Returns the Duration between from and to fields.

Example:

Given: today().to(tomorrow).duration then duration is 86400000 milliseconds.

Given: tomorrow().to(today).duration then duration is -86400000 milliseconds.

The first Element returned by the iterator, if any. This should always produce the same value as iterable.iterator().head. It also represents the caller that created the Range:

Example: today().to(tomorrow) -> in this case today() is the caller/creator of the range.

This implementation respect the constraint that if x==y then x.hash==y.hash.

Returns the Period between from and to fields.

Example:

Given: today().to(tomorrow).duration then duration is 1 day.

Given: tomorrow().to(today).duration then duration is -1 day.

Customized way to iterate over each element, it does not interfer in from and to fields, but it does not guarantee that to will be included in iterator.

Returns ISO-8601 formatted String representation of this Range.

Reference: https://en.wikipedia.org/wiki/ISO_8601#Time_intervals

The limit of the Range where.

Example:

Given: today().to(tomorrow) then tomorrow is the to element.

Given: tomorrow.to(today()) then today() is the to element.

Returns true if both: this and other are same type and have equal fields from and to.

Returns empty or a new Range:

• Each Range is considered a set then [A..B] is equivalent to [B..A]
• The precision is based on the lowest unit
• When the new Range exists it will follow these rules:

Given: [A..B] gap [C..D]

When: AB < CD

[1..2] gap [5..6] = (2,5)

[1..2] gap [6..5] = (2,5)

[2..1] gap [5..6] = (2,5)

[2..1] gap [6..5] = (2,5)

Given: [A..B] gap [C..D]

When: AB > CD

[5..6] gap [1..2] = (2,5)

[5..6] gap [2..1] = (2,5)

[6..5] gap [1..2] = (2,5)

[6..5] gap [2..1] = (2,5)

Returns empty or a new Range:

• Each Range is considered a set then [A..B] is equivalent to [B..A]
• The precision is based on the lowest unit
• When the new Range exists it will follow these rules:

Given: [A..B] overlap [C..D]

When: AB < CD

[1..6] overlap [3..9] = [3,6]

[1..6] overlap [9..3] = [3,6]

[6..1] overlap [3..9] = [3,6]

[6..1] overlap [9..3] = [3,6]

Given: [A..B] overlap [C..D]

When: AB > CD

[3..9] overlap [1..6] = [3,6]

[3..9] overlap [6..1] = [3,6]

[9..3] overlap [1..6] = [3,6]

[9..3] overlap [6..1] = [3,6]

Define how this Range will get next or previous element while iterating.