OpenEuphoria

Re: Missing in misc.e

• Posted by CChris <christian.cuvier at agric?lture?gouv.fr> Jul 20, 2007
• 703 views

Pete Lomax wrote:
> 
> 
> OK, here's a single min() function that does the three things it ought to.
> CChris may need medical assistance after seeing how many tests I just put in.
> }}}
<eucode>
> constant GREATER = 1,
> 	 LESS = -1
> 
> sequence s	    -- non empty sequence to find min/max in.
> object sfrom, sto   -- as passed or 1 & length(s).
> integer relation    -- GREATER or LESS required from compare().
> integer return_idx  -- if non-0 return idx, else return value.
> 
> function min_or_max()
> -- internal routine
> object x
> integer index
> 
>     x = s[sfrom]
>     index = sfrom
>     for i = sfrom+1 to sto do
> 	if compare(s[i], x) = relation then
> 	    x = s[i]
> 	    index = i
> 	end if
>     end for
>     if return_idx then
> 	return index
>     end if
>     return x
> end function
> 
> constant MM_SEQ = #01,
> 	 MM_VAL = 0,
> 	 MM_IDX = #02
> 
> global constant MM_PAIR = 0,
> 		MM_SEQVAL = MM_SEQ,
> 		MM_SEQIDX = MM_SEQ+MM_IDX
> 
> procedure Abort(sequence msg) puts(1,msg) ?9/0 end procedure
> 
> global function min(object a, object b, object mode)
> -- returns the minimum of a pair of values, or the minimum in a sequence.
> -- mode must be one of:
> --	MM_PAIR (=0) - return the minimum of two values passed in a & b
> --	 (if mode is not 0 then parameter b is unused and must be 0)
> --	MM_SEQVAL     - return the minimum value in sequence a
> --	MM_SEQIDX   - return the index of ""
> -- if mode is a sequence of length 3, the first must be MM_SEQVAL/IDX,
> --  and the second and third elements indicate the start and end points.
> --
> -- examples:
> --	?min(3.5,5.5,0) 		    -- prints 3.5
> --	?min(13.5,5.5,0)		    -- prints 5.5
> --	?max(13.5,5.5,0)		    -- prints 13.5
> --	?max(3.5,5.5,0) 		    -- prints 5.5
> --	?min({1,3,5,7},0,MM_SEQVAL)	    -- prints 1
> --	?min({1,3,5,7},0,{MM_SEQVAL,2,3})   -- prints 3
> --	?max({1,3,5,7},0,{MM_SEQVAL,2,3})   -- prints 5
> --	?max({1,3,5,7},0,MM_SEQVAL)	    -- prints 7
> --	?min({1,3,5,7},0,MM_SEQIDX)	    -- prints 1
> --	?min({1,3,5,7},0,{MM_SEQIDX,2,3})   -- prints 2
> --	?max({1,3,5,7},0,{MM_SEQIDX,2,3})   -- prints 3
> --	?max({1,3,5,7},0,MM_SEQIDX)	    -- prints 4
> 
>     if equal(mode,MM_PAIR) then
> 	if compare(a,b)<0 then return a end if return b
>     elsif not equal(b,0) then
> 	Abort("parameter b must be 0 for mode MM_SEQ")
>     elsif compare(a,{})<1 then
> 	Abort("parameter a must be sequence of length >=1 for mode MM_SEQ")
>     end if
>     if sequence(mode) then
> 	if length(mode)!=3 then
> 	    Abort("third parameter to min() must be a sequence of length 3")
> 	end if
> 	sfrom = mode[2]
> 	if not integer(sfrom) or sfrom<1 or sfrom>length(a) then
> 	    Abort("start point parameter out of bounds")
> 	end if
> 	sto = mode[3]
> 	if not integer(sto) or sto<sfrom then
> 	    Abort("end point parameter out of bounds")
> 	end if
> 	mode = mode[1]
>     else
> 	sfrom = 1
> 	sto = length(a)
>     end if
>     if not and_bits(mode,MM_SEQ) then
> 	Abort("mode MM_SEQ expected")
>     end if
>     return_idx = and_bits(mode,MM_IDX)
>     relation = LESS
>     s = a
>     return min_or_max()
> end function
> 
> global function max(object a, object b, object mode)
> -- returns the maximum of a pair of values, or the maximum in a sequence.
> -- mode must be one of:
> --	MM_PAIR (=0) - return the maximum of two values passed in a & b
> --	 (if mode is not 0 then parameter b is unused and must be 0)
> --	MM_SEQVAL   - return the maximum value in sequence a
> --	MM_SEQIDX   - return the index of ""
> -- if mode is a sequence of length 3, the first must be MM_SEQVAL/IDX,
> --  and the second and third elements indicate the start and end points.
> --
> -- examples:
> --	?min(3.5,5.5,0) 		    -- prints 3.5
> --	?min(13.5,5.5,0)		    -- prints 5.5
> --	?max(13.5,5.5,0)		    -- prints 13.5
> --	?max(3.5,5.5,0) 		    -- prints 5.5
> --	?min({1,3,5,7},0,MM_SEQVAL)	    -- prints 1
> --	?min({1,3,5,7},0,{MM_SEQVAL,2,3})   -- prints 3
> --	?max({1,3,5,7},0,{MM_SEQVAL,2,3})   -- prints 5
> --	?max({1,3,5,7},0,MM_SEQVAL)	    -- prints 7
> --	?min({1,3,5,7},0,MM_SEQIDX)	    -- prints 1
> --	?min({1,3,5,7},0,{MM_SEQIDX,2,3})   -- prints 2
> --	?max({1,3,5,7},0,{MM_SEQIDX,2,3})   -- prints 3
> --	?max({1,3,5,7},0,MM_SEQIDX)	    -- prints 4
> 
>     if equal(mode,MM_PAIR) then
> 	if compare(a,b)>0 then return a end if return b
>     elsif not equal(b,0) then
> 	Abort("parameter b must be 0 for mode MM_SEQ")
>     elsif compare(a,{})<1 then
> 	Abort("parameter a must be sequence of length >=1 for mode MM_SEQ")
>     end if
>     if sequence(mode) then
> 	if length(mode)!=3 then
> 	    Abort("third parameter to max() must be a sequence of length 3")
> 	end if
> 	sfrom = mode[2]
> 	if not integer(sfrom) or sfrom<1 or sfrom>length(a) then
> 	    Abort("start point parameter out of bounds")
> 	end if
> 	sto = mode[3]
> 	if not integer(sto) or sto<sfrom then
> 	    Abort("end point parameter out of bounds")
> 	end if
> 	mode = mode[1]
>     else
> 	sfrom = 1
> 	sto = length(a)
>     end if
>     if not and_bits(mode,MM_SEQ) then
> 	Abort("mode MM_SEQ expected")
>     end if
>     return_idx = and_bits(mode,MM_IDX)
>     relation = GREATER
>     s = a
>     return min_or_max()
> end function
> </eucode>
{{{

> 
> Regards,
> Pete

I don't know if you ever heard about the Shadoks, a "new look" (for the time)
french cartoon of the late 60s. One of their great thoughts was "Why make it
simple since we can make it more complicated?".

CChris