From 925f0423dcc9040fa530e9090db2b7c914243451 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Paul=20H=C3=A4nsch?= <paul@plutz.net>
Date: Thu, 22 Jun 2023 16:37:18 +0200
Subject: [PATCH] unified headline function

---
 markdown.awk | 65 +++++++++++++++++++++++-----------------------------
 1 file changed, 29 insertions(+), 36 deletions(-)

diff --git a/markdown.awk b/markdown.awk
index 0e6d949..a2bb989 100755
--- a/markdown.awk
+++ b/markdown.awk
@@ -307,19 +307,34 @@ function inline( line, LOCAL, len, code, href, guard ) {
   }
 }
 
+function headline( hlvl, htxt, LOCAL, sec, n, HL) {
+  split( gensub( /^(.* )?(([0-9]+ ){5}[0-9]+)$/, "\\2" ,"1", hstack),  HL);
+
+  for ( n = hlvl; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
+  HL[hlvl]++; for ( n = hlvl + 1; n <= 6; n++) { HL[n] = 0;}
+  hid = HL[1]; for ( n = 2; n <= hlvl; n++) { hid = hid "." HL[n] ; }
+  # hid = hid ":" URL(htxt, 1);
+
+  hstack = HL[1] " " HL[2] " " HL[3] " " HL[4] " " HL[5] " " HL[6];
+
+  return sec "<section class=\"h1\"" ((blvl > 10)?"":" id=\"" hid "\"") ">" \
+         "<h1>" inline( htxt ) \
+         ((blvl > 0)?"":"<a class=\"anchor\" href=\"#" hid "\"></a>") \
+         "</h1>\n\n";
+}
+
 # Nested Block, resets heading counters
 function _nblock( block, LOCAL, hlsav, sec ) {
-  # Keeping arrays in a local scope is awkward, so we serialize the HL array
-  # into the scalar hlsav
-  hlsav = HL[1] " " HL[2] " " HL[3] " " HL[4] " " HL[5] " " HL[6];
-  HL[1] = 0; HL[2] = 0; HL[3] = 0; HL[4] = 0; HL[5] = 0; HL[6] = 0;
+  hlsav = hstack;
+  hstack = "0 0 0 0 0 0";
 
   # Block Level
   blvl++;
 
   block = _block( block );
+  split( gensub( /^(.* )?(([0-9]+ ){5}[0-9]+)$/, "\2" ,"1", hstack),  HL);
   sec = ""; for ( n = 1; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
-  split(hlsav, HL); blvl--;
+  hstack = hlsav; blvl--;
   return block sec;
 }
 
@@ -573,48 +588,26 @@ function _block( block, LOCAL, st, len, hlvl, htxt, sec, guard, code, indent, at
 
   # First Order Heading H1
   } else if ( match( block, /^[^\n]+\n===+(\n|$)/ ) ) {
-    len = RLENGTH; sec = "";
-
-    for ( n = 1; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
-    HL[1]++; HL[2] = 0; HL[3] = 0; HL[4] = 0; HL[5] = 0; HL[6] = 0;
-    hid = HL[1] ":" URL(gensub( /\n.*$/, "", "g", block ), 1);
+    len = RLENGTH;
 
-    return sec "<section class=\"h1\"" ((blvl > 1)?"":" id=\"" hid "\"") ">" \
-           "<h1>" inline( gensub( /\n.*$/, "", "g", block ) ) \
-           ((blvl > 1)?"":"<a class=\"anchor\" href=\"#" hid "\"></a>") \
-           "</h1>\n\n" \
+    return headline(1, gensub( /\n.*$/, "", "g", block )) \
            _block( substr( block, len + 1 ) );
 
   # Second Order Heading H2
   } else if ( match( block, /^[^\n]+\n---+(\n|$)/ ) ) {
-    len = RLENGTH; sec = "";
-
-    for ( n = 2; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
-    HL[2]++; HL[3] = 0; HL[4] = 0; HL[5] = 0; HL[6] = 0;
-    hid= HL[1] "." HL[2] ":" URL(gensub( /\n.*$/, "", "g", block ), 1);
+    len = RLENGTH;
 
-    return sec "<section class=\"h2\"" ((blvl > 1)?"":" id=\"" hid "\"") ">" \
-           "<h2>" inline( gensub( /\n.*$/, "", "g", block ) ) \
-           ((blvl > 1)?"":"<a class=\"anchor\" href=\"#" hid "\"></a>") \
-           "</h2>\n\n" \
+    return headline(2, gensub( /\n.*$/, "", "g", block )) \
            _block( substr( block, len + 1) );
 
   # Nth Order Heading H1 H2 H3 H4 H5 H6
   } else if ( match( block, /^#{1,6}[ \t]*[^\n]+([ \t]*#*)(\n|$)/ ) ) {
-    len = RLENGTH; sec = "";
-
-    hlvl = length( gensub( /^(#{1,6}).*$/, "\\1", "g", block ) );
-    htxt = gensub(/^#{1,6}[ \t]*(([^ \t\n]+|[ \t]+[^ \t\n#]|[ \t]+#+[^\n#])+)([ \t]*#*)(\n.*)?$/, "\\1", 1, block);
-
-    for ( n = hlvl; n <= 6; n++ ) { sec = sec (HL[n]?"</section>":""); }
-    HL[hlvl]++; for ( n = hlvl + 1; n <= 6; n++) { HL[n] = 0;}
-    hid = HL[1]; for ( n = 2; n <= hlvl; n++) { hid = hid "." HL[n] ; }
-    hid = hid ":" URL(htxt, 1);
+    len = RLENGTH;
 
-    return sec "<section class=\"h" hlvl "\"" ((blvl > 1)?"":" id=\"" hid "\"") ">" \
-           "<h" hlvl ">" inline( htxt ) \
-           ((blvl > 1)?"":"<a class=\"anchor\" href=\"#" hid "\"></a>") \
-           "</h" hlvl ">\n\n" \
+    return headline( \
+             length( gensub( /^(#{1,6}).*$/, "\\1", "g", block ) ), \
+             gensub(/^#{1,6}[ \t]*(([^ \t\n]+|[ \t]+[^ \t\n#]|[ \t]+#+[^\n#])+)([ \t]*#*)(\n.*)?$/, "\\1", 1, block) \
+           ) \
            _block( substr( block, len + 1) );
 
   # block images (wrapped in <figure>)
-- 
2.39.2