“Pure LISP” never existed - LISP had assignmentand goto before it had conditional expressions and recursion.
I’m not sure about the choice of the word “before”. As far as I remember, conditional expressions were one of the core concepts (ie if) of lisp, even before it’s first implementation.
Yeah, I was a bit confused by this statement as well. Skimming the original paper, McCarthy mentions both COND (a generalized conditional expression) and recursive functions, but also mentions that Lisp contains a
“program feature” [that] allows programs containing assignment and go to statements in the style of ALGOL
I’m not sure about the choice of the word “before”. As far as I remember, conditional expressions were one of the core concepts (ie
if) of lisp, even before it’s first implementation.Yeah, I was a bit confused by this statement as well. Skimming the original paper, McCarthy mentions both
COND(a generalized conditional expression) and recursive functions, but also mentions that Lisp contains a