lvalue: identifier $ $number lvalue [ expression ] * expression ` expression ` ( lvalue )
The dollar sign $
is the actual argument list of a function; $
number is
the number-th argument where number
is a decimal integer constant.
An lvalue followed by an expression in square brackets is an lvalue. The intuitive meaning is that of a subscript. The lvalue must have type string or list. The expression must be of integer type.
The unary *
operator means indirection: the
expression must be a pointer, the result is an lvalue.
An expression enclosed in a pair of `
(open quotes) is a lvalue where the
expression must be of string type. The object, referred to by it, is the
object having the name identical to the string. For instance,
`"A"`
is
equivalent to the object A
.
A parenthesized lvalue is a lvalue which is identical to the unadorned lvalue.