Implement #continuedo <number>

check/features.frm

@@ -2390,11 +2390,91 @@ assert succeeded?
 assert result("F") =~ expr("f(1,2,4,5)")
 *--#] Issue243_1 : 
 *--#[ Issue243_2 :
-#continuedo
+NF f;
+L F = 1;
+#define i "9"
+#do i=1,2
+  #do i=1,3
+    #do i=1,8
+      #if `i' == 3
+        #continuedo 2
+      #endif
+      multiply right, f(`i');
+    #enddo
+    multiply right, f(-`i');
+  #enddo
+  multiply right, f(-`i');
+#enddo
+multiply right, f(`i');
+chainin f;
+P;
 .end
-assert preprocess_error?
-assert stdout =~ exact_pattern("#continuedo without #do")
+assert succeeded?
+assert result("F") =~ expr("f(1,2,1,2,1,2,-1,1,2,1,2,1,2,-2,9)")
 *--#] Issue243_2 : 
+*--#[ Issue243_3 :
+NF f;
+L F = 1;
+#do i=1,3
+  #do i=1,2
+    #continuedo 0
+    multiply right, f(`i');
+  #enddo
+#enddo
+chainin f;
+P;
+.end
+assert succeeded?
+assert result("F") =~ expr("f(1,2,1,2,1,2)")
+*--#] Issue243_3 : 
+*--#[ Issue243_e1 :
+#continuedo
+.end
+assert preprocess_error?("#continuedo without #do")
+*--#] Issue243_e1 : 
+*--#[ Issue243_e2 :
+#do i=1,3
+  #continuedo -1
+#enddo
+.end
+assert preprocess_error?("Improper syntax of #continuedo instruction")
+*--#] Issue243_e2 : 
+*--#[ Issue243_e3 :
+#do i=1,3
+  #continuedo 1a
+#enddo
+.end
+assert preprocess_error?("Improper syntax of #continuedo instruction")
+*--#] Issue243_e3 : 
+*--#[ Issue243_e4 :
+#do i=1,3
+  #continuedo 2
+#enddo
+.end
+assert preprocess_error?("Too many loop levels requested in #continuedo instruction")
+*--#] Issue243_e4 : 
+*--#[ Issue243_e5 :
+#procedure foo
+  #continuedo
+#endprocedure
+#do i=1,3
+  #call foo
+#enddo
+.end
+assert preprocess_error?("Trying to jump out of a procedure with a #continuedo instruction")
+*--#] Issue243_e5 : 
+*--#[ Issue243_e6 :
+#procedure foo
+  #continuedo 2
+#endprocedure
+#do i=1,3
+  #do j=1,3
+    #call foo
+  #enddo
+#enddo
+.end
+assert preprocess_error?("Trying to jump out of a procedure with a #continuedo instruction")
+*--#] Issue243_e6 : 
 *--#[ Issue392_ContinuationLines_1 :
 #: ContinuationLines 1
 * Setting ContinuationLines to 0 should remove continuation line limit.

doc/manual/prepro.tex

@@ -632,6 +632,28 @@ \section{\#commentchar}
 The default commentary character is $\ast$.
 
 %--#] commentchar : 
+%--#[ continuedo :
+
+\section{\#continuedo}
+\label{precontinuedo}
+
+\noindent Syntax:
+
+\#continuedo [{\tt<}number{\tt>}]
+
+\noindent See also \#do (\ref{predo}) and \#enddo (\ref{preenddo})
+
+\noindent The \#continuedo\index{\#continuedo} instruction allows one to
+jump to the next iteration of a \#do loop.
+If a (nonzero integer) number is specified
+it indicates the number of enclosing loops
+that the program should continue to the next iteration of.
+Control will continue at the beginning of the next iteration
+of the enclosing loop indicated by `number'.
+The default value is one.
+If the value is zero the instruction has no effect.
+
+%--#] continuedo : 
 %--#[ create :
 
 \section{\#create}

sources/pre.c

@@ -32,6 +32,7 @@
   	#[ Includes :
 */
 #include "form3.h"
+#include "comtool.h"
 #ifdef WITHFLOAT
 #include "math.h"
 #endif
@@ -43,6 +44,8 @@ static STREAM *oldstream = 0;
 static UBYTE underscore[2] = {'_',0};
 static PREVAR *ThePreVar = 0;
 
+static int ExitDoLoops(int, const char *);
+
 static KEYWORD precommands[] = {
 	 {"add"          , DoPreAdd       , 0, 0}
 	,{"addseparator" , DoPreAddSeparator,0,0}
@@ -2783,9 +2786,22 @@ int DoTerminate(UBYTE *s)
  		#[ DoContinueDo :
 */
 
+/**
+ * Jumps forward to the corresponding `#enddo` of the specified number of outer `#do` loops.
+ *
+ * @par Syntax:
+ * @code
+ *   #continuedo [<number>=1]
+ * @endcode
+ *
+ * If `number` is omitted, it defaults to 1.
+ * If `number` is zero then the instruction has no effect.
+ */
 int DoContinueDo(UBYTE *s)
 {
 	DOLOOP *loop;
+	WORD levels;
+	int result;
 
 	if ( AP.PreSwitchModes[AP.PreSwitchLevel] != EXECUTINGPRESWITCH ) return(0);
 	if ( AP.PreIfStack[AP.PreIfLevel] != EXECUTINGIF ) return(0);
@@ -2795,6 +2811,37 @@ int DoContinueDo(UBYTE *s)
 		return(1);
 	}
 
+	SkipSpaces(&s);
+	if ( *s == 0 ) {
+		levels = 1;
+	}
+	else if ( FG.cTable[*s] == 1 ) {
+		ParseNumber(levels,s);
+		SkipSpaces(&s);
+		if ( *s != 0 ) goto improper;
+	}
+	else {
+improper:
+		MesPrint("@Improper syntax of %#continuedo instruction");
+		return(1);
+	}
+
+	if ( levels > NumDoLoops ) {
+		MesPrint("@Too many loop levels requested in %#continuedo instruction");
+		return(1);
+	}
+
+	result = ExitDoLoops(levels-1,"continuedo");
+	if ( result != 0 ) return(result);
+
+	if ( levels <= 0 ) return(0);
+
+	if ( AC.CurrentStream->type == PREREADSTREAM3
+		|| AP.PreTypes[AP.NumPreTypes] == PRETYPEPROCEDURE ) {
+			MesPrint("@Trying to jump out of a procedure with a %#continuedo instruction");
+			return(1);
+		}
+
 	loop = &(DoLoops[NumDoLoops-1]);
 	AP.NumPreTypes = loop->NumPreTypes+1;
 	AP.PreIfLevel = loop->PreIfLevel;
@@ -3031,7 +3078,6 @@ illdo:;
 
 int DoBreakDo(UBYTE *s)
 {
-	DOLOOP *loop;
 	WORD levels;
 
 	if ( AP.PreSwitchModes[AP.PreSwitchLevel] != EXECUTINGPRESWITCH ) return(0);
@@ -3062,6 +3108,19 @@ int DoBreakDo(UBYTE *s)
 		MesPrint("@Too many loop levels requested in %#breakdo instruction");
 		Terminate(-1);
 	}
+	return(ExitDoLoops(levels,"breakdo"));
+}
+
+/**
+ * Exits the specified number of nested `#do` loops.
+ *
+ * @param levels The number of loops to exit.
+ * @param instruction The instruction name used for error reporting.
+ * @return 0 on success, nonzero on error.
+ */
+static int ExitDoLoops(int levels, const char *instruction)
+{
+	DOLOOP *loop;
 	while ( levels > 0 ) {
 		while ( AC.CurrentStream->type != PREREADSTREAM
 		  && AC.CurrentStream->type != PREREADSTREAM2
@@ -3072,16 +3131,13 @@ int DoBreakDo(UBYTE *s)
 		&& AP.PreTypes[AP.NumPreTypes] != PRETYPEPROCEDURE ) AP.NumPreTypes--;
 		if ( AC.CurrentStream->type == PREREADSTREAM3
 		|| AP.PreTypes[AP.NumPreTypes] == PRETYPEPROCEDURE ) {
-			MesPrint("@Trying to jump out of a procedure with a %#breakdo instruction");
-			Terminate(-1);
+			MesPrint("@Trying to jump out of a procedure with a %#%s instruction",instruction);
+			return(1);
 		}
 		loop = &(DoLoops[NumDoLoops-1]);
 		AP.NumPreTypes = loop->NumPreTypes;
 		AP.PreIfLevel = loop->PreIfLevel;
 		AP.PreSwitchLevel = loop->PreSwitchLevel;
-/*
-		AP.NumPreTypes--;
-*/
 		NumDoLoops--;
 		DoUndefine(loop->name);
 		M_free(loop->p.buffer,"loop->p.buffer");