STEP contentslist

Marks the items in the contents list for stepping.

Whenever a stepped procedure is invoked, each instruction line in the procedure body is displayed in a dialog box before being executed and FMSLogo waits for the user to press the OK button before continuing. The line is truncated according to the current values of PRINTWIDTHLIMIT and PRINTDEPTHLIMIT.

Whenever a stepped variable is "shadowed", a message to this effect is printed to the commander's Commander History/Output box. A variable is shadowed whenever a variable of the same name is created with the LOCAL command or when a procedure is invoked that has an input with the same name. If the variable was shadowed by LOCAL, then the instruction line that caused the shadowing is printed after the message. This instruction line is truncated according to the current values of PRINTWIDTHLIMIT and PRINTDEPTHLIMIT.

STEP has no effect on property lists.

It is possible to mark a procedure, variable, or property list for stepping before it is defined. If you mark soemthing for stepping that is not defined, it does not appear in the output of STEPPED, but if it is later defined, it will then appear in the output of STEPPED. That is, it will behave as stepped as soon as it is defined. Similarly, if you ERASE something that is stepped then redefine it, it will also reappear as stepped as soon as it is redefined.

STEP does not throw an error if asked to mark a primitive for stepping.

See the Workspace Queries section for an explanation of the contentslist input.

You can step all procedures and variables with the Step Button.

TO MYPROGRAM
  FORWARD 10
  RIGHT   90
  FORWARD 20
  LEFT    90
END

STEP "MYPROGRAM
MYPROGRAM
Each line of MYPROGRAM is displayed and waits for OK to continue to next line.
UNSTEP "MYPROGRAM
MYPROGRAM