From f702e46e23302bba7ad3286d0ca273863ada380d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20Ankarstr=C3=B6m?= <john@ankarstrom.se>
Date: Sat, 19 Jun 2021 20:15:09 +0200
Subject: Have c copy font family and point size from l environment

---
 example.t | 182 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
 g.tmac    |  19 ++++---
 2 files changed, 178 insertions(+), 23 deletions(-)

diff --git a/example.t b/example.t
index 5f9789f..84e65ec 100644
--- a/example.t
+++ b/example.t
@@ -1,27 +1,43 @@
 .so g.tmac
-.p
-.ta 3n +3n +3n +3n
+.
+. _e p
+.  nr sq \n(sp
+.  nr sp 0
+. _e
+.
+._e e
+. _ec p
+. ta 3n +3n +3n +3n
+._e
+.
+.de e
+. nr ei \\$1+1
+. br
+. _e e
+. ti \n(tiu
+\\n(ei.	\c
+..
+.
 .t
 .x Mg ,
 a simple macro package for troff
 .n
 John Ankarstr\[u00F6]m
 .d
+.
+.
 .h
 Introduction
 .p
 .i Mg
 is a simple macro package for troff with the following features:
-.p
-1.	\c
+.e 0
 It is designed to be easy to understand and to customize
 by editing the source code.
-.p
-2.	\c
+.e
 It makes use of the extended support for environments
 offered by many modern troff implementations.
-.p
-3.	\c
+.e
 It is designed to be practically easy to use.
 Macros are consistently one letter long and written in lowercase.
 .p
@@ -35,8 +51,9 @@ Users of
 .i mg
 are encouraged to modify the source code
 according to their own needs.
-.s
-Internal design
+.
+.h
+Environments
 .p
 .i Mg
 makes heavy use of named environments,
@@ -92,14 +109,147 @@ First paragraph.
 In addition to the normal environment-relevant settings,
 .i mg
 manually associates a few special registers with the current environment:
-.p
-1.	\c
+.e 0
 .c sp ,
-the amount of vertical space to add before environment.
-.p
-2.	\c
+the amount of vertical space to add before an environment
+.e
+.c sq ,
+the amount of vertical space to add before a different type of environment
+.e
 .c ti ,
-the indentation of the first line in the environment.
+the indentation of the first line in some environments
+(currently only
+.c p )
 .p
 These can be set inside a given environment
 to control its behavior when invoked.
+The only exception is the footnote environment
+.c _f ), (
+which is treated specially
+and does not support these registers.
+.
+.
+.h
+Macros
+.
+.p
+.i Mg
+defines a number of macros.
+Some of them are used internally by
+.i mg
+itself;
+these carry an underscore prefix
+and are not explained here.
+The rest provide useful features,
+like headings, subheadings and paragraphs.
+.s
+Inline macros
+.p
+There is a group of macros that provide
+convenient inline formatting.
+All take three arguments:
+the text to be formatted,
+the text to be placed immediately after
+and the text to be placed immediately before.
+The inline macros are the following:
+.e 0
+.c b ,
+bold font
+.e
+.c c ,
+constant-width font
+.e
+.c i ,
+italic font
+.e
+.c i ,
+bold italic font
+.p
+For example, the following request outputs
+.i mg .\(rq: \(lq
+.l
+\&.i mg .
+.
+.p
+Note that
+.c c
+uses the font family and point size
+set in the
+.c l
+environment (see below).
+.s
+Block-level macros
+.p
+There is a large group of macros that provide
+block-level formatting:
+.e 0
+.c d ,
+centered date (or given string)
+.e
+.c h ,
+heading
+.e
+.c l ,
+literal display (for source code)
+.e
+.c n ,
+centered name of author
+.e
+.c p ,
+paragraph
+.e
+.c s ,
+subheading
+.e
+.c t ,
+centered title of document
+.
+.s
+Other macros
+.p
+Finally, there are a few macros
+that belong to neither category.
+.e 0
+.c q ,
+quotation
+.e
+.c ( ,
+begin footnote
+.e
+.c ) ,
+end footnote
+.p
+By default,
+.c q
+behaves like an inline macro,
+surrounding text in quotation marks,
+but if no arguments are given to it,
+it starts an indented block quotation instead.
+.p
+The footnote macros are used like this\c
+.(
+Note that
+.c (
+and
+.c )
+take an optional argument,
+which is output immediately before or after
+the footnote number.
+.) :
+.l
+.eo
+.cc ,
+a line of text\c
+.(
+a footnote
+.) .
+,cc
+.ec
+.p
+Note that
+.i mg
+does not account for cases where a footnote, because of its height,
+pushes the place where it is referenced to the next page.
+In such cases, the reference will simply appear on the page
+following the footnote.
+When this happens, the user must account for it manually.
diff --git a/g.tmac b/g.tmac
index 6461c60..bb7e2cd 100644
--- a/g.tmac
+++ b/g.tmac
@@ -25,8 +25,6 @@
 . \" configure initial options
 . _nr mt 1i \" margin top
 . _nr mb 1i \" margin bottom
-. _ds cfam C \" inline constant-width font family
-. _ds cps -1p \" inline constant-width font size
 .
 . \" initialize document
 . wh 0 _ht
@@ -48,7 +46,7 @@
 .  _ec 0
 .  nr sp 0.3v
 .  nf
-.  in 0.5c
+.  in 18p
 .  fam C
 .  ps -1p
 .  vs -1p
@@ -59,13 +57,13 @@
 . _e p \" paragraph
 .  _ec 0
 .  nr sp 0.3v
-.  nr ti 0.5c
+.  nr ti 18p
 .  ad b
 . _e q \" quotation
 .  _ec 0
 .  nr sp 0.3v
 .  nr ti 1c
-.  in 0.5c
+.  in 18p
 .  ps -1p
 .  vs -1p
 . _e s \" section heading
@@ -217,9 +215,16 @@ ___________________
 .
 .\" c -- constant-width font
 .de c
+.
+. \" copy family and point size from l environment
+. _E l
+. ds _fam \n[.fam]
+. nr _s \n(.s
+. _E
+.
 \$3\c
-. fam \*[cfam]
-. ps \*[cps]
+. fam \*[_fam]
+. ps \n(_s
 \$1\c
 . fam
 . ps
-- 
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