emacs-lisp

elisp equivvalent of switch in java and match in python.

cases

each case is (PATTERN CODE)

patterns

• _ -> anything
• ’VAL -> symbol ’VAL
• (pred FUN) (pred (not FUN)) -> if (FUN EXP) return nil or non-nil
• (app FUN PAT) -> if (FUN EXP) return PAT
• (guard BOOLEXP) -> if BOOLEXP return non-nil
• (and PAT …), (or PAT …)

the same as (function a-symbol). It’s difference with ' = (qoute a-symbol):

• compiler use #' to find compile time warning like function not defined
• signify that this is a function
• when used with lambda:
  • #'(lambda ...), (lambda ...), evaluates to a function.
  • '(lambda ...) evaluates to a list.