[texhax] Confused on \let for space

[Doug McKenna]

Reinhard Kotucha wrote -

>>Quick question based on some kinda TeX primitive/syntax confusion in my 
>>head:
>>
>>How does one give a name, using \let, to a space character?  E.g., in
>>
>>  \let \blankspace =
>>
>>what comes after the '=' so that, for instance
>>
>>  AB.C\ignorespaces    \blankspace   D
>>
>>will be typest as "AB.CD"?
>>
>>Or am I hallucinating that this \let is possible?  It works fine for 
>>other non-space characters, e.g.,
>>
>>  \let\bgroup={
>
>Just a guess, does \let\blankspace\  work?

Not really.  It comes out as "AB. CD".  In other words, \  (backslash 
space) breaks \ignorespaces's concentration before it gets to the 'D'.

If one can define a name for a simple single input character (such as a 
left brace), how does one do it for a blank space character?  Or is it 
impossible by design, given how spaces are generally coalesced and turned 
into skip glue?


Doug McKenna