Using CALL ON ERROR

If there were a way to recover, such as by typing another file name, you could use CALL ON to recover and resume processing:

           /* example of error recovery */
           call on error
                .
                .
                .
     ┌──── "COPY"  file1 file2
     │     say "Using" file2 ─────────────────┐
     │          .                              │
     │          .                              │
     │           exit                          │
     └─── error:                              │
           say "Can not find" file1            │
           say "Type Y to continue anyway."    │
           pull ans                            │
           if ans = "Y" then                   │
              do                               │
                 /* create dummy file */       │
                      .                        │
                      .                        │
                      .                        │
                 file2 = "dummy.fil"           │
                 RETURN ───────────────────────┘
                 end
           else exit