pointer->integer returns unexpected value on Windows

[Takashi Kato]

Prepare C function;

void set_int(int *i) { *i = 0xF5; }

call above from Scheme like this;

(let ((p (integer->pointer -1))
       (set-int (c-function void set_int (void*))))
  (set-int (address p))
  (pointer->integer p))

This should return #xF5 but return something very huge.

[Takashi Kato]

This is probably an expected behaviour on 64 bit Windows. The actual cause is the different size of void* and long.

So actual pointer value is 0xFFFFFFFFFFFFFFFF and set_int only sets 32 bit. then after setting the pointer value would be 0xFFFFFFFF000000F5. pointer->integer converts this value to a negative integer.

So if the value is expected to be an 32 bit size then it's better to get pointer value directly (slot ref return uintptr_t value) and mask it.

I'll add 4 procedures to handle this case

• pointer->uinteger
• uinteger->pointer (this is only for consistency)
• pointer->long
• pointer->ulong

pointer->long and pointer->ulong would do the same as pointer->integer and pointer->uinteger on the environment which has the same size of void* and long.

[Takashi Kato]

Added pointer->uinteger, pointer->long, pointer->ulong and uinteger->pointer (fixes #22)

→ <<cset c0b2d67bfc02>>

[Takashi Kato]

This doesn't work if void* = long = 8 environment (64 bit linux). it's better to let user specify how much pointer value want

so pointer->integer and pointer->uinteger should have optional argument which specify the bits. (by default all)

[Takashi Kato]

Removed pointer->long and pointer->ulong. Added optional argument bits to pointer->integer and pointer->uinteger (Fixes #22)

→ <<cset 9d735e3096a7>>