Merge pull request #5399 from poorna2152/master_worker_with_on_fail

[Master] Add named worker with on fail clause bbe

examples/index.json

@@ -1482,6 +1482,13 @@
         "verifyOutput": true,
         "isLearnByExample": true
       },
+      {
+        "name": "Named worker with on fail clause",
+        "url": "named-worker-with-on-fail-clause",
+        "verifyBuild": true,
+        "verifyOutput": true,
+        "isLearnByExample": true
+      },
       {
         "name": "Synchronize message passing",
         "url": "synchronize-message-passing",

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.bal

@@ -0,0 +1,20 @@
+import ballerina/io;
+
+public function main() {
+    int[] values = [2, 3, 4, 5];
+    int value = 0;
+
+    worker w1 {
+        int index = check getIndex(values, value);
+        index -> function;
+    } on fail {
+        // Handle the error thrown in the worker body.
+        -1 -> function;
+    }
+
+    int|error:NoMessage result = <- w1 | w1;
+    io:println(result);
+}
+
+function getIndex(int[] values, int value) returns int|error =>
+    let int? index = values.indexOf(value) in index ?: error("value not found");

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.md

@@ -0,0 +1,7 @@
+# Named worker with on fail clause
+
+The `on fail` clause can be used with a named worker, to handle any errors that occur within the worker's body.
+
+::: code named_worker_with_on_fail_clause.bal :::
+
+::: out named_worker_with_on_fail_clause.out :::

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.metatags

@@ -0,0 +1,2 @@
+description: This BBE demonstrates the use of `on fail` clause with named workers
+keywords: ballerina, ballerina by example, bbe, worker, named workers, on fail

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.out

@@ -0,0 +1,2 @@
+$ bal run named_worker_with_on_fail_clause.bal
+-1