Analysis of common vim syntax group mappings. Shows several areas whe…

…re a

better hierarchy will be invaluable. Of course, I don't know how to apply it to
existing syntaxes without having a syntax file about 10,000 lines long...

analysis/vim/analyze-mappings.rb

@@ -0,0 +1,69 @@
+#!/usr/bin/env ruby
+
+def up(c,last)
+  return nil if (c.nil? || c.length == 0)
+  return last if c.upcase == c.downcase
+  return c.upcase == c
+end
+
+FULLWORDS = ['preproc', 'nontext', 'specialkey', 'errormsg', 'moremsg',
+  'warningmsg', 'modemsg', 'matchparen','spellbad', 'spellrare', 'spellcap',
+  'spelllocal', 'specialchar', 'precondit', 'specialcomment', 'storageclass',
+  'typedef', 'colorcolumn'].join('|')
+
+def wordparts(word)
+  word = word.strip.gsub(/#{FULLWORDS}/ium){|m| m.capitalize}
+  res = []; acc = []; upc = nil
+  word = word.split //um
+  begin
+    letter = word.shift
+    cupc = up(letter, upc)
+    if cupc != upc
+      if cupc # lowercase to uppercase
+        res << acc.join('').downcase unless acc.size == 0
+        acc = [letter]
+      else # uppercase to lowercase
+        mine = acc.pop
+        res << acc.join('').downcase unless acc.size == 0
+        acc = [mine, letter]
+      end
+    else acc << letter end
+    upc = cupc
+  end while word.size > 0
+  res << acc.join('').downcase unless acc.size == 0
+  res = res.join('_')
+  return res.split(/_+/).reject{|s|(s.nil? || s.length==0)}.compact
+end
+
+mappings = {}
+IO.readlines('./statements.list').each do |stmt|
+  orig = stmt
+  next unless stmt.start_with? 'map'
+  stmt = stmt.split(' ')
+  next unless stmt.size == 3
+  _, from, to = stmt
+  from = wordparts(from)
+  to = wordparts(to)
+  from[0] = '(lang)' if from.size > 1
+
+  fr = []
+  begin
+    fr << from.pop
+    fr << from.pop if from.last == '(lang)'
+    source = fr.reverse.join('/')
+    dest = to.join('/')
+    source = "#{from.size}/#{source}" if from.size > 0
+    mappings[dest] ||= {}
+    mappings[dest][source] ||= 0
+    mappings[dest][source] += 1
+  end while from.size > 0
+end
+
+mappings = mappings.map do |dest, sources|
+  sources = sources.to_a.reject{|src,num| num < 3 }
+  sources = sources.to_a
+  mag = sources.inject(0){|a,sn| a + sn[1]}
+  [dest, mag, sources.sort_by{|s,n| - n}]
+end
+require 'pp'
+pp mappings.sort_by{|d,mag,srs| - mag }.reject{|d,mag,srs| (mag < 2 || srs.size == 0)}