Binary notation integers (0b100 as 4).

jashkenas · Oct 21, 2011 · 264f881 · 264f881
1 parent d359764
commit 264f881
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Showing 3 changed files with 23 additions and 4 deletions.
diff --git a/lib/coffee-script/lexer.js b/lib/coffee-script/lexer.js
diff --git a/src/lexer.coffee b/src/lexer.coffee
@@ -133,8 +133,14 @@ exports.Lexer = class Lexer
   numberToken: ->
     return 0 unless match = NUMBER.exec @chunk
     number = match[0]
+    numlen = number.length
+    # Now, since it is not JavaScript-descended, if it is binary, we will have
+    # to massage it into something similar and then hand it over. May the user
+    # forgive us.
+    is_binary = /0b([01]+)/.exec number
+    number = (parseInt is_binary[1], 2).toString() if is_binary
     @token 'NUMBER', number
-    number.length
+    numlen
 
   # Matches strings, including multi-line strings. Ensures that quotation marks
   # are balanced within the string's contents, and within nested interpolations.
@@ -578,6 +584,7 @@ IDENTIFIER = /// ^
 
 NUMBER     = ///
   ^ 0x[\da-f]+ |                              # hex
+  ^ 0b[01]+ |                              # binary
   ^ \d*\.?\d+ (?:e[+-]?\d+)?  # decimal
 ///i
 

diff --git a/test/numbers.coffee b/test/numbers.coffee
@@ -7,8 +7,17 @@
 # * Scientific Notation Integer Literals
 # * Scientific Notation Non-Integer Literals
 # * Non-Integer Literals
+# * Binary Integer Literals
 
 
+# Binary Integer Literals
+# Binary notation is understood as would be decimal notation.
+
+test "Parser recognises binary numbers", ->
+  eq 4, 0b100.valueOf()
+  eq '11', 0b100.toString 3
+  eq '100', 0b100['toString'] 2
+
 # Decimal Integer Literals
 
 test "call methods directly on numbers", ->