Ruby: Kernel#fw (formula weight) is implemented.

git-svn-id: svn+ssh://svn.sourceforge.jp/svnroot/molby/trunk@466 a2be9bc6-48de-4e38-9406-05402d4bc13c

diff --git a/Scripts/formula.rb b/Scripts/formula.rb
index d8bb57a..c44d650 100755 (executable)
--- a/Scripts/formula.rb
+++ b/Scripts/formula.rb
@@ -685,3 +685,68 @@ class Molecule
   end
 
 end
+
+module Kernel
+  #  Calculate formula weight
+  def fw_sub(str, idx = 0)
+    idx0 = idx
+    f = 0.0
+       c = str[idx]
+       rp = nil
+       case c
+       when ?(
+         rp = ?)
+       when ?{
+         rp = ?}
+       when ?[
+         rp = ?]
+       end
+       if rp
+         f, idx = fw_sub(str, idx + 1)
+         if str[idx] != rp
+           raise "Missing right parenthesis"
+         end
+         idx += 1
+       else
+         s = str[idx..-1]
+         p = Parameter.builtin.elements.find { |pp| s.rindex(pp.name, 0) == 0 }
+         if p
+           f = p.weight
+               idx += p.name.length
+         else
+           key = Molecule.lookup_fragment_from_string(s)
+           if key != nil
+             f = Molecule.known_fragment(key).atoms.sum { |ap| Parameter.builtin.elements[ap.atomic_number].weight }
+                 idx += key.length
+           else
+             ss = str[0..idx - 1] + "<?>" + str[idx..-1]
+             raise "Cannot find atom/fragment that matches \"#{s}\": #{ss}"
+           end
+         end
+       end
+       c = str[idx]
+       if c && c >= ?0 && c <= ?9
+         n = c.ord - 48
+         idx += 1
+         while (c = str[idx]) != nil && c >= ?0 && c <= ?9
+               n = n * 10 + c.ord - 48
+               idx += 1
+         end
+         f *= n
+       end
+       return f, idx
+  end
+  def fw(str)
+    idx = 0
+       ff = 0.0
+       while idx < str.length
+         fff, idx = fw_sub(str, idx)
+         ff += fff
+         c = str[idx]
+         while (c = str[idx]) == "." || c == "+" || c == "_" || c == " "
+           idx += 1
+         end
+       end
+       ff
+  end
+end