Improve tokenising of numbers in Elixir lexer (#1225)

The Elixir lexer does not include sophisticated rules for tokenising
numbers. This commit adds rules for distinguishing between integer,
float, hexadecimal, octal and binary representations.

lib/rouge/lexers/elixir.rb

@@ -38,8 +38,11 @@ class Elixir < RegexLexer
         rule %r/[a-zA-Z_!]\w*[!\?]?/, Name
         rule %r{::|[%(){};,/\|:\\\[\]]}, Punctuation
         rule %r/@[a-zA-Z_]\w*|&\d/, Name::Variable
-        rule %r{\b(0[xX][0-9A-Fa-f]+|\d(_?\d)*(\.(?![^\d\s])
-             (_?\d)*)?([eE][-+]?\d(_?\d)*)?|0[bB][01]+)\b}x, Num
+        rule %r{\b\d(_?\d)*(\.(?![^\d\s])(_?\d)+)([eE][-+]?\d(_?\d)*)?\b}, Num::Float
+        rule %r{\b0x[0-9A-Fa-f](_?[0-9A-Fa-f])*\b}, Num::Hex
+        rule %r{\b0o[0-7](_?[0-7])*\b}, Num::Oct
+        rule %r{\b0b[01](_?[01])*\b}, Num::Bin
+        rule %r{\b\d(_?\d)*\b}, Num::Integer
 
         mixin :strings
         mixin :sigil_strings

spec/visual/samples/elixir

@@ -1,3 +1,10 @@
+# numbers
+291         # integer
+0b100100011 # binary
+0o443       # octal
+0x123       # hexadecimal
+291.0       # float
+
 # keywords with no following whitespace
 (cond)
 (do)