The expression to evaluate only one time

Property definitions

	# The expression to evaluate only one time
	var n_expr: AExpr is writable, noinit

src/parser/parser_nodes.nit:2135,2--2136,38

	redef fun n_expr=(node)
	do
		_n_expr = node
		node.parent = self
	end

src/parser/parser_prod.nit:3605,2--3609,4