DOCUMENTATION.markdown @ aaf09c52cad9

Fix hash table pretty printing.  Thanks, CLR.
author Steve Losh <steve@stevelosh.com>
date Fri, 09 Nov 2018 21:23:48 -0500
parents de9d10a9b4b5
children e844dad54ef3
# Documentation for `cl-losh`

This library is my own personal utility belt.

  Everything I write in here is MIT licensed, so you're free to use it if
  you want.  But I make no guarantees about backwards compatibility -- I might
  change and break things at any time.  Use this at your own risk.
  

  [TOC]

## Package `LOSH`

This package exports all of the symbols in the other packages.

  If you just want to get everything you can `:use` this one and be done with
  it.  Otherwise you can `:use` only the ones you need.

  

## Package `LOSH.ARRAYS`

Utilities related to arrays.

### `BISECT-LEFT` (function)

    (BISECT-LEFT PREDICATE VECTOR TARGET)

Bisect `vector` based on `(predicate el target)` and return the LEFT element.

  `vector` must be sorted (with `predicate`) before this function is called
  (this is not checked).

  You can think of this function as partitioning the elements into two halves:
  those that satisfy `(predicate el target)` and those that don't, and then
  selecting the element on the LEFT side of the split:

      satisfying  not statisfying
    #(..........  ...............)
               ^
               |
          result

  Two values will be returned: the element and its index.  If no element
  satisfies the predicate `nil` will be returned for both values.

  Examples:

    ;                 index
    ;              0 1 2 3 4 5          val  index
    (bisect #'<  #(1 3 5 7 7 9) 5) ; =>   3, 1
    (bisect #'<= #(1 3 5 7 7 9) 5) ; =>   5, 2
    (bisect #'<= #(1 3 5 7 7 9) 7) ; =>   7, 4
    (bisect #'<  #(1 3 5 7 7 9) 1) ; => nil, nil
    (bisect #'>  #(9 8 8 8 1 0) 5) ; =>   8, 3

  

### `BISECT-RIGHT` (function)

    (BISECT-RIGHT PREDICATE VECTOR TARGET)

Bisect `vector` based on `(predicate el target)` and return the RIGHT element.

  `vector` must be sorted (with `predicate`) before this function is called
  (this is not checked).

  You can think of this function as partitioning the elements into two halves:
  those that satisfy `(predicate el target)` and those that don't, and then
  selecting the element on the RIGHT side of the split:

      satisfying  not statisfying
    #(..........  ...............)
                  ^
                  |
                  result

  Two values will be returned: the element and its index.  If every element
  satisfies the predicate `nil` will be returned for both values.

  Examples:

    ;                 index
    ;               0 1 2 3 4 5           val  index
    (rbisect #'<  #(1 3 5 7 7 9) 5)  ; =>   5, 2
    (rbisect #'<= #(1 3 5 7 7 9) 5)  ; =>   7, 3
    (rbisect #'<= #(1 3 5 7 7 9) 7)  ; =>   9, 5
    (rbisect #'<  #(1 3 5 7 7 9) 10) ; => nil, nil
    (rbisect #'>  #(9 8 8 8 1 0) 5)  ; =>   1, 4

  

### `DO-ARRAY` (macro)

    (DO-ARRAY (VALUE ARRAY)
      &BODY
      BODY)

Perform `body` once for each element in `array` using `value` for the place.

  `array` can be multidimensional.

  `value` will be `symbol-macrolet`ed to the appropriate `aref`, so you can use
  it as a place if you want.

  Returns the array.

  Example:

    (let ((arr (vector 1 2 3)))
      (do-array (x arr)
        (setf x (1+ x))))
    => #(2 3 4)

  

### `FILL-MULTIDIMENSIONAL-ARRAY` (function)

    (FILL-MULTIDIMENSIONAL-ARRAY ARRAY ITEM)

Fill `array` with `item`.

  Unlike `fill`, this works on multidimensional arrays.  It won't cons on SBCL,
  but it may in other implementations.

  

### `FILL-MULTIDIMENSIONAL-ARRAY-FIXNUM` (function)

    (FILL-MULTIDIMENSIONAL-ARRAY-FIXNUM ARRAY ITEM)

Fill `array` (which must be of type `(array FIXNUM *)`) with `item`.

  Unlike `fill`, this works on multidimensional arrays.  It won't cons on SBCL,
  but it may in other implementations.

  

### `FILL-MULTIDIMENSIONAL-ARRAY-SINGLE-FLOAT` (function)

    (FILL-MULTIDIMENSIONAL-ARRAY-SINGLE-FLOAT ARRAY ITEM)

Fill `array` (which must be of type `(array SINGLE-FLOAT *)`) with `item`.

  Unlike `fill`, this works on multidimensional arrays.  It won't cons on SBCL,
  but it may in other implementations.

  

### `FILL-MULTIDIMENSIONAL-ARRAY-T` (function)

    (FILL-MULTIDIMENSIONAL-ARRAY-T ARRAY ITEM)

Fill `array` (which must be of type `(array T *)`) with `item`.

  Unlike `fill`, this works on multidimensional arrays.  It won't cons on SBCL,
  but it may in other implementations.

  

### `VECTOR-LAST` (function)

    (VECTOR-LAST VECTOR)

Return the last element of `vector`, or `nil` if it is empty.

  A second value is returned, which will be `t` if the vector was not empty and
  `nil` if it was.

  The vector's fill-pointer will be respected.

  

## Package `LOSH.BITS`

Utilities for low-level bit stuff.

### `+/16` (function)

    (+/16 X Y)

Perform 16-bit signed addition of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `+/32` (function)

    (+/32 X Y)

Perform 32-bit signed addition of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `+/64` (function)

    (+/64 X Y)

Perform 64-bit signed addition of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `+/8` (function)

    (+/8 X Y)

Perform 8-bit signed addition of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `-/16` (function)

    (-/16 X Y)

Perform 16-bit signed subtraction of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `-/32` (function)

    (-/32 X Y)

Perform 32-bit signed subtraction of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `-/64` (function)

    (-/64 X Y)

Perform 64-bit signed subtraction of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

### `-/8` (function)

    (-/8 X Y)

Perform 8-bit signed subtraction of `x` and `y`.

  Returns two values: the result and a boolean specifying whether
  underflow/overflow occurred.

  

## Package `LOSH.CHILI-DOGS`

Gotta go FAST.

### `DEFUN-INLINE` (macro)

    (DEFUN-INLINE NAME
      &BODY
      BODY)

Like `defun`, but declaims `name` to be `inline`.

### `DEFUN-INLINEABLE` (macro)

    (DEFUN-INLINEABLE NAME
      &BODY
      BODY)

Like `defun-inline`, but declaims `name` to be `notinline` afterword.

  This is useful when you don't want to inline a function everywhere, but *do*
  want to have the ability to inline it on demand with (declare (inline ...)).

  

## Package `LOSH.CLOS`

Utilities for working with CLOS.

### `DEFCLASS*` (macro)

    (DEFCLASS* NAME-AND-OPTIONS DIRECT-SUPERCLASSES SLOTS &REST OPTIONS)

`defclass` without the tedium.

  This is like `defclass`, but the `:initarg` and `:accessor` slot options will
  automatically be filled in with sane values if they aren't given.

  

## Package `LOSH.CONTROL-FLOW`

Utilities for managing control flow.

### `-<>` (macro)

    (-<> EXPR &REST FORMS)

Thread the given forms, with `<>` as a placeholder.

### `DO-RANGE` (macro)

    (DO-RANGE RANGES
      &BODY
      BODY)

Perform `body` on the given `ranges`.

  Each range in `ranges` should be of the form `(variable from below)`.  During
  iteration `body` will be executed with `variable` bound to successive values
  in the range [`from`, `below`).

  If multiple ranges are given they will be iterated in a nested fashion.

  Example:

    (do-range ((x  0  3)
               (y 10 12))
      (pr x y))
    ; =>
    ; 0 10
    ; 0 11
    ; 1 10
    ; 1 11
    ; 2 10
    ; 2 11

  

### `DO-REPEAT` (macro)

    (DO-REPEAT N
      &BODY
      BODY)

Perform `body` `n` times.

### `GATHERING` (macro)

    (GATHERING
      &BODY
      BODY)

Run `body` to gather some things and return a fresh list of them.

  `body` will be executed with the symbol `gather` bound to a function of one
  argument.  Once `body` has finished, a list of everything `gather` was called
  on will be returned.

  It's handy for pulling results out of code that executes procedurally and
  doesn't return anything, like `maphash` or Alexandria's `map-permutations`.

  The `gather` function can be passed to other functions, but should not be
  retained once the `gathering` form has returned (it would be useless to do so
  anyway).

  Examples:

    (gathering
      (dotimes (i 5)
        (gather i))
    =>
    (0 1 2 3 4)

    (gathering
      (mapc #'gather '(1 2 3))
      (mapc #'gather '(a b)))
    =>
    (1 2 3 a b)

  

### `GATHERING-VECTOR` (macro)

    (GATHERING-VECTOR OPTIONS
      &BODY
      BODY)

Run `body` to gather some things and return a fresh vector of them.

  `body` will be executed with the symbol `gather` bound to a function of one
  argument.  Once `body` has finished, a vector of everything `gather` was
  called on will be returned.  This vector will be adjustable and have a fill
  pointer.

  It's handy for pulling results out of code that executes procedurally and
  doesn't return anything, like `maphash` or Alexandria's `map-permutations`.

  The `gather` function can be passed to other functions, but should not be
  retained once the `gathering` form has returned (it would be useless to do so
  anyway).

  Examples:

    (gathering-vector ()
      (dotimes (i 5)
        (gather i))
    =>
    #(0 1 2 3 4)

    (gathering-vector ()
      (mapc #'gather '(1 2 3))
      (mapc #'gather '(a b)))
    =>
    #(1 2 3 a b)

  

### `IF-FOUND` (macro)

    (IF-FOUND (VAR LOOKUP-EXPR) THEN ELSE)

Perform `then` or `else` depending on the results of `lookup-expr`.

  `lookup-expr` should be an expression that returns two values, the first being
  the result and the second indicating whether the lookup was successful.  The
  standard `gethash` is an example of a function that behaves like this.

  If the lookup was successful, `then` will be executed with `var` bound to the
  result, and its value returned.

  Otherwise `else` will be executed and returned, without any extra bindings.

  Example:

    (multiple-value-bind (val found) (gethash :foo hash)
      (if found
        'yes
        'no))

    ; becomes

    (if-found (val (gethash :foo hash))
      'yes
      'no)

  

### `IF-LET` (macro)

    (IF-LET BINDINGS
      &BODY
      BODY)

Bind `bindings` in parallel and execute `then` if all are true, or `else` otherwise.

  `body` must be of the form `(...optional-declarations... then else)`.

  This macro combines `if` and `let`.  It takes a list of bindings and binds
  them like `let` before executing the `then` branch of `body`, but if any
  binding's value evaluate to `nil` the process stops there and the `else`
  branch is immediately executed (with no bindings in effect).

  If any `optional-declarations` are included they will only be in effect for
  the `then` branch.

  Examples:

    (if-let ((a (progn (print :a) 1))
             (b (progn (print :b) 2))
             (c (progn (print :c) 3)))
      (list a b c)
      'nope)
    ; =>
    :A
    :B
    :C
    (1 2 3)

    (if-let ((a (progn (print :a) 1))
             (b (progn (print :b) nil))
             (c (progn (print :c) 3)))
      (list a b c)
      'nope)
    ; =>
    :A
    :B
    NOPE

  

### `IF-LET*` (macro)

    (IF-LET* BINDINGS
      &BODY
      BODY)

Bind `bindings` sequentially and execute `then` if all are true, or `else` otherwise.

  `body` must be of the form `(...optional-declarations... then else)`.

  This macro combines `if` and `let*`.  It takes a list of bindings and binds
  them like `let*` before executing the `then` branch of `body`, but if any
  binding's value evaluate to `nil` the process stops there and the `else`
  branch is immediately executed (with no bindings in effect).

  If any `optional-declarations` are included they will only be in effect for
  the `then` branch.

  Examples:

    (if-let* ((a (progn (print :a) 1))
              (b (progn (print :b) 2))
              (c (progn (print :c) 3)))
      (list a b c)
      'nope)
    ; =>
    :A
    :B
    :C
    (1 2 3)

    (if-let* ((a (progn (print :a) 1))
              (b (progn (print :b) nil))
              (c (progn (print :c) 3)))
      (list a b c)
      'nope)
    ; =>
    :A
    :B
    NOPE

  

### `MULTIPLE-VALUE-BIND*` (macro)

    (MULTIPLE-VALUE-BIND* BINDINGS
      &BODY
      BODY)

Bind each pair in `bindings` with `multiple-value-bind` sequentially.

  Example:

    (multiple-value-bind*
        (((a b) (values 0 1))
         ((c) (values (1+ b)))
      (list a b c))
    ; =>
    ; (0 1 2)

  From https://github.com/phoe/m-m-v-b

  

### `NEST` (macro)

    (NEST &REST FORMS)

Thread the given forms, putting each as the body of the previous.

  Example:

    (nest (multiple-value-bind (a b c) (foo))
          (when (and a b c))
          (multiple-value-bind (d e f) (bar))
          (when (and d e f))
          (do-something))

  macroexpands to:

    (multiple-value-bind (a b c) (foo)
      (when (and a b c)
        (multiple-value-bind (d e f) (bar)
          (when (and d e f)
            (do-something)))))

  

### `RECURSIVELY` (macro)

    (RECURSIVELY BINDINGS
      &BODY
      BODY)

Execute `body` recursively, like Clojure's `loop`/`recur`.

  `bindings` should contain a list of symbols and (optional) starting values.

  In `body` the symbol `recur` will be bound to the function for recurring.

  This macro doesn't perform an explicit tail-recursion check like Clojure's
  `loop`.  You know what you're doing, right?

  Example:

      (defun length (some-list)
        (recursively ((list some-list)
                      (n 0))
          (if (null list)
            n
            (recur (cdr list) (1+ n)))))

  

### `WHEN-FOUND` (macro)

    (WHEN-FOUND (VAR LOOKUP-EXPR)
      &BODY
      BODY)

Perform `body` with `var` bound to the result of `lookup-expr`, when valid.

  `lookup-expr` should be an expression that returns two values, the first being
  the result (which will be bound to `var`) and the second indicating whether
  the lookup was successful.  The standard `gethash` is an example of a function
  that behaves like this.

  If the lookup was successful, `body` will be executed and its value returned.

  Example:

    (multiple-value-bind (val found) (gethash :foo hash)
      (when found
        body))

    ; becomes

    (when-found (val (gethash :foo hash))
      body)

  

### `WHEN-LET` (macro)

    (WHEN-LET BINDINGS
      &BODY
      BODY)

Bind `bindings` in parallel and execute `body`, short-circuiting on `nil`.

  This macro combines `when` and `let`.  It takes a list of bindings and binds
  them like `let` before executing `body`, but if any binding's value evaluates
  to `nil` the process stops there and `nil` is immediately returned.

  Examples:

    (when-let ((a (progn (print :a) 1))
               (b (progn (print :b) 2))
               (c (progn (print :c) 3)))
      (list a b c))
    ; =>
    :A
    :B
    :C
    (1 2 3)

    (when-let ((a (progn (print :a) 1))
               (b (progn (print :b) nil))
               (c (progn (print :c) 3)))
      (list a b c))
    ; =>
    :A
    :B
    NIL

  

### `WHEN-LET*` (macro)

    (WHEN-LET* BINDINGS
      &BODY
      BODY)

Bind `bindings` sequentially and execute `body`, short-circuiting on `nil`.

  This macro combines `when` and `let*`.  It takes a list of bindings and binds
  them like `let` before executing `body`, but if any binding's value evaluates
  to `nil` the process stops there and `nil` is immediately returned.

  Examples:

    (when-let* ((a (progn (print :a) 1))
                (b (progn (print :b) 2))
                (c (progn (print :c) 3)))
      (list a b c))
    ; =>
    :A
    :B
    :C
    (1 2 3)

    (when-let* ((a (progn (print :a) 1))
                (b (progn (print :b) nil))
                (c (progn (print :c) 3)))
      (list a b c))
    ; =>
    :A
    :B
    NIL

  

## Package `LOSH.DEBUGGING`

Utilities for figuring out what the hell is going on.

### `AESTHETIC-STRING` (function)

    (AESTHETIC-STRING THING)

Return the string used to represent `thing` when printing aesthetically.

### `BITS` (function)

    (BITS &OPTIONAL (N *) (SIZE 8) (STREAM T))

Print the bits of the `size`-bit two's complement integer `n` to `stream`.

  Examples:

    (bits 5 10)
    => 0000000101

    (bits -5 10)
    => 1111111011

  

### `COMMENT` (macro)

    (COMMENT
      &BODY
      BODY)

Do nothing with a bunch of forms.

  Handy for block-commenting multiple expressions.

  

### `DIS` (macro)

    (DIS
      &BODY
      BODY)

Disassemble the code generated for a `lambda` with `arglist` and `body`.

  It will also spew compiler notes so you can see why the garbage box isn't
  doing what you think it should be doing.

  

### `GIMME` (macro)

    (GIMME N
      &BODY
      BODY)

### `HEX` (function)

    (HEX &OPTIONAL (THING *) (STREAM T))

Print the `thing` to `stream` with numbers in base 16.

  Examples:

    (hex 255)
    => FF

    (hex #(0 128))
    => #(0 80)

  

### `PHT` (function)

    (PHT HASH-TABLE &OPTIONAL (STREAM T))

Synonym for `print-hash-table` for less typing at the REPL.

### `PR` (function)

    (PR &REST ARGS)

Print `args` readably, separated by spaces and followed by a newline.

  Returns the first argument, so you can just wrap it around a form without
  interfering with the rest of the program.

  This is what `print` should have been.

  

### `PRINT-HASH-TABLE` (function)

    (PRINT-HASH-TABLE HASH-TABLE &OPTIONAL (STREAM T))

Print a pretty representation of `hash-table` to `stream.`

  Respects `*print-length*` when printing the elements.

  

### `PRINT-HASH-TABLE-CONCISELY` (function)

    (PRINT-HASH-TABLE-CONCISELY HASH-TABLE &OPTIONAL (STREAM T))

Print a concise representation of `hash-table` to `stream.`

  Should respect `*print-length*` when printing the elements.

  

### `PRINT-TABLE` (function)

    (PRINT-TABLE ROWS)

Print `rows` as a nicely-formatted table.

  Each row should have the same number of colums.

  Columns will be justified properly to fit the longest item in each one.

  Example:

    (print-table '((1 :red something)
                   (2 :green more)))
    =>
    1 | RED   | SOMETHING
    2 | GREEN | MORE

  

### `PRL` (macro)

    (PRL &REST ARGS)

Print `args` labeled and readably.

  Each argument form will be printed, then evaluated and the result printed.
  One final newline will be printed after everything.

  Returns the last result.

  Examples:

    (let ((i 1)
          (l (list 1 2 3)))
      (prl i (second l)))
    ; =>
    i 1
    (second l) 2

  

### `PROFILE` (macro)

    (PROFILE
      &BODY
      BODY)

Profile `body` and dump the report to `lisp.prof`.

### `SHUT-UP` (macro)

    (SHUT-UP
      &BODY
      BODY)

Run `body` with stdout and stderr redirected to the void.

### `START-PROFILING` (function)

    (START-PROFILING &KEY CALL-COUNT-PACKAGES (MODE :CPU))

Start profiling performance.  SBCL only.

  `call-count-packages` should be a list of package designators.  Functions in
  these packages will have their call counts recorded via
  `sb-sprof::profile-call-counts`.

  

### `STOP-PROFILING` (function)

    (STOP-PROFILING &OPTIONAL (FILENAME lisp.prof))

Stop profiling performance and dump a report to `filename`.  SBCL only.

### `STRUCTURAL-STRING` (function)

    (STRUCTURAL-STRING THING)

Return the string used to represent `thing` when printing structurally.

## Package `LOSH.ELDRITCH-HORRORS`

Abandon all hope, ye who enter here.

### `DEFINE-WITH-MACRO` (macro)

    (DEFINE-WITH-MACRO TYPE-AND-OPTIONS &REST SLOTS)

Define a with-`type` macro for the given `type` and `slots`.

  This new macro wraps `with-accessors` so you don't have to type `type-`
  a billion times.

  The given `type` must be a symbol naming a struct or class.  It must have the
  appropriate accessors with names exactly of the form `type`-`slot`.

  The defined macro will look something like this:

    (define-with-macro foo a b)
    =>
    (defmacro with-foo ((foo &optional (a-symbol 'a) (b-symbol 'b))
                        &body body)
      `(with-accessors ((,a-symbol foo-a) (,b-symbol foo-b))
           ,foo
         ,@body))

  There's a lot of magic here, but it cuts down on boilerplate for simple things
  quite a lot.

  Example:

    (defstruct foo x y)
    (define-with-macro foo x y)

    (defparameter *f* (make-foo :x 10 :y 20))
    (defparameter *g* (make-foo :x 555 :y 999))

    (with-foo (*f*)
      (with-foo (*g* gx gy)
        (print (list x y gx gy))))
    =>
    (10 20 555 999)

  

### `EVAL-DAMMIT` (macro)

    (EVAL-DAMMIT
      &BODY
      BODY)

Just evaluate `body` all the time, jesus christ lisp.

## Package `LOSH.FUNCTIONS`

Utilities for working with higher-order functions.

## Package `LOSH.GNUPLOT`

Utilities for plotting data with gnuplot.

### `GNUPLOT` (function)

    (GNUPLOT DATA &REST ARGS &KEY (X #'CAR) (Y #'CDR) (SPEW-OUTPUT NIL)
             &ALLOW-OTHER-KEYS)

Plot `data` to `filename` with gnuplot.

  This will (silently) quickload the `external-program` system to handle the
  communication with gnuplot.

  `data` should be a sequence of data points to plot.

  `x` should be a function to pull the x-values from each item in data.

  `y` should be a function to pull the y-values from each item in data.

  See the docstring of `gnuplot-args` for other keyword arguments.

  

### `GNUPLOT-ARGS` (function)

    (GNUPLOT-ARGS &KEY (OUTPUT :QT) (FILENAME plot.png) (STYLE :LINES)
                  (SIZE-X 1200) (SIZE-Y 800) (LABEL-X) (LABEL-Y)
                  (LINE-TITLE 'DATA) (LINE-WIDTH 4) (SMOOTH NIL) (AXIS-X NIL)
                  (AXIS-Y NIL) (MIN-X NIL) (MAX-X NIL) (MIN-Y NIL) (MAX-Y NIL)
                  (TICS-X NIL) (GRAPH-TITLE) (LOGSCALE-X NIL) (LOGSCALE-Y NIL)
                  (BOX-WIDTH NIL) &ALLOW-OTHER-KEYS)

Return the formatted command line arguments for the given gnuplot arguments.

  You shouldn't call this function directly — it's exposed just so you can see
  the list of possible gnuplot arguments all in one place.

  

### `GNUPLOT-EXPR` (macro)

    (GNUPLOT-EXPR EXPR &REST ARGS)

Plot `expr` (an expression involving `x`) with gnuplot.

  See the docstring of `gnuplot-args` for other keyword arguments.

  

### `GNUPLOT-FUNCTION` (function)

    (GNUPLOT-FUNCTION FUNCTION &REST ARGS &KEY (START 0.0) (END 1.0) (STEP 0.1)
                      (INCLUDE-END NIL) &ALLOW-OTHER-KEYS)

Plot `function` over [`start`, `end`) by `step` with gnuplot.

  If `include-end` is `t` the `end` value will also be plotted.

  See the docstring of `gnuplot-args` for other keyword arguments.

  

### `GNUPLOT-HISTOGRAM` (function)

    (GNUPLOT-HISTOGRAM DATA &KEY (BIN-WIDTH 1) SPEW-OUTPUT)

Plot `data` as a histogram with gnuplot.

  `bin-width` should be the desired width of the bins.  The bins will be
  centered on multiples of this number, and data will be rounded to the nearest
  bin.

  

## Package `LOSH.HASH-SETS`

Simple hash set implementation.

### `COPY-HASH-SET` (function)

    (COPY-HASH-SET HSET)

Create a (shallow) copy of the given hash set.

  Only the storage for the hash set itself will be copied -- the elements
  themselves will not be copied.

  

### `HASH-SET` (struct)

Slots: `STORAGE`

### `HSET-CLEAR!` (function)

    (HSET-CLEAR! HSET)

Remove all elements from `hset`.

  Returns nothing.

  

### `HSET-CONTAINS-P` (function)

    (HSET-CONTAINS-P HSET ELEMENT)

Return whether `hset` contains `element`.

### `HSET-COUNT` (function)

    (HSET-COUNT HSET)

Return the number of elements in `hset`.

### `HSET-DIFFERENCE` (function)

    (HSET-DIFFERENCE HSET &REST OTHERS)

Return a fresh hash set containing the difference of the given hash sets.

### `HSET-DIFFERENCE!` (function)

    (HSET-DIFFERENCE! HSET &REST OTHERS)

Destructively update `hset` to contain the difference of itself with `others`.

### `HSET-ELEMENTS` (function)

    (HSET-ELEMENTS HSET)

Return a fresh list containing the elements of `hset`.

### `HSET-EMPTY-P` (function)

    (HSET-EMPTY-P HSET)

Return whether `hset` is empty.

### `HSET-FILTER` (function)

    (HSET-FILTER HSET PREDICATE)

Return a fresh hash set containing elements of `hset` satisfying `predicate`.

### `HSET-FILTER!` (function)

    (HSET-FILTER! HSET PREDICATE)

Destructively update `hset` to contain only elements satisfying `predicate`.

### `HSET-INSERT!` (function)

    (HSET-INSERT! HSET &REST ELEMENTS)

Insert each element in `elements` into `hset`.

  Returns nothing.

  

### `HSET-INTERSECTION` (function)

    (HSET-INTERSECTION HSET &REST OTHERS)

Return a fresh hash set containing the intersection of the given hash sets.

### `HSET-INTERSECTION!` (function)

    (HSET-INTERSECTION! HSET &REST OTHERS)

Destructively update `hset` to contain the intersection of itself with `others`.

### `HSET-MAP` (function)

    (HSET-MAP HSET FUNCTION &KEY NEW-TEST)

Return a fresh hash set containing the results of calling `function` on elements of `hset`.

  If `new-test` is given, the new hash set will use this as its `test`.

  

### `HSET-MAP!` (function)

    (HSET-MAP! HSET FUNCTION &KEY NEW-TEST)

Destructively update `hset` by calling `function` on each element.

   If `new-test` is given the hash set's `test` will be updated.

   

### `HSET-POP!` (function)

    (HSET-POP! HSET)

Remove and return an arbitrarily-chosen element from `hset`.

  An error will be signaled if the hash set is empty.

  

### `HSET-REDUCE` (function)

    (HSET-REDUCE HSET FUNCTION &KEY (INITIAL-VALUE NIL IVP))

Reduce `function` over the elements of `hset`.

  The order in which the elements are processed is undefined.

  

### `HSET-REMOVE!` (function)

    (HSET-REMOVE! HSET &REST ELEMENTS)

Remove each element in `elements` from `hset`.

  If an element is not in `hset`, it will be ignored.

  Returns nothing.

  

### `HSET-UNION` (function)

    (HSET-UNION HSET &REST OTHERS)

Return a fresh hash set containing the union of the given hash sets.

### `HSET-UNION!` (function)

    (HSET-UNION! HSET &REST OTHERS)

Destructively update `hset` to contain the union of itself with `others`.

### `HSET=` (function)

    (HSET= HSET &REST OTHERS)

Return whether all the given hash sets contain exactly the same elements.

  All the hash sets are assumed to use the same `test` -- the consequences are
  undefined if this is not the case.

  

### `MAKE-HASH-SET` (function)

    (MAKE-HASH-SET &KEY (TEST 'EQL) (SIZE 16) (INITIAL-CONTENTS 'NIL))

Create a fresh hash set.

  `size` should be a hint as to how many elements this set is expected to
  contain.

  `initial-contents` should be a sequence of initial elements for the set
  (duplicates are fine).

  

## Package `LOSH.HASH-TABLES`

Utilities for operating on hash tables.

### `HASH-TABLE-CONTENTS` (function)

    (HASH-TABLE-CONTENTS HASH-TABLE)

Return a fresh list of `(key value)` elements of `hash-table`.

### `MUTATE-HASH-VALUES` (function)

    (MUTATE-HASH-VALUES FUNCTION HASH-TABLE)

Replace each value in `hash-table` with the result of calling `function` on it.

  Returns the hash table.

  

## Package `LOSH.IO`

Utilities for input/output/reading/etc.

### `READ-ALL-FROM-FILE` (function)

    (READ-ALL-FROM-FILE PATH)

Read all forms from the file at `path` and return them as a fresh list.

### `READ-ALL-FROM-STRING` (function)

    (READ-ALL-FROM-STRING STRING)

Read all forms from `string` and return them as a fresh list.

## Package `LOSH.ITERATE`

Custom `iterate` drivers and clauses.

### `MACROEXPAND-ITERATE` (function)

    (MACROEXPAND-ITERATE CLAUSE)

Macroexpand the given iterate clause/driver.

  Example:

    (macroexpand-iterate '(averaging (+ x 10) :into avg))
    =>
    (PROGN
     (FOR #:COUNT630 :FROM 1)
     (SUM (+ X 10) :INTO #:TOTAL631)
     (FOR AVG = (/ #:TOTAL631 #:COUNT630)))

  

## Package `LOSH.LISTS`

Utilities for operating on lists.

### `SOMELIST` (function)

    (SOMELIST PREDICATE LIST &REST MORE-LISTS)

Call `predicate` on successive sublists of `list`, returning the first true result.

  `somelist` is to `some` as `maplist` is to `mapcar`.

  

## Package `LOSH.MATH`

Utilities related to math and numbers.

### `1/2TAU` (variable)

### `1/4TAU` (variable)

### `1/8TAU` (variable)

### `2/4TAU` (variable)

### `2/8TAU` (variable)

### `3/4TAU` (variable)

### `3/8TAU` (variable)

### `4/8TAU` (variable)

### `5/8TAU` (variable)

### `6/8TAU` (variable)

### `7/8TAU` (variable)

### `CLAMP` (function)

    (CLAMP FROM TO VALUE)

Clamp `value` between `from` and `to`.

### `DEGREES` (function)

    (DEGREES RADIANS)

Convert `radians` into degrees.

  The result will be the same type as `tau` and `pi`.

  

### `DIGIT` (function)

    (DIGIT POSITION INTEGER &OPTIONAL (BASE 10))

Return the value of the digit at `position` in `integer`.

  Examples:

    (digit 0 135) ; => 5
    (digit 1 135) ; => 3
    (digit 2 135) ; => 1

    (digit 0 #xD4 16) ; => 4
    (digit 1 #xD4 16) ; => 13

  

### `DIVIDESP` (function)

    (DIVIDESP N DIVISOR)

Return whether `n` is evenly divisible by `divisor`.

  The value returned will be the quotient when true, `nil` otherwise.

  

### `IN-RANGE-P` (function)

    (IN-RANGE-P LOW VALUE HIGH)

Return whether `low` <= `value` < `high`.

### `LERP` (function)

    (LERP FROM TO N)

Lerp together `from` and `to` by factor `n`.

  You might want `precise-lerp` instead.

  

### `MAP-RANGE` (function)

    (MAP-RANGE SOURCE-FROM SOURCE-TO DEST-FROM DEST-TO SOURCE-VAL)

Map `source-val` from the source range to the destination range.

  Example:

    ;          source    dest        value
    (map-range 0.0 1.0   10.0 20.0   0.2)
    => 12.0

  

### `NORM` (function)

    (NORM MIN MAX VAL)

Normalize `val` to a number between `0` and `1` (maybe).

  If `val` is between `max` and `min`, the result will be a number between `0`
  and `1`.

  If `val` lies outside of the range, it'll be still be scaled and will end up
  outside the 0/1 range.

  

### `PRECISE-LERP` (function)

    (PRECISE-LERP FROM TO N)

Lerp together `from` and `to` by factor `n`, precisely.

  Vanilla lerp does not guarantee `(lerp from to 0.0)` will return exactly
  `from` due to floating-point errors.  This version will return exactly `from`
  when given a `n` of `0.0`, at the cost of an extra multiplication.

  

### `RADIANS` (function)

    (RADIANS DEGREES)

Convert `degrees` into radians.

  The result will be the same type as `tau` and `pi`.

  

### `SQUARE` (function)

    (SQUARE X)

### `TAU` (variable)

### `TAU/2` (variable)

### `TAU/4` (variable)

### `TAU/8` (variable)

## Package `LOSH.MUTATION`

Utilities for mutating places in-place.

### `CALLF` (macro)

    (CALLF &REST PLACE-FUNCTION-PAIRS)

Set each `place` to the result of calling `function` on its current value.

  Examples:

    (let ((x 10) (y 20))
      (callf x #'1-
             y #'1+)
      (list x y))
    =>
    (9 21)
  

### `CLAMPF` (macro)

    (CLAMPF PLACE FROM TO)

Clamp `place` between `from` and `to` in-place.

### `DIVF` (macro)

    (DIVF PLACE &OPTIONAL DIVISOR)

Divide `place` by `divisor` in-place.

  If `divisor` is not given, `place` will be set to `(/ 1 place)`.

  

### `MODF` (macro)

    (MODF PLACE DIVISOR)

Modulo `place` by `divisor` in-place.

### `MULF` (macro)

    (MULF PLACE FACTOR)

Multiply `place` by `factor` in-place.

### `NEGATEF` (macro)

    (NEGATEF PLACE)

Negate the value of `place`.

### `NOTF` (macro)

    (NOTF PLACE)

Set `place` to `(not place)` in-place.

### `REMAINDERF` (macro)

    (REMAINDERF PLACE DIVISOR)

Remainder `place` by `divisor` in-place.

### `ZAPF` (macro)

    (ZAPF &REST PLACE-EXPR-PAIRS)

Update each `place` by evaluating `expr` with `%` bound to the current value.

  `zapf` works like `setf`, but when evaluating the value expressions the symbol
  `%` will be bound to the current value of the place.

  Examples:

    (zapf foo (1+ %)
          (car bar) (if (> % 10) :a :b))

  

## Package `LOSH.PRIORITY-QUEUES`

Jankass priority queue implementation.

### `MAKE-PRIORITY-QUEUE` (function)

    (MAKE-PRIORITY-QUEUE &KEY (PRIORITY-PREDICATE #'<) (ELEMENT-TEST #'EQL))

Create and return a fresh priority queue.

  `priority-predicate` is the comparison function used to compare priorities,
  and should be a `<`-like predicate.

  `element-test` should be the equality predicate for elements.

  

### `PQ-DEQUEUE` (function)

    (PQ-DEQUEUE PQ)

Remove and return the element in `pq` with the lowest-numbered priority.

  If `pq` is empty `nil` will be returned.

  A second value is also returned, which will be `t` if an element was present
  or `nil` if the priority queue was empty.

  

### `PQ-ENSURE` (function)

    (PQ-ENSURE PQ ELEMENT PRIORITY)

Ensure `element` is in `pq` with `priority`.

  If `element` is already in `pq` its priority will be set to `priority`.
  Otherwise it will be inserted as if by calling `pq-insert`.

  Returns `pq` (which may have been modified).

  

### `PQ-INSERT` (function)

    (PQ-INSERT PQ ELEMENT PRIORITY)

Insert `element` into `pq` with `priority`.

  Returns `pq` (which has been modified).

  

### `PRIORITY-QUEUE` (struct)

Slots: `CONTENTS`, `PREDICATE`, `TEST`

## Package `LOSH.QUEUES`

A simple queue implementation.

### `DEQUEUE` (function)

    (DEQUEUE QUEUE)

Dequeue an item from `queue` and return it.

### `ENQUEUE` (function)

    (ENQUEUE ITEM QUEUE)

Enqueue `item` in `queue`, returning the new size of the queue.

### `MAKE-QUEUE` (function)

    (MAKE-QUEUE)

Allocate and return a fresh queue.

### `QUEUE` (struct)

Slots: `CONTENTS`, `LAST`, `SIZE`

### `QUEUE-APPEND` (function)

    (QUEUE-APPEND QUEUE LIST)

Enqueue each element of `list` in `queue` and return the queue's final size.

### `QUEUE-CONTENTS` (function)

    (QUEUE-CONTENTS VALUE INSTANCE)

### `QUEUE-EMPTY-P` (function)

    (QUEUE-EMPTY-P QUEUE)

Return whether `queue` is empty.

### `QUEUE-SIZE` (function)

    (QUEUE-SIZE VALUE INSTANCE)

## Package `LOSH.RANDOM`

Utilities related to randomness.

### `D` (function)

    (D N SIDES &OPTIONAL (PLUS 0))

Roll some dice.

  Examples:

    (d 1 4)     ; rolls 1d4
    (d 2 8)     ; rolls 2d8
    (d 1 10 -1) ; rolls 1d10-1

  

### `RANDOM-AROUND` (function)

    (RANDOM-AROUND VALUE SPREAD &OPTIONAL (GENERATOR #'RANDOM))

Return a random number within `spread` of `value` (inclusive).

### `RANDOM-ELT` (function)

    (RANDOM-ELT SEQ &OPTIONAL (GENERATOR #'RANDOM))

Return a random element of `seq`, and whether one was available.

  This will NOT be efficient for lists.

  Examples:

    (random-elt #(1 2 3))
    => 1
       T

    (random-elt nil)
    => nil
       nil

  

### `RANDOM-GAUSSIAN` (function)

    (RANDOM-GAUSSIAN MEAN STANDARD-DEVIATION &OPTIONAL (GENERATOR #'RANDOM))

Return a random float from a gaussian distribution.  NOT THREAD-SAFE (yet)!

### `RANDOM-GAUSSIAN-INTEGER` (function)

    (RANDOM-GAUSSIAN-INTEGER MEAN STANDARD-DEVIATION &OPTIONAL
                             (GENERATOR #'RANDOM))

Return a random integer from a gaussian distribution.  NOT THREAD-SAFE (yet)!

### `RANDOM-RANGE` (function)

    (RANDOM-RANGE MIN MAX &OPTIONAL (GENERATOR #'RANDOM))

Return a random number in [`min`, `max`).

### `RANDOM-RANGE-EXCLUSIVE` (function)

    (RANDOM-RANGE-EXCLUSIVE MIN MAX &OPTIONAL (GENERATOR #'RANDOM))

Return a random number in (`min`, `max`).

### `RANDOM-RANGE-INCLUSIVE` (function)

    (RANDOM-RANGE-INCLUSIVE MIN MAX &OPTIONAL (GENERATOR #'RANDOM))

Return a random number in [`min`, `max`].

### `RANDOMP` (function)

    (RANDOMP &OPTIONAL (CHANCE 0.5) (GENERATOR #'RANDOM))

Return a random boolean with `chance` probability of `t`.

## Package `LOSH.SEQUENCES`

Utilities for operating on sequences.

### `DOSEQ` (macro)

    (DOSEQ (VAR SEQUENCE)
      &BODY
      BODY)

Perform `body` with `var` bound to each element in `sequence` in turn.

  It's like `cl:dolist`, but for all sequences.

  

### `DROP` (function)

    (DROP N SEQ)

Return a fresh copy of the `seq` without the first `n` elements.

  The result will be of the same type as `seq`.

  If `seq` is shorter than `n` an empty sequence will be returned.

  Example:

    (drop 2 '(a b c))
    => (c)

    (drop 4 #(1))
    => #()

  From Serapeum.

  

### `DROP-WHILE` (function)

    (DROP-WHILE PREDICATE SEQ)

Drop elements from `seq` as long as `predicate` remains true.

  The result will be a fresh sequence of the same type as `seq`.

  Example:

    (drop-while #'evenp '(2 4 5 6 7 8))
    ; => (5 6 7 8)

    (drop-while #'evenp #(2))
    ; => #(2)

  

### `ENUMERATE` (function)

    (ENUMERATE SEQUENCE &KEY (START 0) (STEP 1) KEY)

Return an alist of `(n . element)` for each element of `sequence`.

  `start` and `step` control the values generated for `n`, NOT which elements of
  the sequence are enumerated.

  Examples:

    (enumerate '(a b c))
    ; => ((0 . A) (1 . B) (2 . C))

    (enumerate '(a b c) :start 1)
    ; => ((1 . A) (2 . B) (3 . C))

    (enumerate '(a b c) :key #'ensure-keyword)
    ; => ((0 . :A) (1 . :B) (2 . :C))

  

### `EXTREMA` (function)

    (EXTREMA PREDICATE SEQUENCE)

Return the smallest and largest elements of `sequence` according to `predicate`.

  `predicate` should be a strict ordering predicate (e.g. `<`).

  Returns the smallest and largest elements in the sequence as two values,
  respectively.

  

### `FREQUENCIES` (function)

    (FREQUENCIES SEQUENCE &KEY (TEST 'EQL))

Return a hash table containing the frequencies of the items in `sequence`.

  Uses `test` for the `:test` of the hash table.

  Example:

    (frequencies '(foo foo bar))
    => {foo 2
        bar 1}

  

### `GROUP-BY` (function)

    (GROUP-BY FUNCTION SEQUENCE &KEY (TEST #'EQL) (KEY #'IDENTITY))

Return a hash table of the elements of `sequence` grouped by `function`.

  This function groups the elements of `sequence` into buckets.  The bucket for
  an element is determined by calling `function` on it.

  The result is a hash table (with test `test`) whose keys are the bucket
  identifiers and whose values are lists of the elements in each bucket.  The
  order of these lists is unspecified.

  If `key` is given it will be called on each element before passing it to
  `function` to produce the bucket identifier.  This does not effect what is
  stored in the lists.

  Examples:

    (defparameter *items* '((1 foo) (1 bar) (2 cats) (3 cats)))

    (group-by #'first *items*)
    ; => { 1 ((1 foo) (1 bar))
    ;      2 ((2 cats))
    ;      3 ((3 cats)) }

    (group-by #'second *items*)
    ; => { foo  ((1 foo))
    ;      bar  ((1 bar))
    ;      cats ((2 cats) (3 cats)) }

    (group-by #'evenp *items* :key #'first)
    ; => { t   ((2 cats))
    ;      nil ((1 foo) (1 bar) (3 cats)) }

  

### `PREFIX-SUMS` (function)

    (PREFIX-SUMS SEQUENCE)

Return a list of the prefix sums of the numbers in `sequence`.

  Example:

    (prefix-sums '(10 10 10 0 1))
    => (10 20 30 30 31)

  

### `PRODUCT` (function)

    (PRODUCT SEQUENCE &KEY KEY)

Return the product of all elements of `sequence`.

  If `key` is given, it will be called on each element to compute the
  multiplicand.

  Examples:

    (product #(1 2 3))
    ; => 6

    (product '("1" "2" "3") :key #'parse-integer)
    ; => 6

    (product '("1" "2" "3") :key #'length)
    ; => 1

  

### `PROPORTIONS` (function)

    (PROPORTIONS SEQUENCE &KEY (TEST 'EQL) (FLOAT T))

Return a hash table containing the proportions of the items in `sequence`.

  Uses `test` for the `:test` of the hash table.

  If `float` is `t` the hash table values will be coerced to floats, otherwise
  they will be left as rationals.

  Example:

    (proportions '(foo foo bar))
    => {foo 0.66666
        bar 0.33333}

    (proportions '(foo foo bar) :float nil)
    => {foo 2/3
        bar 1/3}

  

### `SUMMATION` (function)

    (SUMMATION SEQUENCE &KEY KEY)

Return the sum of all elements of `sequence`.

  If `key` is given, it will be called on each element to compute the addend.

  This function's ugly name was chosen so it wouldn't clash with iterate's `sum`
  symbol.  Sorry.

  Examples:

    (sum #(1 2 3))
    ; => 6

    (sum '("1" "2" "3") :key #'parse-integer)
    ; => 6

    (sum '("1" "2" "3") :key #'length)
    ; => 3

  

### `TAKE` (function)

    (TAKE N SEQ)

Return a fresh sequence of the first `n` elements of `seq`.

  The result will be of the same type as `seq`.

  If `seq` is shorter than `n` a shorter result will be returned.

  Example:

    (take 2 '(a b c))
    => (a b)

    (take 4 #(1))
    => #(1)

  From Serapeum.

  

### `TAKE-WHILE` (function)

    (TAKE-WHILE PREDICATE SEQ)

Take elements from `seq` as long as `predicate` remains true.

  The result will be a fresh sequence of the same type as `seq`.

  Example:

    (take-while #'evenp '(2 4 5 6 7 8))
    ; => (2 4)

    (take-while #'evenp #(1))
    ; => #()

  

## Package `LOSH.WEIGHTLISTS`

A simple data structure for choosing random items with weighted probabilities.

### `MAKE-WEIGHTLIST` (function)

    (MAKE-WEIGHTLIST WEIGHTS-AND-ITEMS)

Make a weightlist of the given items and weights.

  `weights-and-items` should be an alist of `(weight . item)` pairs.

  Weights can be any `real` numbers.  Weights of zero are fine, as long as at
  least one of the weights is nonzero (otherwise there's nothing to choose).

  

### `WEIGHTLIST` (struct)

Slots: `WEIGHTS`, `SUMS`, `ITEMS`, `TOTAL`

### `WEIGHTLIST-ITEMS` (function)

    (WEIGHTLIST-ITEMS VALUE INSTANCE)

### `WEIGHTLIST-RANDOM` (function)

    (WEIGHTLIST-RANDOM WEIGHTLIST)

Return a random item from the weightlist, taking the weights into account.

### `WEIGHTLIST-WEIGHTS` (function)

    (WEIGHTLIST-WEIGHTS VALUE INSTANCE)