// Literal     = BasicLit | CompositeLit | FunctionLit .
// BasicLit    = int_lit | float_lit | imaginary_lit | rune_lit | string_lit .
// OperandName = identifier | QualifiedIdent.
func (p *parser) operand(keep_parens bool) Expr {
	if trace {
		defer p.trace("operand " + p.tok.String())()
	}

	switch p.tok {
	case _Name:
		return p.name()

	case _Literal:

		p.advance(exprEnd)
		return &ast.BadExpr{From: pos, To: p.pos}
	}

	return typ
}

func (p *parser) parseQualifiedIdent(ident *ast.Ident) ast.Expr {
	if p.trace {
		defer un(trace(p, "QualifiedIdent"))
	}

	typ := p.parseTypeName(ident)
	if p.tok == token.LBRACK {
		typ = p.parseTypeInstance(typ)
	}

	return typ
}

// If the result is an identifier, it is not resolved.