v3: param, dal_syntax, document header (simple regex) substitution list

* $ and curly braces are escaped (within sisu) to allow the following:
  @make:\n :substitute: /${linux-distro}/,'Debian' /${stable}/,'Squeeze' \
  /${testing}/,'Wheezy'
* changes are not made within text object types: code-blocks, tables or
  metadata (document headers). Marked up document remains self-referential.
* Note: the substitution list must be written on a single line, without
  line-breaks.
* [Substitutions possibility requested by Debian-live, live-manual (Ben
  Armstrong & Daniel Baumann)]

1 files changed, 20 insertions, 0 deletions

diff --git a/lib/sisu/v3/param.rb b/lib/sisu/v3/param.rb
index 5563f780..60f5345b 100644
--- a/lib/sisu/v3/param.rb
+++ b/lib/sisu/v3/param.rb
@@ -803,6 +803,26 @@ module SiSU_Param
           else nil
           end
         end
+        def substitute
+          m=@h['substitute']
+          z=if m
+            w=m.scan(/\/(.+?)\/(i?,)\s*'(.+?)'(?:\s+|\s*;\s*|$)/)
+            arr_hash=[]
+            matches=''
+            w.each do |x|
+              c=(x[1] =~/[i],/) ? :i : :s
+              matches=matches + x[0].gsub(/([${}])/,'\\\\\1') + '|'  
+              arr_hash << { 
+                match: x[0].gsub(/([${}])/,'\\\\\1'),
+                replace: x[2],
+                case_s: c
+              }
+            end
+            matches.chop!
+            { match_and_replace: arr_hash, matches: matches }
+          else nil
+          end
+        end
         def plaintext_wrap
           if @h['plaintext_wrap'].to_s =~/\d\d+/ \
           and @h['plaintext_wrap'].to_i > 19 \