[clean-list] Where is floor :: !Real -> Real?

[John van Groningen]

Vag Vagoff wrote:
>Very important procedures seems to be missing in Clean standard library:
>
>    floor :: !Real -> Real
>    ceiling :: !Real -> Real
>
>How to fix that?

If the result can fit in an Int use fromInt or toReal and:

entier :: !Real -> Int

to implement floor. Use

~ (entier (~ x))

to compute the ceiling of x.

On a 64 bit computer no rounding is necessary for Real's that are
too large for type Int. So depending on the size use fromInt and entier,
or do nothing.

On computers using the 32 bit intel/AMD instruction set, you can use:

floorR_IA32 :: !Real -> Real;
floorR_IA32 r = code {
	| 83 ec 08                sub    $0x8,%esp
	instruction 131
	instruction 236
	instruction 8
	| 9b d9 3c 24             fstcw  (%esp)
	instruction 155
	instruction 217
	instruction 60
	instruction 36
	| 66 8b 04 24             mov    (%esp),%ax
	instruction 102
	instruction 139
	instruction 4
	instruction 36
	| 66 25 ff f3             and    $0xf3ff,%ax
	instruction 102
	instruction 37
	instruction 255
	instruction 243
	| 66 0d 00 04             or     $0x400,%ax
	instruction 102
	instruction 13
	instruction 0
	instruction 4
	| 66 89 44 24 02          mov    %ax,0x2(%esp)
	instruction 102
	instruction 137
	instruction 68
	instruction 36
	instruction 2
	| d9 6c 24 02             fldcw  0x2(%esp)
	instruction 217
	instruction 108
	instruction 36
	instruction 2
	| d9 fc                   frndint
	instruction 217
	instruction 252
	| d9 2c 24                fldcw  (%esp)
	instruction 217
	instruction 44
	| 83 c4 08                add    $0x8,%esp
	instruction 36
	instruction 131
	instruction 196
	instruction 8
}

ceilR_IA32 :: !Real -> Real;
ceilR_IA32 r = code {
	| 83 ec 08                sub    $0x8,%esp
	instruction 131
	instruction 236
	instruction 8
	| 9b d9 3c 24             fstcw  (%esp)
	instruction 155
	instruction 217
	instruction 60
	instruction 36
	| 66 8b 04 24             mov    (%esp),%ax
	instruction 102
	instruction 139
	instruction 4
	instruction 36
	| 66 25 ff f3             and    $0xf3ff,%ax
	instruction 102
	instruction 37
	instruction 255
	instruction 243
	| 66 0d 00 04             or     $0x800,%ax
	instruction 102
	instruction 13
	instruction 0
	instruction 8
	| 66 89 44 24 02          mov    %ax,0x2(%esp)
	instruction 102
	instruction 137
	instruction 68
	instruction 36
	instruction 2
	| d9 6c 24 02             fldcw  0x2(%esp)
	instruction 217
	instruction 108
	instruction 36
	instruction 2
	| d9 fc                   frndint
	instruction 217
	instruction 252
	| d9 2c 24                fldcw  (%esp)
	instruction 217
	instruction 44
	| 83 c4 08                add    $0x8,%esp
	instruction 36
	instruction 131
	instruction 196
	instruction 8
}

Kind regards,

John van Groningen