Recently, I was reading article "Root Of Lisp" from Paul Graham.I encountered some questions.From the book, it defines expression as two :1.atom;2.list, while list is consisted of zero or many expressions.Then it sayes that a list can be evaluated.Now I hava some problems:
- Can every list be evaluated?Is every list an expression?
- If a list can be evaluated, then it may have its first element as an operator,so an operator is an expression?Is operator atomic or another?
- The operator
car
returns the first element of a list, if the list can be evaluated, then what will it return , the operator?Can you give me some sample of this to show how to use the returned value? - The operator
cdr
returns elements besides the first element as a list,then this returned list can't be evaluated?
I am a freshman for Lisp,I don't know whether I hava explained my problems clearly.