If you think brackets are the core innovation of Smalltalk to make lambdas practical, then Lisp has no problem providing it, too: CL-USER 19 > (defun brack

If you think brackets are the core innovation of Smalltalk to make lambdas practical, then Lisp has no problem providing it, too: CL-USER 19 > (defun bracket-reader (stream char) (declare (ignore char)) `(lambda () ,@(read-delimited-list #\] stream t))) BRACKET-READER CL-USER 20 > (set-macro-character #\[ #'bracket-reader) T CL-USER 21 > (let ((a 10)) (my-if (> a 5) [(print 'hello)] [(print 'world)]) 'done) HELLO DONE With a bit more effort, we could also parse a parameter list. But Lisp does not go the route of making IF a function, because it typically provides three different types of language expressions and IF then is a special operator: 1) function calls 2) macro forms 3) a small set of special operators, which are implemented as built-in functionality. One of them is a core conditional operator. More complex conditional operators then are implemented as macros, which expand eventually into the core conditional operator. The interpreter and compiler will have to specially recognize and implement these special operators. See IF: http://clhs.lisp.se/Body/s_if.htm http://clhs.lisp.se/Body/s_if.htm The usual Lisp view is that [(print 'hello)] is no useful improvement over (lambda () (print 'hello)) Some disagree, but most of the time the pattern (<operator> <expr0> ... <exprn>) is preferred in Lisp over <fancy-character> <expr0> ... <exprn> <another-fancy-character>