add test case for file importing and fix a couple of bugs

Gemfile

@@ -6,7 +6,6 @@ group :development do
   gem "rubyXL", "~> 1.2.7"
   gem "nokogiri", ">= 1.4.4"
   gem "rubyzip", ">= 0.9.4"
-# gem "rcov", ">= 0"
 end
 
 group :test do

README.md

@@ -89,12 +89,20 @@ Soroban has a built-in importer for xlsx files. It requires the [RubyXL](https:/
 require 'rubyXL'
 
 BINDINGS = {
-  :gravity => :B1,
+  :planet => :B1,
   :mass => :B2,
-  :force => :B10
+  :force => :B3
 }
 
-s = Soroban::Import::rubyXL("/Users/kranzky/Desktop/Physics.xlsx", 0, BINDINGS )
+s = Soroban::Import::rubyXL("files/Physics.xlsx", 0, BINDINGS )
+
+s.planet = 'Earth'
+s.mass = 80
+puts s.force          # => 783.459251241996
+
+s.planet = 'Venus'
+s.mass = 80
+puts s.force          # => 710.044826106394
 ```
 
 This import process returns a new Soroban::Sheet object that contains all the

lib/soroban/cell.rb

@@ -30,6 +30,8 @@ def get
       raise Soroban::RecursionError, "Loop detected when evaluating '#{@excel}'" if @touched
       @touched = true
       eval(@ruby, @binding)
+    rescue TypeError, RangeError, ZeroDivisionError
+      nil
     ensure
       @touched = false
     end

lib/soroban/functions/vlookup.rb

@@ -3,8 +3,11 @@
 Soroban::define :VLOOKUP => lambda { |value, range, col, inexact|
   fc, fr, tc, tr = Soroban::getRange(range)
   i = walk("#{fc}#{fr}:#{fc}#{tr}").find_index(value)
-  return nil if i.nil?
-  (0...i).each { fr.next! }
-  (1...col).each { fc.next! }
-  eval("@#{fc}#{fr}.get")
+  if i.nil?
+    nil
+  else
+    (0...i).each { fr.next! }
+    (1...col).each { fc.next! }
+    eval("@#{fc}#{fr}.get")
+  end
 }

lib/soroban/helpers.rb

@@ -41,7 +41,7 @@ def self.getRange(range)
   def self.getPos(label)
     # TODO: fix for labels such as "BC42"
     match = /^([a-zA-Z]+)([\d]+)$/.match(label.to_s)
-    return match[2].to_i - 1, match[1].upcase[0]-"A"[0]
+    return match[2].to_i - 1, match[1].upcase[0].ord-"A"[0].ord
   end
 
   # Return an array of values for the supplied arguments (which may be numbers, labels and ranges).

lib/soroban/import/ruby_xl_importer.rb

@@ -46,7 +46,6 @@ def _addCell(label)
         data = cell.formula rescue nil
         data = "=#{data}" unless data.nil?
         data ||= cell.value.to_s rescue nil
-        puts "#{label} => #{row},#{col} = #{data}"
         @model.set(label.to_sym => data)
       end
 

lib/soroban/label_walker.rb

@@ -12,9 +12,15 @@ def initialize(range)
 
     # Yield the label of each cell referenced by the supplied range.
     def each
-      (@fc..@tc).each do |col|
-        (@fr..@tr).each do |row|
-          yield "#{col}#{row}"
+      col, row = @fc, @fr
+      while true do
+        yield "#{col}#{row}"
+        break if row == @tr && col == @tc
+        if row == @tr
+          row = @fr
+          col = col.next
+        else
+          row = row.next
         end
       end
     end

lib/soroban/parser/nodes.rb

@@ -51,14 +51,7 @@ def rewrite(value)
       "'#{value}'"
     end
     def extract(value)
-      fc, fr, tc, tr = Soroban::getRange(value) 
-      retval = []
-      (fc..tc).each do |cc|
-        (fr..tr).each do |cr|
-          retval << "#{cc}#{cr}".to_sym
-        end
-      end
-      retval
+      LabelWalker.new(value).map { |label| "#{label}".to_sym }
     end
   end
 

spec/import_spec.rb

@@ -0,0 +1,27 @@
+require File.expand_path(File.dirname(__FILE__) + '/spec_helper')
+
+describe "Documentation", :if => Gem.available?("rubyXL") do
+
+  it "can import xlsx files using RubyXL" do
+
+    BINDINGS = {
+      :planet => :B1,
+      :mass => :B2,
+      :force => :B3
+    }
+
+    s = Soroban::Import::rubyXL("files/Physics.xlsx", 0, BINDINGS )
+
+    s.planet = 'Earth'
+    s.mass = 80
+    puts s.force          # => 783.459251241996
+    s.force.should be_within(0.01).of(783.46)
+
+    s.planet = 'Venus'
+    s.mass = 80
+    puts s.force          # => 710.044826106394
+    s.force.should be_within(0.01).of(710.04)
+
+  end
+
+end