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instance method

Enumerable#slice_when

slice_when {|element, next_element| ... } → enumerator

static VALUE
enum_slice_when(VALUE enumerable)
{
    VALUE enumerator;
    VALUE pred;

    pred = rb_block_proc();

    enumerator = rb_obj_alloc(rb_cEnumerator);
    rb_ivar_set(enumerator, id_slicewhen_enum, enumerable);
    rb_ivar_set(enumerator, id_slicewhen_pred, pred);
    rb_ivar_set(enumerator, id_slicewhen_inverted, Qfalse);

    rb_block_call(enumerator, idInitialize, 0, 0, slicewhen_i, enumerator);
    return enumerator;
}

The returned enumerator uses the block to partition elements into arrays (“slices”); it calls the block with each element and its successor; begins a new slice if and only if the block returns a truthy value:

Example

a = [0, 1, 2, 4, 5, 6, 8, 9]
e = a.slice_when {|i, j| j != i + 1 }
e.each {|array| p array }

Output:

Example

[0, 1, 2]
[4, 5, 6]
[8, 9]

See also #slice_before #sort #slice_after #sort_by also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.0

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