3.3 KiB
This library contains a javascript implementation of Lisp-like cons(), using vectors
Purpose
I kinda got tired of my broken list implementations that I was working with in each and every variant of Lisp I wrote while working my way through List In Small Pieces, so I decided to break it out into its own managed repo.
API
A cons is a singly-link list consisting of cells, two-position objects. In a true cons list, the leftmost cell (the "car") contains a data object of interest, and the rightmost cell (the "cdr") contains a pointer to the next cell. (A cell in which the second object is not a pointer to the next cell is called a pair.) Cons lists traditionally end with a cdr object pointing to an empty list. The following functions are provided to create, identify, traverse, and modify cons lists.
nil: An empty list, used as a static sentinel
cons(): Construct an empty list
cons(obj): Create a new list of one object
cons(obj, lst): Append an object to the head of an existing list
car(lst): Return the contents of the current cell, or nil.
cdr(lst): Return a reference to the next item in the list, or nil.
nilp(lst): (Boolean) is list an empty list?
pairp(lst): (Boolean) is this a cell object?
listp(lst): (Boolean) si this a list object?
list:(a, b, ...): Construct a list out of the arguments
vectorToList(v): Return a cons list from a vector. Recursive: if a vector is encountered inside v, it will be converted to a cons list.
listToVector(l): Return a vector given a cons list. Recursive: if car(l) is a vector, the return list will contain a list at that position.
setcar(obj, l): Replace the contents of car(l) with obj
setcdr(obj, l): Replace the contents of cdr(l) with obj
cadr, cddr, cdar, caar, caddr, cdddr, cadar, cddar, caadr, cdadr: Common lisp functions that extend standard list addressing.
metacadr(string): For more complex addressing, metacadr() can be provided with a string that describes the address desired, and returns the qualifying function. For example, this library does not provide caddddr(), but it can easily be generated: metacadr("caddddr") will return a function to get the data content of the fifth cell.
LICENSE AND COPYRIGHT NOTICE: NO WARRANTY GRANTED OR IMPLIED
Copyright (c) 2015 Elf M. Sternberg
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- Elf M. Sternberg elf@pendorwright.com