refs #22 more docs, fixed EH bug

+shortcut throw "message"

library/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt

@@ -725,7 +725,9 @@ class Compiler(
     private fun parseThrowStatement(cc: CompilerContext): Statement {
         val throwStatement = parseStatement(cc) ?: throw ScriptError(cc.currentPos(), "throw object expected")
         return statement {
-            val errorObject = throwStatement.execute(this)
+            var errorObject = throwStatement.execute(this)
+            if( errorObject is ObjString )
+                errorObject = ObjException(this, errorObject.value)
             if( errorObject is ObjException )
                 raiseError(errorObject)
             else raiseError("this is not an exception object: $errorObject")
@@ -816,11 +818,10 @@ class Compiler(
                     for (exceptionClassName in cdata.classNames) {
                         val exObj = ObjException.getErrorClass(exceptionClassName)
                             ?: raiseSymbolNotFound("error clas not exists: $exceptionClassName")
-                        println("exObj: $exObj")
-                        println("objException: ${objException.objClass}")
-                        if( objException.isInstanceOf(exObj) )
+                        if( objException.isInstanceOf(exObj) ) {
                             exceptionObject = objException
                             break
+                        }
                     }
                     if( exceptionObject != null ) {
                         val catchContext = this.copy(pos = cdata.catchVar.pos)

library/src/commonMain/kotlin/net/sergeych/lyng/Obj.kt

@@ -347,13 +347,16 @@ open class ObjException(exceptionClass: ExceptionClass, val context: Context, va
 
         class ExceptionClass(val name: String,vararg parents: ObjClass) : ObjClass(name, *parents) {
             override suspend fun callOn(context: Context): Obj {
-                return ObjException(this, context, name).apply {
-                    println(">>>> "+this)
-                }
+                val message = context.args.getOrNull(0)?.toString() ?: name
+                return ObjException(this, context, message)
             }
             override fun toString(): String = "ExceptionClass[$name]@${hashCode().encodeToHex()}"
         }
-        val Root = ExceptionClass("Throwable")
+        val Root = ExceptionClass("Throwable").apply {
+            addConst("message", statement {
+                (thisObj as ObjException).message.toObj()
+            })
+        }
 
         private val op = ProtectedOp()
         private val existingErrorClasses = mutableMapOf<String, ExceptionClass>()

library/src/commonTest/kotlin/ScriptTest.kt

@@ -1813,4 +1813,24 @@ class ScriptTest {
         """.trimIndent())
     }
 
+    @Test
+    fun testAccessEHData() = runTest {
+        eval("""
+            val x = IllegalArgumentException("test")
+            val m = try {
+                throw x
+                null
+            }
+            catch(e) {
+                println(e)
+                println(e::class)
+                println(e.message)
+                println("--------------")
+                e.message    
+            }
+            println(m)
+            assert( m == "test" )
+            """.trimIndent())
+    }
+
 }

library/src/jvmTest/kotlin/BookTest.kt

@@ -268,4 +268,9 @@ class BookTest {
     fun testArgumentBooks() = runTest {
         runDocTests("../docs/declaring_arguments.md")
     }
+
+    @Test
+    fun testExceptionsBooks() = runTest {
+        runDocTests("../docs/exceptions_handling.md")
+    }
 }