KUTILS

Introduction

This package contains utilities that I find useful in writing programs; that is, it is a collection of generally-useful functions and macros. Some of these I've written, and some of these derive from other sources.

The utilities can be categorised as

• Those from On Lisp,
• Those from Let Over Lambda,
• The hash-table functions,
• Miscellanea

On Lisp

• mkstr: concatenates its symbols and returns the printable representation of the result
• symb: passes its arguments to mkstr to produce a printable representation, and returns the symbol built from this result; if the symbol does not exist, it will be created.
• group: takes a list as input and produces a list of sublists of length n.
• flatten: Returns a list of all atoms present in the provided list.
• compose: allows a number of functions with the same arity to be composed together in a chain.

Let Over Lambda

• defmacro!: provides automatic gensyms and once-only evaluation. Arguments that begin with g! will be automatically gensym'd, and arguments that begin with o! will only be evaluated once. Inside the body, the o! arguments should be called as their equivalent g! argument: o!x should be called in the body as g!x.

hash-table functions

• sethash: convenience function for setting a value in a hash table.
• hashkeys: returns a list of all the keys in a hash table.
• hash-table-to-alist: converts the hash table to an alist of (key . value) pairs.
• alist-to-hash-table: converts an alist to a hash table.
• enable-hash-table-reader: enables the reader macro #{}# for hash tables. The resulting hash-table will use #'equal for equality. For example,

  #{:a :b :c :d}#
  

  will create a hash-table with the keys :a and :c. :a stores the value :b, and :c stores the value :d.

Miscellaneous

• interpose: places a separator between each element of a list.
• build-list: if arg is an atom, return it as a list. If it's a list, return the arg. If it's a vector, coerce it to a list. Otherwise, return nil.
• partial: provides partial function application. It returns a lambda that will call the function given with the intial args and any additional args provided to the lambda.
• macroexpand-n: expand the macro n times.

Quicklisp installation

Clone into your Quicklisp project's local-projects/ subdirectory, and call (ql:quickload :kutils).

Git

You can browse the Github repository.