[truffle] Implement str to int coercion

Author: pmurias

src/vm/jvm/Truffle.nqp

@@ -818,6 +818,9 @@ class QAST::TruffleCompiler does SerializeOnce {
                 if $got == $NUM {
                     return TAST.new($INT, ['coerce-num-to-int', $tast.tree]);
                 }
+                if $got == $STR {
+                    return TAST.new($INT, ['coerce-str-to-int', $tast.tree]);
+                }
             }
 
             # TODO - Perl 6 proper does it differently than nqp

src/vm/jvm/runtime/org/perl6/nqp/truffle/nodes/expression/NQPCoerceStrToIntNode.java

@@ -0,0 +1,27 @@
+package org.perl6.nqp.truffle.nodes.expression;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.nodes.NodeInfo;
+import org.perl6.nqp.truffle.nodes.NQPNode;
+import org.perl6.nqp.truffle.nodes.NQPIntNode;
+import org.perl6.nqp.dsl.Deserializer;
+
+@NodeInfo(shortName = "coerce an str to int")
+public final class NQPCoerceStrToIntNode extends NQPIntNode {
+    @Child private NQPNode argNode;
+
+    @Deserializer("coerce-str-to-int")
+    public NQPCoerceStrToIntNode(NQPNode argNode) {
+        this.argNode = argNode;
+    }
+
+    @Override
+    public long executeInt(VirtualFrame frame) {
+        String value = argNode.executeStr(frame);
+        try {
+            return Long.parseLong(value);
+        }
+        catch (NumberFormatException e) {
+            return 0;
+        }
+    }
+}