From 0f1ea4aa2005e6ee991a052211455da60fc9ca92 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Fri, 21 May 2021 16:01:04 +0200
Subject: [PATCH] Further simplification

---
 .../schema/src/compiler/genunconverter.ts     | 23 ++++++++-----------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/implementations/javascript/packages/schema/src/compiler/genunconverter.ts b/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
index 9a9065d..e891910 100644
--- a/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
+++ b/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
@@ -17,19 +17,16 @@ export function unconverterForDefinition(
                         return [seq(`return `, unconverterFor(
                             ctx, p.pattern, hasValueField ? `${src}.value` : src))];
                     })))))];
-        case 'and': {
-            const ps = [def.pattern0, def.pattern1, ... def.patternN];
-            const cs = ps.flatMap(p => {
-                if (p._variant === 'anonymous' && p.value._variant === 'SimplePattern') {
-                    return [];
-                } else {
-                    return [unconverterForNamed(ctx, p, src)];
-                }
-            });
-            return [seq(`return `, (cs.length === 1)
-                ? cs[0]
-                : seq(`_.merge`, parens(`(a, b) => (a === b) ? a : void 0`, ... cs)))];
-        }
+        case 'and':
+            return [seq(`return _.merge`, parens(
+                `(a, b) => (a === b) ? a : void 0`,
+                ... [def.pattern0, def.pattern1, ... def.patternN].flatMap(p => {
+                    if (p._variant === 'anonymous' && p.value._variant === 'SimplePattern') {
+                        return [];
+                    } else {
+                        return [unconverterForNamed(ctx, p, src)];
+                    }
+                })))];
         case 'Pattern':
             return [seq(`return `, unconverterFor(ctx, def.value, `${src}`))];
     }