Malli Compatibility Matrix¶

Balli is a Malli clone for Basilisp. This matrix tracks the major Malli feature families Balli covers and calls out runtime or ecosystem differences where Basilisp/Python diverge from Clojure/JVM.

Area	Balli status
Vector syntax	Supported
Map syntax / schema AST	Supported via raw schema input, balli.core/ast, and balli.core/from-ast
Lite syntax	Supported explicitly via balli.lite/form and balli.lite/schema
Validation / explain / humanize	Supported
Spell checking and custom messages	Supported, including schema messages, locale maps, caller overrides, and global message formatting
Value transformation / coercion	Supported, including non-throwing reports and roundtrip checks
Integration transformer presets	Supported for env/config maps, query params, and JSON API payloads
Parse / unparse	Supported
Sequence regex schemas	Supported
:seqable / :every	Supported, including bounded-prefix :every checks
Function schemas / instrumentation	Supported, including :->, :=>, :function, wrapper ergonomics, and contract metadata
Generative function checking	Supported
Value generation / sampling	Supported
Reusable generator objects	Supported via balli.generator/generator and :gen/gen
Generator combinators	Supported via Balli-native generator objects (return, elements, fmap, bind)
Generator property checks	Supported via balli.generator/check and check-roundtrip reports
Shrinking	Heuristic Balli shrinker with shrink-trace; not Clojure test.check shrinking
Provider inference	Supported
Provider closed-map/common-key inference	Supported via {:closed-maps true} and {:optional-threshold f} metadata
Provider fit reports	Supported via balli.provider/provide-report
Destructuring	Supported via balli.destructure
Immutable/custom registries	Supported
Mutable default registry	Supported
Dynamic registry	Supported
Lazy registry	Supported
Local property registry	Supported
Var registry	Supported via derefable schema refs
JSON Schema export	Supported
OpenAPI / Swagger export	Supported
DOT / PlantUML visualization	Supported
English descriptions	Supported
malli.util-style map introspection	Supported via entries, keys, required-key?, and optional-key?
malli.util-style map surgery	Supported via set-entry, update-entry, rename-keys, and transform-entries
malli.util-style path utilities	Supported via path-map, update-at, and diff
EDN schema persistence	Supported safely via named function refs
Experimental schema analysis	Balli-native data-only helpers via balli.experimental, including dependency graphs, migration impact, and risk reports
Python ecosystem integrations	Supported at adapter boundaries via balli.integrations, including callable validators and coercers
Static schema inspection	Supported via balli.inspect
SCI integration	Data-only host context via balli.sci; no Clojure SCI runtime
clj-kondo / static analyzer integration	Data export via balli.clj-kondo; no Clojure analyzer runtime
malli.experimental	Not ported as executable Clojure experimental APIs

Compatibility Corpus Categories¶

The executable corpus in tests/test_compatibility_corpus.lpy uses three working categories:

• Supported: behavior Balli implements and tests directly.
• Intentionally different: behavior Balli documents where Python/Basilisp semantics differ from JVM/Clojure, such as scalar type distinctions.
• Not applicable: Clojure runtime ecosystem APIs that do not have a direct Basilisp/Python equivalent, such as browser/ClojureScript integrations.

Evidence¶

Compatibility claims are backed by CI tests where practical. See Compatibility Evidence and tests/test_compatibility_corpus.lpy for the executable corpus.