From b9d9adf426d70fdfa6fdb7b486eb63232354e1a9 Mon Sep 17 00:00:00 2001
From: toshinagata1964 <toshinagata1964@a2be9bc6-48de-4e38-9406-05402d4bc13c>
Date: Fri, 14 Mar 2014 09:44:49 +0000
Subject: [PATCH] Ruby: Kernel#fw (formula weight) is implemented.

git-svn-id: svn+ssh://svn.sourceforge.jp/svnroot/molby/trunk@466 a2be9bc6-48de-4e38-9406-05402d4bc13c
---
 Scripts/formula.rb | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/Scripts/formula.rb b/Scripts/formula.rb
index d8bb57a..c44d650 100755
--- 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
-- 
2.11.0