2. Identifiers

Identifiers in Gazprea must start with either an underscore or a letter (upper or lower cased). Subsequent characters can be an underscore, letter (upper or lower case), or number. An identifier may not be any of Gazprea’s keywords. Here are some valid identifiers in Gazprea:

hello
h3ll0
_h3LL0
_Hi
Hi
_3

The following are some examples of invalid identifiers. They begin with a number, contain invalid characters, or are a keyword:

3d
in
a-bad-variable-name
no@twitter
we.don't.like.punctuation

Gazprea imposes no restrictions on the length of identifiers.

3. Namespaces

Identifiers are used by variables, user-defined types, functions and procedures.

For the most part, user-defined types are in their own namespace because their usage does not collide with variables or functions. The one exception is that struct literals can look like function calls:

struct A (integer i, real j);
A a = A(i, j);

Consequently, struct literals and functions share the same namespace. In the above example, a definition of function A should generate a SymbolError, but a definition of variable A would not. Outside of types, variables and functions/procedures share the same namespace in a scope and shadowing is possible between these types.

function x() returns integer; // "x" refers to this function in the global scope

procedure main() {
  integer x = 3; // "x" refers to this variable in the scope of main
}
...