Date: Dec 28, 2012 5:33 AM
Author: Murray Eisenberg
Subject: Re: Usage Messages in Mathematica

And yet usage messages for built-in objects seem to handle in-line 
expressions and subscripts with aplomb. See, for example:

Subscript::usage


On Dec 27, 2012, at 5:04 AM, djmpark <djmpark@comcast.net> wrote:

> An extremely weak features of Mathematica is the design of Usage messages,
> which seems to be stuck at Version 1, although the technology has moved far
> beyond that.
>
> The present design is not up to the task and full of gotchas. For example,
> how does one include a box structure, for example a subscripted symbol,
> within a usage message? If one just enters a subscript then the first time
> the message is displayed there are quotes around it and the second time the
> quotes go away. If one starts an InlineCell within the string and enters the
> expression then that problem goes away. If one then moves the usage
> definition to a package and Runs the package it works OK. But if one saves
> and closes the package, quits the kernel and then reinitializes, loading the
> package, the usage message is defective giving the InputForm of the box
> expression. Mathematica parses and changes the usage messages when the file
> is read.
>
> The String form is just not adequate for usage messages. Nor is it adequate
> to contain information on overloading functions. Usage definitions should be
> expressions. Something like the following:
>
> Usage[FunctionName] = {{template, usageExpression}..}
>
> (The usageExpression might be a Row containing Strings and mathematical
> expressions.)...


---
Murray Eisenberg murray@math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2838 (W)
710 North Pleasant Street fax 413 545-1801
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