Soloway's recurring rainfall: Difference between revisions

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@@ Line 76: / Line 76: @@
 <syntaxhighlight lang="algol68">
 BEGIN # read a sequence of integers, terminated by 99999 and outpout their average #
-    INT end value = 99999;
+    INT end value       = 99999;
-    INT sum      := 0;
+    INT sum            := 0;
-    INT count    := 0;
+    INT count          := 0;
+    BOOL invalid value := FALSE;
+    on value error( stand in, ( REF FILE f )BOOL: invalid value := TRUE );
     WHILE
         INT n := 0;
         WHILE
-            STRING s;
             print( ( "Enter rainfall (integer) or ", whole( end value, 0 ), " to quit: " ) );
-            read( ( s, newline ) );
+            read( ( n, newline ) );
-            BOOL valid := UPB s >= LWB s; # invalid if the string is empty #
+            invalid value
-            FOR s pos FROM LWB s TO UPB s WHILE valid DO
-                IF valid := s[ s pos ] >= "0" AND s[ s pos ] <= "9"
-                THEN
-                    n *:= 10 +:= ( ABS s[ s pos ] - ABS "0" )
-                FI
-            OD;
-            NOT valid
         DO
-            print( ( "Invalid input, please enter an integer", newline ) )
+            print( ( "Invalid input, please enter an integer", newline ) );
+            invalid value := FALSE
         OD;
         n /= end value