Setup project with KotlinType operations API for plugin

core/build.gradle.kts

@@ -45,6 +45,7 @@ dependencies {
     implementation(libs.kotlin.stdlib.jdk8)
     // TODO: check if all compiler tests run pass with implementation
     api("org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.0-RC")
+    api(project(":type-api"))
 
     api(libs.commonsCsv)
     implementation(libs.klaxon)

settings.gradle.kts

@@ -35,4 +35,4 @@ include("dataframe-excel")
 include("core")
 include("plugins:dataframe-introspection")
 findProject(":plugins:dataframe-introspection")?.name = "dataframe-introspection"
-
+include("type-api")

type-api/build.gradle.kts

@@ -0,0 +1,32 @@
+plugins {
+    kotlin("jvm") version "1.7.10"
+    id("java")
+    kotlin("libs.publisher") version "0.0.60-dev-30"
+}
+
+group = "org.jetbrains.kotlinx.dataframe"
+version = "0.9.0-dev"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    compileOnly(kotlin("compiler-embeddable"))
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.8.1")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.8.1")
+}
+
+tasks.getByName<Test>("test") {
+    useJUnitPlatform()
+}
+
+kotlinPublications {
+    publication {
+        publicationName.set("api")
+        artifactId.set("types-api")
+        description.set("Data processing in Kotlin")
+        packageName.set(artifactId)
+    }
+}
+

type-api/settings.gradle.kts

@@ -0,0 +1,2 @@
+rootProject.name = "type-api"
+

type-api/src/main/kotlin/org/jetbrains/kotlinx/dataframe/Main.kt

@@ -0,0 +1,46 @@
+package org.jetbrains.kotlinx.dataframe
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+
+val DF_CLASS_ID: ClassId
+    get() = ClassId.topLevel(FqName.fromSegments(listOf("org", "jetbrains", "kotlinx", "dataframe", "DataFrame")))
+
+val COLUM_GROUP_CLASS_ID: ClassId
+    get() = ClassId(FqName("org.jetbrains.kotlinx.dataframe.columns"), Name.identifier("ColumnGroup"))
+
+class KotlinTypeFacade(private val session: FirSession) {
+
+    val anyDataFrame = ConeClassLikeTypeImpl(
+        ConeClassLikeLookupTagImpl(DF_CLASS_ID),
+        typeArguments = arrayOf(session.builtinTypes.anyType.type),
+        isNullable = false
+    ).wrap()
+
+    fun Marker.toColumnGroup() = ConeClassLikeTypeImpl(
+        ConeClassLikeLookupTagImpl(COLUM_GROUP_CLASS_ID),
+        typeArguments = arrayOf(type.typeArguments[0]),
+        isNullable = false
+    ).wrap()
+
+}
+
+class Marker(internal val type: ConeKotlinType) {
+    override fun toString(): String {
+        return "Marker(type=$type)"
+    }
+}
+
+class LazyMarker(internal val factory: (FirSession) -> ConeKotlinType)
+
+fun ConeKotlinType.wrap(): Marker = Marker(this)
+
+//fun ConeKotlinType
+
+
+