[groff] 02/09: groff_char(7): Clarify font-invariance of glyphs.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit a69e365708cbd6339bd14ada38dee90d7869529f
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Wed Sep 2 23:01:15 2020 +1000

    groff_char(7): Clarify font-invariance of glyphs.
    
    ...namely that they're invariant only on typesetters.  Terminals get
    whatever the device renders, including bold and/or italicized
    (underlined) bracket-building glyphs.
    
    Also fix error: there is no such glyph name as "overline".  Correct to
    "rn".
    
    Also fix style issues.
    
    * Add roman closing bracket to syntax synopsis of combining Unicode
      special character escapes (to mark the end of an optional component.
    * Coalesce one-sentence paragraph into predecessor.
    * Indent paragraph pertaining to foregoing tag.
    * Sort basic Latin table by code point (moves the \[ha] line).
    * Fix inelegant wording.
    * Fix spurious word.
    * Fix missing .ME call which kept my email address from being shown.
---
 man/groff_char.7.man | 53 +++++++++++++++++++++++++++++++---------------------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/man/groff_char.7.man b/man/groff_char.7.man
index bac054a..c4fa494 100644
--- a/man/groff_char.7.man
+++ b/man/groff_char.7.man
@@ -345,7 +345,7 @@ this will
 .I not
 be the case on more-capable devices.
 .
-Review your document on as many different postprocessors as possible.
+Review your document using as many different postprocessors as possible.
 .
 .\" XXX: move these to tty.tmac instead?
 .fchar \[u02C6] ^
@@ -704,7 +704,7 @@ where all Unicode glyphs are maximally decomposed.
 .BI \[rs][u base-glyph\c
 .RB [ _\c
 .I combining-component\c
-.BR ] .\|.\|.
+.RB ].\|.\|. ]
 constructs a composite glyph from Unicode numeric special character
 escapes.
 .
@@ -764,8 +764,6 @@ character
 (ordinary or special)
 that normally produces the glyph.
 .
-.
-.IP
 Some code points have multiple glyph names.
 .
 .
@@ -808,7 +806,7 @@ When using the AT&T special character syntax
 , widespread portability can be expected from such names.
 .
 .
-.P
+.IP
 Entries marked with \[lq]***\[rq] denote glyphs used for mathematical
 purposes.
 .
@@ -876,8 +874,8 @@ _
 \[at]  \e[at]  at      u0040   at sign
 \[lB]  \e[lB]  bracketleft     u005B   left square bracket
 \[rs]  \e[rs]  backslash       u005C   reverse solidus
-\[ha]  \e[ha]  asciicircum     u005E   circumflex, caret, \[lq]hat\[rq] +
 \[rB]  \e[rB]  bracketright    u005D   right square bracket
+\[ha]  \e[ha]  asciicircum     u005E   circumflex, caret, \[lq]hat\[rq] +
 \[ul]  \e[ul]  underscore      u005F   underscore, low line +
 \[lC]  \e[lC]  braceleft       u007B   left brace
 |      |       bar     u007C   bar
@@ -1090,7 +1088,18 @@ _
 .SS Brackets
 .\" ====================================================================
 .
-The extensible bracket pieces are font-invariant glyphs.
+On typestter devices,
+the bracket extensions are font-invariant glyphs;
+that is,
+they are rendered the same way regardless of font.
+.
+On terminals,
+they are
+.I not
+font-invariant,
+.I groff
+maps them rather arbitrarily to U+23AA
+(\[lq]curly bracket extension\[rq]).
 .
 In AT&T
 .IR troff ,
@@ -1101,13 +1110,10 @@ and
 parentheses:
 .BR \[rs](bv .
 .
-We map it rather arbitrarily to U+23AA
-(\[lq]curly bracket extension\[rq]).
 .
 .
 .P
-Note that not all devices contain extensible bracket pieces which can
-be piled up with
+Not all devices supply bracket pieces which can be piled up with
 .B \[rs]b
 due to the restrictions of the escape's piling algorithm.
 .
@@ -1253,7 +1259,9 @@ _
 .SS "Rules and lines"
 .\" ====================================================================
 .
-The font-invariant glyphs
+On typesetter devices,
+the font-invariant glyphs
+(see subsection \[lq]Brackets\[rq] above)
 .BR \[rs][br] ,
 .BR \[rs][ul] ,
 and
@@ -1261,6 +1269,9 @@ and
 form corners when adjacent;
 they can be used to build boxes.
 .
+On terminal devices,
+they are mapped as shown in the table.
+.
 Note that both the AGL and the Unicode-derived names of these three
 glyphs are rough approximations.
 .
@@ -1278,13 +1289,13 @@ The baseline rule
 is a font-invariant glyph,
 namely a rule of one-half em.
 .
-.
-.P
-Use
+In
+.IR groff ,
+use
 .B \[rs][radicalex]
-(see subsection \[lq]Mathematical symbols\[rq] below),
-not
-.BR \[rs][overline] ,
+(see subsection \[lq]Mathematical symbols\[rq] below)
+instead of
+.BR \[rs][rn] ,
 for continuation of radical signs
 (e.g.,
 square roots).
@@ -1414,8 +1425,7 @@ _
 .\" ====================================================================
 .
 .B \[rs][Fn]
-also appears in see subsection \[lq]Supplementary Latin letters\[rq]
-above.
+also appears in subsection \[lq]Supplementary Latin letters\[rq] above.
 .
 Note the two varieties of the
 plus-minus,
@@ -1641,7 +1651,8 @@ Eric S.\& Raymond
 .ME ,
 and largely rewritten by
 .MT g\:.branden\:.robinson@\:gmail\:.com
-G.\& Branden Robinson.
+G.\& Branden Robinson
+.ME .
 .
 .
 .\" ====================================================================