4.1.2 Functions

Function: applicable-when FUN TEST

Package

data-lens

Source

lens.lisp (file)

Function: combine-matching-lists &key TEST &allow-other-keys

Package

data-lens

Source

lens.lisp (file)

Function: compress-runs &key COLLECTOR TEST KEY

Package

data-lens

Source

lens.lisp (file)

Function: cumsum &key ADD-FUN KEY COMBINE ZERO

Package

data-lens

Source

lens.lisp (file)

Function: denest &key RESULT-TYPE

Package

data-lens

Source

lens.lisp (file)

Function: derive DIFF-FUN &key KEY

Package

data-lens

Source

lens.lisp (file)

Function: element NUM

Package

data-lens

Source

lens.lisp (file)

Function: exclude PRED

Package

data-lens

Source

lens.lisp (file)

Function: include PRED

Package

data-lens

Source

lens.lisp (file)

Function: juxt FUN1 &rest R

Package

data-lens

Source

lens.lisp (file)

Function: key KEY

Package

data-lens

Source

lens.lisp (file)

Function: key-transform FUN KEY-GET KEY-SET

Package

data-lens

Source

lens.lisp (file)

Function: make-alist-lens KEY

A lens for updating a alist, discarding previous values

Package

data-lens.lenses

Source

lens.lisp (file)

Function: make-hash-table-lens KEY

A lens for updating a hash-table, discarding previous values

Package

data-lens.lenses

Source

lens.lisp (file)

Function: make-plist-lens KEY

A lens for updating a plist, preserving previous values

Package

data-lens.lenses

Source

lens.lisp (file)

Function: maximizing RELATION MEASURE

Package

data-lens

Source

lens.lisp (file)

Function: of-length LEN

Package

data-lens

Source

lens.lisp (file)

Function: of-max-length LEN

Package

data-lens

Source

lens.lisp (file)

Function: of-min-length LEN

Package

data-lens

Source

lens.lisp (file)

Function: on FUN KEY

Package

data-lens

Source

lens.lisp (file)

Function: over FUN &key RESULT-TYPE

Package

data-lens

Source

lens.lisp (file)

Function: over LENS CB REC

Given a lens, a callback and a record, apply the lens to the
record, transform it by the callback and return copy of the record,
updated to contain the result of the callback. This is the fundamental operation on a lens and SET and VIEW are implemented in terms of it.

A lens is any function of the form (lambda (fun) (lambda (rec) ...))
that obeys the lens laws (where == is some reasonable equality
operator):

(== (view lens (set lens value rec))
value)

(== (set lens (view lens rec) rec)
rec)

(== (set lens value2 (set lens value1 rec))
(set lens value2 rec))

The inner lambda returns a functor that determines the policy to be
applied to the focused part. By default, this only uses IDENTITY- and CONSTANT- in order to implement the lens operations over, set and
view.

If these conditions are met, (over (data-lens:<>1 lens1 lens2) ...) is equivalent to using lens2 to focus the part lens1 focuses: note that composition is "backwards" from what one might expect: this is
because composition composes the wrapper lambdas and applies the
lambda that actually pulls a value out of a record later.

Package

data-lens.lenses

Source

lens.lisp (file)

Function: pick SELECTOR

Package

data-lens

Source

lens.lisp (file)

Function: regex-match REGEX

Package

data-lens

Source

lens.lisp (file)

Function: set LENS V REC

Given a lens, a value and a rec, immutably update the rec to
contain the new value at the location focused by the lens.

Package

data-lens.lenses

Source

lens.lisp (file)

Function: slice START &optional END

Package

data-lens

Source

lens.lisp (file)

Function: sorted COMPARATOR &rest R &key KEY

Package

data-lens

Source

lens.lisp (file)

Function: splice-elt ELT FUN

Package

data-lens

Source

lens.lisp (file)

Function: transform-elt ELT FUN

Package

data-lens

Source

lens.lisp (file)

Function: transform-head FUN

Package

data-lens

Source

lens.lisp (file)

Function: transform-tail FUN

Package

data-lens

Source

lens.lisp (file)

Function: view LENS REC

Given a lens and a rec, return the focused value

Package

data-lens.lenses

Source

lens.lisp (file)

Function: zipping RESULT-TYPE &key FILL-VALUE

Package

data-lens

Source

lens.lisp (file)