Trivial Utilities Manual

[in package TRIVIAL-UTILITIES]

Description

A collection of useful types, functions and macros.

Installing trivial-utilities

This project is available in the latest QuickLisp distribution, so installing it is reduced to calling:

(ql:quickload :trivial-utilities)

But if you want access to the latest updates, install it by cloning the Git repository with

cd $HOME/quicklisp/local-projects
git clone https://gitlab.com/ediethelm/trivial-utilities.git

and then loading it as usual via QuickLisp as above.

Commonly used types

• [type] NEGATIVE-FIXNUM

  Defines all negative integer types upto and including -1.

• [type] NON-POSITIVE-FIXNUM

  Defines all non-positive integer types upto and including 0.

• [type] NON-NEGATIVE-FIXNUM

  Defines all non-negative integer types starting from and including 0.

• [type] POSITIVE-FIXNUM

  Defines all positive integer types starting from and including 1.

From Graham's On Lisp

• [macro] AIF TEST THEN &OPTIONAL ELSE

  Similar to the normal IF, but binds the result of TEST via LET to IT.

• [macro] AWHEN TEST &BODY THEN

  Similar to the normal WHEN, but binds the result of TEST via LET to IT.

• [macro] AUNLESS TEST &BODY ELSE

  Similar to the normal UNLESS, but binds the result of TEST via LET to IT.

• [macro] APROG1 FIRST &BODY BODY

  Similar to the normal PROG1, but binds the result of FIRST via LET to IT and returns IT.

• [macro] BLAMBDA PARMS &BODY BODY

  Similar to LAMBDA, but defines an unnamed BLOCK from which one can RETURN.

• [macro] ALAMBDA PARMS &BODY BODY

  Similar to LAMBDA, but defines SELF via LABELS which contains the BODY. SELF can be referenced in BODY.

• [generic-function] FLATTEN OBJ

  Flattens the structure of an object.

  An implementation for LISTs already exists. Add specific implementations for special objects.

• [method] FLATTEN OBJ

  Returns a list with the flatten contents of the LIST OBJ.

• [function] MKSTR &REST ARGS

  Creates a string out of all elements in ARGS. Each element must be printable per PRINC.

• [function] SYMB &REST ARGS

  Creates a new and internalized SYMBOL, named by applying MKSTR to ARGS.

• [function] SINGLE LST

  Predicate verifying that LST is a list containing exactly one element.

• [function] MKLIST OBJ

  Returns a new list containing OBJ, or OBJ itself if it is already a list.

From Seibel's Practical Common Lisp

• [macro] ONCE-ONLY (&REST NAMES) &BODY BODY

  Protects against multiple evaluation of NAMES during macro-expansion. Usualy used inside of other macros.

Other useful stuff

• [function] PARTITION PRED SEQ

  Separates the contents of SEQ into two lists, depending on the result of PRED when applied to each element of SEQ.

Example usage of PARTITION

(partition #'evenp '(1 2 3 4 5 6))
((2 4 6) (1 3 5))

• [function] DEMULTIPLEX INPUT &OPTIONAL (BINDINGS NIL)

  Given a LIST of LISTs returns all combinations of the elements in each of the LISTs in INPUT.

Example output for DEMULTIPLEX

(demultiplex '((a b c) (x) (1 2)))
=> ((A X 1) (A X 2) (B X 1) (B X 2) (C X 1) (C X 2))

• [function] MERGE-LAMBDA-LISTS &REST LISTS

  Given two lambda lists, return one representing the unification of both.

• [generic-function] EQUALS OBJ1 OBJ2 &KEY &ALLOW-OTHER-KEYS

  A generic equality comparison function.

• [method] EQUALS OBJ1 OBJ2

  Default method if all other cases fail. Uses cl:equal for comparison.

• [method] EQUALS (OBJ1 NULL) (OBJ2 NULL)

  Equality comparison of two NULL symbols always results in NIL.

• [method] EQUALS (OBJ1 LIST) (OBJ2 LIST)

  Equality comparison of two LISTs requires both to have the same length and each element to be equaly comparable (EQUALS).

• [method] EQUALS (OBJ1 STRING) (OBJ2 STRING)

  Equality comparison of two STRINGs falls back to string=.

• [generic-function] CLONE OBJ &KEY &ALLOW-OTHER-KEYS

  A generic function to clone objects.

• [function] ALL-SLOTS CLASS

  Create a list containing all slots defined for class, including slots defined (recursively) in all superclasses.

• [function] COLLECT-PERSISTENT-SLOTS INSTANCE &KEY SLOTS-TO-IGNORE

  Any slot which defines :initarg, is bound to a value and is not listed in slots-to-ignore will be appended in the form (initarg value).

• [macro] EXTRACT-ADDITIONAL-KEYS (KEYS ARGS) &BODY BODY

  Convenience macro to extract keywords including default values from a plist, such as (:a 1 :b 2 :c 3). Usually used in conjunction with (&rest keys &key &allow-other-keys).
  KEYS - The keys to be extracted. This follows the syntax of let. Example: ((a nil) b (c t c-was-in-args-p))
  ARGS - A property list of keyword-value pairs
  BODY - Code to be executed and which uses the extracted keys.

License Information

This library is released under the MIT License. Please refer to the LICENSE to get the full licensing text.

Contributing to this project

Please refer to the CONTRIBUTING document for more information.