Semantics : PrimaryExpr

PrimaryExpr  ::=  ObjectAllocator | JavaAllocator | JavaClassAllocator | LambdaDeclaration | ${ IDENTIFIER } | & IDENTIFIER | AtomicExpr

Used by:  

The primary expression is the smallest unit of any expressions.

The ObjectAllocator, JavaAllocator, JavaClassAllocator and LambdaDeclaration create various objects that can be assigned to some variable.

The ${ } expression is an alias for the call to system function getEnvVar(). This expression can appear and function the same within string literals as well, including here-docs.

The & operator takes a reference for a function to assign to a variable.

The AtomicExpr represents individual variables, object member access, array access, function calls and combinations of all these.