[Inquiry] Re: Theme One Program -- Commentary -- Gage

[Jon Awbrey]

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TOP.  Commentary Note 33

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Gage.

Gage is a transformation of ideas that is composed of
the recognizer Gram followed by the constructor Gist.
Gram acts as the identity on any argument idea whose
form contains a 'sign' that is something other than
a comma, a left parenthesis, or a right parenthesis,
returning nil on anything else.  Gist constructs a
cog-type structure with the same 'sign' and 'alias'
as any significant idea-form that it gets as input.

Step 1.
            ^ this^.as
             \
              o-----o
              | a   |
              o-----o
              ^
         this |
              @

Step 2.  For "a" not equal to comma, left parens, right parens:

            ^ this^.as        ^ this^.as
             \              o--\----------o
              o-----o       |   o-----o   |
              | a   |       o-->| a 0 |---o
              o-----o           o-----o
              ^                 ^
         this |            gage |
              @                 @

function gage (this: idea): idea;
begin
 gage := gist (gram (this))
end;

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