Why does using keywords or symbols as functions to lookup values from maps work?

by

Citation from official documentation:

Keywords implement IFn for invoke() of one argument (a map) with an optional second argument (a default value). For example (:mykey my-hash-map :none) means the same as (get my-hash-map :mykey :none). See get.

And Clojure can call keyword as function, because it implements same interface as function. The same is for symbols…

More Related Contents:

  1. Clojure – Combining Two vectors into a vector of vectors [duplicate]
  2. Why exactly is eval evil?
  3. What is the difference between Lisp-1 and Lisp-2?
  4. How to handle java variable length arguments in clojure?
  5. Difference between doseq and for in Clojure
  6. conda, condi, conde, condu
  7. Clojure: reduce vs. apply
  8. What is zip (functional programming?)
  9. Idiomatic clojure map lookup by keyword
  10. Matrix transposition in clojure
  11. difference between use and require
  12. How do I avoid Clojure’s chunking behavior for lazy seqs that I want to short circuit?
  13. How do I find the index of an item in a vector?
  14. What do Clojure symbols do when used as functions?
  15. How to convert lazy sequence to non-lazy in Clojure
  16. How to list the functions of a namespace?
  17. Producer consumer with qualifications
  18. Wrong number of args (0) passed to: PersistentVector on loop/recur function
  19. Fast Prime Number Generation in Clojure
  20. How Are Lazy Sequences Implemented in Clojure?
  21. Constructing a map on anonymous function in Clojure
  22. How many primitives does it take to build a LISP machine? Ten, seven or five?
  23. Clojure multimethods vs. protocols
  24. How can I display the definition of a function in Clojure at the REPL?
  25. How many arguments does an anonymous function expect in clojure?
  26. Function call in -> threading macro
  27. Why such implementation of partial in clojure.core
  28. Clojure binding of dynamic var not working as expected
  29. Difference between Symbols and Vars in Clojure
  30. When to use a Var instead of a function?

Leave a Comment