Rell System Library/[root]/range

range

type range : iterable<integer>

A range of integer values. Ranges represent arithmetic sequences with defined start and end points, and a constant difference between consecutive elements. Ranges can be empty or contain any natural number of elements.

Range is a subtype of iterable<integer>.

Since

0.6.0

See also

iterable

for inherited values and methods

Constructors

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pure constructor(end: integer)

Construct a range, starting at 0 (inclusive), ending at end (exclusive), with a step size of 1.

Examples:

  • list(range(0)) returns [].

  • list(range(1)) returns [0].

  • list(range(2)) returns [0, 1].

  • list(range(10)) returns [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].

Note that range(x) is equivalent to range(0, x, 1).

pure constructor(start: integer, end: integer, [step: integer])

Construct a range, starting at start (inclusive), ending at end (exclusive), with a "step size" (i.e. difference between consecutive values) of step.

If start > end, then step must be negative. Conversely, if start < end, the step must be positive. step cannot be 0.

Examples:

  • list(range(1, 23, 3)) returns [1, 4, 7, 10, 13, 16, 19, 22].

  • list(range(20, 1, -2)) returns [20, 18, 16, 14, 12, 10, 8, 6, 4, 2].

  • list(range(-2, -8, -1)) returns [-2, -3, -4, -5, -6, -7].

  • list(range(3, 3, 7)) returns []. Indeed, for all x, and for all y != 0, range(x, x, y) returns [].

Note that range(0, x, 1) is equivalent to range(x).

Functions

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pure function join_to_text([separator: text], [prefix: text], [postfix: text], [limit: integer?], [truncated: text], [transform: (integer) -> text]): text

Generate a textual representation of this iterable.

An optional separator, prefix and postfix can be provided. One can also provide a limit: integer?. If there are more elements in the result than limit, the elements whose indices exceed limit are omitted, and the passed truncated: text is included instead.

Examples:

  • [1, 2, 3].join_to_text() returns '1, 2, 3'.

  • [1, 2, 3].join_to_text('_') returns '1_2_3'.

  • [1, 2, 3].join_to_text('*', '(', ')') returns '(1*2*3)'.

  • list<T>().join_to_text('!', '(', ')') returns '()' (where T is a valid type).

  • range(10).join_to_text('', '', '', 5) returns '01234...'.

  • range(10).join_to_text('', '', '', 5, 'more') returns '01234more'.

Where the function even is defined:

function even(x: integer): text {
   return if (x % 2 == 0) 'EVEN' else 'ODD';
}
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Then:

  • range(10).join_to_text('->', '{', '}', 5, '...', even(*)) returns {EVEN->ODD->EVEN->ODD->EVEN->...}.