Just finished reading through Racket's lens library to compare. Specter can do everything that Racket's lens library can do, but the converse is not true. Specter's navigators can do more than lenses.
The lens-like navigators are the most obviously useful parts of Specter, and maybe for some people that's all they need and they would prefer to hide the other functionality. If so, it looks to me like it would be trivial to build a lens library like Racket's out of Specter, and it would almost certainly be higher performance than the "obvious" implementation of lenses. But I don't agree at all with the claim that Specter is some sort of offbeat, ill-researched version of lenses. It is something more advanced. If Nathan had constrained his thinking to these other approaches, Specter wouldn't have such richness of functionality and pragmatic performance considerations. On Wed, Mar 8, 2017 at 5:35 PM, Brandon Bloom <brandon.d.bl...@gmail.com> wrote: > Responsible adults sometimes needs to access and modify deeply nested data >> structures > > > So far, my experience has been that it is almost always better to build a > pair of flattening and unflattening transforms on the data. Especially > since you frequently want only one flattening, but potentially many > un-flattenings. The "unflattened" form (aka "documents") is usually an > end-point where data goes to die; assuming it isn't immediately displayed > on the screen. > > However, having said that, path-dependent / context-sensitive query is a > very rich and interesting space that does have meaningful utility, > especially in the context of graph-like datasets. This is especially true > when combined with some kind of algebra for unioning/intersecting/etc. I'm > also interested in this sort of thing for programmable user-interface use > cases: Think text editors with multiple-cursors. > > I think experimentation is in order >> > > Agreed. Here's some starting points for pre-hammock reading/viewing > materials: > > *Tree Traversal * > > - XPath: https://www.w3.org/TR/xpath/ > - CSS: https://www.w3.org/TR/css3-selectors/ > > *Richer Tree Querying* > > - XQuery: https://www.w3.org/TR/xquery/ > - jQuery: https://api.jquery.com > > *Second-Class "Generalized References" (nee "L-values")* > > - Common Lisp: http://www.lispworks.com/documentation/lw50/CLHS/ > Body/05_a.htm > - C/C++: http://eli.thegreenplace.net/2011/12/15/ > understanding-lvalues-and-rvalues-in-c-and-c > > <http://eli.thegreenplace.net/2011/12/15/understanding-lvalues-and-rvalues-in-c-and-c> > > *Lenses in Other Languages* > > - Haskell: https://skillsmatter.com/skillscasts/4251-lenses- > compositional-data-access-and-manipulation > > <https://skillsmatter.com/skillscasts/4251-lenses-compositional-data-access-and-manipulation> > (great overview of key concepts!) > - Racket: https://docs.racket-lang.org/lens/index.html > > *Graph Querying* > > - Neo4j Cypher: https://neo4j.com/developer/cypher-query-language/ > - TinkerPop Gremlin: https://tinkerpop.apache.org/gremlin.html > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
