Special characters - ObjectVision/GeoDMS GitHub Wiki
Configuration examples Special characters
In the GeoDMS escape characters can be used to configure special characters, see the examples:
parameter<string> SingleQuote := '\''';
parameter<string> DoubleQuote := '\"';
// The double quote with an escape character is needed in the expression syntax with expr = ".."
//, as the double quote is also used in this syntax to indicate the start and end of the expression.
parameter<string> tab := '\t';
parameter<string> newline := '\n';
parameter<string> backslash : ['\\'];
parameter<string> forwardslash : ['//'];
parameter<string> copyright := '\xA9'; // U+00A9 © in Latin-1 / CP1252
parameter<string> maxstring := '\xFF\xFF\xFF\xFF'; // four raw bytes 0xFF
The \xHH escape (two hexadecimal digits, case-insensitive) embeds a single raw byte with the given value. It is recognised in both single-quoted ('...') and double-quoted ("...") string literals, and also in the data-block array notation ([...]). This is the recommended way to embed non-UTF-8 or non-printable bytes in a configuration file without breaking UTF-8 editors.
Missing data (null values) can be configured, based on the value types, in different ways; see the examples:
parameter<uint32> null_u32 := 4294967295;
parameter<uint32> null_u32 := 0 / 0;
// The null value for uint32 is used as the transparent colour in items with colour visualisation style.
parameter<uint8> null_u8 := 255b;
or parameter<uint32> null_u8 := 0b / 0b;
parameter<string> null_string := string(0 / 0);
parameter<string> emptystring := '';
The emptystring parameter does not configure a null value, but a string with no characters.