Purescript
Haskellっぽく、高度な型システムと強力な型推論、純粋な計算と副作用の分離、そしてJavascriptに簡単にコンパイルできる小さな言語です。
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The unsafe side
I like Haskell and Purescript, and I love telling people how safe they are. However, they are not perfect, there are still unsafe aspects and I have to be honest about them. "If it compiles, it works" isn't always true.