fix #37 AppliedContext optimization

lynglib/src/commonMain/kotlin/net/sergeych/lyng/AppliedContext.kt

@@ -0,0 +1,17 @@
+package net.sergeych.lyng
+
+/**
+ * Special version of the [Context] used to `apply` new this object to
+ * _parent context property.
+ *
+ * @param _parent context to apply to
+ * @param args arguments for the new context
+ * @param appliedContext the new context to apply, it will have lower priority except for `this` which
+ *      will be reset by appliedContext's `this`.
+ */
+class AppliedContext(_parent: Context, args: Arguments, val appliedContext: Context)
+    : Context(_parent, args, appliedContext.pos, appliedContext.thisObj) {
+    override fun get(name: String): ObjRecord? =
+        if (name == "this") thisObj.asReadonly
+        else super.get(name) ?: appliedContext[name]
+}

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

@@ -387,14 +387,14 @@ class Compiler(
         val argsDeclaration = parseArgsDeclaration(cc)
         if (argsDeclaration != null && argsDeclaration.endTokenType != Token.Type.ARROW)
             throw ScriptError(startPos, "lambda must have either valid arguments declaration with '->' or no arguments")
-        val pos = cc.currentPos()
+
         val body = parseBlock(cc, skipLeadingBrace = true)
 
         var closure: Context? = null
 
         val callStatement = statement {
             // and the source closure of the lambda which might have other thisObj.
-            val context = closure!!.copy(pos, args).applyContext(this)
+            val context = AppliedContext(closure!!,args,this)
             if (argsDeclaration == null) {
                 // no args: automatic var 'it'
                 val l = args.list

lynglib/src/commonMain/kotlin/net/sergeych/lyng/Context.kt

@@ -1,6 +1,6 @@
 package net.sergeych.lyng
 
-class Context(
+open class Context(
     val parent: Context?,
     val args: Arguments = Arguments.EMPTY,
     var pos: Pos = Pos.builtIn,
@@ -13,15 +13,6 @@ class Context(
     )
             : this(Script.defaultContext, args, pos)
 
-    /**
-     * Making this context priority one
-     */
-    fun applyContext(other: Context): Context {
-        if (other.thisObj != ObjVoid) thisObj = other.thisObj
-        appliedContext = other
-        return this
-    }
-
     fun raiseNotImplemented(what: String = "operation"): Nothing = raiseError("$what is not implemented")
 
     @Suppress("unused")
@@ -74,15 +65,13 @@ class Context(
     inline fun <reified T : Obj> thisAs(): T = (thisObj as? T)
         ?: raiseClassCastError("Cannot cast ${thisObj.objClass.className} to ${T::class.simpleName}")
 
-    internal var appliedContext: Context? = null
     internal val objects = mutableMapOf<String, ObjRecord>()
 
-    operator fun get(name: String): ObjRecord? =
+    open operator fun get(name: String): ObjRecord? =
         if (name == "this") thisObj.asReadonly
         else {
             objects[name]
                 ?: parent?.get(name)
-                ?: appliedContext?.get(name)
         }
 
     fun copy(pos: Pos, args: Arguments = Arguments.EMPTY, newThisObj: Obj? = null): Context =
@@ -137,5 +126,4 @@ class Context(
 
     fun containsLocal(name: String): Boolean = name in objects
 
-
 }

lynglib/src/commonTest/kotlin/ScriptTest.kt

@@ -1,4 +1,3 @@
-package io.github.kotlin.fibonacci
 
 import kotlinx.coroutines.test.runTest
 import net.sergeych.lyng.*

lynglib/src/commonTest/kotlin/TypesTest.kt

@@ -0,0 +1,10 @@
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+
+class TypesTest {
+
+    @Test
+    fun testTypeCollection1() = runTest {
+
+    }
+}