RANDOM_CALL, RANDOM_FOLLOW

Author: Asbelos

EXRAIL2.cpp

@@ -969,7 +969,33 @@ void RMFT2::loop2() {
     progCounter=routeLookup->find(operand);
     if (progCounter<0) kill(F("CALL unknown"),operand);
     return;
-    
+   
+  
+  case OPCODE_RANDOM_FOLLOW:
+    // operand is number to choose from
+    { 
+      auto newroute=getOperand(1+(millis()%operand));
+      progCounter=routeLookup->find(newroute);
+      if (progCounter<0) kill(F("RANDOM_FOLLOW unknown"), newroute); 
+    }
+    return;
+	
+	 case OPCODE_RANDOM_CALL:
+    // operand is number to choose from
+    if (stackDepth==MAX_STACK_DEPTH) {
+      kill(F("CALL stack"), stackDepth);
+      return;
+    }
+    {
+      auto newroute=getOperand(1+(millis()%operand));
+      
+      // return position is after the RANDOM_CALL + all its operands
+      callStack[stackDepth++]=progCounter+3*(operand+1);
+      progCounter=routeLookup->find(newroute);
+      if (progCounter<0) kill(F("CALL unknown"),newroute);
+    }
+    return;
+  
   case OPCODE_RETURN:
     if (stackDepth==0) {
       kill(F("RETURN stack"));

EXRAIL2.h

@@ -88,6 +88,7 @@ enum OPCODE : byte {OPCODE_THROW,OPCODE_CLOSE,OPCODE_TOGGLE_TURNOUT,
              OPCODE_WAIT_WHILE_RED,
              OPCODE_SAVE_SPEED,OPCODE_RESTORE_SPEED,
              OPCODE_XSAVE_SPEED,OPCODE_XRESTORE_SPEED,
+             OPCODE_RANDOM_CALL,OPCODE_RANDOM_FOLLOW,
 
              // OPcodes below this point are skip-nesting IF operations
              // placed here so that they may be skipped as a group

EXRAIL2MacroReset.h

@@ -154,6 +154,8 @@
 #undef POM
 #undef POWEROFF
 #undef POWERON
+#undef RANDOM_CALL
+#undef RANDOM_FOLLOW
 #undef READ_LOCO 
 #undef RED 
 #undef RESERVE 
@@ -1070,6 +1072,23 @@
  * @brief Powers ON all tracks 
  */
 #define POWERON
+/**
+ * @def RANDOM_CALL(sequence_id...)
+ * @brief CALL to another sequence randomly chosen from list
+ * @see CALL
+ * @param sequence_id.. list of SEQUENCE that may be called, each must terminate or RETURN
+ *  
+ */
+#define RANDOM_CALL(sequence_id...)
+
+/**
+ * @def RANDOM_FOLLOW(sequence_id...)
+ * @brief jump to another sequence randomly chosen from list
+ * @see FOLLOW
+ * @param sequence_id.. list of SEQUENCE that may be followed  
+ */
+#define RANDOM_FOLLOW(sequence_id...)
+
 /**
  * @def READ_LOCO
  * @brief Reads loco Id from prog track and sets currenmt task loco id.

EXRAILAsserts.h

@@ -99,6 +99,14 @@ constexpr bool unsafePin(const int16_t value, const int16_t pos=0 ) {
 #define CALL(id) static_assert(seqCount(id)>0,"Sequence  not found");
 #undef FOLLOW
 #define FOLLOW(id)  static_assert(seqCount(id)>0,"Sequence not found");
+
+// random call and follow will generate CALL macros here which
+// will check for invalid sequences
+#define RANDOM_CALL(...) \
+  ZCRIP(FOR_EACH_NARG(__VA_ARGS__))(__VA_ARGS__)
+#define RANDOM_FOLLOW(...) \
+  ZCRIP(FOR_EACH_NARG(__VA_ARGS__))(__VA_ARGS__)
+
 #undef START
 #define START(id)  static_assert(seqCount(id)>0,"Sequence not found");
 #undef START_SHARED

EXRAILMacros.h

@@ -80,6 +80,27 @@
 // NEOPIXEL RG generator for NEOPIXEL_SIGNAL 
 #define NeoRGB(red,green,blue) (((uint32_t)(red & 0xff)<<16) | ((uint32_t)(green & 0xff)<<8) | (uint32_t)(blue & 0xff))  
 
+// Collection of macros to assist variadic exrail macros
+// in particular RANDOMCALL and RANDOMFOLLOW
+// Count the number of arguments
+#define FOR_EACH_NARG(...) FOR_EACH_NARG_HELPER(__VA_ARGS__,8,7, 6,5,4, 3, 2, 1, 0)
+#define FOR_EACH_NARG_HELPER(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
+// Force proper expansion (extra indirection to resolve `##`)
+#define _CONCAT_(a, b) a##b
+#define _EXPAND_(a) a
+
+#define ZC0()                      
+#define ZC1(_1)                      CALL(_1) 
+#define ZC2(_1,_2)                   CALL(_1) CALL(_2)
+#define ZC3(_1,_2,_3)                CALL(_1) CALL(_2) CALL(_3)
+#define ZC4(_1,_2,_3,_4)             CALL(_1) CALL(_2) CALL(_3) CALL(_4)
+#define ZC5(_1,_2,_3,_4,_5)          CALL(_1) CALL(_2) CALL(_3) CALL(_4) CALL(_5)
+#define ZC6(_1,_2,_3,_4,_5,_6)       CALL(_1) CALL(_2) CALL(_3) CALL(_4) CALL(_5) CALL(_6)
+#define ZC7(_1,_2,_3,_4,_5,_6,_7)    CALL(_1) CALL(_2) CALL(_3) CALL(_4) CALL(_5) CALL(_6) CALL(_7)
+#define ZC8(_1,_2,_3,_4,_5,_6,_7,_8) CALL(_1) CALL(_2) CALL(_3) CALL(_4) CALL(_5) CALL(_6) CALL(_7) CALL(_8)
+#define ZCRIP(count) _EXPAND_(_CONCAT_(ZC,count))
+
+
 // Pass 1 Implements aliases 
 #include "EXRAIL2MacroReset.h"
 #undef ALIAS
@@ -596,6 +617,12 @@ int RMFT2::onLCCLookup[RMFT2::countLCCLookup];
 #define POWERON OPCODE_POWERON,0,0,
 #define PRINT(msg) OPCODE_PRINT,V(__COUNTER__ - StringMacroTracker2),
 #define PARSE(msg) PRINT(msg)
+#define RANDOM_CALL(...) \
+  OPCODE_RANDOM_CALL,V(FOR_EACH_NARG(__VA_ARGS__)), \
+  ZCRIP(FOR_EACH_NARG(__VA_ARGS__))(__VA_ARGS__)
+#define RANDOM_FOLLOW(...) \
+  OPCODE_RANDOM_FOLLOW,V(FOR_EACH_NARG(__VA_ARGS__)), \
+  ZCRIP(FOR_EACH_NARG(__VA_ARGS__))(__VA_ARGS__)
 #define READ_LOCO OPCODE_READ_LOCO1,0,0,OPCODE_READ_LOCO2,0,0,
 #define RED(signal_id) OPCODE_RED,V(signal_id),
 #define RESERVE(blockid) OPCODE_RESERVE,V(blockid),

EXRAILTest.h

@@ -96,4 +96,20 @@ ROUTE(7000, "Route state tests")
       XRESTORE_SPEED(4)
       PRINT("7401 Speed 4 restored")
       DONE
-      
+      
+SEQUENCE(7500)
+  PRINT("7500 Testing RANDOM_CALL and RANDOM_FOLLOW")
+  RANDOM_CALL(7501, 7502, 7503,9191)
+  PRINT("7500 Returned from RANDOM_CALL")
+  RANDOM_FOLLOW(7511, 7512, 7513)
+  PRINT("7500 ERROR Returned from RANDOM_FOLLOW")
+  DONE
+
+  SEQUENCE(7501) PRINT("7501 RANDOM_CALL") RETURN
+  SEQUENCE(7502) PRINT("7502 RANDOM_CALL") RETURN
+  SEQUENCE(7503) PRINT("7503 RANDOM_CALL") RETURN
+
+  SEQUENCE(7511) PRINT("7511 RANDOM_FOLLOW") DONE
+  SEQUENCE(7512) PRINT("7512 RANDOM_FOLLOW") DONE
+  SEQUENCE(7513) PRINT("7513 RANDOM_FOLLOW") DONE
+