avoid-for

avoid-for is a skill for Claude Code from ncaq/konoka. It costs 63 tokens per session (2,245 once invoked), scanned A, original, Apache-2.0.

A TypeScript and JavaScript coding rule that replaces loop statements with named array operations such as map, filter, find, and reduce.

In plain words
What is it for?
Use it when writing or reviewing iteration over arrays, objects, maps, sets, or strings. TypeScript and JavaScript are programming languages used widely for web applications.
Why use it?
It makes the intended operation more visible and avoids loop code that can mix transformation, filtering, searching, and side effects in one block.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the web-tasuke plugin — 17 skills shipped together

Good fit Use it when writing or reviewing iteration over arrays, objects, maps, sets, or strings. TypeScript and JavaScript are programming languages used widely for web applications.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ncaq/konoka/avoid-for
View source ↗ ncaq/konoka
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ncaq/konoka --skill avoid-for
Clone the repo
git clone --depth 1 https://github.com/ncaq/konoka

Made for: Claude Code.

Or install web-tasuke, the plugin that ships this one along with the rest of its 17 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for avoid-for

README.md
[![agentmods](https://agentmods.dev/badge/skills/ncaq/konoka/avoid-for/github.svg)](https://agentmods.dev/skills/ncaq/konoka/avoid-for)
Your own site
<a href="https://agentmods.dev/skills/ncaq/konoka/avoid-for"><img src="https://agentmods.dev/badge/skills/ncaq/konoka/avoid-for/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for avoid-for

Your own site · 80×15
<a href="https://agentmods.dev/skills/ncaq/konoka/avoid-for"><img src="https://agentmods.dev/badge/skills/ncaq/konoka/avoid-for.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,245 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00063 $0.02245
Opus 5 $0.00032 $0.01123
Sonnet 5 $0.00013 $0.00449
Haiku 4.5 $0.00006 $0.00225

Measured 4d ago against content hash 41b40d9724de, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

avoid-for scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/web-tasuke/skills/avoid-for/SKILL.md · 248 lines

How it starts

The opening of the file, as written. The whole thing — 248 lines — stays where its author put it; the contents beside it link to each section on GitHub.

for文をなるべく避ける

for文は強力すぎて、 コードの意図が読み取りにくくなります。 構造化プログラミングにおいてgoto相当の機能を避けるのと同じ理由で、 for文もなるべく避けてください。

避ける対象は以下の全てです。

  • C言語方式のfor (let i = 0; i < n; i++)
  • for...of
  • for...in

forではありませんが、 同じくループ構文の以下も避けてください。

  • while
  • do...while

なぜ避けるのか

for文は何でもできてしまいます。

  • 要素の変換
  • 絞り込み
  • 集計
  • 検索
  • 副作用の実行

どの操作をしているのかはループ本体を注意深く読まないと分かりません。

mapfilterのような高抽象度の関数は、 名前を見ただけで「変換している」「絞り込んでいる」と意図が伝わります。 gotoが制御フローを自由にしすぎて構造化プログラミングで避けられたのと同じく、 forはデータの流れを自由にしすぎます。 より弱く意図の限定された関数に置き換えることで、 読み手の負担が減ります。

Arrayの場合

Arrayのメソッドでやりたいことに対応するものを選びます。

やりたいこと forの代替
各要素を変換する map
変換して一段平坦化する flatMap
条件で絞り込む filter
最初の一致を探す find / findIndex
最後の一致を探す findLast / findLastIndex
含まれるか調べる includes
位置を調べる indexOf / lastIndexOf
一つでも満たすか調べる some
すべて満たすか調べる every
単一の値に集計する reduce / reduceRight
副作用だけ実行する forEach
ネストした配列を平坦化する flat
文字列に連結する join
並べ替える toSorted
逆順にする toReversed

変換と絞り込みはチェーンで素直に書けます。

// 避ける
const result = [];
for (let i = 0; i < users.length; i++) {
  if (users[i].active) {
    result.push(users[i].name);
  }
}

// 良い
const result = users.filter((user) => user.active).map((user) => user.name);

大域脱出が必要な場合

途中で打ち切りたい(break相当の)場合は、 専用のメソッドで表現できます。

  • 一つでも条件を満たすか: some
  • すべて満たすか: every
  • 最初の一致を取得: find
// 避ける
let found = false;
for (const user of users) {
  if (user.id === targetId) {
    found = true;
    break;
  }
}

// 良い
const found = users.some((user) => user.id === targetId);

Read the full file on GitHub · 248 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 248 lines · 63 tokens per session scan A 41b40d9724de

Subscribe to this mod's changes

avoid-for is a skill published in the GitHub repository ncaq/konoka (3 stars, last pushed yesterday), licensed Apache-2.0. It adds 63 tokens to every session and 2,245 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.

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