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From: Cecil Westerhof <Cecil@decebal.nl>
Newsgroups: comp.lang.postscript
Subject: Re: Type of element on stack
Organization: Decebal Computing
References: <87fw4gnafj.fsf@Compaq.site.inet> <agdtriFrm26U1@mid.individual.net> <87pq3ij9ou.fsf@Compaq.site.inet> <k86l65$c3f$1@dont-email.me>
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Date: Sat, 17 Nov 2012 14:39:00 +0100
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Xref: csiph.com comp.lang.postscript:1054

Op zaterdag 17 nov 2012 01:19 CET schreef luser droog:

> The next cool bit is 'exec'.
> 'type' returns an executable name, so you can do type-dispatch with a
> dictionary. eg.
>
> /do { %different things to different types
> <<
> /integertype{1 add}
> /booleantype{not}
> /realtype{2 exp}
> /stringtype{cvr 1 add}
>>> 1 index type  % x dict x-type
> 2 copy known not {pop/default} if
> get exec % x'
> } def
>
> Wait. rats. that doesn't use the 'executable' part.
> How about...
>
> /do2 { %coerce input to integer
> <<
> /integertype{}
> /realtype{cvi}
> /booleantype{{1}{0}ifelse}
> /stringtype{cvr round cvi}
>>> begin
> dup type exec
> end
> } def

I have to look into this, to understand what is happening here, but I
gladly will do so. ;-}

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof