A compiler bug blocks the the Hash Xxx commands for a Hash data type passed by-reference. On the other hand, the hash [ ] - operator syntax works well. The Hash Xxx commands work correctly for a local Hash data type, the one that is not passed as an argument to the procedure. The logical conclusion is to declare and use a temporary local Hash of the same data type and then somehow 'assign the hash parameter to the local hash'.
GFA-BASIC 32 has a two constructions to do just that:
- Declaring a variable p As Pointer To data-type and than use Pointer(p) = address command to assign the pointer (<=> variable) an address.
- Swapping the descriptors of the Hash variables: Swap hs1, hs2.
Dim hs As Pointer Hash IntThe swap method should work as well, but again it doesn't. The compiler doesn't know what to do with Swapping two Hash variables. However there is light at the end of the tunnel, Swap works for all other GFA-BASIC 32 data types including the UDT (Type). And that's the one we are going to use to Swap the hash variables, hence the procedure SwapHash().
Local hsInt As Hash Int hashtest(HB) Proc hashtest(ByRef HS As Hash Int) Dim ths As Hash Int ' temporary Hash SwapHash( *HS, *ths ) ' swap descriptors ' Now ONLY use ths Hash Add ths["dd"], 7 ths ["aa"] = 8 ' ... SwapHash( *HS, *ths ) ' swap back EndProc Proc SwapHash(ptrHash1%, ptrHash2%) Naked Local hsdesc1 As Pointer HashDesc Pointer(hsdesc1) = ptrHash1 Local hsdesc2 As Pointer HashDesc Pointer(hsdesc2) = ptrHash2 ' Make sure the types are the same: Assert hsdesc1.pType == hsdesc2.pType _ ' SwapHash() - Hash type mismatch Swap hsdesc1, hsdesc2 Type HashDesc ' The Hash Descriptor pHashData As Long ' pointer to memory pType As Long ' Hash data type EndType EndProc
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