Fix some XSD grammar issues for DECIMAL and DOUBLE.

Author: gkellogg

lib/rdf/model/literal/decimal.rb

@@ -12,7 +12,7 @@ module RDF; class Literal
   # @since 0.2.1
   class Decimal < Numeric
     DATATYPE = RDF::URI("http://www.w3.org/2001/XMLSchema#decimal")
-    GRAMMAR  = /^[\+\-]?\d+(\.\d*)?$/.freeze
+    GRAMMAR  = /^[\+\-]?(?:(?:\d+(?:\.\d*)?)|(?:\.\d+))$/.freeze
 
     ##
     # @param  [String, BigDecimal, Numeric] value

lib/rdf/model/literal/double.rb

@@ -12,7 +12,7 @@ module RDF; class Literal
   # @since 0.2.1
   class Double < Numeric
     DATATYPE = RDF::URI("http://www.w3.org/2001/XMLSchema#double")
-    GRAMMAR  = /^(?:NaN|\-?INF|[+\-]?(?:\d+(:?\.\d*)?|\.\d+)(?:[eE][\+\-]?\d+)?)$/.freeze
+    GRAMMAR  = /^(?:NaN|[+\-]?INF|[+\-]?(?:\d+(:?\.\d*)?|\.\d+)(?:[eE][\+\-]?\d+)?)$/.freeze
 
     ##
     # @param  [String, Float, #to_f] value

spec/model_literal_spec.rb

@@ -540,6 +540,7 @@ def self.literals(*selector)
       %w(0123                           123.0),
       %w(-1                             -1.0),
       %w(1.                             1.0),
+      %w(+.7                            0.7),
       %w(1.0                            1.0),
       %w(1.00                           1.0),
       %w(+001.00                        1.0),
@@ -561,6 +562,7 @@ def self.literals(*selector)
         1.
         1.0
         1.00
+        +.7
         +001.00
         123.456
         1.000000000
@@ -625,7 +627,8 @@ def self.literals(*selector)
       %w(0123      1.23E2),
       %w(-1        -1.0E0),
       %w(+01.000   1.0E0),
-      #%w(1.        1.0E0),
+      %w(-.2e3     -2.0E2),
+      %w(1.        1.0E0),
       %w(1.0       1.0E0),
       %w(123.456   1.23456E2),
       %w(1.0e+1    1.0E1),
@@ -647,6 +650,7 @@ def self.literals(*selector)
         -1
         +01.000
         1.0
+        -.2e3
         123.456
         1.0e+1
         1.0e-10