Refactor host configuration handling and script definition creation

so it is possible now to create custom host configuration with template
and all configurations are handled consistenly.
Also introduce and use new ScriptDefinition class wrapping compilation
and evaluation configurations, that could be consistenly created from a
template.

libraries/scripting/jvm-host/src/kotlin/script/experimental/jvmhost/BasicJvmScriptingHost.kt

@@ -3,19 +3,18 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
+@file:Suppress("unused")
+
 package kotlin.script.experimental.jvmhost
 
 import kotlin.script.experimental.api.*
-import kotlin.script.experimental.host.ScriptingHostConfiguration
-import kotlin.script.experimental.host.createCompilationConfigurationFromTemplate
-import kotlin.script.experimental.host.BasicScriptingHost
-import kotlin.script.experimental.host.createEvaluationConfigurationFromTemplate
+import kotlin.script.experimental.host.*
 import kotlin.script.experimental.jvm.BasicJvmScriptEvaluator
 import kotlin.script.experimental.jvm.defaultJvmScriptingHostConfiguration
 
 open class BasicJvmScriptingHost(
-    val hostConfiguration: ScriptingHostConfiguration = defaultJvmScriptingHostConfiguration,
-    compiler: JvmScriptCompiler = JvmScriptCompiler(hostConfiguration),
+    val baseHostConfiguration: ScriptingHostConfiguration? = null,
+    compiler: JvmScriptCompiler = JvmScriptCompiler(baseHostConfiguration.withDefaultsFrom(defaultJvmScriptingHostConfiguration)),
     evaluator: ScriptEvaluator = BasicJvmScriptEvaluator()
 ) : BasicScriptingHost(compiler, evaluator) {
 
@@ -23,31 +22,43 @@ open class BasicJvmScriptingHost(
         script: SourceCode,
         noinline compilation: ScriptCompilationConfiguration.Builder.() -> Unit = {},
         noinline evaluation: ScriptEvaluationConfiguration.Builder.() -> Unit = {}
-    ): ResultWithDiagnostics<EvaluationResult> =
-        eval(
-            script,
-            createJvmCompilationConfigurationFromTemplate<T>(hostConfiguration, compilation),
-            createJvmEvaluationConfigurationFromTemplate<T>(hostConfiguration, evaluation)
-        )
+    ): ResultWithDiagnostics<EvaluationResult> {
+        val definition =
+            createJvmScriptDefinitionFromTemplate<T>(baseHostConfiguration, compilation, evaluation)
+        return eval(script, definition.compilationConfiguration, definition.evaluationConfiguration)
+    }
 }
 
 
 inline fun <reified T : Any> createJvmCompilationConfigurationFromTemplate(
-    hostConfiguration: ScriptingHostConfiguration = defaultJvmScriptingHostConfiguration,
+    baseHostConfiguration: ScriptingHostConfiguration? = null,
     noinline body: ScriptCompilationConfiguration.Builder.() -> Unit = {}
 ): ScriptCompilationConfiguration = createCompilationConfigurationFromTemplate(
     KotlinType(T::class),
-    hostConfiguration,
+    baseHostConfiguration.withDefaultsFrom(defaultJvmScriptingHostConfiguration),
     ScriptCompilationConfiguration::class,
     body
 )
 
 inline fun <reified T : Any> createJvmEvaluationConfigurationFromTemplate(
-    hostConfiguration: ScriptingHostConfiguration = defaultJvmScriptingHostConfiguration,
+    baseHostConfiguration: ScriptingHostConfiguration? = null,
     noinline body: ScriptEvaluationConfiguration.Builder.() -> Unit = {}
 ): ScriptEvaluationConfiguration = createEvaluationConfigurationFromTemplate(
     KotlinType(T::class),
-    hostConfiguration,
+    baseHostConfiguration.withDefaultsFrom(defaultJvmScriptingHostConfiguration),
     ScriptEvaluationConfiguration::class,
     body
 )
+
+inline fun <reified T : Any> createJvmScriptDefinitionFromTemplate(
+    baseHostConfiguration: ScriptingHostConfiguration? = null,
+    noinline compilation: ScriptCompilationConfiguration.Builder.() -> Unit = {},
+    noinline evaluation: ScriptEvaluationConfiguration.Builder.() -> Unit = {}
+): ScriptDefinition = createScriptDefinitionFromTemplate(
+    KotlinType(T::class),
+    baseHostConfiguration.withDefaultsFrom(defaultJvmScriptingHostConfiguration),
+    ScriptCompilationConfiguration::class,
+    compilation,
+    evaluation
+)
+