calc: Information about Compositions
7.8.10.5 Information about Compositions
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The functions in this section are actual functions; they compose their
arguments according to the current language and other display modes,
then return a certain measurement of the composition as an integer.
The ‘cwidth’ function measures the width, in characters, of a
composition. For example, ‘cwidth(a + b)’ is 5, and ‘cwidth(a / b)’ is
5 in Normal mode, 1 in Big mode, and 11 in TeX mode (for ‘{a \over b}’).
The argument may involve the composition functions described in this
section.
The ‘cheight’ function measures the height of a composition. This is
the total number of lines in the argument’s printed form.
The functions ‘cascent’ and ‘cdescent’ measure the amount of the
height that is above (and including) the baseline, or below the
baseline, respectively. Thus ‘cascent(X) + cdescent(X)’ always equals
‘cheight(X)’. For a one-line formula like ‘a + b’, ‘cascent’ returns 1
and ‘cdescent’ returns 0. For ‘a / b’ in Big mode, ‘cascent’ returns 2
and ‘cdescent’ returns 1. The only formula for which ‘cascent’ will
return zero is ‘cvspace(0)’ or equivalents.
Info Catalog
calc: Other Compositions
calc: Compositions
calc: User-Defined Compositions