pattern/bencode: Various fixes (#393)

* Fix bencode dictionary

When parsing a bencode dictionary, the end character 'e' was never
consumed. This caused a misinterpretation of the character as struct Value of
an unknown type 'e'.

* Fix bencode list

A list was not included in the Value's parsing logic so it may have
been mistakenly parsed as a string.

* Fix std::ctype::isprint not including space

The space character, 0x20, is considered as a printable character in ASCII
and in >=C89. Adding it to the range of std::ctype::isprint also fixes
other std::ctype functions that use it.

* Fix bencode byte string formatting

Byte strings do not render nicely in pattern data's value column if they
contain non-printable characters. This commit makes the value of byte
strings to be surrounded by quotation marks, and renders a warning text
without quotation marks if the byte string contains non-printable
characters.

Author: Niketin

includes/std/ctype.pat

@@ -85,7 +85,7 @@ namespace auto std::ctype {
         @return True if `c` is part of this range, false otherwise
     */
     fn isprint(char c) {
-        return c >= '0' && c <= '~';
+        return c >= ' ' && c <= '~';
     };
 
     /**

patterns/bencode.hexpat

@@ -38,10 +38,15 @@ namespace bencode {
 		ASCIIDecimal length;
 		char separator [[hidden]];
 		char value[length];
-	} [[sealed, format("bencode::format_string"), transform("bencode::format_string")]];
+	} [[sealed, format("bencode::format_string")]];
 
 	fn format_string(String string) {
-		return string.value;
+		for (u64 i = 0, i < string.length, i = i + 1) {
+			if (!std::ctype::isprint(string.value[i])) {
+				return "Contains non-printable characters";
+			}
+		}
+		return std::format("\"{}\"", string.value);
 	};
 
 	using Bencode;
@@ -57,6 +62,10 @@ namespace bencode {
 
 		if (type == Type::Dictionary) {
 			DictionaryEntry entry[while(std::mem::read_unsigned($, 1) != 'e')];
+			char end;
+		} else if (type == Type::List) {
+			  Value entry[while(std::mem::read_unsigned($, 1) != 'e')];
+			  char end;
 		} else if (type == Type::Integer) {
 			ASCIIDecimal value;
 			char end;