Add a version of compose for named functions

This version is interesting because it works with macros
This commit is contained in:
Ivan Malison 2016-06-21 15:54:57 -07:00
parent 490c4c758b
commit 1eb3f48dfc

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@ -468,6 +468,21 @@ Here is a unary version which avoids all the calls to imalison:make-list
'arg 'arg
`(funcall ,(car funcs) (imalison:compose-helper-unary ,(cdr funcs))))) `(funcall ,(car funcs) (imalison:compose-helper-unary ,(cdr funcs)))))
#+END_SRC #+END_SRC
Here is a version that will support macros and requires unary functions after the first one
#+BEGIN_SRC emacs-lisp
(defmacro imalison:compose-named-functions (arguments &rest funcs)
"Build a new function with NAME that is the composition of FUNCS."
`(lambda ,arguments
(imalison:compose-named-functions-helper ,funcs ,arguments)))
(defmacro imalison:compose-named-functions-helper (funcs arguments)
"Builds funcalls of FUNCS applied to the arg."
(if (equal (length funcs) 1)
`(,(car funcs) ,@arguments)
`(,(car funcs)
(imalison:compose-named-functions-helper ,(cdr funcs) ,arguments))))
#+END_SRC
** prefix-alternatives ** prefix-alternatives
Prefix alternatives is a macro that builds a function that selects one of a collection of functions that are provided to the macro based on the value of the prefix argument. Prefix alternatives is a macro that builds a function that selects one of a collection of functions that are provided to the macro based on the value of the prefix argument.
#+BEGIN_SRC emacs-lisp #+BEGIN_SRC emacs-lisp