Monadic Expressions

Monadic expressions are expressions with monadic operators, together with a few more specialized notations:

monad-expression:
	term
	monad-operator monad-expression
	array [expression] of data-type
	array [expressionopt] of { init-list }
	list of {expression-list}
	chan of data-type
	data-type monad-expression

monad-operator: one of
	+ - ! ~ ref * <- hd tl len tagof