Just pasted a huge JSON sequence into https://malli.io and got a nice, readable schema out, with optional values, sequences and everything in place. What a pleasure! Thanks! 🙏

Hi! I'm trying to mu/merge two specs [:map ...] and [:multi ... ]. Why I always have only one of them in a result? Is there any examples?

@mike1452 they are of different types and the last one wins (like with clojure.core/merge)

@ikitommi thanx.

but, the merge is far from perfect, not sure what happens if one merges two multis for example.

i would assume that they get merged together, but not sure if the impl has a special condition just for :map (should be for MapSchemas, which both multi and map are)

… with that change, could actually merge those togerher. not sure if that’s a good idea thou :thinking_face:

another question: when I generate multi spec, why I have random values in dispatch type instead of those values that in multi spec?

(def mumap
  [:multi {:dispatch :db/shared-channel}
   ["folder" [:map [:db/shared-channel string?] [:db/shared-channel-folder string?]]]
   ["web" [:map [:db/shared-channel string?] [:db/shared-channel-url string?]]]])

instead of "folder" and "web" in shared channel i have random values. I expect only these two values

the generator is picked from the multi branch, which doesn’t limit the key.

try:

[:map [:db/shared-channel [:= "folder"]] [:db/shared-channel-folder string?]]

It helps, thanks!

as the dispatch can be anything, it’s non-trivial to use the branch name in a generator automatically

I have data structure in which first half is always the same and second half is multi-spec based on :db/shared-channel value

(def sample1 {:db/type                  "h2",
              :h2/user                  "sa",
              :h2/filename              "./boxdb",

              :db/shared-channel        "folder",
              :db/shared-channel-folder "dev/resources/shared"})

(def sample2 {:db/type               "h2",
              :h2/user               "sa",
              :h2/filename           "./boxdb",

              :db/shared-channel     "web",
              :db/shared-channel-url ""})

I did multi spec

(def mumap
  [:multi {:dispatch :db/shared-channel}
   ["folder" [:map [:db/shared-channel [:= "folder"]] [:db/shared-channel-folder string?]
              [:db/type [:and string? [:fn {:error/message "should not be empty string"} not-empty-string?]]]
              [:h2/filename {:default "./boxdb"} string?]
              [:h2/user {:default "sa"} string?]]]
   ["web" [:map [:db/shared-channel [:= "web"]] [:db/shared-channel-url string?]
           [:db/type [:and string? [:fn {:error/message "should not be empty string"} not-empty-string?]]]
           [:h2/filename {:default "./boxdb"} string?]
           [:h2/user {:default "sa"} string?]]]])

Question: how to avoid duplication of first half? (merge is not work like in spec1)

I need something like:

[:map
 [:db/type [:and string? [:fn {:error/message "should not be empty string"} not-empty-string?]]]
 [:h2/filename {:default "./boxdb"} string?]
 [:h2/user {:default "sa"} string?]
 [:multi {:dispatch :db/shared-channel}
  ["folder" [:map [:db/shared-channel [:= "folder"]] [:db/shared-channel-folder string?]]]
  ["web" [:map [:db/shared-channel [:= "web"]] [:db/shared-channel-web string?]]]]]

many ways to do that, one would be to create a basemap, and merge that in all branches:

(def BaseMap
  [:map
   [:db/type [:and string? [:fn {:error/message "should not be empty string"} not-empty-string?]]]
   [:h2/filename {:default "./boxdb"} string?]
   [:h2/user {:default "sa"} string?]])

(def Multi
  [:multi {:dispatch :db/shared-channel}
    ["folder" (mu/merge BaseMap [:map [:db/shared-channel [:= "folder"]] [:db/shared-channel-folder string?]])]
    ["web" (mu/merge BaseMap [:map [:db/shared-channel [:= "web"]] [:db/shared-channel-web string?]]])]])

@ikitommi 👍

the oldest non-resolved issue in malli: https://github.com/metosin/malli/issues/14

kinda like select in spec2.

https://malli.io seems to fail to infer the schema of values containing instants. Example value:

{:some-date #inst "2020-02-02"}

I would not expect that. from a repl:

(require '[malli.provider :as mp])

(mp/provide [{:some-date #inst "2020-02-02"}])
; => [:map [:some-date inst?]]

@ikitommi for https://github.com/metosin/malli/issues/180, do we want to also add support for :+ :* :? and some other operators? in the :cat driven sequence?

I hope to start this issue if I have some time this weekend.

that would be awesome!

(if I have time)

did an intial spike, using the net.cgrand/seqexp , something like:

(def registry
  (merge
    default-registry
    {:cat (cat-schema :cat)
     :| (cat-schema :|)
     :* (regex-schema :* se/*)
     :*? (regex-schema : se/*?)
     :+ (regex-schema :+ se/+)
     :+? (regex-schema :+? se/+?)
     :? (regex-schema :? se/?)
     :?? (regex-schema :?? se/??)
     :repeat (regex-schema :repeat? se/repeat)
     :repeat? (regex-schema :repeat? se/repeat?)}))

didn’t get very far thou.

Could you push this to a branch ?

sure, doesn’t do anything thou

why not just "steal" the impl from spec?

Using malli.provider/provide does the trick! Thanks. I was surprised by what happened when I forgot to provide a sequence:

(mp/provide {:some-date #inst "2020-02-02"})
;; => [:vector some?]

com.github.metosin/malli {:git/url ""
                            :sha "9db4ff998b641d4a0cff4eb6d772fd0cb5d3b56c"}

taking the impl from spec is always an option.

last time I checked, the regexs where implemented using regular hashmaps in spec, would need at least some wrapping, don’t want to reserve maps for any one schema (family) type.

grand’s lib is 6y+ old, so “prior art” for this and all libs by Christophe have been great, also perf).

ok