vendor/quickutils.lisp @ cd5ecc8e47cd

Generalize the story generator to arbitrary data
author Steve Losh <steve@stevelosh.com>
date Mon, 09 Jan 2017 18:35:14 +0000
parents 5cace362d318
children 4add15d40994
;;;; This file was automatically generated by Quickutil.
;;;; See http://quickutil.org for details.

;;;; To regenerate:
;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:COMPOSE :COPY-ARRAY :CURRY :DEFINE-CONSTANT :ENSURE-BOOLEAN :ENSURE-GETHASH :ENSURE-LIST :EXTREMUM :FLIP :HASH-TABLE-ALIST :HASH-TABLE-KEYS :HASH-TABLE-PLIST :HASH-TABLE-VALUES :IOTA :N-GRAMS :ONCE-ONLY :RANGE :RCURRY :READ-FILE-INTO-STRING :REQUIRED-ARGUMENT :RIFFLE :SEPARATED-STRING-APPEND :SUBDIVIDE :SYMB :TREE-COLLECT :WITH-GENSYMS) :ensure-package T :package "SAND.QUICKUTILS")

(eval-when (:compile-toplevel :load-toplevel :execute)
  (unless (find-package "SAND.QUICKUTILS")
    (defpackage "SAND.QUICKUTILS"
      (:documentation "Package that contains Quickutil utility functions.")
      (:use #:cl))))

(in-package "SAND.QUICKUTILS")

(when (boundp '*utilities*)
  (setf *utilities* (union *utilities* '(:MAKE-GENSYM-LIST :ENSURE-FUNCTION
                                         :COMPOSE :COPY-ARRAY :CURRY
                                         :DEFINE-CONSTANT :ENSURE-BOOLEAN
                                         :ENSURE-GETHASH :ENSURE-LIST :EXTREMUM
                                         :FLIP :HASH-TABLE-ALIST :MAPHASH-KEYS
                                         :HASH-TABLE-KEYS :HASH-TABLE-PLIST
                                         :MAPHASH-VALUES :HASH-TABLE-VALUES
                                         :IOTA :TAKE :N-GRAMS :ONCE-ONLY :RANGE
                                         :RCURRY :WITH-OPEN-FILE*
                                         :WITH-INPUT-FROM-FILE
                                         :READ-FILE-INTO-STRING
                                         :REQUIRED-ARGUMENT :RIFFLE
                                         :SEPARATED-STRING-APPEND :SUBDIVIDE
                                         :MKSTR :SYMB :TREE-COLLECT
                                         :STRING-DESIGNATOR :WITH-GENSYMS))))
(eval-when (:compile-toplevel :load-toplevel :execute)
  (defun make-gensym-list (length &optional (x "G"))
    "Returns a list of `length` gensyms, each generated as if with a call to `make-gensym`,
using the second (optional, defaulting to `\"G\"`) argument."
    (let ((g (if (typep x '(integer 0)) x (string x))))
      (loop repeat length
            collect (gensym g))))
  )                                        ; eval-when
(eval-when (:compile-toplevel :load-toplevel :execute)
  ;;; To propagate return type and allow the compiler to eliminate the IF when
  ;;; it is known if the argument is function or not.
  (declaim (inline ensure-function))

  (declaim (ftype (function (t) (values function &optional))
                  ensure-function))
  (defun ensure-function (function-designator)
    "Returns the function designated by `function-designator`:
if `function-designator` is a function, it is returned, otherwise
it must be a function name and its `fdefinition` is returned."
    (if (functionp function-designator)
        function-designator
        (fdefinition function-designator)))
  )                                        ; eval-when

  (defun compose (function &rest more-functions)
    "Returns a function composed of `function` and `more-functions` that applies its ;
arguments to to each in turn, starting from the rightmost of `more-functions`,
and then calling the next one with the primary value of the last."
    (declare (optimize (speed 3) (safety 1) (debug 1)))
    (reduce (lambda (f g)
              (let ((f (ensure-function f))
                    (g (ensure-function g)))
                (lambda (&rest arguments)
                  (declare (dynamic-extent arguments))
                  (funcall f (apply g arguments)))))
            more-functions
            :initial-value function))

  (define-compiler-macro compose (function &rest more-functions)
    (labels ((compose-1 (funs)
               (if (cdr funs)
                   `(funcall ,(car funs) ,(compose-1 (cdr funs)))
                   `(apply ,(car funs) arguments))))
      (let* ((args (cons function more-functions))
             (funs (make-gensym-list (length args) "COMPOSE")))
        `(let ,(loop for f in funs for arg in args
                     collect `(,f (ensure-function ,arg)))
           (declare (optimize (speed 3) (safety 1) (debug 1)))
           (lambda (&rest arguments)
             (declare (dynamic-extent arguments))
             ,(compose-1 funs))))))
  

  (defun copy-array (array &key (element-type (array-element-type array))
                                (fill-pointer (and (array-has-fill-pointer-p array)
                                                   (fill-pointer array)))
                                (adjustable (adjustable-array-p array)))
    "Returns an undisplaced copy of `array`, with same `fill-pointer` and
adjustability (if any) as the original, unless overridden by the keyword
arguments."
    (let* ((dimensions (array-dimensions array))
           (new-array (make-array dimensions
                                  :element-type element-type
                                  :adjustable adjustable
                                  :fill-pointer fill-pointer)))
      (dotimes (i (array-total-size array))
        (setf (row-major-aref new-array i)
              (row-major-aref array i)))
      new-array))
  

  (defun curry (function &rest arguments)
    "Returns a function that applies `arguments` and the arguments
it is called with to `function`."
    (declare (optimize (speed 3) (safety 1) (debug 1)))
    (let ((fn (ensure-function function)))
      (lambda (&rest more)
        (declare (dynamic-extent more))
        ;; Using M-V-C we don't need to append the arguments.
        (multiple-value-call fn (values-list arguments) (values-list more)))))

  (define-compiler-macro curry (function &rest arguments)
    (let ((curries (make-gensym-list (length arguments) "CURRY"))
          (fun (gensym "FUN")))
      `(let ((,fun (ensure-function ,function))
             ,@(mapcar #'list curries arguments))
         (declare (optimize (speed 3) (safety 1) (debug 1)))
         (lambda (&rest more)
           (apply ,fun ,@curries more)))))
  

  (defun %reevaluate-constant (name value test)
    (if (not (boundp name))
        value
        (let ((old (symbol-value name))
              (new value))
          (if (not (constantp name))
              (prog1 new
                (cerror "Try to redefine the variable as a constant."
                        "~@<~S is an already bound non-constant variable ~
                       whose value is ~S.~:@>" name old))
              (if (funcall test old new)
                  old
                  (restart-case
                      (error "~@<~S is an already defined constant whose value ~
                              ~S is not equal to the provided initial value ~S ~
                              under ~S.~:@>" name old new test)
                    (ignore ()
                      :report "Retain the current value."
                      old)
                    (continue ()
                      :report "Try to redefine the constant."
                      new)))))))

  (defmacro define-constant (name initial-value &key (test ''eql) documentation)
    "Ensures that the global variable named by `name` is a constant with a value
that is equal under `test` to the result of evaluating `initial-value`. `test` is a
function designator that defaults to `eql`. If `documentation` is given, it
becomes the documentation string of the constant.

Signals an error if `name` is already a bound non-constant variable.

Signals an error if `name` is already a constant variable whose value is not
equal under `test` to result of evaluating `initial-value`."
    `(defconstant ,name (%reevaluate-constant ',name ,initial-value ,test)
       ,@(when documentation `(,documentation))))
  

  (defun ensure-boolean (x)
    "Convert `x` into a Boolean value."
    (and x t))
  

  (defmacro ensure-gethash (key hash-table &optional default)
    "Like `gethash`, but if `key` is not found in the `hash-table` saves the `default`
under key before returning it. Secondary return value is true if key was
already in the table."
    `(multiple-value-bind (value ok) (gethash ,key ,hash-table)
       (if ok
           (values value ok)
           (values (setf (gethash ,key ,hash-table) ,default) nil))))
  

  (defun ensure-list (list)
    "If `list` is a list, it is returned. Otherwise returns the list designated by `list`."
    (if (listp list)
        list
        (list list)))
  

  (defun extremum (sequence predicate &key key (start 0) end)
    "Returns the element of `sequence` that would appear first if the subsequence
bounded by `start` and `end` was sorted using `predicate` and `key`.

`extremum` determines the relationship between two elements of `sequence` by using
the `predicate` function. `predicate` should return true if and only if the first
argument is strictly less than the second one (in some appropriate sense). Two
arguments `x` and `y` are considered to be equal if `(funcall predicate x y)`
and `(funcall predicate y x)` are both false.

The arguments to the `predicate` function are computed from elements of `sequence`
using the `key` function, if supplied. If `key` is not supplied or is `nil`, the
sequence element itself is used.

If `sequence` is empty, `nil` is returned."
    (let* ((pred-fun (ensure-function predicate))
           (key-fun (unless (or (not key) (eq key 'identity) (eq key #'identity))
                      (ensure-function key)))
           (real-end (or end (length sequence))))
      (cond ((> real-end start)
             (if key-fun
                 (flet ((reduce-keys (a b)
                          (if (funcall pred-fun
                                       (funcall key-fun a)
                                       (funcall key-fun b))
                              a
                              b)))
                   (declare (dynamic-extent #'reduce-keys))
                   (reduce #'reduce-keys sequence :start start :end real-end))
                 (flet ((reduce-elts (a b)
                          (if (funcall pred-fun a b)
                              a
                              b)))
                   (declare (dynamic-extent #'reduce-elts))
                   (reduce #'reduce-elts sequence :start start :end real-end))))
            ((= real-end start)
             nil)
            (t
             (error "Invalid bounding indexes for sequence of length ~S: ~S ~S, ~S ~S"
                    (length sequence)
                    :start start
                    :end end)))))
  

  (defun flip (f)
    "Return a function whose argument order of a binary function `f` is reversed."
    #'(lambda (y x)
        (funcall f x y)))
  

  (defun hash-table-alist (table)
    "Returns an association list containing the keys and values of hash table
`table`."
    (let ((alist nil))
      (maphash (lambda (k v)
                 (push (cons k v) alist))
               table)
      alist))
  

  (declaim (inline maphash-keys))
  (defun maphash-keys (function table)
    "Like `maphash`, but calls `function` with each key in the hash table `table`."
    (maphash (lambda (k v)
               (declare (ignore v))
               (funcall function k))
             table))
  

  (defun hash-table-keys (table)
    "Returns a list containing the keys of hash table `table`."
    (let ((keys nil))
      (maphash-keys (lambda (k)
                      (push k keys))
                    table)
      keys))
  

  (defun hash-table-plist (table)
    "Returns a property list containing the keys and values of hash table
`table`."
    (let ((plist nil))
      (maphash (lambda (k v)
                 (setf plist (list* k v plist)))
               table)
      plist))
  

  (declaim (inline maphash-values))
  (defun maphash-values (function table)
    "Like `maphash`, but calls `function` with each value in the hash table `table`."
    (maphash (lambda (k v)
               (declare (ignore k))
               (funcall function v))
             table))
  

  (defun hash-table-values (table)
    "Returns a list containing the values of hash table `table`."
    (let ((values nil))
      (maphash-values (lambda (v)
                        (push v values))
                      table)
      values))
  

  (declaim (inline iota))
  (defun iota (n &key (start 0) (step 1))
    "Return a list of `n` numbers, starting from `start` (with numeric contagion
from `step` applied), each consequtive number being the sum of the previous one
and `step`. `start` defaults to `0` and `step` to `1`.

Examples:

    (iota 4)                      => (0 1 2 3)
    (iota 3 :start 1 :step 1.0)   => (1.0 2.0 3.0)
    (iota 3 :start -1 :step -1/2) => (-1 -3/2 -2)"
    (declare (type (integer 0) n) (number start step))
    (loop repeat n
          ;; KLUDGE: get numeric contagion right for the first element too
          for i = (+ (- (+ start step) step)) then (+ i step)
          collect i))
  

  (defun take (n sequence)
    "Take the first `n` elements from `sequence`."
    (subseq sequence 0 n))
  

  (defun n-grams (n sequence)
    "Find all `n`-grams of the sequence `sequence`."
    (assert (and (plusp n)
                 (<= n (length sequence))))
    
    (etypecase sequence
      ;; Lists
      (list (loop :repeat (1+ (- (length sequence) n))
                  :for seq :on sequence
                  :collect (take n seq)))
      
      ;; General sequences
      (sequence (loop :for i :to (- (length sequence) n)
                      :collect (subseq sequence i (+ i n))))))
  

  (defmacro once-only (specs &body forms)
    "Evaluates `forms` with symbols specified in `specs` rebound to temporary
variables, ensuring that each initform is evaluated only once.

Each of `specs` must either be a symbol naming the variable to be rebound, or of
the form:

    (symbol initform)

Bare symbols in `specs` are equivalent to

    (symbol symbol)

Example:

    (defmacro cons1 (x) (once-only (x) `(cons ,x ,x)))
      (let ((y 0)) (cons1 (incf y))) => (1 . 1)"
    (let ((gensyms (make-gensym-list (length specs) "ONCE-ONLY"))
          (names-and-forms (mapcar (lambda (spec)
                                     (etypecase spec
                                       (list
                                        (destructuring-bind (name form) spec
                                          (cons name form)))
                                       (symbol
                                        (cons spec spec))))
                                   specs)))
      ;; bind in user-macro
      `(let ,(mapcar (lambda (g n) (list g `(gensym ,(string (car n)))))
              gensyms names-and-forms)
         ;; bind in final expansion
         `(let (,,@(mapcar (lambda (g n)
                             ``(,,g ,,(cdr n)))
                           gensyms names-and-forms))
            ;; bind in user-macro
            ,(let ,(mapcar (lambda (n g) (list (car n) g))
                    names-and-forms gensyms)
               ,@forms)))))
  

  (defun range (start end &key (step 1) (key 'identity))
    "Return the list of numbers `n` such that `start <= n < end` and
`n = start + k*step` for suitable integers `k`. If a function `key` is
provided, then apply it to each number."
    (assert (<= start end))
    (loop :for i :from start :below end :by step :collecting (funcall key i)))
  

  (defun rcurry (function &rest arguments)
    "Returns a function that applies the arguments it is called
with and `arguments` to `function`."
    (declare (optimize (speed 3) (safety 1) (debug 1)))
    (let ((fn (ensure-function function)))
      (lambda (&rest more)
        (declare (dynamic-extent more))
        (multiple-value-call fn (values-list more) (values-list arguments)))))
  

  (defmacro with-open-file* ((stream filespec &key direction element-type
                                                   if-exists if-does-not-exist external-format)
                             &body body)
    "Just like `with-open-file`, but `nil` values in the keyword arguments mean to use
the default value specified for `open`."
    (once-only (direction element-type if-exists if-does-not-exist external-format)
      `(with-open-stream
           (,stream (apply #'open ,filespec
                           (append
                            (when ,direction
                              (list :direction ,direction))
                            (when ,element-type
                              (list :element-type ,element-type))
                            (when ,if-exists
                              (list :if-exists ,if-exists))
                            (when ,if-does-not-exist
                              (list :if-does-not-exist ,if-does-not-exist))
                            (when ,external-format
                              (list :external-format ,external-format)))))
         ,@body)))
  

  (defmacro with-input-from-file ((stream-name file-name &rest args
                                                         &key (direction nil direction-p)
                                                         &allow-other-keys)
                                  &body body)
    "Evaluate `body` with `stream-name` to an input stream on the file
`file-name`. `args` is sent as is to the call to `open` except `external-format`,
which is only sent to `with-open-file` when it's not `nil`."
    (declare (ignore direction))
    (when direction-p
      (error "Can't specifiy :DIRECTION for WITH-INPUT-FROM-FILE."))
    `(with-open-file* (,stream-name ,file-name :direction :input ,@args)
       ,@body))
  

  (defun read-file-into-string (pathname &key (buffer-size 4096) external-format)
    "Return the contents of the file denoted by `pathname` as a fresh string.

The `external-format` parameter will be passed directly to `with-open-file`
unless it's `nil`, which means the system default."
    (with-input-from-file
        (file-stream pathname :external-format external-format)
      (let ((*print-pretty* nil))
        (with-output-to-string (datum)
          (let ((buffer (make-array buffer-size :element-type 'character)))
            (loop
              :for bytes-read = (read-sequence buffer file-stream)
              :do (write-sequence buffer datum :start 0 :end bytes-read)
              :while (= bytes-read buffer-size)))))))
  

  (defun required-argument (&optional name)
    "Signals an error for a missing argument of `name`. Intended for
use as an initialization form for structure and class-slots, and
a default value for required keyword arguments."
    (error "Required argument ~@[~S ~]missing." name))
  

  (defun riffle (list obj)
    "Insert the item `obj` in between each element of `list`."
    (loop :for (x . xs) :on list
          :collect x
          :when xs
            :collect obj))
  

  (defun separated-string-append* (separator sequence-of-strings)
    "Concatenate all of the strings in SEQUENCE-OF-STRINGS separated
    by the string SEPARATOR."
    (etypecase sequence-of-strings
      (null "")
      
      (cons (with-output-to-string (*standard-output*)
              (mapl #'(lambda (tail)
                        (write-string (car tail))
                        (unless (null (cdr tail))
                          (write-string separator)))
                    sequence-of-strings)))
      
      (sequence
       (let ((length (length sequence-of-strings)))
         (with-output-to-string (*standard-output*)
           (map nil #'(lambda (string)
                        (write-string string)
                        (unless (zerop (decf length))
                          (write-string separator)))
                sequence-of-strings))))))
  
  (defun separated-string-append (separator &rest strings)
    "Concatenate the strings STRINGS separated by the string
SEPARATOR."
    (separated-string-append* separator strings))
  

  (defun subdivide (sequence chunk-size)
    "Split `sequence` into subsequences of size `chunk-size`."
    (check-type sequence sequence)
    (check-type chunk-size (integer 1))
    
    (etypecase sequence
      ;; Since lists have O(N) access time, we iterate through manually,
      ;; collecting each chunk as we pass through it. Using SUBSEQ would
      ;; be O(N^2).
      (list (loop :while sequence
                  :collect
                  (loop :repeat chunk-size
                        :while sequence
                        :collect (pop sequence))))
      
      ;; For other sequences like strings or arrays, we can simply chunk
      ;; by repeated SUBSEQs.
      (sequence (loop :with len := (length sequence)
                      :for i :below len :by chunk-size
                      :collect (subseq sequence i (min len (+ chunk-size i)))))))
  

  (defun mkstr (&rest args)
    "Receives any number of objects (string, symbol, keyword, char, number), extracts all printed representations, and concatenates them all into one string.

Extracted from _On Lisp_, chapter 4."
    (with-output-to-string (s)
      (dolist (a args) (princ a s))))
  

  (defun symb (&rest args)
    "Receives any number of objects, concatenates all into one string with `#'mkstr` and converts them to symbol.

Extracted from _On Lisp_, chapter 4.

See also: `symbolicate`"
    (values (intern (apply #'mkstr args))))
  

  (defun tree-collect (predicate tree)
    "Returns a list of every node in the `tree` that satisfies the `predicate`. If there are any improper lists in the tree, the `predicate` is also applied to their dotted elements."
    (let ((sentinel (gensym)))
      (flet ((my-cdr (obj)
               (cond ((consp obj)
                      (let ((result (cdr obj)))
                        (if (listp result)
                            result
                            (list result sentinel))))
                     (t
                      (list sentinel)))))
        (loop :for (item . rest) :on tree :by #'my-cdr
              :until (eq item sentinel)
              :if (funcall predicate item) collect item
                :else
                  :if (listp item)
                    :append (tree-collect predicate item)))))
  

  (deftype string-designator ()
    "A string designator type. A string designator is either a string, a symbol,
or a character."
    `(or symbol string character))
  

  (defmacro with-gensyms (names &body forms)
    "Binds each variable named by a symbol in `names` to a unique symbol around
`forms`. Each of `names` must either be either a symbol, or of the form:

    (symbol string-designator)

Bare symbols appearing in `names` are equivalent to:

    (symbol symbol)

The string-designator is used as the argument to `gensym` when constructing the
unique symbol the named variable will be bound to."
    `(let ,(mapcar (lambda (name)
                     (multiple-value-bind (symbol string)
                         (etypecase name
                           (symbol
                            (values name (symbol-name name)))
                           ((cons symbol (cons string-designator null))
                            (values (first name) (string (second name)))))
                       `(,symbol (gensym ,string))))
            names)
       ,@forms))

  (defmacro with-unique-names (names &body forms)
    "Binds each variable named by a symbol in `names` to a unique symbol around
`forms`. Each of `names` must either be either a symbol, or of the form:

    (symbol string-designator)

Bare symbols appearing in `names` are equivalent to:

    (symbol symbol)

The string-designator is used as the argument to `gensym` when constructing the
unique symbol the named variable will be bound to."
    `(with-gensyms ,names ,@forms))
  
(eval-when (:compile-toplevel :load-toplevel :execute)
  (export '(compose copy-array curry define-constant ensure-boolean
            ensure-gethash ensure-list extremum flip hash-table-alist
            hash-table-keys hash-table-plist hash-table-values iota n-grams
            once-only range rcurry read-file-into-string required-argument
            riffle separated-string-append separated-string-append* subdivide
            symb tree-collect with-gensyms with-unique-names)))

;;;; END OF quickutils.lisp ;;;;