expandUnquotes(oop scope, oop obj)
 {
     obj = clone(obj);