s interpolator constantenates

scala · Apr 5, 2023 · 59f62b5 · 59f62b5
1 parent b7d4a61
commit 59f62b5
Showing 1 changed file with 16 additions and 1 deletion.
diff --git a/src/compiler/scala/tools/reflect/FastStringInterpolator.scala b/src/compiler/scala/tools/reflect/FastStringInterpolator.scala
@@ -12,6 +12,8 @@
 
 package scala.tools.reflect
 
+import scala.PartialFunction.cond
+
 trait FastStringInterpolator extends FormatInterpolator {
   import c.universe._
 
@@ -57,7 +59,20 @@ trait FastStringInterpolator extends FormatInterpolator {
           case iue: StringContext.InvalidUnicodeEscapeException => c.abort(parts.head.pos.withShift(iue.index), iue.getMessage)
         }
 
-      concatenate(treated, args)
+      if (args.forall(cond(_) { case Literal(c @ Constant(_)) => c.isSuitableLiteralType })) {
+        val it1 = treated.iterator
+        val it2 = args.iterator
+        val res = new StringBuilder
+        def add(t: Tree) = res.append(t.asInstanceOf[Literal].value.value)
+        add(it1.next())
+        while (it2.hasNext) {
+          add(it2.next())
+          add(it1.next())
+        }
+        val k = Constant(res.toString)
+        Literal(k).setType(ConstantType(k))
+      }
+      else concatenate(treated, args)
 
     // Fallback -- inline the original implementation of the `s` or `raw` interpolator.
     case t@Apply(Select(someStringContext, _interpol), args) =>