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Exegesis 7: Option Key Validity

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Gregor N. Purdy
February 28, 2004 07:24
Exegesis 7: Option Key Validity
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In "Thou shalt have my best gown to make thee a pair...", we are
given a reason to use the option syntax vs. the pair constructing
fat comma C<< => >>: "...we're guaranteed that the key of the
resulting pair is a string, that the string [...] contains a valid
identifier, and that the compiler can check the validity before
the program starts."

(Do we need both "...a valid..." and "...check the validity..."?)

We aren't told what validity checking the compiler is doing. I
figure its looking for some in-scope declaration of that identifier,
but what would such a declaration look like? Where exactly does the
set of valid option identifiers *for C<form>* come from, and are they
tied *to C<form>*, or floating in a global space, free to collide
with other (option key) identifier declarations?

It seems like there's more to this story...


-- Gregor

Gregor Purdy                  
Focus Research, Inc.     

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