问题
On page 41 after simplification of the rember
function, there is a question-respond that I don't understand very well.
Q: So why don't we simplify right away? R: Because then a function's structure does not coincide with its argument's structure.
I have tried to figure it out for a couple of days, but I don't understand what exactly means that question-respond.
Could anyone explain me what Friedman want to show with that question-respond?
Thanks in advance
回答1:
Up until this point in the chapter, recursions on lists had been written using a cond
with two conditions, where the second condition was in turn another cond
. That's what the author meant with "the argument structure" (a list) not coinciding with "the function structure" (a two-condition cond
) - because now the function is structured as a single cond
with three conditions, simpler and easier to understand.
来源:https://stackoverflow.com/questions/12399015/the-little-schemer-4th-edition-rember-function-discussion