Robust :and parser, add :andn
#1182
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frenchy64
changed the title
:and parser, add :andn:and parser, add :andn
| ; :flat [#malli.core.Tag{:key :name, :value "x"} | ||
| ; #malli.core.Tag{:key :id, :value 1} | ||
| ; #malli.core.Tag{:key :name, :value "y"} | ||
| ; #malli.core.Tag{:key :id, :value 2}]}} |
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yeah, this behaviour makes sense, I get it
| (if (-ref-schema? this) | ||
| (-parser-info (-deref this)) | ||
| (when (-> this -parent -type-properties ::simple-parser) | ||
| {:simple-parser true})))) |
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what's the need for both ParserInfo and -type-properties ::simple-parser?
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Could get away with just ParserInfo. It seemed neater at the time to have it at the type-level for trivial types.
| (defmethod accept :orn [_ s children _] | ||
| (let [children (map last children) | ||
| base (-base s children)] | ||
| (assoc base :x-anyOf children))) |
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thanks for adding this missing case!
| (reduced ::invalid) | ||
| (cond-> acc | ||
| (not simple) (conj v'))))) | ||
| (if simple x []) x)] |
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I didn't understand the changes around here. Is there a corresponding test?
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Since we know the child has a simple parser, we don't need to rebuild the result, since it means the results of parsing is either ::invalid or x.
The "then" branch of malli.parser/ensure-parser-type tests this. For example, [:vector ::HOLE] with ::HOLE being a simple parsing schema like :any is expected to be a simple parser (expected-simple == true) so any mg/samples we take of it will {un}parse back to the identical sampled value.
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aha, this is the optimisation you mention in the PR description, right?
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Yes, specifically for :map-of, -collection-schema, and :map's default value.
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Letting @ikitommi have a look as well. |
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Thanks for looking @opqdonut. |
Close #1166
Close #1173
This tightens up
-parserfor:andin several ways.The essential insight is that there are two kinds of parsers, I'm calling transforming (e.g.,
:orn,-collection-schema) and simple (e.g.,:any,-simple-schema). Simple parsers return identical input on success. Everything else is transforming.In all cases I've seen so far, it's possible to accurately predict whether a parser is simple based on its schema. With this information, we can now improve
:and's parser by::andThis automatically handles
[:and S [:fn ..]]and makes it more robust, as:fnis now passed the input value instead of the parsed value and the conjuncts can be in any order.Extras:
Adds a new schema
:andnfor when you really want multiple transforming parsers in a conjunction. It reparses the input for each conjunct and returns in a Tags. Unparser only unparses the leftmost child, which enables users to transform the unparsed results by removing the other results.We can now more aggressively optimize simple (un)parsers upfront to not build a result when it will be identical to the input.
Includes a fix for #1173 by bumping up the
:max-triesfor generating distinct vectors.