Add Apache JEXL as a dependency, as part of an exploration of on-the-fly contract specialisation (this solution may not be taken forward but suffices to unblock other work)

build.gradle

@@ -91,6 +91,11 @@ dependencies {
     compile("com.intellij:forms_rt:7.0.3") {
         exclude group: "asm"
     }
+
+    // Force commons logging to version 1.2 to override Artemis, which pulls in 1.1.3 (ARTEMIS-424)
+    compile("commons-logging:commons-logging:1.2") {
+        force = true
+    }
 }
 
 // These lines tell Gradle to add a couple of JVM command line arguments to unit test and program runs, which set up

core/build.gradle

@@ -42,5 +42,9 @@ dependencies {
     compile "io.reactivex:rxkotlin:0.40.1"
 
     // Quasar: for the bytecode rewriting for state machines.
-    compile("co.paralleluniverse:quasar-core:${quasar_version}:jdk8")
+    compile "co.paralleluniverse:quasar-core:${quasar_version}:jdk8"
+
+    // Apache JEXL: An embeddable expression evaluation library.
+    // This may be temporary until we experiment with other ways to do on-the-fly contract specialisation via an API.
+    compile "org.apache.commons:commons-jexl3:3.0"
 }

core/src/test/kotlin/core/utilities/EmbeddedExpressionsTest.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2015 Distributed Ledger Group LLC.  Distributed as Licensed Company IP to DLG Group Members
+ * pursuant to the August 7, 2015 Advisory Services Agreement and subject to the Company IP License terms
+ * set forth therein.
+ *
+ * All other rights reserved.
+ */
+
+package core.utilities
+
+import org.apache.commons.jexl3.JexlBuilder
+import org.apache.commons.jexl3.MapContext
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class EmbeddedExpressionsTest {
+    @Test
+    fun basic() {
+        val jexl = JexlBuilder().create()
+        val result = jexl.createExpression("2 + 2").evaluate(MapContext())
+        assertEquals(4, result)
+    }
+}