Added testing for \0 escape sequence and update grammar/spec

Signed-off-by: Stefan Marr <[email protected]>

Author: smarr

TestSuite/StringTest.som

@@ -98,6 +98,7 @@ StringTest = TestCase (
      \f	  a formfeed character
      \'	  a single quote character
      \\	  backslash character
+     \0   zero byte character
     "
 
     self assert: '\t' equals: '\t'.
@@ -123,6 +124,10 @@ StringTest = TestCase (
 
     self assert: '\\' equals: '\\'.
     self assert: 1 equals: '\\' length.
+
+    self assert: '\0' equals: '\0'.
+    self assert: 1 equals: '\0' length.
+    self assert: 5 equals: '\0rest' length.
   )
 
   testHash = (

specification/SOM.g4

@@ -217,6 +217,7 @@ STString:
       | '\\n'
       | '\\r'
       | '\\f'
+      | '\\0'
       | '\\\''
       | '\\\\'
       |  ~('\''| '\\')