cl-op is a partial application and partial evaluation library for Common Lisp inspired by Goo's op function and SRFI 26 (Notation for Specializing Parameters without Currying).
Release notes
- 0.7.0: Rewrote code walker in CPS.
Better lifting from special forms.
Added compiler macro for beta reduction.
BREAKING CHANGE -- renamed CL-OP-HOF to CL-OP.HOF
- 0.6.1: Added GENERATOR to CL-OP-HOF.
Refactored WALK.
- 0.6.0: Better invariant lifting of macro forms containing slots.
Added compose.
BREAKING CHANGE: Moved the utility higher order functions (flip, conjoin, disjoin, compose) to a seperate package cl-op-hof.
- 0.5.2: Major refactoring.
Added conjoin.
Exported conjoin and disjoin.
- 0.5.1: Made environment passing explicit.
Added CHANGELOG.txt
- 0.5.0: BREAKING CHNAGE -- removed papply, papply*, pfuncall, pfuncall*, pmultiple-value-bind, pmultiple-value-bind*, *walker-ignore-list*
- 0.4.2: added support for nested ops.
- 0.4.0: made invariant lifting less aggressive but more robust.
- 0.3.2: minor cleanup.
- 0.3.1: bugfix: improper handling of lambda macro.
- 0.3.0: macroexpanding only to determine whether to lift.
- 0.2.0: BREAKING CHANGE -- op now takes a function name or a lambda expression as the function argument (instead of a function designator as before).
Added pfuncall and pmultiple-value-call.
- 0.1.0: initial release.
Installation
cl-op is ASDF installable.
Documentation
Package cl-op
Macro op, op*
Syntax:
op fn &rest args+ => function op* fn &rest args+ => function
Description:
op creates an anonymous function with implicitly defined arguments.
fn is either a function name or a lambda expression (not a function designator. In this regard op is more akin to function than funcall). Each arg is either a slot for an implicit required parameter _ or rest parameter __ or an s-expression potentially containing further slots or op forms (see below). Non-slot args are evaluated.
op* is like op except it defers evaluation of non-slot arguments. It is primarily intended to be used with functions with side-effects.
Examples:
(mapcar (op / _ 2) '(1 2 4 8 10)) => '(1/2 1 2 4 5) (mapcar (op / (+ _ _)) '(2 3 4) '(2 3 4)) => '(1/4 1/6 1/8) (mapcar (op + _ (random 100)) '(1 1 1 1 1)) => '(26 26 26 26 26) (mapcar (op* + _ (random 100)) '(1 1 1 1 1)) => '(51 51 89 13 99)
Notes:
op forms can be meaningfully nested. Slots in nested op forms are not added to the surrounding op argument list.
Symbols _ and __ can still be used as arguments if quoted:
(defun __ (x y) (equal x y)) (mapcar (op subst _ '_ _ :test #'__) '(a b c) '((foo _ bar _ _ baz) (_ _) (1 2 _ d))) => '((FOO A BAR A A BAZ) (B B) (1 2 C D))
Function argument as slot can be simulated by using funcall or apply:
(mapcar (op funcall _ '(1 2 3 4 5)) (list #'first (op nth 2 _))) => '(1 3)
Package cl-op-hof
Function conjoin
Syntax:
conjoin &rest predicates => function
Description:
conjoin combines predicates by (logical) and.
Function disjoin
Syntax:
disjoin &rest predicates => function
Description:
disjoin combines predicates by (logical) or.
Function compose
Syntax:
compose &rest functions => function
Description:
compose composes functions.
Function flip
Syntax:
flip fn => function
Description:
flip switches the first two arguments of fn.
Among other things it somewhat compensates for op's strict left-to-right argument order.
Examples:
(mapcar (flip #'/) '(2 2 2) (1 2 3)) => '(1/2 1 3/2)
Macro generator
Syntax:
generator &body body => function
Description:
generator makes an anonymous function with body body that takes any number of arguments (but ignores them).
Examples:
(mapcar (generator (1- (random 2.0))) '(2 2 2)) => '(-0.864053 0.52210474 -0.8798127)
Deprecated
[deprecated] Macro papply, papply*, pfuncall, pfuncall*, pmultiple-value-call, pmultiple-value-call*
Syntax:
papply &rest args+ => function papply* &rest args+ => function pfuncall &rest args+ => function pfuncall* &rest args+ => function pmultiple-value-call &rest args+ => function pmultiple-value-call* &rest args+ => function
Description:
papply, pfuncall and pmultiple-value-call are op equivalents of apply, funcall and multiple-value-call respectively.
[deprecated] Special variable *walker-ignore-list*
Description:
Parser ignores forms starting with a symbol from this list. Used in situations where _ or __ already have an established meaning (e.g. to facilitate op nesting).
Related work
- curly
- Alexandria (curry and rcurry)
- arnesi (L# -- A reader macro for simple lambdas )
- F-underscore
