Command interpreter takes x,x as an address

spec/atom/command-interpreter-spec.coffee

@@ -27,3 +27,11 @@ describe "CommandInterpreter", ->
         interpreter.eval(editor, 's/current/foo/g')
         expect(buffer.lineForRow(6)).toBe '      foo < pivot ? left.push(foo) : right.push(current);'
 
+      describe "when prefixed with an address", ->
+        it "only makes substitutions within given lines", ->
+          interpreter.eval(editor, '4,7s/ /!/g')
+          expect(buffer.lineForRow(2)).toBe '    if (items.length <= 1) return items;'
+          expect(buffer.lineForRow(3)).toBe '!!!!var!pivot!=!items.shift(),!current,!left!=![],!right!=![];'
+          expect(buffer.lineForRow(4)).toBe '!!!!while(items.length!>!0)!{'
+          expect(buffer.lineForRow(5)).toBe '!!!!!!current!=!items.shift();'
+          expect(buffer.lineForRow(6)).toBe '      current < pivot ? left.push(current) : right.push(current);'

src/atom/command-interpreter.coffee

@@ -7,6 +7,6 @@ class CommandInterpreter
     @parser = PEG.buildParser(fs.read(require.resolve 'commands.pegjs'))
 
   eval: (editor, command) ->
-    operation = @parser.parse(command)
-    operation.execute(editor)
+    operations = @parser.parse(command)
+    operation.execute(editor) for operation in operations
 

src/atom/command-interpreter/address.coffee

@@ -0,0 +1,14 @@
+Range = require 'range'
+
+module.exports =
+class Address
+  startRow: null
+  endRow: null
+
+  constructor: (start, end) ->
+    @startRow = start - 1
+    @endRow = end - 1
+
+  execute: (editor) ->
+    range = new Range([@startRow, 0], [@endRow, 0])
+    editor.getSelection().setBufferRange(range)

src/atom/commands.pegjs

@@ -1,10 +1,27 @@
 {
   var Substitution = require('command-interpreter/substitution');
+  var Address = require('command-interpreter/address');
 }
 
+start
+  = address:address? _ command:substitution {
+    var operations = [];
+    if (address) operations.push(address);
+    operations.push(command);
+    return operations;
+  }
+
+address
+  = start:integer _ ',' _ end:integer {
+    return new Address(start, end)
+  }
+
 substitution
   = "s" _ "/" find:([^/]*) "/" replace:([^/]*) "/" _ options:[g]* {
-    return new Substitution(find.join(''), replace.join(''), options)
+    return new Substitution(find.join(''), replace.join(''), options);
   }
 
+integer
+  = digits:[0-9]+ { return parseInt(digits.join('')); }
+
 _ = " "*