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Interview: Lennart Augustsson on DSLs Written in Haskell


In this interview filmed at QCon SF 2008, Lennart Augustsson talks about writing DSLs in Haskell, presenting the advantages offered by the language. In that context, he talks about embedded DSLs, static and dynamic languages, syntax and semantics, monads and many other related topics.

Watch: Lennart Augustsson on DSLs Written in Haskell (25 min.)

Lennart starts by making a distinction between external DSLs - programming languages written in another language - and internal or embedded DSLs. He points out to the simple Haskell syntax which helps building a cleaner DSL. Also, he advertises Haskell’s closures allowing for lazy evaluation of code.

While some advocate Ruby and SmallTalk for writing DSLs due to their dynamic behavior, Lennart dismisses the claims that a statically typed language can’t be as useful as a dynamic one. He does not see any impediment in a static language when it comes to DSLs, but there rather benefits due to compile time type checking which eliminates some of the errors.

Lennart answers other questions about Haskell and it’s ability to write good DSLs. He also mentions F# and Scala as languages which are poised to become mainstream.

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Community comments

  • Industrial maturity?

    by Steve Van Hoyweghen,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    Funny I’m bumping into Haskell in a DSL context after all these years again. I used it in the context of my master thesis: However not much heard about it since then …

  • DSL in Java and Haskell

    by Kamil D. Skajotde,

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    From some times I'm interested in DSL and readable domain, specially in Java. Java has few important limitations to implement elegant DSL. After this article I plan to try Haskell, but it looks like it doesn't have good integration with JVM. I'll compare Haskell with Scala which is also static typed and is more abstract than Java.

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