Hacker News new | ask | show | jobs
by midnight_eclair 77 days ago
> DSLs typically involves constructing macros that are domain specific

a DSL is a constrained language for expressing domain concepts.

in traditional Lisps they are often syntax-oriented, because code is lists and macros are a natural tool.

in Clojure, pervasive use of keywords, vectors and maps allows you to shift DSL design towards data interpretation rather than syntax transformation.

so in Clojure doesn't discourage DSLs - clojure practicioners simply prefer data-oriented DSLs to macro-oriented ones, mostly because they are easier to reason about and process with existing tools, while macros are used more selectively.
1 comments
geokon 77 days ago
The original comment you took issue with "The point being made is that the Clojure style discourages building DSLs and the like and prefers to remain close to Clojure types and constructs". You seemingly read half the sentence and in the most unfavorable way possible. (in context it's clearly not talking about "data-oriented DSLs)

> DSL is a constrained language for expressing domain concepts

What you're calling "data-oriented DSLs" is not constrained.

I guess this is all semantic, but in my book just specifying a data-structure doesn't make a language. You're not extending the host language in any way

link
midnight_eclair 76 days ago
> What you're calling "data-oriented DSLs" is not constrained

constraints come from the interpreter, not from the syntax

> in my book just specifying a data-structure doesn't make a language

correct, it does not

what makes it a language is defining constraints on that structure and rules for how it's interpreted

that works both for clojure (where the data structure can involve lists, vectors, maps and primitives) and traditional lisps (where data structure is lists, or to be precise cons cells and primitives)

in both cases macros can be used and are used (but don't have to be used) to prevent immediate evaluation of those data structures according to host language rules and instead change how they are evaluated according to DSL author's rules

for example, datomic queries are just data structures, but they clearly form a constrained language with well defined semantics and the fact that they're not implemented via macros doesn't make them less of a DSL

link