[groff] 18/28: [man]: Lightly refactor paragraph tag writing.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 80fe96a568c76c193ba485da4677f4749f32187e
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Jun 19 11:38:19 2021 +1000

    [man]: Lightly refactor paragraph tag writing.
    
    * tmac/an-old.tmac (an-write-paragraph-tag): Lightly refactor for
      clarity and to reduce code duplicated in both branches of an `ie`/`el`
      structure.
    
    Also clarify some comments.
---
 ChangeLog        |  6 ++++++
 tmac/an-old.tmac | 36 +++++++++++++++---------------------
 2 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f80b8ae..964b1b9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2021-06-19  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       * tmac/an-old.tmac (an-write-paragraph-tag): Lightly refactor
+       for clarity and to reduce code duplicated in both branches of an
+       `ie`/`el` structure.
+
+2021-06-19  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * tmac/an-old.tmac: Rename `an-HF-remap-I-style` register to
        `an-remap-I-style-in-headings` for greater clarity.
 
diff --git a/tmac/an-old.tmac b/tmac/an-old.tmac
index 1657bd2..56e691c 100644
--- a/tmac/an-old.tmac
+++ b/tmac/an-old.tmac
@@ -446,23 +446,16 @@
 .  in \\n[an-margin]u
 .  \" Prevent page break between the tag and the rest of the paragraph.
 .  ne (2v + 1u)
-.  \" Is the tag too wide?
-.  ie (\\n[dl] + \\n[an-tag-separation] > \\n[an-prevailing-indent]) \{\
-.    an-div
-.    ev
-.    in (\\n[an-margin]u + \\n[an-prevailing-indent]u)
-.  \}
-.  el \{\
-.    DEVTAG-COL 1
-.    an-div
-.    sp -1v
-.    ev
-.    \" In nroff mode, the indentation value should be an integer
-.    \" multiple of the character cell, to avoid different results
-.    \" compared to the .ie part above.
-.    in (\\n[an-margin]u + \\n[an-prevailing-indent]u)
-.    DEVTAG-COL-NEXT 2
-.  \}
+.  \" Does the tag fit within the paragraph indentation?
+.  nr an-tag-fits \
+     (\\n[dl] + \\n[an-tag-separation] <= \\n[an-prevailing-indent])
+.  if \\n[an-tag-fits] .DEVTAG-COL 1
+.  an-div
+.  if \\n[an-tag-fits] .sp -1v
+.  ev
+.  in (\\n[an-margin]u + \\n[an-prevailing-indent]u)
+.  if \\n[an-tag-fits] .DEVTAG-COL 2
+.  rr an-tag-fits
 ..
 .
 .\" Handle macros that may take an "argument" on the next input line;
@@ -918,7 +911,7 @@
 .\"
 .\" \n[C] may get set to 1 redundantly in the below; we could replace
 .\" that with a complex conditional, but it doesn't seem to be worth the
-.\" trouble given AT&T-compatible restrictions on '!' placement.
+.\" trouble given restrictions on use of '!', '&', and ':' operators.
 .ie !r C \
 .  nr C 0
 .el \
@@ -960,7 +953,7 @@
 .\" TH macro places page location traps only if not continuously
 .\" rendering.
 .if r FT \{\
-.  \" Validate it. Continuous rendering ignores FT.  Measuring a footer
+.  \" Validate it.  Continuous rendering ignores FT.  Measuring a footer
 .  \" distance from the page top isn't done.  A footer distance of over
 .  \" half the page length is unlikely.  A footer distance of less than
 .  \" one line height is too.
@@ -995,8 +988,9 @@
 .
 .\" standard indentation
 .if !r IN \{\
-.  \" We must select an integer indentation value for nroff; see comment
-.  \" in an-write-paragraph-tag.
+.  \" We select an integer indentation value in nroff mode because this
+.  \" value is used additively for multiple purposes; rounding of
+.  \" accumulating fractions would produce inconsistent results.
 .  ie t \
 .    nr IN 7.2n
 .  el \