Re: if-else

[Vaughan McAlley <ockegheim@...>]

On 14 April 2010 00:41, Francisco <xxleite@gmail.com> wrote:
> very compact!
> x=(vXSTX>vXSX or vXSTX>vXSY) and vXSX+vXSTX or vXSX

This produces the following byte-code:
	13	[5]	GETGLOBAL	0 -1	; vXSTX
	14	[5]	GETGLOBAL	1 -4	; vXSX
	15	[5]	LT       	1 1 0
	16	[5]	JMP      	4	; to 21
	17	[5]	GETGLOBAL	0 -1	; vXSTX
	18	[5]	GETGLOBAL	1 -5	; vXSY
	19	[5]	LT       	0 1 0
	20	[5]	JMP      	5	; to 26
	21	[5]	GETGLOBAL	0 -4	; vXSX
	22	[5]	GETGLOBAL	1 -1	; vXSTX
	23	[5]	ADD      	0 0 1
	24	[5]	TEST     	0 0 1
	25	[5]	JMP      	1	; to 27
	26	[5]	GETGLOBAL	0 -4	; vXSX
	27	[5]	SETGLOBAL	0 -6	; x


...whereas the more readable:

x = vXSX
if (vXSTX > vXSX) or (vXSTX > vXSY) then
    x = x + vXSTX
end

...produces

	13	[6]	GETGLOBAL	0 -4	; vXSX
	14	[6]	SETGLOBAL	0 -6	; x
	15	[7]	GETGLOBAL	0 -1	; vXSTX
	16	[7]	GETGLOBAL	1 -4	; vXSX
	17	[7]	LT       	1 1 0
	18	[7]	JMP      	4	; to 23
	19	[7]	GETGLOBAL	0 -1	; vXSTX
	20	[7]	GETGLOBAL	1 -5	; vXSY
	21	[7]	LT       	0 1 0
	22	[7]	JMP      	4	; to 27
	23	[8]	GETGLOBAL	0 -6	; x
	24	[8]	GETGLOBAL	1 -1	; vXSTX
	25	[8]	ADD      	0 0 1
	26	[8]	SETGLOBAL	0 -6	; x

... which makes it marginally more compact in terms of byte code
(though the variable names are the least readable I’ve seen in a
while!)

Vaughan