Types

Loop[T] = object index*: int ## which element (start from 1) index0*: int ## which elemen (start from 0) first*: bool ## if this is the first loop iteration last*: bool ## if this is the last loop iteration previtem*: Option[T] ## get the item from the last loop iteration nextitem*: Option[T] ## get the item from the next loop iteration length*: int ## the length of the seq, (same as mySeq.len()) revindex0*: int ## which element, counted from the end (last one is 0) revindex*: int ## which element, counted from the end (last one is 1)
Loopable[T] = concept x {...}{.explain.} x.len() is int x[int] is T x.items is T

Procs

proc cycle[T](loop: Loop; elems: openArray[T]): T

within a loop you can cycle through elements:

{% for loop, row in rows.loop() %}
    <li class="{{ loop.cycle(@["odd", "even"]) }}">{{ row }}</li>
{% endfor %}

Iterators

iterator loop[T](a: Loopable[T]): tuple[loop: Loop[T], val: T] {...}{.inline.}

yields a Loop object with every item. Inside the loop body you have access to the following fields.

{% for loop, row in rows.loop() %}
    {{ loop.index0 }}
    {{ loop.index }}
    {{ loop.revindex0 }}
    {{ loop.revindex }}
    {{ loop.length }}
    {% if loop.first %}The first item{% endif %}
    {% if loop.last %}The last item{% endif %}
    {% if loop.previtem.isSome %}{{ loop.previtem.get() }}{% endif %}
    {% if loop.nextitem.isSome %}{{ loop.nextitem.get() }}{% endif %}
    <li class="{{ loop.cycle(@["odd", "even"]) }}">{{row}}</li>
{% endfor %}

however, the element you iterate over must match the Concept Loopable.

nimjautils

Types

Procs

Iterators