Re: New User
Derek Parnell wrote:
> A string manipulation library is a great idea. It can help you learn lots
> about Euphoria's capabilites fairly quickly. In fact, this type of library
> is almost a rite of passage for new Eu coders. Please don't hestate to ask
> questions or look at similar attempts from the RDS Archives.
Yes, welcome Peter. I am rather new here too. I had just commented before
you arrived how easy it is to manipulate strings in Euphoria, even easier
than in BASIC. Someone pointed me at the find command as their "friend",
and indeed it is.
An example. I am writing a system that has prototype letters with tags of
the form <XXX> (where XXX is three letters) that represent various things
like names, addresses, dates etc and that must be replaced by some text
that has the particular value of that variable for the particular person
that the letter is being sent to.
To make matters more complicated, I don't even know what the full list of
tags is (and don't want to thank you very much as there are about a
hundred of them and they get extended) but my person file has matched
pairs of tag and value. So I read in a person's data and store in a couple
of sequences as "tag" and "value" (where value[1] goes with tag[1] etc.).
So I don't have any variable names such as "name", "address" and so on as
the variable names are all stored in "tag" and the values of the variables
in "value" in the matching position. This makes my program much smaller
and it works when new variables are added without any changes being made.
One function that I obviously want is to get into "thisvalue" the matching
value of a tag whose value I have in "thistag" so all I need to code is:
thisvalue=value[find(thistag,tag)]
No loops, no searching. I suppose I should have an error test for not found.
Next I want to take my letter and replace all tags by their values. Hey, I
do need a string function for this and I don't see it anywhere as yet. It
is a simple replace command something like:
resultstring=replace(findstring,replacestring,originalstring)
well, let me see if I can write this here and now without any testing...
function replace (structure findstring, structure replacestring,
structure originalstring)
atom ix
ix=find (findstring, originalstring)
return originalstring[1..ix-1] & replacestring &
originalstring[ix+length(findstring)..length(originalstring)]
end function
again I haven't done any check to see if it exists. But you can see how
string functions in Euphoria almost write themselves - particularly when
you know how useful find is.
Another string function that I want is for the same program. I want to
output some text in a text box with automatic wrap at a point NOT the same
as the width of the text field and then put some more text to begin at the
point where the wrapping was occurring and also to wrap but now using the
full window. e.g. the result might look like this:
(my text box is this big) ---------------------------------------------V
(my wrap point is initially set here)-----------------V
Did you ever live in another country? If so, please
tell about that experience. No. ~
Did you ever travel overseas to countries that speak
different languages than your native language? If so,
please tell about your experience. Yes. I went to
Europe and visited England, France, Italy and Germany with very brief
stops in Switzerland and Austria. Mostly we managed quite well speaking
English and with our primitive French. Bonjour!
The idea is that the person reading the answers can easily see the Yes or
No and can then read the text for the Yes answers. At the same time, it
minimizes the size of the output in printed pages. Incidentally, the
Yes/No and the detailed answers are substituted from <TAG>s as described
above.
Ideally I want to do this using variable fonts (I can do it without too
much difficulty with a fixed font). I suppose that this is possible as I
saw a function somewhere(the name of which I forget) that returns the
pixel length of a string so I can keep adding another word until I pass
the place that I want to stop and then take one word back, chuck in a NL
and carry on.
Ray
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