STACKFREE()
 Determines the remaining stack space
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 Syntax

     STACKFREE() --> nFreeByte

 Returns

     STACKFREE() returns the number of bytes available on the stack.

 Description

     This function helps avoid system crashes.  If the returned value falls
     below 100, do not permit deeper branching.  Either change the program so
     that a large nesting depth cannot be reached, or increase the stack size
     when linking.

 Note

     .  The stack is a low-level system area.  Each DO requires some
        memory bytes, before a RETURN can ensue.

 Examples

     .  Query the stack size:

        ? STACKFREE()               // < 100 ??

     .  Link the application within increased stack size:

        RTLINK FI Test /ST:8000