chickadee » srfi-45 » lazy-strict

lazy-strict #!optional STRICT?procedure

The body EXPRESSION of a lazy promise must produce a result of type promise according to SRFI 45. This is the default behavior of this implementation. To accept a more lenient interpretation call with a value of #f for STRICT?.

The "improper use of `lazy'" error from force serves notice that a lazy expression was not of the correct type.