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| -rw-r--r-- | chapter/4/dist-langs.md | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/chapter/4/dist-langs.md b/chapter/4/dist-langs.md index 39da2d0..fd9a7d3 100644 --- a/chapter/4/dist-langs.md +++ b/chapter/4/dist-langs.md @@ -414,18 +414,35 @@ Actors: * Message-passing chapter -## Support for Distribution +## Thoughts on System Design ### Intro -* What is a DSL? +The definition of a domain-specific language is a hot topic and there have been several attempts to concretely define what exactly *it* is. + +Here is the definition as given by { // TODO cite when and how }: > Domain-specific languages are languages tailored to a specific application domain. -Another definition: +Another definition is offered (and commonly cited) by { // TODO cite annotated bib }: > A domain-specific language is a programming language or executable specification language that offers, through appropriate notations and abstractions, expressive power focused on, and usually restricted to, a particular problem domain. +Generally, I would refer to a domain-specific language (DSL) as a *system*, be it a standalone language, compiler extension, library, set of macros, etc., that is designed for common operations in a problem domain to be easily expressed. + +For example, the python twitter library is designed for easily expressing operations that manage a twitter account. + +The problem in defining this term (I believe) is the the vagueness of the components *domain* and *language*. +Depending on the classification, a set of problems designated in a certain domain may span a "wide" or "narrow" scope. +For example, does "tweeting" qualify as a domain (within the twitter library)? +Would "social media sharing" qualify as a domain (containing the twitter library)? +For my purposes I will accept the definition of a domain as a "well-defined, highly cohesive set of operations." + +It is also difficult to come up with a definition for a language. +A language may be qualified if it has its own compiler. +An orthogonal definition qualifies a language by its style, as in the case of sets of macros. +This confusion is why I adopt the even more vague term of *system* in my own definition. + ### Where is it in the stack? * Libraries: |