1. Forward Referencing
- Posted by Icy_Viking May 18, 2023
- 634 views
Will Euphoria 4.2.0 have support for forward referencing in enums?
This feature would come in handy for wrapping libraries.
2. Re: Forward Referencing
- Posted by petelomax May 20, 2023
- 616 views
I'm intrigued: I cannot think of any reason why/where that would be useful, can you give an example?
3. Re: Forward Referencing
- Posted by Icy_Viking May 20, 2023
- 618 views
I'm intrigued: I cannot think of any reason why/where that would be useful, can you give an example?
Well here is one example.
public enum type SDL_Keymod SDL_KMOD_NONE = 0x0000, SDL_KMOD_LSHIFT = 0x0001, SDL_KMOD_RSHIFT = 0x0002, SDL_KMOD_LCTRL = 0x0040, SDL_KMOD_RCTRL = 0x0080, SDL_KMOD_LALT = 0x0100, SDL_KMOD_RALT = 0x0200, SDL_KMOD_LGUI = 0x0400, SDL_KMOD_RGUI = 0x0800, SDL_KMOD_NUM= 0x1000, SDL_KMOD_CAPS = 0x2000, SDL_KMOD_MODE = 0x4000, SDL_KMOD_SCROLL = 0x8000, SDL_KMOD_RESERVED = SDL_KMOD_SCROLL end type --These should be part of the enum, but since forward referencing isn't allowed in Euphoria, I had to declare them outside of the enum public constant SDL_KMOD_CTRL = or_all({SDL_KMOD_LCTRL,SDL_KMOD_RCTRL}) public constant SDL_KMOD_SHIFT = or_all({SDL_KMOD_LSHIFT,SDL_KMOD_RSHIFT}) public constant SDL_KMOD_ALT = or_all({SDL_KMOD_LALT,SDL_KMOD_RALT}) public constant SDL_KMOD_GUI = or_all({SDL_KMOD_LGUI,SDL_KMOD_RGUI})
Maybe its not the biggest deal, but it would be nice to have.
4. Re: Forward Referencing
- Posted by ghaberek (admin) May 22, 2023
- 565 views
Will Euphoria 4.2.0 have support for forward referencing in enums?
This feature would come in handy for wrapping libraries.
I think the "forward referencing" message given by the interpreter is a bit of a red herring. It's more to do with enums only allowing literal numeric values, as opposed to constants which have always allowed any value and computing values at runtime. The docs specifically state:
Well here is one example.
Maybe its not the biggest deal, but it would be nice to have.
In this case I would simply pre-compute the OR'd values and include them in the enum block.
public enum type SDL_Keymod SDL_KMOD_NONE = 0x0000, SDL_KMOD_LSHIFT = 0x0001, SDL_KMOD_RSHIFT = 0x0002, SDL_KMOD_LCTRL = 0x0040, SDL_KMOD_RCTRL = 0x0080, SDL_KMOD_LALT = 0x0100, SDL_KMOD_RALT = 0x0200, SDL_KMOD_LGUI = 0x0400, SDL_KMOD_RGUI = 0x0800, SDL_KMOD_NUM = 0x1000, SDL_KMOD_CAPS = 0x2000, SDL_KMOD_MODE = 0x4000, SDL_KMOD_SCROLL = 0x8000, SDL_KMOD_SHIFT = 0x0003, -- SDL_KMOD_LSHIFT | SDL_KMOD_RSHIFT SDL_KMOD_CTRL = 0x00C0, -- SDL_KMOD_LCTRL | SDL_KMOD_RCTRL SDL_KMOD_ALT = 0x0300, -- SDL_KMOD_LALT | SDL_KMOD_RALT SDL_KMOD_GUI = 0x0C00, -- SDL_KMOD_LGUI | SDL_KMOD_RGUI SDL_KMOD_RESERVED = SDL_KMOD_SCROLL end type
I typically use the Windows calculator "Programmer" mode for this, but you could also do it in code, e.g.
printf(1, "SDL_KMOD_SHIFT = 0x%04x\n", or_bits(SDL_KMOD_LSHIFT,SDL_KMOD_RSHIFT) )
Not entirely related, but I'd also suggest avoiding or_all() when you only have two values, as or_bits() is a builtin and or_all() comes from std/math.e. It just makes for cleaner code and avoids unnecessary include files (assuming you don't need std/math.e elsewhere).
-Greg
5. Re: Forward Referencing
- Posted by Icy_Viking May 22, 2023
- 570 views
Will Euphoria 4.2.0 have support for forward referencing in enums?
This feature would come in handy for wrapping libraries.
I think the "forward referencing" message given by the interpreter is a bit of a red herring. It's more to do with enums only allowing literal numeric values, as opposed to constants which have always allowed any value and computing values at runtime. The docs specifically state:
Well here is one example.
Maybe its not the biggest deal, but it would be nice to have.
In this case I would simply pre-compute the OR'd values and include them in the enum block.
public enum type SDL_Keymod SDL_KMOD_NONE = 0x0000, SDL_KMOD_LSHIFT = 0x0001, SDL_KMOD_RSHIFT = 0x0002, SDL_KMOD_LCTRL = 0x0040, SDL_KMOD_RCTRL = 0x0080, SDL_KMOD_LALT = 0x0100, SDL_KMOD_RALT = 0x0200, SDL_KMOD_LGUI = 0x0400, SDL_KMOD_RGUI = 0x0800, SDL_KMOD_NUM = 0x1000, SDL_KMOD_CAPS = 0x2000, SDL_KMOD_MODE = 0x4000, SDL_KMOD_SCROLL = 0x8000, SDL_KMOD_SHIFT = 0x0003, -- SDL_KMOD_LSHIFT | SDL_KMOD_RSHIFT SDL_KMOD_CTRL = 0x00C0, -- SDL_KMOD_LCTRL | SDL_KMOD_RCTRL SDL_KMOD_ALT = 0x0300, -- SDL_KMOD_LALT | SDL_KMOD_RALT SDL_KMOD_GUI = 0x0C00, -- SDL_KMOD_LGUI | SDL_KMOD_RGUI SDL_KMOD_RESERVED = SDL_KMOD_SCROLL end type
I typically use the Windows calculator "Programmer" mode for this, but you could also do it in code, e.g.
printf(1, "SDL_KMOD_SHIFT = 0x%04x\n", or_bits(SDL_KMOD_LSHIFT,SDL_KMOD_RSHIFT) )
Not entirely related, but I'd also suggest avoiding or_all() when you only have two values, as or_bits() is a builtin and or_all() comes from std/math.e. It just makes for cleaner code and avoids unnecessary include files (assuming you don't need std/math.e elsewhere).
-Greg
Thanks for the tips, Greg. Helpful advice as always.
