Re: RFC: String interpolation

[Richard Stallman]

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  > (let ((thing-formatted (replace-regexp-in-string " +" " " thing)))
  >   (fmt "This is %{thing-formatted}.2f"))

  > That is, you're forced to both name and introduce a new temporary
  > variable, and you have to alter the format statement itself.  (This is
  > what PHP programmers do all the time, and it kinda sucks.)

  > With the optional keyword arguments, you just add it:

  >   (fmt "This is %{thing}.2f"
  >        :thing (replace-regexp-in-string " +" " " thing))

If we are going to allow referencing variables, and referencing
keyword arguments, we should distinguish them in the syntax.

Perhaps write a colon to reference a keyword argument,
like this:

    > (fmt "This is %{:thing}.2f"
    >      :thing (replace-regexp-in-string " +" " " thing))

Another syntactical issue is that '%{thing}.2f' has a problem:
Does it mean %{thing} formatted according to '.2f', or
%{thing} followed by the text '.2f'?

Using the syntax '%[.2f]{thing}' is superior because it avoids
any syntactic ambiguity.


-- 
Dr Richard Stallman
President, Free Software Foundation (gnu.org, fsf.org)
Internet Hall-of-Famer (internethalloffame.org)
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