From a19a010d1e5a0d9bf474d2f432c977d30b25117e Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Wed, 21 Apr 2021 00:04:45 +0200
Subject: [PATCH] Add WIP version for a M_LET recursive

---
 m-core.h           | 26 ++++++++++++++++----------
 tests/test-mcore.c | 24 ++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/m-core.h b/m-core.h
index e9e114ef..8b6977db 100644
--- a/m-core.h
+++ b/m-core.h
@@ -2879,9 +2879,13 @@ static inline size_t m_core_cstr_hash(const char str[])
 
 /* API transformation support:
    transform the call to the method into the supported API by the method.
-   Example of usage in oplist: ( INIT_WITH(API_1(method)) ) */
+   Example of usage in oplist: ( INIT_WITH(API_1(method)) )
+   NOTE: It uses M_RET_ARG3 instead of M_RET_ARG2 since M_GET_METHOD
+   uses M_RET_ARG2: to be able to use M_GET_METHOD within a M_APPLY_API
+   we need another macro to avoid being marked.
+*/
 #define M_APPLY_API(method, oplist, ...)                                      \
-  M_RET_ARG2(M_C(M_OPLAPI_INDIRECT_, method)(M_C(M_OPLAPI_EXTRACT_,method),oplist,__VA_ARGS__), method(__VA_ARGS__),)
+  M_RET_ARG3( , M_C(M_OPLAPI_INDIRECT_, method)(M_C(M_OPLAPI_EXTRACT_,method),oplist,__VA_ARGS__), M_DELAY2(method)(__VA_ARGS__),)
 
 /* API Transformation :
    0: Method has been disable. It shall not be called. Raised an error.
@@ -2889,16 +2893,18 @@ static inline size_t m_core_cstr_hash(const char str[])
    API_2: by addr for first argument, API_3: oplist given,
    API_4 :by affectation for first argument, 5: API_by affectation + oplist
    API_6 :by addr for two arguments, 5: API_by address for both + oplist
+
+   NOTE: It starts by a comma, to ack the success of the transformation.
 */
 #define M_OPLAPI_ERROR(method, oplist, ...)  , M_STATIC_FAILURE(M_LIB_DISABLED_METHOD, "The method has been explictly disabled for the requested operator, yet it has been called by the container")
-#define M_OPLAPI_0(method, oplist, ...)      , method(__VA_ARGS__)
-#define M_OPLAPI_1(method, oplist, ...)      , method(oplist, __VA_ARGS__)
-#define M_OPLAPI_2(method, oplist, ...)      , method(& __VA_ARGS__)
-#define M_OPLAPI_3(method, oplist, ...)      , method(oplist, &__VA_ARGS__)
-#define M_OPLAPI_4(method, oplist, x, ...)   , x = method(__VA_ARGS__)
-#define M_OPLAPI_5(method, oplist, x, ...)   , x = method(oplist, __VA_ARGS__)
-#define M_OPLAPI_6(method, oplist, x, ...)   , method(&x, &__VA_ARGS__)
-#define M_OPLAPI_7(method, oplist, x, ...)   , method(oplist, &x, &__VA_ARGS__)
+#define M_OPLAPI_0(method, oplist, ...)      , M_DELAY3(method)(__VA_ARGS__)
+#define M_OPLAPI_1(method, oplist, ...)      , M_DELAY3(method)(oplist, __VA_ARGS__)
+#define M_OPLAPI_2(method, oplist, ...)      , M_DELAY3(method)(& __VA_ARGS__)
+#define M_OPLAPI_3(method, oplist, ...)      , M_DELAY(method)(oplist, &__VA_ARGS__)
+#define M_OPLAPI_4(method, oplist, x, ...)   , x = M_DELAY3(method)(__VA_ARGS__)
+#define M_OPLAPI_5(method, oplist, x, ...)   , x = M_DELAY3(method)(oplist, __VA_ARGS__)
+#define M_OPLAPI_6(method, oplist, x, ...)   , M_DELAY3(method)(&x, &__VA_ARGS__)
+#define M_OPLAPI_7(method, oplist, x, ...)   , M_DELAY3(method)(oplist, &x, &__VA_ARGS__)
 /* API transformation support for indirection */
 #define M_OPLAPI_INDIRECT_0          M_OPLAPI_ERROR
 #define M_OPLAPI_INDIRECT_API_0(...) M_OPLAPI_0
diff --git a/tests/test-mcore.c b/tests/test-mcore.c
index efda592d..53a1111e 100644
--- a/tests/test-mcore.c
+++ b/tests/test-mcore.c
@@ -263,6 +263,30 @@ static void test_let(void)
   }
   assert(b);
 
+  // Test of recursive INIT_WITH within M_LET
+  // We need to use M_APPLY_APIA / M_APPLY_APIB for this.
+#define OPL1 (TYPE(int), INIT_WITH(OPL1_F))
+#define OPL1_F(d, x) ((d) = (x))
+#define OPL2 (TYPE(int), INIT_WITH(API_1(OPL2_F)), OPLIST(OPL1) )
+#define OPL2_F(opl, d, x) M_APPLY_API(M_GET_INIT_WITH M_GET_OPLIST opl, M_GET_OPLIST opl, d, x)
+#define OPL3 (TYPE(int), INIT_WITH(API_1(OPL3_F)), OPLIST(OPL2) )
+#define OPL3_F(opl, d, x) M_APPLY_API(M_GET_INIT_WITH M_GET_OPLIST opl, M_GET_OPLIST opl, d, x)
+#define OPL4 (TYPE(int), INIT_WITH(API_1(OPL4_F)), OPLIST(OPL3) )
+#define OPL4_F(opl, d, x) M_APPLY_API(M_GET_INIT_WITH M_GET_OPLIST opl, M_GET_OPLIST opl, d, x)
+#define OPL5 (TYPE(int), INIT_WITH(API_1(OPL5_F)), OPLIST(OPL4) )
+#define OPL5_F(opl, d, x) M_APPLY_API(M_GET_INIT_WITH M_GET_OPLIST opl, M_GET_OPLIST opl, d, x)
+  
+  M_LET( (x, 4585) , OPL1)
+    assert (x == 4585);
+  M_LET( (x, 4586) , OPL2)
+    assert (x == 4586);
+  M_LET( (x, 4587) , OPL3)
+    assert (x == 4587);
+  M_LET( (x, 4588) , OPL4)
+    assert (x == 4588);
+  M_LET( (x, 4589) , OPL5)
+    assert (x == 4589);
+    
   int c = 0;
   M_LET_IF( assert(c++ == 0), (assert(c++ == 1), true), assert(c++ == 3)) {
     assert(c++ == 2);