# Hand-built counters and flag loops

*Code longer than it needs to be*: one of the ways AI coding agents bloat software, from lessloc's [pattern catalog](https://lessloc.org/patterns/index.md). lessloc catches it as [`simpler`](https://lessloc.org/guide/reference.md#tier-2).

## What makes hand-built counters and flag loops a bad practice?

The standard that calls it a bad practice: Fowler: Replace Loop with Pipeline.

## What does lessloc do about hand-built counters and flag loops?

lessloc catches it as [`simpler`](https://lessloc.org/guide/reference.md#tier-2).

- `simpler` (tier 2): Brute-force code with a shorter idiom: `== True`, an if/else that returns the condition, an index loop that only reads `xs[i]`, `.filter(...).length > 0`, a catch that only rethrows, a flag loop that is `any()`, a hand-built counter, an `__init__` that `@dataclass` writes, a React Effect that only sets state. ruff and clippy add more.

## Examples

Caught as `simpler`:

```python [u.py]
def has_refund(orders):
    found = False
    for order in orders:
        if order.refunded:
            found = True
            break
    return found
```

Written well:

```python [u.py]
def has_refund(orders):
    return any(order.refunded for order in orders)
```

Caught as `simpler`:

```python [v.py]
def tally(words):
    counts = {}
    for w in words:
        if w in counts:
            counts[w] += 1
        else:
            counts[w] = 1
    return counts
```

Written well:

```python [v.py]
from collections import Counter


def tally(words):
    return Counter(words)
```

## Related patterns

The other patterns in [Code longer than it needs to be](https://lessloc.org/patterns/index.md#code-longer-than-it-needs-to-be):

- [Brute-force idioms](https://lessloc.org/patterns/brute-force.md): lessloc catches it as `simpler`, built in for Python, JS/TS, Go, Rust, Java and C#. ruff (in every hook) and clippy (in `ci`) go deeper.
- [A catch that only rethrows](https://lessloc.org/patterns/catch-rethrow.md): lessloc catches it as `simpler`.
- [A promise wrapped in new Promise](https://lessloc.org/patterns/promise-wrap.md): lessloc catches it as `simpler`.
- [Annotating types the compiler infers](https://lessloc.org/patterns/inferred-types.md): lessloc catches it as `simpler`.
- [A React Effect that only sets state from other values](https://lessloc.org/patterns/derived-effect.md): lessloc catches it as `simpler`.
- [Functions with many parameters (8 or more)](https://lessloc.org/patterns/long-params.md): lessloc catches it as `long-params`.
- [Deep nesting](https://lessloc.org/patterns/deep-nesting.md): lessloc catches it as `deep-nesting`.
- [Long functions](https://lessloc.org/patterns/long-function.md): lessloc catches it as `long-function`.
- [If-chains on literal values](https://lessloc.org/patterns/if-chain.md): lessloc catches it as `if-chain`.
- [A file that keeps growing](https://lessloc.org/patterns/swollen-file.md): lessloc catches it as `swollen-file`.
- [Reformatting lines the task did not change](https://lessloc.org/patterns/churn.md): lessloc gives every session a rule against it and catches it as `churn`.
- [Net growth past a budget](https://lessloc.org/patterns/net-growth.md): lessloc catches it as `net-growth`.
- [Golfed code](https://lessloc.org/patterns/golfed-code.md): lessloc catches it as `clever` and `dense-lines`.