12.21 data.range - レンジ

Module: data.range ¶

レンジオブジェクトはO(1)で要素にアクセスでき、 そして各要素が手続き的に計算されるような不変なシーケンスです。 例えば、0からNまでの整数のレンジ、というのは、i番目の要素を計算する手続きが identityであるようなレンジとして簡単に実現できるでしょう。 これは、全ての整数を持つシーケンスを作るよりずっと軽いです。

レンジはまた、一部分だけ取り出したレンジを作ったり、 レンジ同士をつなげたりする操作を効率的に行えます。

レンジオブジェクトはSRFI-42 先行評価的内包表記の:range qualifierに 渡すこともできます (srfi.42 - 先行評価的内包表記参照)。

ポータブルなレンジオブジェクトのインタフェースはsrfi.196で 規定されています。Gaucheではレンジオブジェクトを<sequence>として 実装し、シーケンスプロトコルも使えるようにしています (gauche.sequence - シーケンスフレームワーク参照)。またこのモジュールではsrfi.196にない 手続きも提供されます。

クラス

Class: <range> ¶

レンジオブジェクトのクラスです。内部的には、異なるレンジの性質に合わせて いくつかのサブクラスを使っていますが、外部的には全てのレンジを <range>クラスのインスタンスとして扱って構いません。

Class: <range-meta> ¶

<range>クラスのメタクラスです。

コンストラクタ

Function: range length indexer ¶

[SRFI-196]{data.range} 長さがlengthで、i番目の要素(0 <= i < length)) が(indexer i)で計算されるようなレンジを作って返します。

手続きindexerはO(1)の時間オーダーで動作し、参照透過でなければなりません。 実装によっては、内部で要素の値をフラットベクタにキャッシュすることもありえます。

(range->list (range 5 (^i (+ i 10))))
 ⇒ (10 11 12 13 14)

Function: numeric-range start end :optional step ¶

[SRFI-196]{data.range} Creates and returns a range of integers starting from start (inclusive) and ending below end (exclusive), increasing with step. The default value of step is 1.

(range->list (numeric-range 2 6))
 ⇒ (2 3 4 5)

(range->list (numeric-range 0 5 2/3))
 ⇒ (0 2/3 4/3 2 8/3 10/3 4 14/3)

Function: iota-range length :optional start step ¶

[SRFI-196]{data.range} Creates and returns a range of integers. Total length of the range is length. The range starts from start (default 0), and increased with step (default 1).

(range->list (iota-range 5))
  ⇒ (0 1 2 3 4)

(range->list (iota-range 7 1 -1/7))
  ⇒ (1 6/7 5/7 4/7 3/7 2/7 1/7)

Function: vector-range vec :optional start end ¶

[SRFI-196+]{data.range} Returns a range over the given vector vec. The vector is kept in the range, so you shouldn’t mutate vec. See also vector->range below.

The optional start and end arguments limits the range of the vector to be used. They are Gauche’s extension and not in SRFI-196.

(range->list (vector-range '#(a b c)))
  ⇒ (a b c)

(range->list (vector-range '#(a b c d e) 1 4))
  ⇒ (b c d)

Function: uvector-range uvec :optional start end ¶

{data.range} Returns a range over the given uniform vector uvec. The uniform vector is kept in the range, so you shouldn’t mutate uvec.

The optional start and end arguments limits the range of the uniorm vector to be used.

Function: bitvector/bool-range bvec :optional start end ¶

Function: bitvector/int-range bvec :optional start end ¶

{data.range} Returns a range over the given bitvector bvec. Bitvector/bool-range regards bvec as a boolean vector, while bitvector/int-range regards it as a vector of 0 and 1. See ビットベクタ, for the details of bitvectors. Note that bvec is kept in the range, so you shouldn’t mutate uvec.

The optional start and end arguments limits the range of the uniorm vector to be used.

Function: string-range str :optional start end ¶

[SRFI-196]{data.range} Returns a range over each character in the given string str. The string is kept in the range, so you shouldn’t mutate str.

The optional start and end arguments limits the range of the vector to be used. They are Gauche’s extension and not in SRFI-196.

(range->list (string-range "abc"))
  ⇒ (#\a #\b #\c)

(range->list (string-range "abcde" 1 4))
  ⇒ (#\b #\c #\d)

Function: range-append range … ¶

[SRFI-196]{data.range} Returns a new range that walks over concatenation of the given ranges.

Function: range-reverse range :optional start end ¶

[SRFI-196+]{data.range} Returns a new range that walks over the elements of range, but in reverse order.

The optional start and end arguments limits the range of the vector to be used. They are Gauche’s extension and not in SRFI-196.

(range->list (range-reverse (string-range "abc")))
  ⇒ (#\c #\b #\a)

(range->list (range-reverse (string-range "abcdef" 1 4)))
  ⇒ (#\d #\c #\b)

Predicates

Function: range? obj ¶

[SRFI-196]{data.range} Returns true iff obj is a range.

Function: range=? elt= range … ¶

[SRFI-196]{data.range} Returns true iff all ranges have the same length, and any pair of corresponding elements in the given ranges are equal in terms of elt= predicate.

As edge cases, when zero or one range is given, #t is returned.

(range=? eqv? (numeric-range 0 5)
              (iota-range 5)
              (vector-range '#(0 1 2 3 4)))
  ⇒ #t

Accessors

Function: range-length range ¶

[SRFI-196]{data.range} Returns the length of range.

Function: range-ref range i :optional fallback ¶

[SRFI-196+]{data.range} Returns the i-th element of range. The index i must be an exact integer.

If i is negative, or greater than or equal to the length of range, fallback is returned if given, or an error is signaled. The fallback argument is Gauche’s extension and not in SRFI-196.

Function: range-first range :optional fallback ¶

[SRFI-196+]{data.range} Returns the first element of range.

If the range is empty, fallback is returned if given, or an error is signaled. The fallback argument is Gauche’s extension and not in SRFI-196.

Function: range-last range :optional fallback ¶

[SRFI-196+]{data.range} Returns the last element of range.

If the range is empty, fallback is returned if given, or an error is signaled. The fallback argument is Gauche’s extension and not in SRFI-196.

Iteration

Function: range-split-at range k ¶

[SRFI-196]{data.range} Returns two ranges, the first one with elements before k-th elements of range, and the second one with k-th elements and after of range.

Function: subrange range start end ¶

[SRFI-196]{data.range} Returns a new range that contains start-th (inclusive) to end-th (exclusive) elements of range.

Function: range-segment range len ¶

[SRFI-196]{data.range} Split range into subranges of length len. The last range may be shorter than len.

(map range->list (range-segment (numeric-range 0 11) 4))
 ⇒ ((0 1 2 3) (4 5 6 7) (8 9 10))

Function: range-take range count ¶

Function: range-take-right range count ¶

[SRFI-196]{data.range} Returns a new range containing initial count elements or last count elements from range, respectively

Function: range-drop range count ¶

Function: range-drop-range range count ¶

[SRFI-196]{data.range} Returns a new range containing elements of range except initial count elements or last count elements, respectively.

Function: range-count pred range range2 … ¶

[SRFI-196]{data.range} A procedure pred must take as many arguments as the given ranges. It is called on each corresponding element of range, range2 …, and the procedure returns the number of times pred returned true.

If more than one ranges are given and not all ranges are of the same length, iteration terminates at the end of the shortest range.

Function: range-any pred range range2 … ¶

[SRFI-196]{data.range} A procedure pred must take as many arguments as the given ranges. It is called on each first element of range, range2 …, then each second element, and so on. As soon as pred returns a true value, the iteration stops and the value pred returns becomes the result of range-any. If pred never returns a true value, #f is returned.

If more than one ranges are given and not all ranges are of the same length, iteration terminates at the end of the shortest range.

Function: range-every pred range range2 … ¶

[SRFI-196]{data.range} A procedure pred must take as many arguments as the given ranges. It is called on each first element of range, range2 …, then each second element, and so on. As soon as pred returns a false value, the iteration stops and range-any returns #f. If all pred returns a true value, the last value is returned.

If more than one ranges are given and not all ranges are of the same length, iteration terminates at the end of the shortest range.

Function: range-map proc range range2 … ¶

Function: range-map->list proc range range2 … ¶

Function: range-map->vector proc range range2 … ¶

[SRFI-196]{data.range} Mapping over ranges. A procedure proc must take as many arguments as the given ranges, and is called on each corresponding element of range, range2 …. The results are collected and returned as a range (range-map), a list (range-map->list, or a vector (range-map->vector. The dynamic order of in which proc is invoked is not specified. Note that range-map computes all elements before returning the result range.

If more than one ranges are given and not all ranges are of the same length, iteration terminates at the end of the shortest range.

Function: range-for-each proc range range2 … ¶

[SRFI-196]{data.range} A procedure proc must take as many arguments as the given ranges. It is invoked with the first elements of each range, and then with the second elements of them, and so on, until the shortest range is exhausted. The result of proc is discarded.

Returns an undefined value.

Function: range-filter pred range ¶

Function: range-filter->list pred range ¶

Function: range-remove pred range ¶

Function: range-remove->list pred range ¶

Function: range-filter-map pred range range2 … ¶

Function: range-filter-map->list pred range range2 … ¶

[SRFI-196]{data.range} A procedure pred must take as many arguments as the given ranges. These are range version of filter, remove, and filter-map (see リストをたどる手続き).

The procedures without ->list returns the result as a range, while the ones with ->list returns the result as a list.

The iteration stops when the shortest range is exhausted. The result is eagerly computed.

(range->list (range-filter odd? (iota-range 10)))
  ⇒ (1 3 5 7 9)
(range-remove->list odd? (iota-range 10))
  ⇒ (0 2 4 6 8)
(range->list (range-filter-map (every-pred odd? square) (iota-range 10)))
  ⇒ (1 9 25 49 81)

Function: range-fold kons knil range range2 … ¶

Function: range-fold-right kons knil range range2 … ¶

[SRFI-196]{data.range} These are range version of fold and fold-right (see リストをたどる手続き). The iteration stops when the shortest range is exhausted.

Searching

Function: range-index pred range range2 … ¶

Function: range-index-right pred range range2 … ¶

[SRFI-196]{data.range} Returns the first or the last index of the element in the input range that satisfies a predicate pred. If there are more than one ranges, pred must take as many arguments as the number of input ranges, and applied on each corresponding elements of the input range.

(range-index > (vector-range '#(1 5 3 2 4))
               (vector-range '#(4 3 0 4 6)))
  ⇒ 1
(range-index-right > (vector-range '#(1 5 3 2 4))
                     (vector-range '#(4 3 0 4 6)))
  ⇒ 2

Function: range-take-while pred range ¶

Function: range-take-while-right pred range ¶

Function: range-drop-while pred range ¶

Function: range-drop-while-right pred range ¶

[SRFI-196]{data.range} Same as take-while, take-while-right, drop-while, and drop-while-right, except those operate on an range and return an range, instead of a list (see scheme.list - R7RSリスト).

Conversion

Function: range->list range ¶

Function: range->vector range ¶

Function: range->string range ¶

[SRFI-196]{data.range} Convert a range to a list, a vector ro a string, respectively. For range->string, the argument must be a range consists solely of characters.

Function: vector->range vec :optional start end ¶

[SRFI-196]{data.range} Returns a range whose elements are those of a vector vec. Unlike vector-range, the content of vec is copied into the range, so mutating vec won’t alter the resulting range.

The optional start and end arguments limit the portion to be used for the result.

Function: range->generator range :optional start end ¶

[SRFI-196]{data.range} Returns a generator that yields each element of range, between start (inclusive) and end (exclusive) indexes. When omitted, start is 0 and end is the size of the range.