Claude-skill-registry kotlin-fundamentals

Kotlin language fundamentals - syntax, null safety, data classes, extensions

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/kotlin-fundamentals" ~/.claude/skills/majiayu000-claude-skill-registry-kotlin-fundamentals && rm -rf "$T"

manifest: skills/data/kotlin-fundamentals/SKILL.md

Kotlin Fundamentals Skill

Master Kotlin programming fundamentals with production-ready patterns.

Topics Covered

Null Safety

// Safe call + Elvis
val name = user?.name ?: "Anonymous"

// requireNotNull for validation
requireNotNull(user) { "User required" }

Data Classes

data class User(val id: Long, val name: String) {
    init { require(name.isNotBlank()) }
}

Scope Functions

Function	Context	Returns	Use Case
`let`	it	Lambda result	Null-safe transforms
`apply`	this	Same object	Object configuration
`run`	this	Lambda result	Object scope + result
`also`	it	Same object	Side effects

Troubleshooting

Issue	Resolution
NPE despite null check	Check platform types from Java
Smart cast fails	Use local variable or let

Usage

Skill("kotlin-fundamentals")