diff --git a/compiler/src/prog8/compiler/Compiler.kt b/compiler/src/prog8/compiler/Compiler.kt
index 27472c2cc..d9d9f214c 100644
--- a/compiler/src/prog8/compiler/Compiler.kt
+++ b/compiler/src/prog8/compiler/Compiler.kt
@@ -18,6 +18,7 @@ import prog8.compiler.target.ICompilationTarget
 import prog8.compiler.target.asmGeneratorFor
 import prog8.optimizer.*
 import prog8.parser.ParsingFailedError
+import prog8.parser.SourceCode
 import prog8.parser.SourceCode.Companion.libraryFilePrefix
 import java.io.File
 import java.nio.file.Path
@@ -185,9 +186,8 @@ fun parseImports(filepath: Path,
     importedModuleResult.onFailure { throw it }
     errors.report()
 
-    val importedFiles = programAst.modules
-        .mapNotNull { it.source }
-        .filter { !it.isFromResources } // TODO: parseImports/importedFiles - maybe rather `source.isFromFilesystem`?
+    val importedFiles = programAst.modules.map { it.source }
+        .filter { it !is SourceCode.Generated && !it.isFromResources }  // TODO: parseImports/importedFiles - maybe rather `source.isFromFilesystem`?
         .map { Path(it.pathString()) }
     val compilerOptions = determineCompilationOptions(programAst, compTarget)
     if (compilerOptions.launcher == LauncherType.BASIC && compilerOptions.output != OutputType.PRG)
diff --git a/compiler/src/prog8/compiler/ModuleImporter.kt b/compiler/src/prog8/compiler/ModuleImporter.kt
index 2e5ec5fca..f8979f9fa 100644
--- a/compiler/src/prog8/compiler/ModuleImporter.kt
+++ b/compiler/src/prog8/compiler/ModuleImporter.kt
@@ -42,7 +42,7 @@ class ModuleImporter(private val program: Program,
         val logMsg = "importing '${filePath.nameWithoutExtension}' (from file $srcPath)"
         println(logMsg)
 
-        return Ok(importModule(SourceCode.fromPath(srcPath)))
+        return Ok(importModule(SourceCode.File(srcPath)))
     }
 
     fun importLibraryModule(name: String): Module? {
@@ -110,11 +110,11 @@ class ModuleImporter(private val program: Program,
     private fun tryGetModuleFromResource(name: String, compilationTargetName: String): SourceCode? {
         // try target speficic first
         try {
-            return SourceCode.fromResources("/prog8lib/$compilationTargetName/$name")
+            return SourceCode.Resource("/prog8lib/$compilationTargetName/$name")
         } catch (e: FileSystemException) {
         }
         try {
-            return SourceCode.fromResources("/prog8lib/$name")
+            return SourceCode.Resource("/prog8lib/$name")
         } catch (e: FileSystemException) {
         }
         return null
@@ -134,7 +134,7 @@ class ModuleImporter(private val program: Program,
 
         locations.forEach {
             try {
-                return SourceCode.fromPath(it.resolve(fileName))
+                return SourceCode.File(it.resolve(fileName))
             } catch (e: NoSuchFileException) {
             }
         }
diff --git a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
index cafce0d3c..511ba12a3 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
@@ -13,6 +13,7 @@ import prog8.compiler.ZeropageType
 import prog8.compiler.functions.BuiltinFunctions
 import prog8.compiler.functions.builtinFunctionReturnType
 import prog8.compiler.target.ICompilationTarget
+import prog8.parser.SourceCode
 import java.io.CharConversionException
 import java.io.File
 import java.util.*
@@ -726,20 +727,16 @@ internal class AstChecker(private val program: Program,
         if (File(filename).isFile)
             return
 
-        var definingModule = directive.parent   // TODO: why not just use directive.definingModule() here?
-        while (definingModule !is Module)
-            definingModule = definingModule.parent
-        if (definingModule.isLibrary)
+        val definingModule = directive.definingModule
+        if (definingModule.isLibrary || definingModule.source is SourceCode.Generated)
             return
 
-        val s = definingModule.source?.pathString()
-        if (s != null) {
-            val sourceFileCandidate = Path(s).resolveSibling(filename).toFile()
-            if (sourceFileCandidate.isFile)
-                return
-        }
-
-        errors.err("included file not found: $filename", directive.position)
+        val s = definingModule.source.pathString()
+        val sourceFileCandidate = Path(s).resolveSibling(filename).toFile()
+        if (sourceFileCandidate.isFile)
+            return
+        else
+            errors.err("included file not found: $filename", directive.position)
     }
 
     override fun visit(array: ArrayLiteralValue) {
diff --git a/compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt b/compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt
index 3ff00f288..f383eb1be 100644
--- a/compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt
+++ b/compiler/src/prog8/compiler/target/cpu6502/codegen/AsmGen.kt
@@ -1325,7 +1325,7 @@ $repeatLabel    lda  $counterVar
             "%asminclude" -> {
                 // TODO: handle %asminclude with SourceCode
                 val includedName = stmt.args[0].str!!
-                val sourcePath = Path(stmt.definingModule.source!!.pathString()) // FIXME: %asminclude inside non-library, non-filesystem module
+                val sourcePath = Path(stmt.definingModule.source.pathString()) // FIXME: %asminclude inside non-library, non-filesystem module
                 loadAsmIncludeFile(includedName, sourcePath).fold(
                     success = { assemblyLines.add(it.trimEnd().trimStart('\n')) },
                     failure = { errors.err(it.toString(), stmt.position) }
@@ -1335,7 +1335,7 @@ $repeatLabel    lda  $counterVar
                 val includedName = stmt.args[0].str!!
                 val offset = if(stmt.args.size>1) ", ${stmt.args[1].int}" else ""
                 val length = if(stmt.args.size>2) ", ${stmt.args[2].int}" else ""
-                val sourcePath = Path(stmt.definingModule.source!!.pathString()) // FIXME: %asmbinary inside non-library, non-filesystem module
+                val sourcePath = Path(stmt.definingModule.source.pathString()) // FIXME: %asmbinary inside non-library, non-filesystem module
                 val includedPath = sourcePath.resolveSibling(includedName)
                 val pathForAssembler = outputDir // #54: 64tass needs the path *relative to the .asm file*
                     .absolute() // avoid IllegalArgumentExc due to non-absolute path .relativize(absolute path)
diff --git a/compiler/test/AsmgenTests.kt b/compiler/test/AsmgenTests.kt
index f1f385f37..c0440c54c 100644
--- a/compiler/test/AsmgenTests.kt
+++ b/compiler/test/AsmgenTests.kt
@@ -15,6 +15,7 @@ import prog8.compiler.*
 import prog8.compiler.target.C64Target
 import prog8.compiler.target.c64.C64MachineDefinition
 import prog8.compiler.target.cpu6502.codegen.AsmGen
+import prog8.parser.SourceCode
 import prog8tests.helpers.DummyFunctions
 import prog8tests.helpers.DummyMemsizer
 import java.nio.file.Path
@@ -67,7 +68,7 @@ locallabel:
         val varInBlock = VarDecl(VarDeclType.VAR, DataType.UWORD, ZeropageWish.DONTCARE, null, "var_outside", null, false, false, false, Position.DUMMY)
         val block = Block("main", null, mutableListOf(labelInBlock, varInBlock, subroutine), false, Position.DUMMY)
 
-        val module = Module("test", mutableListOf(block), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(block), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
diff --git a/compiler/test/TestMemory.kt b/compiler/test/TestMemory.kt
index 6f6fef236..07982be04 100644
--- a/compiler/test/TestMemory.kt
+++ b/compiler/test/TestMemory.kt
@@ -14,6 +14,7 @@ import prog8.ast.expressions.NumericLiteralValue
 import prog8.ast.expressions.PrefixExpression
 import prog8.ast.statements.*
 import prog8.compiler.target.C64Target
+import prog8.parser.SourceCode
 import prog8tests.helpers.DummyFunctions
 import prog8tests.helpers.DummyMemsizer
 import kotlin.test.assertFalse
@@ -91,7 +92,7 @@ class TestMemory {
         val target = AssignTarget(null, null, DirectMemoryWrite(memexpr, Position.DUMMY), Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         module.linkParents(program.namespace)
         return target
     }
@@ -110,7 +111,7 @@ class TestMemory {
         val target = AssignTarget(IdentifierReference(listOf("address"), Position.DUMMY), null, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
@@ -124,7 +125,7 @@ class TestMemory {
         val target = AssignTarget(IdentifierReference(listOf("address"), Position.DUMMY), null, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
@@ -138,7 +139,7 @@ class TestMemory {
         val target = AssignTarget(IdentifierReference(listOf("address"), Position.DUMMY), null, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
@@ -152,7 +153,7 @@ class TestMemory {
         val target = AssignTarget(null, arrayindexed, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
@@ -167,7 +168,7 @@ class TestMemory {
         val target = AssignTarget(null, arrayindexed, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
@@ -182,7 +183,7 @@ class TestMemory {
         val target = AssignTarget(null, arrayindexed, null, Position.DUMMY)
         val assignment = Assignment(target, NumericLiteralValue.optimalInteger(0, Position.DUMMY), Position.DUMMY)
         val subroutine = Subroutine("test", emptyList(), emptyList(), emptyList(), emptyList(), emptySet(), null, false, false, mutableListOf(decl, assignment), Position.DUMMY)
-        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, null)
+        val module = Module("test", mutableListOf(subroutine), Position.DUMMY, SourceCode.Generated("test"))
         val program = Program("test", DummyFunctions, DummyMemsizer)
             .addModule(module)
         module.linkParents(program.namespace)
diff --git a/compilerAst/src/prog8/ast/AstToplevel.kt b/compilerAst/src/prog8/ast/AstToplevel.kt
index dd8dd937f..3a28bc837 100644
--- a/compilerAst/src/prog8/ast/AstToplevel.kt
+++ b/compilerAst/src/prog8/ast/AstToplevel.kt
@@ -246,7 +246,8 @@ class Program(val name: String,
 
     init {
         // insert a container module for all interned strings later
-        val internedStringsModule = Module(internedStringsModuleName, mutableListOf(), Position.DUMMY, null)
+        val internedStringsModule = Module(internedStringsModuleName, mutableListOf(),
+            Position.DUMMY, SourceCode.Generated(internedStringsModuleName))
         val block = Block(internedStringsModuleName, null, mutableListOf(), true, Position.DUMMY)
         internedStringsModule.statements.add(block)
 
@@ -350,7 +351,7 @@ class Program(val name: String,
 open class Module(override val name: String,
              override var statements: MutableList<Statement>,
              final override val position: Position,
-             val source: SourceCode?) : Node, INameScope {
+             val source: SourceCode) : Node, INameScope {
 
     override lateinit var parent: Node
     lateinit var program: Program
@@ -380,7 +381,7 @@ open class Module(override val name: String,
     fun accept(visitor: IAstVisitor) = visitor.visit(this)
     fun accept(visitor: AstWalker, parent: Node) = visitor.visit(this, parent)
 
-    val isLibrary get() = (source == null) || source.isFromResources
+    val isLibrary get() = source.isFromResources
 }
 
 
diff --git a/compilerAst/src/prog8/parser/SourceCode.kt b/compilerAst/src/prog8/parser/SourceCode.kt
index 44436b44a..df1975aef 100644
--- a/compilerAst/src/prog8/parser/SourceCode.kt
+++ b/compilerAst/src/prog8/parser/SourceCode.kt
@@ -3,6 +3,7 @@ package prog8.parser
 import org.antlr.v4.runtime.CharStream
 import org.antlr.v4.runtime.CharStreams
 import java.io.File
+import java.io.IOException
 import java.nio.file.Path
 import kotlin.io.path.absolutePathString
 import kotlin.io.path.exists
@@ -13,7 +14,7 @@ import kotlin.io.path.isReadable
  * Encapsulates - and ties together - actual source code (=text)
  * and its [origin].
  */
-abstract class SourceCode {
+sealed class SourceCode {
 
     /**
      * To be used *only* by the parser (as input to a TokenStream).
@@ -23,16 +24,16 @@ abstract class SourceCode {
 
     /**
      * Whether this [SourceCode] instance was created by
-     * factory method [fromResources]
+     * factory method [Resource]
      */
     abstract val isFromResources: Boolean
 
     /**
      * Where this [SourceCode] instance came from.
      * This can be one of the following:
-     * * a normal string representation of a [java.nio.file.Path], if it originates from a file (see [fromPath])
-     * * `<String@44c56085>` if was created via [of]
-     * * `library:/x/y/z.ext` if it is a library file that was loaded from resources (see [fromResources])
+     * * a normal string representation of a [java.nio.file.Path], if it originates from a file (see [File])
+     * * `<String@44c56085>` if was created via [String]
+     * * `library:/x/y/z.ext` if it is a library file that was loaded from resources (see [Resource])
      */
     abstract val origin: String
 
@@ -42,9 +43,7 @@ abstract class SourceCode {
      * This is really just [origin] with any stuff removed that would render it an invalid path name.
      * (Note: a *valid* path name does NOT mean that the denoted file or folder *exists*)
      */
-    fun pathString() =
-        origin
-            .substringAfter("<").substringBeforeLast(">") // or from plain string?
+    fun pathString() = origin.substringAfter("<").substringBeforeLast(">") // or from plain string?
 
     /**
      * The source code as plain string.
@@ -58,42 +57,39 @@ abstract class SourceCode {
      */
     final override fun toString() = "${this.javaClass.name}[${this.origin}]"
 
-    // "static" factory methods
     companion object {
 
         /**
          * filename prefix to designate library files that will be retreived from internal resources rather than disk
          */
         const val libraryFilePrefix = "library:"
+    }
 
-        /**
-         * Turn a plain String into a [SourceCode] object.
-         * [origin] will be something like `<String@44c56085>`.
-         */
-        fun of(text: String): SourceCode {
-            return object : SourceCode() {
-                override val isFromResources = false
-                override val origin = "<String@${System.identityHashCode(text).toString(16)}>"
-                override fun getCharStream(): CharStream {
-                    return CharStreams.fromString(text)
-                }
-            }
-        }
+    /**
+     * Turn a plain String into a [SourceCode] object.
+     * [origin] will be something like `<String@44c56085>`.
+     */
+    class Text(val text: String): SourceCode() {
+        override val isFromResources = false
+        override val origin = "<String@${System.identityHashCode(text).toString(16)}>"
+        override fun getCharStream(): CharStream = CharStreams.fromString(text)
+    }
 
-        /**
-         * Get [SourceCode] from the file represented by the specified Path.
-         * This does not actually *access* the file, but it does check
-         * whether it
-         * * exists
-         * * is a regular file (ie: not a directory)
-         * * and is actually readable
-         *
-         * [origin] will be the given path in absolute and normalized form.
-         * @throws NoSuchFileException if the file does not exist
-         * @throws AccessDeniedException if the given path points to a directory or the file is non-readable for some other reason
-         */
-        fun fromPath(path: Path): SourceCode {
-            val normalized = path.normalize()
+    /**
+     * Get [SourceCode] from the file represented by the specified Path.
+     * This does not actually *access* the file, but it does check
+     * whether it
+     * * exists
+     * * is a regular file (ie: not a directory)
+     * * and is actually readable
+     *
+     * [origin] will be the given path in absolute and normalized form.
+     * @throws NoSuchFileException if the file does not exist
+     * @throws AccessDeniedException if the given path points to a directory or the file is non-readable for some other reason
+     */
+    class File(path: Path): SourceCode() {
+        private val normalized = path.normalize()
+        init {
             val file = normalized.toFile()
             if (!path.exists())
                 throw NoSuchFileException(file)
@@ -101,40 +97,48 @@ abstract class SourceCode {
                 throw AccessDeniedException(file, reason = "Not a file but a directory")
             if (!path.isReadable())
                 throw AccessDeniedException(file, reason = "Is not readable")
-            return object : SourceCode() {
-                override val isFromResources = false
-                override val origin = normalized.absolutePathString()
-                override fun getCharStream(): CharStream {
-                    return CharStreams.fromPath(normalized)
-                }
-            }
         }
 
-        /**
-         * [origin]: `<library:/x/y/z.p8>` for a given `pathString` of "x/y/z.p8"
-         */
-        fun fromResources(pathString: String): SourceCode {
-            val path = Path.of(pathString).normalize()
-            val sep = "/"
-            val normalized = sep + path.toMutableList().joinToString(sep)
-            val rscURL = object{}.javaClass.getResource(normalized)
+        override val isFromResources = false
+        override val origin = normalized.absolutePathString()
+        override fun getCharStream(): CharStream = CharStreams.fromPath(normalized)
+    }
+
+    /**
+     * [origin]: `<library:/x/y/z.p8>` for a given `pathString` of "x/y/z.p8"
+     */
+    class Resource(pathString: String): SourceCode() {
+        private val normalized = "/" + Path.of(pathString).normalize().toMutableList().joinToString("/")
+
+        init {
+            val rscURL = object {}.javaClass.getResource(normalized)
             if (rscURL == null) {
-                val rscRoot = object{}.javaClass.getResource("/")
+                val rscRoot = object {}.javaClass.getResource("/")
                 throw NoSuchFileException(
                     File(normalized),
-                    reason = "looked in resources rooted at $rscRoot")
-            }
-            return object : SourceCode() {
-                override val isFromResources = true
-                override val origin = "$libraryFilePrefix$normalized"
-                override fun getCharStream(): CharStream {
-                    val inpStr = object {}.javaClass.getResourceAsStream(normalized)
-                    return CharStreams.fromStream(inpStr)
-                }
+                    reason = "looked in resources rooted at $rscRoot"
+                )
             }
         }
 
-        // TODO: possibly more, like fromURL(..)
+        override val isFromResources = true
+        override val origin = "$libraryFilePrefix$normalized"
+        override fun getCharStream(): CharStream {
+            val inpStr = object {}.javaClass.getResourceAsStream(normalized)
+            return CharStreams.fromStream(inpStr)
+        }
+    }
+
+    /**
+     * SourceCode for internally generated nodes (usually Modules)
+     */
+    class Generated(name: String) : SourceCode() {
+        override fun getCharStream(): CharStream = throw IOException("generated code doesn't have a stream to read")
+        override val isFromResources: Boolean = false
+        override val origin: String = name
+    }
+
+    // TODO: possibly more, like fromURL(..)
 /*      // For `jar:..` URLs
         // see https://stackoverflow.com/questions/22605666/java-access-files-in-jar-causes-java-nio-file-filesystemnotfoundexception
         var url = URL("jar:file:/E:/x16/prog8(meisl)/compiler/build/libs/prog8compiler-7.0-BETA3-all.jar!/prog8lib/c64/textio.p8")
@@ -143,5 +147,4 @@ abstract class SourceCode {
         val fs = FileSystems.newFileSystem(URI.create(parts[0]), mutableMapOf(Pair("", "")) )
         val path = fs.getPath(parts[1])
 */
-    }
 }
diff --git a/compilerAst/test/TestAstToSourceCode.kt b/compilerAst/test/TestAstToSourceCode.kt
index bf1918101..82fa0384b 100644
--- a/compilerAst/test/TestAstToSourceCode.kt
+++ b/compilerAst/test/TestAstToSourceCode.kt
@@ -31,7 +31,7 @@ class TestAstToSourceCode {
     private fun roundTrip(module: Module): Pair<String, Module> {
         val generatedText = generateP8(module)
         try {
-            val parsedAgain = parseModule(SourceCode.of(generatedText))
+            val parsedAgain = parseModule(SourceCode.Text(generatedText))
             return Pair(generatedText, parsedAgain)
         } catch (e: ParseError) {
             assert(false) { "should produce valid Prog8 but threw $e" }
@@ -41,7 +41,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testMentionsInternedStringsModule() {
-        val orig = SourceCode.of("\n")
+        val orig = SourceCode.Text("\n")
         val (txt, _) = roundTrip(parseModule(orig))
         // assertContains has *actual* first!
         assertContains(txt, Regex(";.*$internedStringsModuleName"))
@@ -49,7 +49,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testImportDirectiveWithLib() {
-        val orig = SourceCode.of("%import textio\n")
+        val orig = SourceCode.Text("%import textio\n")
         val (txt, _) = roundTrip(parseModule(orig))
         // assertContains has *actual* first!
         assertContains(txt, Regex("%import +textio"))
@@ -57,7 +57,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testImportDirectiveWithUserModule() {
-        val orig = SourceCode.of("%import my_own_stuff\n")
+        val orig = SourceCode.Text("%import my_own_stuff\n")
         val (txt, _) = roundTrip(parseModule(orig))
         // assertContains has *actual* first!
         assertContains(txt, Regex("%import +my_own_stuff"))
@@ -66,7 +66,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testStringLiteral_noAlt() {
-        val orig = SourceCode.of("""
+        val orig = SourceCode.Text("""
             main {
                 str s = "fooBar\n"
             }
@@ -78,7 +78,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testStringLiteral_withAlt() {
-        val orig = SourceCode.of("""
+        val orig = SourceCode.Text("""
             main {
                 str sAlt = @"fooBar\n"
             }
@@ -90,7 +90,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testCharLiteral_noAlt() {
-        val orig = SourceCode.of("""
+        val orig = SourceCode.Text("""
             main {
                 ubyte c = 'x'
             }
@@ -102,7 +102,7 @@ class TestAstToSourceCode {
 
     @Test
     fun testCharLiteral_withAlt() {
-        val orig = SourceCode.of("""
+        val orig = SourceCode.Text("""
             main {
                 ubyte cAlt = @'x'
             }
diff --git a/compilerAst/test/TestProg8Parser.kt b/compilerAst/test/TestProg8Parser.kt
index 7e3c6d3fe..b5786b8a9 100644
--- a/compilerAst/test/TestProg8Parser.kt
+++ b/compilerAst/test/TestProg8Parser.kt
@@ -39,7 +39,7 @@ class TestProg8Parser {
             @Test
             fun `is not required - #40, fixed by #45`() {
                 val nl = "\n" // say, Unix-style (different flavours tested elsewhere)
-                val src = SourceCode.of("foo {" + nl + "}")   // source ends with '}' (= NO newline, issue #40)
+                val src = SourceCode.Text("foo {" + nl + "}")   // source ends with '}' (= NO newline, issue #40)
 
                 // #40: Prog8ANTLRParser would report (throw) "missing <EOL> at '<EOF>'"
                 val module = parseModule(src)
@@ -50,7 +50,7 @@ class TestProg8Parser {
             fun `is still accepted - #40, fixed by #45`() {
                 val nl = "\n" // say, Unix-style (different flavours tested elsewhere)
                 val srcText = "foo {" + nl + "}" + nl  // source does end with a newline (issue #40)
-                val module = parseModule(SourceCode.of(srcText))
+                val module = parseModule(SourceCode.Text(srcText))
                 assertEquals(1, module.statements.size)
             }
         }
@@ -65,22 +65,22 @@ class TestProg8Parser {
             // GOOD: 2nd block `bar` does start on a new line; however, a nl at the very end ain't needed
             val srcGood = "foo {" + nl + "}" + nl + "bar {" + nl + "}"
 
-            assertFailsWith<ParseError> { parseModule(SourceCode.of(srcBad)) }
-            val module = parseModule(SourceCode.of(srcGood))
+            assertFailsWith<ParseError> { parseModule(SourceCode.Text(srcBad)) }
+            val module = parseModule(SourceCode.Text(srcGood))
             assertEquals(2, module.statements.size)
         }
 
         @Test
         fun `is required between two Blocks or Directives - #47`() {
             // block and block
-            assertFailsWith<ParseError>{ parseModule(SourceCode.of("""
+            assertFailsWith<ParseError>{ parseModule(SourceCode.Text("""
                 blockA {
                 } blockB {            
                 }            
             """)) }
 
             // block and directive
-            assertFailsWith<ParseError>{ parseModule(SourceCode.of("""
+            assertFailsWith<ParseError>{ parseModule(SourceCode.Text("""
                 blockB {            
                 } %import textio            
             """)) }
@@ -89,12 +89,12 @@ class TestProg8Parser {
             // Leaving them in anyways.
 
             // dir and block
-            assertFailsWith<ParseError>{ parseModule(SourceCode.of("""
+            assertFailsWith<ParseError>{ parseModule(SourceCode.Text("""
                 %import textio blockB {            
                 }            
             """)) }
 
-            assertFailsWith<ParseError>{ parseModule(SourceCode.of("""
+            assertFailsWith<ParseError>{ parseModule(SourceCode.Text("""
                 %import textio %import syslib            
             """)) }
         }
@@ -123,7 +123,7 @@ class TestProg8Parser {
                 "}" +
                 nlUnix      // end with newline (see testModuleSourceNeedNotEndWithNewline)
 
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             assertEquals(2, module.statements.size)
         }
     }
@@ -142,7 +142,7 @@ class TestProg8Parser {
                 blockA {            
                 }
             """
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             assertEquals(1, module.statements.size)
         }
 
@@ -159,7 +159,7 @@ class TestProg8Parser {
                 blockB {            
                 }
             """
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             assertEquals(2, module.statements.size)
         }
 
@@ -174,7 +174,7 @@ class TestProg8Parser {
                 ; comment
                 
             """
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             assertEquals(1, module.statements.size)
         }
     }
@@ -187,7 +187,7 @@ class TestProg8Parser {
             val importedNoExt = assumeNotExists(fixturesDir, "i_do_not_exist")
             assumeNotExists(fixturesDir, "i_do_not_exist.p8")
             val text = "%import ${importedNoExt.name}"
-            val module = parseModule(SourceCode.of(text))
+            val module = parseModule(SourceCode.Text(text))
 
             assertEquals(1, module.statements.size)
         }
@@ -198,14 +198,14 @@ class TestProg8Parser {
     inner class EmptySourcecode {
         @Test
         fun `from an empty string should result in empty Module`() {
-            val module = parseModule(SourceCode.of(""))
+            val module = parseModule(SourceCode.Text(""))
             assertEquals(0, module.statements.size)
         }
 
         @Test
         fun `from an empty file should result in empty Module`() {
             val path = assumeReadableFile(fixturesDir, "empty.p8")
-            val module = parseModule(SourceCode.fromPath(path))
+            val module = parseModule(SourceCode.File(path))
             assertEquals(0, module.statements.size)
         }
     }
@@ -218,7 +218,7 @@ class TestProg8Parser {
                 main {
                 }
             """.trimIndent()
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
 
             // Note: assertContains has *actual* as first param
             assertContains(module.name, Regex("^anonymous_[0-9a-f]+$"))
@@ -227,7 +227,7 @@ class TestProg8Parser {
         @Test
         fun `parsed from a file`() {
             val path = assumeReadableFile(fixturesDir, "simple_main.p8")
-            val module = parseModule(SourceCode.fromPath(path))
+            val module = parseModule(SourceCode.File(path))
             assertEquals(path.nameWithoutExtension, module.name)
         }
     }
@@ -287,9 +287,9 @@ class TestProg8Parser {
         fun `in ParseError from bad string source code`() {
             val srcText = "bad * { }\n"
 
-            assertFailsWith<ParseError> { parseModule(SourceCode.of(srcText)) }
+            assertFailsWith<ParseError> { parseModule(SourceCode.Text(srcText)) }
             try {
-                parseModule(SourceCode.of(srcText))
+                parseModule(SourceCode.Text(srcText))
             } catch (e: ParseError) {
                 assertPosition(e.position, Regex("^<String@[0-9a-f]+>$"), 1, 4, 4)
             }
@@ -299,9 +299,9 @@ class TestProg8Parser {
         fun `in ParseError from bad file source code`() {
             val path = assumeReadableFile(fixturesDir, "file_with_syntax_error.p8")
 
-            assertFailsWith<ParseError> { parseModule(SourceCode.fromPath(path)) }
+            assertFailsWith<ParseError> { parseModule(SourceCode.File(path)) }
             try {
-                parseModule(SourceCode.fromPath(path))
+                parseModule(SourceCode.File(path))
             } catch (e: ParseError) {
                 assertPosition(e.position, path.absolutePathString(), 2, 6) // TODO: endCol wrong
             }
@@ -313,7 +313,7 @@ class TestProg8Parser {
                 main {
                 }
             """.trimIndent()
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             assertPositionOf(module, Regex("^<String@[0-9a-f]+>$"), 1, 0) // TODO: endCol wrong
         }
 
@@ -321,7 +321,7 @@ class TestProg8Parser {
         fun  `of Module parsed from a file`() {
             val path = assumeReadableFile(fixturesDir, "simple_main.p8")
 
-            val module = parseModule(SourceCode.fromPath(path))
+            val module = parseModule(SourceCode.File(path))
             assertPositionOf(module, path.absolutePathString(), 1, 0) // TODO: endCol wrong
         }
 
@@ -329,7 +329,7 @@ class TestProg8Parser {
         fun `of non-root Nodes parsed from file`() {
             val path = assumeReadableFile(fixturesDir, "simple_main.p8")
 
-            val module = parseModule(SourceCode.fromPath(path))
+            val module = parseModule(SourceCode.File(path))
             val mpf = module.position.file
 
             assertPositionOf(module, path.absolutePathString(), 1, 0) // TODO: endCol wrong
@@ -360,7 +360,7 @@ class TestProg8Parser {
                     }
                 }
             """.trimIndent()
-            val module = parseModule(SourceCode.of(srcText))
+            val module = parseModule(SourceCode.Text(srcText))
             val mpf = module.position.file
 
             val targetDirective = module.statements.filterIsInstance<Directive>()[0]
@@ -388,7 +388,7 @@ class TestProg8Parser {
 
         @Test
         fun `in argument position, no altEnc`() {
-            val src = SourceCode.of("""
+            val src = SourceCode.Text("""
                  main {
                     sub start() {
                         chrout('\n')
@@ -409,7 +409,7 @@ class TestProg8Parser {
 
         @Test
         fun `on rhs of block-level var decl, no AltEnc`() {
-            val src = SourceCode.of("""
+            val src = SourceCode.Text("""
                 main {
                     ubyte c = 'x'
                 }
@@ -426,7 +426,7 @@ class TestProg8Parser {
 
         @Test
         fun `on rhs of block-level const decl, with AltEnc`() {
-            val src = SourceCode.of("""
+            val src = SourceCode.Text("""
                 main {
                     const ubyte c = @'x'
                 }
@@ -443,7 +443,7 @@ class TestProg8Parser {
 
         @Test
         fun `on rhs of subroutine-level var decl, no AltEnc`() {
-            val src = SourceCode.of("""
+            val src = SourceCode.Text("""
                 main {
                     sub start() {
                         ubyte c = 'x'
@@ -463,7 +463,7 @@ class TestProg8Parser {
 
         @Test
         fun `on rhs of subroutine-level const decl, with AltEnc`() {
-            val src = SourceCode.of("""
+            val src = SourceCode.Text("""
                 main {
                     sub start() {
                         const ubyte c = @'x'
@@ -487,7 +487,7 @@ class TestProg8Parser {
 
         @Test
         fun `in for-loops`() {
-            val module = parseModule(SourceCode.of("""
+            val module = parseModule(SourceCode.Text("""
                 main {
                     sub start() {
                         ubyte ub
diff --git a/compilerAst/test/TestSourceCode.kt b/compilerAst/test/TestSourceCode.kt
index 1597b7ad7..c012e031a 100644
--- a/compilerAst/test/TestSourceCode.kt
+++ b/compilerAst/test/TestSourceCode.kt
@@ -22,7 +22,7 @@ class TestSourceCode {
         val text = """
             main { }
         """.trimIndent()
-        val src = SourceCode.of(text)
+        val src = SourceCode.Text(text)
         val actualText = src.getCharStream().toString()
 
         assertContains(src.origin, Regex("^<String@[0-9a-f]+>$"))
@@ -33,26 +33,26 @@ class TestSourceCode {
     fun testFromPathWithNonExistingPath() {
         val filename = "i_do_not_exist.p8"
         val path = assumeNotExists(fixturesDir, filename)
-        assertFailsWith<NoSuchFileException> { SourceCode.fromPath(path) }
+        assertFailsWith<NoSuchFileException> { SourceCode.File(path) }
     }
 
     @Test
     fun testFromPathWithMissingExtension_p8() {
         val pathWithoutExt = assumeNotExists(fixturesDir,"simple_main")
         assumeReadableFile(fixturesDir,"simple_main.p8")
-        assertFailsWith<NoSuchFileException> { SourceCode.fromPath(pathWithoutExt) }
+        assertFailsWith<NoSuchFileException> { SourceCode.File(pathWithoutExt) }
     }
 
     @Test
     fun testFromPathWithDirectory() {
-        assertFailsWith<AccessDeniedException> { SourceCode.fromPath(fixturesDir) }
+        assertFailsWith<AccessDeniedException> { SourceCode.File(fixturesDir) }
     }
 
     @Test
     fun testFromPathWithExistingPath() {
         val filename = "simple_main.p8"
         val path = assumeReadableFile(fixturesDir, filename)
-        val src = SourceCode.fromPath(path)
+        val src = SourceCode.File(path)
 
         val expectedOrigin = path.normalize().absolutePathString()
         assertEquals(expectedOrigin, src.origin)
@@ -64,7 +64,7 @@ class TestSourceCode {
         val filename = "simple_main.p8"
         val path = Path(".", "test", "..", "test", "fixtures", filename)
         val srcFile = assumeReadableFile(path).toFile()
-        val src = SourceCode.fromPath(path)
+        val src = SourceCode.File(path)
 
         val expectedOrigin = path.normalize().absolutePathString()
         assertEquals(expectedOrigin, src.origin)
@@ -75,7 +75,7 @@ class TestSourceCode {
     fun testFromResourcesWithExistingP8File_withoutLeadingSlash() {
         val pathString = "prog8lib/math.p8"
         val srcFile = assumeReadableFile(resourcesDir, pathString).toFile()
-        val src = SourceCode.fromResources(pathString)
+        val src = SourceCode.Resource(pathString)
 
         assertEquals("$libraryFilePrefix/$pathString", src.origin)
         assertEquals(srcFile.readText(), src.asString())
@@ -85,7 +85,7 @@ class TestSourceCode {
     fun testFromResourcesWithExistingP8File_withLeadingSlash() {
         val pathString = "/prog8lib/math.p8"
         val srcFile = assumeReadableFile(resourcesDir, pathString.substring(1)).toFile()
-        val src = SourceCode.fromResources(pathString)
+        val src = SourceCode.Resource(pathString)
 
         assertEquals("$libraryFilePrefix$pathString", src.origin)
         assertEquals(srcFile.readText(), src.asString())
@@ -95,7 +95,7 @@ class TestSourceCode {
     fun testFromResourcesWithExistingAsmFile_withoutLeadingSlash() {
         val pathString = "prog8lib/math.asm"
         val srcFile = assumeReadableFile(resourcesDir, pathString).toFile()
-        val src = SourceCode.fromResources(pathString)
+        val src = SourceCode.Resource(pathString)
 
         assertEquals("$libraryFilePrefix/$pathString", src.origin)
         assertEquals(srcFile.readText(), src.asString())
@@ -106,7 +106,7 @@ class TestSourceCode {
     fun testFromResourcesWithExistingAsmFile_withLeadingSlash() {
         val pathString = "/prog8lib/math.asm"
         val srcFile = assumeReadableFile(resourcesDir, pathString.substring(1)).toFile()
-        val src = SourceCode.fromResources(pathString)
+        val src = SourceCode.Resource(pathString)
 
         assertEquals("$libraryFilePrefix$pathString", src.origin)
         assertEquals(srcFile.readText(), src.asString())
@@ -116,7 +116,7 @@ class TestSourceCode {
     fun testFromResourcesWithNonNormalizedPath() {
         val pathString = "/prog8lib/../prog8lib/math.p8"
         val srcFile = assumeReadableFile(resourcesDir, pathString.substring(1)).toFile()
-        val src = SourceCode.fromResources(pathString)
+        val src = SourceCode.Resource(pathString)
 
         assertEquals("$libraryFilePrefix/prog8lib/math.p8", src.origin)
         assertEquals(srcFile.readText(), src.asString())
@@ -129,14 +129,14 @@ class TestSourceCode {
         val pathString = "/prog8lib/i_do_not_exist"
         assumeNotExists(resourcesDir, pathString.substring(1))
 
-        assertFailsWith<NoSuchFileException> { SourceCode.fromResources(pathString) }
+        assertFailsWith<NoSuchFileException> { SourceCode.Resource(pathString) }
     }
     @Test
     fun testFromResourcesWithNonExistingFile_withoutLeadingSlash() {
         val pathString = "prog8lib/i_do_not_exist"
         assumeNotExists(resourcesDir, pathString)
 
-        assertFailsWith<NoSuchFileException> { SourceCode.fromResources(pathString) }
+        assertFailsWith<NoSuchFileException> { SourceCode.Resource(pathString) }
     }
 
     @Test
@@ -144,7 +144,7 @@ class TestSourceCode {
     fun testFromResourcesWithDirectory() {
         val pathString = "/prog8lib"
         assumeDirectory(resourcesDir, pathString.substring(1))
-        assertFailsWith<AccessDeniedException> { SourceCode.fromResources(pathString) }
+        assertFailsWith<AccessDeniedException> { SourceCode.Resource(pathString) }
     }
 
 }
diff --git a/compilerAst/test/ast/ProgramTests.kt b/compilerAst/test/ast/ProgramTests.kt
index e01e44324..16059ee3d 100644
--- a/compilerAst/test/ast/ProgramTests.kt
+++ b/compilerAst/test/ast/ProgramTests.kt
@@ -11,6 +11,7 @@ import prog8.ast.Module
 import prog8.ast.Program
 import prog8.ast.base.Position
 import prog8.ast.internedStringsModuleName
+import prog8.parser.SourceCode
 import prog8tests.helpers.DummyFunctions
 import prog8tests.helpers.DummyMemsizer
 import kotlin.test.assertContains
@@ -39,7 +40,7 @@ class ProgramTests {
         @Test
         fun withEmptyModule() {
             val program = Program("foo", DummyFunctions, DummyMemsizer)
-            val m1 = Module("bar", mutableListOf(), Position.DUMMY, null)
+            val m1 = Module("bar", mutableListOf(), Position.DUMMY, SourceCode.Generated("bar"))
 
             val retVal = program.addModule(m1)
 
@@ -73,15 +74,15 @@ class ProgramTests {
         @Test
         fun withForeignModule() {
             val program = Program("foo", DummyFunctions, DummyMemsizer)
-            val m = Module("bar", mutableListOf(), Position.DUMMY, null)
+            val m = Module("bar", mutableListOf(), Position.DUMMY, SourceCode.Generated("bar"))
 
             assertFailsWith<IllegalArgumentException> { program.moveModuleToFront(m) }
         }
         @Test
         fun withFirstOfPreviouslyAddedModules() {
             val program = Program("foo", DummyFunctions, DummyMemsizer)
-            val m1 = Module("bar", mutableListOf(), Position.DUMMY, null)
-            val m2 = Module("qmbl", mutableListOf(), Position.DUMMY, null)
+            val m1 = Module("bar", mutableListOf(), Position.DUMMY, SourceCode.Generated("bar"))
+            val m2 = Module("qmbl", mutableListOf(), Position.DUMMY, SourceCode.Generated("qmbl"))
             program.addModule(m1)
             program.addModule(m2)
 
@@ -92,8 +93,8 @@ class ProgramTests {
         @Test
         fun withSecondOfPreviouslyAddedModules() {
             val program = Program("foo", DummyFunctions, DummyMemsizer)
-            val m1 = Module("bar", mutableListOf(), Position.DUMMY, null)
-            val m2 = Module("qmbl", mutableListOf(), Position.DUMMY, null)
+            val m1 = Module("bar", mutableListOf(), Position.DUMMY, SourceCode.Generated("bar"))
+            val m2 = Module("qmbl", mutableListOf(), Position.DUMMY, SourceCode.Generated("qmbl"))
             program.addModule(m1)
             program.addModule(m2)
 
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index ca5aac3fe..f79ba3bd1 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -4,7 +4,6 @@ TODO
 For next compiler release
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - can we derive module.name from module.source (taking just the filename base)?
-- can Position.file be a Path- making the source variable for nodes unnecessary?
 
 
 Blocked by Commander-x16 v39 release
diff --git a/examples/test.p8 b/examples/test.p8
index 665e629a0..e52d7a5c9 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -1,7 +1,14 @@
-%option enable_floats
+%import textio
+
 main {
-    sub start() {
-        float[] cs = 1 to 42 ; values are computed at compile time
-        cs[0] = 23 ; keep optimizer from removing it
-    }
+    str myBar = "main.bar"
+
+foo_bar:
+    %asminclude "compiler/test/fixtures/foo_bar.asm22"   ; FIXME: should be accessible from inside start() but give assembler error
+
+	sub start() {
+	    txt.print(myBar)
+	    txt.print(&foo_bar)
+	    return
+	}
 }