Raw-string literals support C0 control characters. (#134)

* Raw-string literals support C0 control characters.

* Added example.

* Removed trailing whitespace.

Co-authored-by: Richard Gibson <[email protected]>

* preserved-escape now supports C0 control characters as well.

Co-authored-by: Richard Gibson <[email protected]>

Author: springcomp

GRAMMAR.ABNF

@@ -611,8 +611,8 @@ expression-type     = "&" expression
 ;; This provides a simple mechanism to explicitly convert types when needed.
 
 raw-string        = "'" *raw-string-char "'" ;; # Raw String Literals \
-raw-string-char   = (%x20-26 / %x28-5B / %x5D-10FFFF) / preserved-escape / raw-string-escape ;; \
-preserved-escape  = escape (%x20-26 / %x28-5B / %x5D-10FFFF) ;; \
+raw-string-char   = (%x00-26 / %x28-5B / %x5D-10FFFF) / preserved-escape / raw-string-escape ;; \
+preserved-escape  = escape (%x00-26 / %x28-5B / %x5D-10FFFF) ;; \
 raw-string-escape = escape ("'" / escape)
 ;; A raw string is an expression that allows for a literal string value to be specified. The result of evaluating the raw
 ;; string literal expression is the literal string value. It is a simpler form of a literal expression that is special
@@ -638,6 +638,8 @@ raw-string-escape = escape ("'" / escape)
 ;; search(' bar ', "") -> " bar "
 ;; search('[baz]', "") -> "[baz]"
 ;; search('\u03bB', "") -> "\\u03bB"
+;; search('foo␊bar', "") -> "foo\nbar"
+;; search('foo\␊bar', "") -> "foo\\\nbar"
 ;; search('\\', "") -> "\\"
 ;; ```