Add single-line addresses to command interpreter

spec/atom/command-interpreter-spec.coffee

@@ -11,9 +11,15 @@ describe "CommandInterpreter", ->
     interpreter = new CommandInterpreter()
 
   describe "addresses", ->
-    it "selects the given lines", ->
-      interpreter.eval(editor, '4,7')
-      expect(editor.selection.getBufferRange()).toEqual [[3, 0], [6, 0]]
+    describe "a line address", ->
+      it "selects the specified line", ->
+        interpreter.eval(editor, '4')
+        expect(editor.selection.getBufferRange()).toEqual [[3, 0], [4, 0]]
+
+    describe "an address range with two line addresses", ->
+      it "selects the given lines", ->
+        interpreter.eval(editor, '4,7')
+        expect(editor.selection.getBufferRange()).toEqual [[3, 0], [7, 0]]
 
   describe "substitution", ->
     it "does nothing if there are no matches", ->
@@ -34,7 +40,7 @@ describe "CommandInterpreter", ->
 
       describe "when prefixed with an address", ->
         it "only makes substitutions within given lines", ->
-          interpreter.eval(editor, '4,7s/ /!/g')
+          interpreter.eval(editor, '4,6s/ /!/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)!{'

src/atom/command-interpreter/address-range.coffee

@@ -0,0 +1,9 @@
+Address = require 'command-interpreter/address'
+Range = require 'range'
+
+module.exports =
+class AddressRange extends Address
+  constructor: (@startAddress, @endAddress) ->
+
+  getRange: ->
+    new Range(@startAddress.getRange().start, @endAddress.getRange().end)

src/atom/command-interpreter/address.coffee

@@ -1,14 +1,4 @@
-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)
+    editor.getSelection().setBufferRange(@getRange())

src/atom/command-interpreter/line-address.coffee

@@ -0,0 +1,10 @@
+Address = require 'command-interpreter/address'
+Range = require 'range'
+
+module.exports =
+class LineAddress extends Address
+  constructor: (lineNumber) ->
+    @row = lineNumber - 1
+
+  getRange: ->
+    new Range([@row, 0], [@row + 1, 0])

src/atom/commands.pegjs

@@ -1,6 +1,7 @@
 {
   var Substitution = require('command-interpreter/substitution');
-  var Address = require('command-interpreter/address');
+  var LineAddress = require('command-interpreter/line-address');
+  var AddressRange = require('command-interpreter/address-range');
 }
 
 start
@@ -11,10 +12,13 @@ start
     return operations;
   }
 
-address
-  = start:integer _ ',' _ end:integer {
-    return new Address(start, end)
-  }
+address = addressRange / primitiveAddress
+
+addressRange
+  = start:primitiveAddress _ ',' _ end:address { return new AddressRange(start, end) }
+
+primitiveAddress
+  = lineNumber:integer { return new LineAddress(lineNumber) }
 
 substitution
   = "s" _ "/" find:pattern "/" replace:pattern "/" _ options:[g]* {