add kotlin API

mirai-console/src/main/kotlin/net/mamoe/mirai/console/utils/Utils.kt

@@ -1,23 +1,57 @@
 package net.mamoe.mirai.console.utils
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
 
 /**
  * 执行N次 builder
  * 成功一次就会结束
  * 否则就会throw
  */
-inline fun <T> tryNTimes(n:Int = 2, builder: () -> T):T {
-    var lastException: Exception? = null
-
+@OptIn(ExperimentalContracts::class)
+@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE", "RESULT_CLASS_IN_RETURN_TYPE")
+@kotlin.internal.InlineOnly
+inline fun <R> retryCatching(n: Int, block: () -> R): Result<R> {
+    contract {
+        callsInPlace(block, InvocationKind.AT_LEAST_ONCE)
+    }
+    require(n >= 0) { "param n for retryCatching must not be negative" }
+    var exception: Throwable? = null
     repeat(n){
         try {
-            return builder.invoke()
-        } catch (e: Exception) {
-            lastException = e
+            return Result.success(block())
+        } catch (e: Throwable) {
+            exception?.addSuppressedMirai(e)
+            exception = e
+        }
+    }
+    return Result.failure(exception!!)
+}
+
+@OptIn(ExperimentalContracts::class)
+inline fun <T> tryNTimes(n: Int, block: () -> T):T {
+    contract {
+        callsInPlace(block, InvocationKind.AT_LEAST_ONCE)
+    }
+    require(n >= 0) { "param n for tryNTimes must not be negative" }
+    var last:Exception? = null
+    repeat(n){
+        try {
+            return block.invoke()
+        }catch (e:Exception){
+            last = e
         }
     }
 
-    throw lastException!!
+    throw last!!
 }
 
-
-
+@PublishedApi
+internal fun Throwable.addSuppressedMirai(e: Throwable) {
+    if (e === this) {
+        return
+    }
+    kotlin.runCatching {
+        this.addSuppressed(e)
+    }
+}