Expressions

Expressions evaluate to a value and may either be function calls, literals or identifiers.

Expression  = FunctionCall | Operand | Cast ;

Function Calls

Function calls consist of the function name (optionally fully qualified) and operand arguments. Function calls may not be nested.

FunctionCall  = FunctionId '(' [ Operands ] ')' ';'
FunctionId    = '@' Identifier [ '.' Identifier  ] ;

Function calls are pass-by-value and return by value.

Operands

Operands, used either as parameters or return values, may only be identifiers or literals.

Operands  = Operand { ',' Operand } ;
Operand   = Identifier [ '.' Identifier ] | Literal ;

Literals

Literals may either be function names, or vectors and consist of the value and associated type. Function literals may omit the declared type.

Literal  = FunctionLiteral | VectorLiteral ;

FunctionLiteral  = FunctionId [ ':' "func" ] ;
VectorLiteral    = Value ':' Type | '(' Value { ',' Value } ')' ':' Type ;

Values within a vector literal must correspond to the declared type (or be compatible, see type conversions).

Cast Expression

A type cast changes the type of the expression to the destination type. See type conversions for more details.

Cast  = "check_cast" '(' Expression ',' Type ')' ;