language-extensions

language-extensions is a skill for Claude Code from ncaq/konoka. It costs 44 tokens per session (863 once invoked), scanned A, original, Apache-2.0.

A Haskell coding guideline for choosing language extensions and language editions such as GHC2024 or GHC2021. It favors GHC2024 when available and otherwise uses GHC2021, with some additional extensions when considered safe and useful.

In plain words
What is it for?
Use it when setting or reviewing Cabal's default language, default extensions, or individual Haskell extensions.
Why use it?
It removes guesswork when configuring a Haskell project and keeps extension choices consistent. It also helps avoid enabling extensions without a clear reason.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the haskell-tasuke plugin — 19 skills shipped together

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.

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

Made for: Claude Code.

Or install haskell-tasuke, the plugin that ships this one along with the rest of its 19 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 language-extensions

README.md
[![agentmods](https://agentmods.dev/badge/skills/ncaq/konoka/language-extensions.svg)](https://agentmods.dev/skills/ncaq/konoka/language-extensions)
Your own site
<a href="https://agentmods.dev/skills/ncaq/konoka/language-extensions"><img src="https://agentmods.dev/badge/skills/ncaq/konoka/language-extensions.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 863 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00044 $0.00863
Opus 5 $0.00022 $0.00432
Sonnet 5 $0.00009 $0.00173
Haiku 4.5 $0.00004 $0.00086

Measured 5d ago against content hash ac314b093739, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

language-extensions 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 5d 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/haskell-tasuke/skills/language-extensions/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

言語拡張の選択方針

Haskellの言語拡張と、 言語拡張のセットである言語バージョンの選択方針について説明します。

基本の方針

Haskellの言語バージョンは使える場合はGHC2024を使用します。

使えない場合はGHC2021を使用します。

GHC2024で有効になっていなくても、 比較的安全で有用な言語拡張は有効にします。

GHC2021に含まれている拡張

  • BangPatterns
  • BinaryLiterals
  • ConstrainedClassMethods
  • ConstraintKinds
  • DeriveDataTypeable
  • DeriveFoldable
  • DeriveFunctor
  • DeriveGeneric
  • DeriveLift
  • DeriveTraversable
  • DoAndIfThenElse
  • EmptyCase
  • EmptyDataDecls
  • EmptyDataDeriving
  • ExistentialQuantification
  • ExplicitForAll
  • FieldSelectors
  • FlexibleContexts
  • FlexibleInstances
  • ForeignFunctionInterface
  • GADTSyntax
  • GeneralisedNewtypeDeriving
  • HexFloatLiterals
  • ImplicitPrelude
  • ImplicitStagePersistence
  • ImportQualifiedPost
  • InstanceSigs
  • KindSignatures
  • MonomorphismRestriction
  • MultiParamTypeClasses
  • NamedFieldPuns
  • NamedWildCards
  • NoExplicitNamespaces
  • NumericUnderscores
  • PatternGuards
  • PolyKinds
  • PostfixOperators
  • RankNTypes
  • RelaxedPolyRec
  • ScopedTypeVariables
  • StandaloneDeriving
  • StandaloneKindSignatures
  • StarIsType
  • TraditionalRecordSyntax
  • TupleSections
  • TypeApplications
  • TypeOperators
  • TypeSynonymInstances

GHC2024に含まれている拡張

上のGHC2021に加えて、 以下の拡張がGHC2024に含まれています。

  • DataKinds
  • DerivingStrategies
  • DisambiguateRecordFields
  • ExplicitNamespaces
  • GADTs
  • LambdaCase
  • RoleAnnotations

cabalファイルの設定例

典型的なcabalファイルでの言語バージョンと言語拡張の設定は以下のようになります。

default-language: GHC2024
default-extensions:
  ApplicativeDo
  BlockArguments
  CPP
  DefaultSignatures
  DerivingVia
  DuplicateRecordFields
  FunctionalDependencies
  LexicalNegation
  LinearTypes
  MonadComprehensions
  MultiWayIf
  NegativeLiterals
  NoFieldSelectors
  NoImplicitPrelude
  OverloadedLabels
  OverloadedRecordDot
  OverloadedStrings
  ParallelListComp
  PatternSynonyms
  QualifiedDo
  QuantifiedConstraints
  QuasiQuotes
  RecordWildCards
  RecursiveDo
  StrictData
  TemplateHaskell
  TypeData
  TypeFamilies
  TypeFamilyDependencies
  ViewPatterns

Read the full file on GitHub · 133 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 133 lines · 44 tokens per session scan A ac314b093739

Subscribe to this mod's changes

language-extensions is a skill published in the GitHub repository ncaq/konoka (3 stars, last pushed 2d ago), licensed Apache-2.0. It adds 44 tokens to every session and 863 once invoked, about $0.0002 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 2026-08-31.

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