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# Localize.Utils.Enum (Localize v0.39.0)

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Enumerable utility functions not provided in the standard library.

Provides reduce with lookahead and list combination operations.

## Summary

### Functions

combine_list(list)

Combines list elements into progressively concatenated prefix strings.

reduce_peeking(list, accumulator, function)

Reduces a list with lookahead by passing both the current element and the remaining tail to the reducing function.

## Functions

# combine_list(list)

Combines list elements into progressively concatenated prefix strings.

Each element in the result is the concatenation of all preceding elements joined by underscores.

### Arguments

- `list` — a list of elements that can be converted to strings.

### Returns

- A list of progressively combined strings.

### Examples

    iex> Localize.Utils.Enum.combine_list([:a, :b, :c])
    ["a", "a_b", "a_b_c"]

# reduce_peeking(list, accumulator, function)

Reduces a list with lookahead by passing both the current element and the remaining tail to the reducing function.

The reducing function receives three arguments: the current element, the remaining tail of the list, and the accumulator. It should return a tagged tuple following the `Enumerable` protocol conventions: `{:cont, acc}`, `{:halt, acc}`, or `{:suspend, acc}`.

### Arguments

- `list` — the list to reduce.

- `accumulator` — the initial accumulator value, or a tagged tuple.

- `function` — a function of arity 3: `(element, tail, accumulator)`.

### Returns

- The final accumulator value.

### Examples

    iex> Localize.Utils.Enum.reduce_peeking([1, 2, 3], [], fn head, tail, acc ->
    ...>   {:cont, [{head, length(tail)} | acc]}
    ...> end)
    [{3, 0}, {2, 1}, {1, 2}]