65 lines
3.4 KiB
Markdown
65 lines
3.4 KiB
Markdown
# A Javascript<sup>1</sup> implementation of Lisp-like cons(), using vectors
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<sup>1</sup>Technically, Coffeescript, but it's just Javascript.
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## Purpose
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I kinda got tired of my broken list implementations that I was working
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with in each and every variant of Lisp I wrote while working my way
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through List In Small Pieces, so I decided to break it out into its own
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managed repo.
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## API
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A cons is a singly-link list consisting of *pairs*, two-position
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objects. In a true cons *list*, the leftmost cell (the "car")
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contains a data object of interest, and the rightmost cell (the "cdr")
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contains a pointer to the next pair. Cons lists traditionally end
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with a cdr object pointing to an empty list. The following functions
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are provided to create, identify, traverse, and modify cons lists.
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* `nil `: An empty list, used as a static sentinel
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* `cons() `: Construct an empty list
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* `cons(obj)`: Create a new list of one object
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* `cons(obj, lst)`: Append an object to the head of an existing list
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* `car(lst)`: Return the contents of the current cell, or nil.
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* `cdr(lst)`: Return a reference to the next item in the list, or nil.
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* `nilp(lst)`: (Boolean) is list an empty list?
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* `pairp(obj)`: (Boolean) is this a object a pair?
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* `listp(obj)`: (Boolean) is this object a list?
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* `list(a, b, ...)`: Construct a list out of the arguments
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* `vectorToList(v)`: Return a cons list given a vector. Recursive: if a vector is encountered inside v, it will be converted to a cons list.
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* `listToVector(l)`: Return a vector given a cons list. Recursive: if car(l) is itself a cons list, the returned vector will contain an internal vector at that position.
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* `setcar(obj, l)`: Replace the contents of car(l) with obj
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* `setcdr(obj, l)`: Replace the contents of cdr(l) with obj
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* `cadr(lst), cddr(lst), cdar(lst), caar(lst), caddr(lst), cdddr(lst), cadar(lst), cddar(lst), caadr(lst), cdadr(lst)`: Common lisp functions that extend standard list addressing.
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* `metacadr(string)`: For more complex addressing, metacadr() can be
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provided with a string that describes the address desired, and returns
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the qualifying function. For example, this library does not provide
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caddddr(), but it can easily be generated: metacadr("caddddr") will
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return a function to get the data content of the fifth cell.
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## LICENSE AND COPYRIGHT NOTICE: NO WARRANTY GRANTED OR IMPLIED
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Copyright (c) 2015 Elf M. Sternberg
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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- Elf M. Sternberg <elf@pendorwright.com>
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