Operands

Operands denote the elementary values in an expression. An operand may be a literal, a (possibly qualified) non-blank identifier denoting a constant, variable, or function, a method expression yielding a function, or a parenthesized expression.

The blank identifier may appear as an operand only on the left-hand side of an assignment.

Operand     = Literal | OperandName | MethodExpr | "(" Expression ")" .
Literal     = BasicLit | CompositeLit | FunctionLit .
BasicLit    = int_lit | float_lit | imaginary_lit | rune_lit | string_lit .
OperandName = identifier | QualifiedIdent.