Tcl/Tk and GRASS

[Simon Cox]

> From: "Mark P. Line" <markline at henson.cc.wwu.edu>
> Subject: Re: Tcl/Tk and GRASS
>
>
> Maybe an example would be in order. The commands d.rast, d.vect, d.sites
> (among others) cause a map layer to be displayed in the active frame. In a
> function-oriented approach, you would select something representing
> 'd.rast' first, for instance, and then you would select a raster map to be
> displayed. In an object-oriented approach, you would first select whatever
> map you want to see, than click on "Display", unless you wanted to
> override defaults. Once you've selected the map, there's not really any
> need for you to say explicitly that you want to display a raster map with
> d.rast, a vector map with d.vect and a sites list with d.sites (or
> whatever). It would not be difficult to get the GUI to know what database
> element a selected map is in, and to run the appropriate command without
> further necessary intervention.
>

Brief observations from one who knows little about oo programming,
modern guis, etc:

(i)  This sequence
 "object - operation"
reminds me of the old RPN HP calculators or low level programming
languages like Forth, etc.  It seemed like a great leap forward when we could
type the way we had learned to write mathematical operations, ie
 "function - argument"

How the worm turns!

(ii)  This discussion should really be on grassp I think.

Simon Cox
----
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      __  L     Dr Simon Cox			
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