Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
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Index Size  : 28056
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View Ref-FileFRE([x])

x: aexp

This function computes the amount of free available memory. The parameter x is
ignored, but if it is present a 'Garbage Collection' is carried out first
(non-current versions of strings are deleted and the memory occupied by them
freed). FRE() results in the free memory being calculated without the Garbage
Collection.

FRE()  - Calculate without Garbage Collection.

FRE(0) - Calculate with Garbage Collection.

Example:

    free%=FRE(0)
    max%=free%/3/4
    DIM x%(max%)
    PRINT free%,max%

--> An array is dimensioned so that it occupies for instance a third of the
    free memory space. An integer array occupies 4 bytes per element, thus the
    extra division by 4.

Memo: A compiled program should regularly force a 'Garbage Collection' to
      insure that the program does not run out of string space. There is a bug
      related to the Garbage Collection.  If the string ram drops to low
      (within 16 bytes of running out of ram) a crash can occur.

Example:

    IF FRE()<32768 !less than 32k of free ram inside our program?
      ~FRE(0)      !force garbage collection and free unused strings
    ENDIF