public static System.Collections.Generic.IEnumerable<System.String> ReadWord( System.String input ) {
	input ??= System.String.Empty;

	var inlen = input.Length;
	System.Int32 start = 0;
	System.Int32 stop;
	System.Func<System.String, System.Int32, System.Int32, System.String> substr = null;
	do {
		while ( ( start < inlen ) && System.Char.IsWhiteSpace( input[ start ] ) ) {
			start++;
		}
		if ( start == inlen ) {
			yield break;
		} else if ( '(' == input[ start ] ) {
			stop = ReadString( input, start );
			substr = ( a, b, c ) => UnescapeString( a.Substring( b, c - b ) );
		} else {
			stop = ReadWord( input, start );
			substr = ( a, b, c ) => a.Substring( b, c - b );
		}
		if ( start == stop ) {
			yield break;
		} else {
			yield return substr( input, start, stop - start );
		}
		start = stop;
	} while ( start < inlen );

	yield break;
}
private static System.String UnescapeString( System.String input ) {
	var sb = new System.Text.StringBuilder( input.Length );

	System.Int32 i = -1;
	System.Char c;
	while ( ++i < input.Length ) {
		c = input[ i ];
		if ( '\\' == c ) {
			switch ( input[ ++i ] ) {
				case '0':
					c = '\0';
					break;
				case 'a':
					c = '\a';
					break;
				case 'b':
					c = '\b';
					break;
				case 'f':
					c = '\f';
					break;
				case 'r':
					c = '\r';
					break;
				case 'n':
					c = '\n';
					break;
				case 't':
					c = '\t';
					break;
				case 'v':
					c = '\v';
					break;
				default:
					c = input[ i ];
					break;
			}
		}
		sb = sb.Append( c );
	}

	return sb.ToString();
}
private static System.Int32 ReadWord( System.String input, System.Int32 pos ) {
	var inlen = input.Length;
	while ( ( pos < inlen ) && !System.Char.IsWhiteSpace( input[ pos ] ) ) {
		pos++;
	}
	return pos;
}
private static System.Int32 ReadString( System.String input, System.Int32 pos ) {
	var inlen = input.Length;
	while ( ( pos < inlen ) && ( ')' != input[ pos ] ) ) {
		if ( '\\' == input[ pos ] ) {
			pos++;
		}
		pos++;
	}
	pos++;
	if ( inlen < pos ) {
		throw new System.InvalidOperationException( "Unterminated string" );
	}
	return pos;
}