[plt-scheme] Can I abuse with quasi...quotes?

From: Jos Koot (jos.koot at telefonica.net)
Date: Wed Jul 18 19:48:12 EDT 2007

Both methods are allright and they are equivalent to each other.
In fact the quasiquote form is expanded into an expression that does the same as 
your example with cons.
In your example I dont see any abuse of quasiquote.
,@ must be followed by an expression that evaluates to a list.
This list is spliced in. This means that , at expr is replaced by the list but 
without its (outer) pair of parentheses.
, at expr must be part of a list (possibly an improper list) Your correct example 
makes me think that you already know this.
Good luck, Jos Koot

----- Original Message ----- 
From: "Paulo J. Matos" <pocm at soton.ac.uk>
To: "mzscheme Mailing List" <plt-scheme at list.cs.brown.edu>
Sent: Thursday, July 19, 2007 12:21 AM
Subject: [plt-scheme] Can I abuse with quasi...quotes?

> Hi all,
> I've been working a lot with propositional logic formulas where the
> operator is prefixed, like:
> '(and x1 (or x2 x3) (<=> x4 (not x1)))
> Now, to build formulas I'm using quasiquote and sometimes even abusing it.
> For example, given two list of variables of equal length. I do the
> following to create an assertion of equivalence between them:
> `(and ,@(map (lambda (var1 var2) `(<=> ,var1 ,var2)) varlst1 varlst2))
> I don't really understand what happens inside with ,@ and , but I keep
> wondering if this is better:
> (cons 'and (map (lambda (var1 var2) (list '<=> var1 var2)) varlst1 varlst2))
> I don't know if it matter but for the record, I don't use list
> mutation, so is this better than the first form?
> Is there a better form?
> Cheers,
> -- 
> Paulo Jorge Matos - pocm at soton.ac.uk
> http://www.personal.soton.ac.uk/pocm
> PhD Student @ ECS
> University of Southampton, UK
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