[tex-k] inconsistent use of "eye", "mouth", "gullet" in The TeXbook

Karl Berry karl at freefriends.org
Wed Apr 14 00:25:19 CEST 2021

    Subject: [tex-k] inconsistent use of "eye", "mouth", "gullet" ...

Ok, thanks. I am not surprised about the inconsistencies, since the
metaphor is hardly rigorous and the different operations are heavily
intermixed anyway.

    Which view should I take if I were to write another article for TUGboat?

It's your choice.

In my mind, I have always thought of "eyes" as tokenization of the
input, "mouth" as expansion of macros, and "stomach" as execution of
primitives. No "gullet". Too ugly a word I guess :).

    But tex.web and mf.web take the former view in the explanation of

The word "gullet" does not appear in {tex,mf}.web.

    (I want to explain that unlike TeX, METAFONT has two kinds of macros,
    one handled in the mouth/gullet and one handled in the stomach.)

What are you referring to? --thanks, karl.

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