Subject: Re: [xsl] How do I get a SUM of the string-length of all child nodes ?? From: Mukul Gandhi <mukul_gandhi@xxxxxxxxx> Date: Sat, 28 May 2005 21:25:54 -0700 (PDT) |
Thank you Dimitre for explanation ;) I am obliged .. Regards, Mukul --- Dimitre Novatchev <dnovatchev@xxxxxxxxx> wrote: > > What does map function do? > > Formal definition in Haskell prelude (Prelude.hs): > > map :: (a -> b) -> [a] -> [b] > map f xs = [ f x | x <- xs ] > > > The first line above defines the type (signature) of > the "map" > function. It takes two arguments: > > - a function of type a -> b (with domain "a" and > codomain "b" -- > this means that the > type of thie arguments is "a" and the type of > the results is "b") > Because "map" has an argument, which is a > function, "map" is a > higher-order > function. > > - a list of elements each of type "a" > > The type of the result is a list of elements of type > "b". > > The second line of the definition above defines > exactly the map > function. We see that the result of applying a > function "map" to its > two arguments -- a function "f" and a list "xs" -- > is the set of all > "f x" (which means f(x)) where "x" belongs to the > list "xs" > > More informally, we have a list of elements of the > same type ("a") and > a function "f", defined on "a" and producing results > of type "b". > > The result of applying "map" on "f" and a list "xs" > (all of whose > elements are of type "a") is another list "ys" , > whose elements "y" > are the results of applying "f" on the corresponding > elements "x" of > "xs". > > > Example: > > map (2 * ) [1,2,3,4] = [2,4,6,8] > > where (2 *) is a function, which produces twice its > argument. > > map string-length ['one', "two", "three", "four"] > = [3, 3, 5, 4] > > then, we'll have: > > sum (map string-length ['one', "two", "three", > "four"] ) = 15 > > > > Please explain what does > > sum(f:map(f:string-length(), /*/node())) mean .. > > Almost the same as the last line above -- I hope it > is clear now. > > > Cheers, > Dimitre Novatchev. > > __________________________________ Do you Yahoo!? Make Yahoo! your home page http://www.yahoo.com/r/hs
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
RE: [xsl] How do I get a SUM of the, Michael Kay | Thread | [xsl] Differences between AWTRender, senetex |
[xsl] grouping in a separate data f, Andrew Kirkpatrick | Date | [xsl] sum function, Andreas Schnabl |
Month |