From 7286851015affcfec4c031ee6e6f7c75ec2b07c4 Mon Sep 17 00:00:00 2001
From: ecyrbe <ecyrbe@gmail.com>
Date: Tue, 1 Aug 2023 15:42:46 +0200
Subject: [PATCH] feat(match): allow to customize predicate

---
 src/internals/match/Match.ts      |  2 +-
 src/internals/match/impl/match.ts | 24 ++++++++++++++----------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/internals/match/Match.ts b/src/internals/match/Match.ts
index 3769ea6..de313cb 100644
--- a/src/internals/match/Match.ts
+++ b/src/internals/match/Match.ts
@@ -22,7 +22,7 @@ import * as Impl from "./impl/match";
  */
 export type Match<
   valueOrWithClauses = unset,
-  withClauses extends Impl.With<any, any, boolean>[] | unset | _ = unset
+  withClauses extends Impl.With<any, any, Fn>[] | unset | _ = unset
 > = PartialApply<
   MatchFn,
   withClauses extends unset
diff --git a/src/internals/match/impl/match.ts b/src/internals/match/impl/match.ts
index 8f34b71..6ffbb59 100644
--- a/src/internals/match/impl/match.ts
+++ b/src/internals/match/impl/match.ts
@@ -18,10 +18,6 @@ type ReplaceArgsWithConstraint<pattern> = pattern extends arg<
   ? { [key in keyof pattern]: ReplaceArgsWithConstraint<pattern[key]> }
   : pattern;
 
-type DoesMatch<value, pattern, exact extends boolean> = exact extends true ?
-  Equal<value, pattern> :
-  value extends ReplaceArgsWithConstraint<pattern> ? true : false;
-
 type ExtractArgObject<value, pattern> = pattern extends arg<infer N, any>
   ? { [K in N]: value }
   : pattern extends []
@@ -61,16 +57,24 @@ type ExtractArgs<value, pattern> = WithDefaultArgs<
   [value]
 >;
 
-export type Match<value, patterns extends With<any, any, boolean>[]> = patterns extends [
-  With<infer pattern, infer handler, infer exact>,
-  ...infer restPatterns extends With<any, any, boolean>[]
+interface PatternMatchFn extends Fn {
+  return: this["arg0"] extends ReplaceArgsWithConstraint<this["arg1"]> ? true : false;
+}
+
+interface ExactMatchFn extends Fn {
+  return: Equal<this["arg0"], this["arg1"]>;
+}
+
+export type Match<value, patterns extends With<any, any, Fn>[]> = patterns extends [
+  With<infer pattern, infer handler, infer predicate>,
+  ...infer restPatterns extends With<any, any, Fn>[]
 ]
-  ? DoesMatch<value, pattern, exact> extends true
+  ? Call<predicate, value, pattern> extends true
   ? handler extends Fn
   ? Call<PartialApply<Extract<handler, Fn>, ExtractArgs<value, pattern>>>
   : handler
   : Match<value, restPatterns>
   : never;
 
-export type With<pattern, handler, exact extends boolean = false> = { exact: exact; pattern: pattern; handler: handler };
-export type WithExact<pattern, handler> = With<pattern, handler, true>;
+export type With<pattern, handler, predicate extends Fn = PatternMatchFn> = { predicate: predicate; pattern: pattern; handler: handler };
+export type WithExact<pattern, handler> = With<pattern, handler, ExactMatchFn>;