Constants

You want numbers? We got numbers. You want strings? We got strings. You want complex numbers, we got complex numbers! Constants are a fast way to place data into a document. For instance, the following code outlines some basic constants:

#we_got_constants {
  int x = 123;
  int y = 0x04;
  double z = 3.14;
  bool b = true;
  principal c = @no_one;
  complex cx = 1 + @i;
}

Details

There are a variety of ways to conjure up constants. The following table illustrates examples:

@who is executing

The @who constant refers to the principal that is executing the current code.

@context of the caller

Within static policies, document constructors and events, and message handlers there is constant @context which is useful for getting access to the origin and ip or the caller.

@web's @parameters and @headers

The web handler has access to the parsed query string and HTTP headers respectively via the @parameters and @headers constants. @parameters is a dynamic with the query string converted to JSON. @headers is a map<string,string>.

Bubble's @viewer

A privacy bubble can access viewer state via the @viewer which behaves like a message.

Dynamic @null

The default dynamic type has a value of "null" which is represented via @null.

String escaping

A character following a backslash (\) is an escape sequence within a string, and it is an escape for the parser to inject special characters. For instance, if you are parsing a string initiated by double quotes, then how does one get a double quote into the string? Well, that's what the escape is for. Adama's strings support the following escape sequences: