diff --git a/compiler/build.gradle b/compiler/build.gradle
index 45f67efa4..31a466a64 100644
--- a/compiler/build.gradle
+++ b/compiler/build.gradle
@@ -1,6 +1,7 @@
 plugins {
     id "org.jetbrains.kotlin.jvm" version "1.3.40"
     id 'application'
+    id 'org.jetbrains.dokka' version "0.9.18"
 }
 
 repositories {
@@ -95,3 +96,9 @@ test {
         events "passed", "skipped", "failed"
     }
 }
+
+
+dokka {
+    outputFormat = 'html'
+    outputDirectory = "$buildDir/kdoc"
+}
diff --git a/compiler/src/prog8/ast/AST.kt b/compiler/src/prog8/ast/AST.kt
index a8b491e61..51277905b 100644
--- a/compiler/src/prog8/ast/AST.kt
+++ b/compiler/src/prog8/ast/AST.kt
@@ -34,7 +34,10 @@ enum class DataType {
     ARRAY_W,
     ARRAY_F;
 
-    fun assignableTo(targetType: DataType) =
+    /**
+     * is the type assignable to the given other type?
+     */
+    infix fun isAssignableTo(targetType: DataType) =
             // what types are assignable to others without loss of precision?
             when(this) {
                 UBYTE -> targetType == UBYTE || targetType == UWORD || targetType==WORD || targetType == FLOAT
@@ -49,8 +52,14 @@ enum class DataType {
             }
 
 
-    fun assignableTo(targetTypes: Set<DataType>) = targetTypes.any { this.assignableTo(it) }
+    infix fun isAssignableTo(targetTypes: Set<DataType>) = targetTypes.any { this isAssignableTo it }
 
+    infix fun biggerThan(other: DataType) =
+            when(this) {
+                in ByteDatatypes -> false
+                in WordDatatypes -> other in ByteDatatypes
+                else -> true
+            }
 }
 
 enum class Register {
@@ -412,7 +421,7 @@ interface INameScope {
         return null
     }
 
-    fun allLabelsAndVariables(): Set<String> =
+    fun allDefinedNames(): Set<String> =
             statements.filterIsInstance<Label>().map { it.name }.toSet() + statements.filterIsInstance<VarDecl>().map { it.name }.toSet()
 
     fun lookup(scopedName: List<String>, localContext: Node) : IStatement? {
@@ -455,8 +464,7 @@ interface INameScope {
     fun containsNoCodeNorVars() = !containsCodeOrVars()
 
     fun remove(stmt: IStatement) {
-        val removed = statements.remove(stmt)
-        if(!removed)
+        if(!statements.remove(stmt))
             throw FatalAstException("stmt to remove wasn't found in scope")
     }
 }
@@ -849,16 +857,16 @@ data class AssignTarget(val register: Register?,
     fun isMemoryMapped(namespace: INameScope): Boolean =
             memoryAddress!=null || (identifier?.targetVarDecl(namespace)?.type==VarDeclType.MEMORY)
 
-    fun isSameAs(value: IExpression): Boolean {
+    infix fun isSameAs(value: IExpression): Boolean {
         return when {
             this.memoryAddress!=null -> false
-            this.register!=null -> value is RegisterExpr && value.register==this.register
-            this.identifier!=null -> value is IdentifierReference && value.nameInSource==this.identifier.nameInSource
+            this.register!=null -> value is RegisterExpr && value.register==register
+            this.identifier!=null -> value is IdentifierReference && value.nameInSource==identifier.nameInSource
             this.arrayindexed!=null -> value is ArrayIndexedExpression &&
-                    value.identifier.nameInSource==this.arrayindexed.identifier.nameInSource &&
+                    value.identifier.nameInSource==arrayindexed.identifier.nameInSource &&
                     value.arrayspec.size()!=null &&
-                    this.arrayindexed.arrayspec.size()!=null &&
-                    value.arrayspec.size()==this.arrayindexed.arrayspec.size()
+                    arrayindexed.arrayspec.size()!=null &&
+                    value.arrayspec.size()==arrayindexed.arrayspec.size()
             else -> false
         }
     }
@@ -912,23 +920,23 @@ interface IExpression: Node {
     fun referencesIdentifier(name: String): Boolean
     fun resultingDatatype(program: Program): DataType?
 
-    fun same(other: IExpression): Boolean {
+    infix fun isSameAs(other: IExpression): Boolean {
         if(this===other)
             return true
         when(this) {
             is RegisterExpr ->
-                return (other is RegisterExpr && other.register==this.register)
+                return (other is RegisterExpr && other.register==register)
             is IdentifierReference ->
-                return (other is IdentifierReference && other.nameInSource==this.nameInSource)
+                return (other is IdentifierReference && other.nameInSource==nameInSource)
             is PrefixExpression ->
-                return (other is PrefixExpression && other.operator==this.operator && other.expression.same(this.expression))
+                return (other is PrefixExpression && other.operator==operator && other.expression isSameAs expression)
             is BinaryExpression ->
-                return (other is BinaryExpression && other.operator==this.operator
-                        && other.left.same(this.left)
-                        && other.right.same(this.right))
+                return (other is BinaryExpression && other.operator==operator
+                        && other.left isSameAs left
+                        && other.right isSameAs right)
             is ArrayIndexedExpression -> {
-                return (other is ArrayIndexedExpression && other.identifier.nameInSource == this.identifier.nameInSource
-                        && other.arrayspec.index.same(this.arrayspec.index))
+                return (other is ArrayIndexedExpression && other.identifier.nameInSource == identifier.nameInSource
+                        && other.arrayspec.index isSameAs arrayspec.index)
             }
             is LiteralValue -> return (other is LiteralValue && other==this)
         }
diff --git a/compiler/src/prog8/ast/AstChecker.kt b/compiler/src/prog8/ast/AstChecker.kt
index e14e853f3..049f87c67 100644
--- a/compiler/src/prog8/ast/AstChecker.kt
+++ b/compiler/src/prog8/ast/AstChecker.kt
@@ -832,7 +832,7 @@ private class AstChecker(private val program: Program,
             else {
                 for (arg in args.withIndex().zip(func.parameters)) {
                     val argDt=arg.first.value.resultingDatatype(program)
-                    if(argDt!=null && !argDt.assignableTo(arg.second.possibleDatatypes)) {
+                    if(argDt!=null && !(argDt isAssignableTo arg.second.possibleDatatypes)) {
                         checkResult.add(ExpressionError("builtin function '${target.name}' argument ${arg.first.index + 1} has invalid type $argDt, expected ${arg.second.possibleDatatypes}", position))
                     }
                 }
@@ -844,7 +844,7 @@ private class AstChecker(private val program: Program,
                         checkResult.add(ExpressionError("swap requires 2 args of identical type", position))
                     else if (args[0].constValue(program) != null || args[1].constValue(program) != null)
                         checkResult.add(ExpressionError("swap requires 2 variables, not constant value(s)", position))
-                    else if(args[0].same(args[1]))
+                    else if(args[0] isSameAs args[1])
                         checkResult.add(ExpressionError("swap should have 2 different args", position))
                     else if(dt1 !in NumericDatatypes)
                         checkResult.add(ExpressionError("swap requires args of numerical type", position))
@@ -856,7 +856,7 @@ private class AstChecker(private val program: Program,
             else {
                 for (arg in args.withIndex().zip(target.parameters)) {
                     val argDt = arg.first.value.resultingDatatype(program)
-                    if(argDt!=null && !argDt.assignableTo(arg.second.type)) {
+                    if(argDt!=null && !(argDt isAssignableTo arg.second.type)) {
                         // for asm subroutines having STR param it's okay to provide a UWORD too (pointer value)
                         if(!(target.isAsmSubroutine && arg.second.type in StringDatatypes && argDt==DataType.UWORD))
                             checkResult.add(ExpressionError("subroutine '${target.name}' argument ${arg.first.index + 1} has invalid type $argDt, expected ${arg.second.type}", position))
diff --git a/compiler/src/prog8/ast/AstIdentifiersChecker.kt b/compiler/src/prog8/ast/AstIdentifiersChecker.kt
index cbdd0cab3..a26242aca 100644
--- a/compiler/src/prog8/ast/AstIdentifiersChecker.kt
+++ b/compiler/src/prog8/ast/AstIdentifiersChecker.kt
@@ -115,7 +115,7 @@ private class AstIdentifiersChecker(private val namespace: INameScope) : IAstPro
                 nameError(subroutine.name, subroutine.position, existing)
 
             // check that there are no local variables that redefine the subroutine's parameters
-            val allDefinedNames = subroutine.allLabelsAndVariables()
+            val allDefinedNames = subroutine.allDefinedNames()
             val paramNames = subroutine.parameters.map { it.name }.toSet()
             val paramsToCheck = paramNames.intersect(allDefinedNames)
             for(name in paramsToCheck) {
diff --git a/compiler/src/prog8/ast/StmtReorderer.kt b/compiler/src/prog8/ast/StmtReorderer.kt
index 4471c21a9..5732e4531 100644
--- a/compiler/src/prog8/ast/StmtReorderer.kt
+++ b/compiler/src/prog8/ast/StmtReorderer.kt
@@ -42,7 +42,7 @@ private class StatementReorderer(private val program: Program): IAstProcessor {
             module.statements.add(0, nonLibBlock.second)
         val mainBlock = module.statements.singleOrNull { it is Block && it.name=="main" }
         if(mainBlock!=null && (mainBlock as Block).address==null) {
-            module.statements.remove(mainBlock)
+            module.remove(mainBlock)
             module.statements.add(0, mainBlock)
         }
 
@@ -64,7 +64,7 @@ private class StatementReorderer(private val program: Program): IAstProcessor {
         // move all subroutines to the end of the block
         for (subroutine in subroutines) {
             if(subroutine.name!="start" || block.name!="main") {
-                block.statements.remove(subroutine)
+                block.remove(subroutine)
                 block.statements.add(subroutine)
             }
             numSubroutinesAtEnd++
@@ -72,7 +72,7 @@ private class StatementReorderer(private val program: Program): IAstProcessor {
         // move the "start" subroutine to the top
         if(block.name=="main") {
             block.statements.singleOrNull { it is Subroutine && it.name == "start" } ?.let {
-                block.statements.remove(it)
+                block.remove(it)
                 block.statements.add(0, it)
                 numSubroutinesAtEnd--
             }
diff --git a/compiler/src/prog8/compiler/Compiler.kt b/compiler/src/prog8/compiler/Compiler.kt
index 556465f3d..6cb25c19a 100644
--- a/compiler/src/prog8/compiler/Compiler.kt
+++ b/compiler/src/prog8/compiler/Compiler.kt
@@ -972,7 +972,7 @@ internal class Compiler(private val program: Program): IAstProcessor {
             throw AstException("swap requires 2 args of identical type")
         if (args[0].constValue(program) != null || args[1].constValue(program) != null)
             throw AstException("swap requires 2 variables, not constant value(s)")
-        if(args[0].same(args[1]))
+        if(args[0] isSameAs args[1])
             throw AstException("swap should have 2 different args")
         if(dt1 !in NumericDatatypes)
             throw AstException("swap requires args of numerical type")
diff --git a/compiler/src/prog8/optimizing/SimplifyExpressions.kt b/compiler/src/prog8/optimizing/SimplifyExpressions.kt
index 171a6fb98..f8debf585 100644
--- a/compiler/src/prog8/optimizing/SimplifyExpressions.kt
+++ b/compiler/src/prog8/optimizing/SimplifyExpressions.kt
@@ -295,8 +295,8 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
 
     private fun determineY(x: IExpression, subBinExpr: BinaryExpression): IExpression? {
         return when {
-            subBinExpr.left.same(x) -> subBinExpr.right
-            subBinExpr.right.same(x) -> subBinExpr.left
+            subBinExpr.left isSameAs x -> subBinExpr.right
+            subBinExpr.right isSameAs x -> subBinExpr.left
             else -> null
         }
     }
@@ -362,7 +362,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
 
         if(leftConstVal==null && rightConstVal!=null) {
-            if(isBiggerType(leftDt, rightDt)) {
+            if(leftDt biggerThan rightDt) {
                 val (adjusted, newValue) = adjust(rightConstVal, leftDt)
                 if (adjusted) {
                     expr.right = newValue
@@ -372,7 +372,7 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
             }
             return false
         } else if(leftConstVal!=null && rightConstVal==null) {
-            if(isBiggerType(rightDt, leftDt)) {
+            if(rightDt biggerThan leftDt) {
                 val (adjusted, newValue) = adjust(leftConstVal, rightDt)
                 if (adjusted) {
                     expr.left = newValue
@@ -386,14 +386,6 @@ internal class SimplifyExpressions(private val program: Program) : IAstProcessor
         }
     }
 
-    private fun isBiggerType(type: DataType, other: DataType) =
-        when(type) {
-            in ByteDatatypes -> false
-            in WordDatatypes -> other in ByteDatatypes
-            else -> true
-        }
-
-
     private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: LiteralValue?, val rightVal: LiteralValue?)
 
     private fun reorderAssociative(expr: BinaryExpression, leftVal: LiteralValue?): ReorderedAssociativeBinaryExpr {
diff --git a/compiler/src/prog8/optimizing/StatementOptimizer.kt b/compiler/src/prog8/optimizing/StatementOptimizer.kt
index f44bf1363..38f6f5c60 100644
--- a/compiler/src/prog8/optimizing/StatementOptimizer.kt
+++ b/compiler/src/prog8/optimizing/StatementOptimizer.kt
@@ -104,7 +104,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
 
         if (removeSubroutines.isNotEmpty()) {
             removeSubroutines.forEach {
-                it.definingScope().statements.remove(it)
+                it.definingScope().remove(it)
             }
         }
 
@@ -116,7 +116,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
         }
 
         if (removeBlocks.isNotEmpty()) {
-            removeBlocks.forEach { it.definingScope().statements.remove(it) }
+            removeBlocks.forEach { it.definingScope().remove(it) }
         }
 
         // remove modules that are not imported, or are empty
@@ -448,7 +448,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
 
         if(assignment.targets.size==1) {
             val target=assignment.targets[0]
-            if(target.isSameAs(assignment.value)) {
+            if(target isSameAs assignment.value) {
                 optimizationsDone++
                 return NopStatement(assignment.position)
             }
@@ -458,7 +458,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
                 val cv = bexpr.right.constValue(program)?.asNumericValue?.toDouble()
                 if(cv==null) {
                     if(bexpr.operator=="+" && targetDt!=DataType.FLOAT) {
-                        if (bexpr.left.same(bexpr.right) && target.isSameAs(bexpr.left)) {
+                        if (bexpr.left isSameAs bexpr.right && target isSameAs bexpr.left) {
                             bexpr.operator = "*"
                             bexpr.right = LiteralValue.optimalInteger(2, assignment.value.position)
                             optimizationsDone++
@@ -466,7 +466,7 @@ internal class StatementOptimizer(private val program: Program, private val opti
                         }
                     }
                 } else {
-                    if (target.isSameAs(bexpr.left)) {
+                    if (target isSameAs bexpr.left) {
                         // remove assignments that have no effect  X=X , X+=0, X-=0, X*=1, X/=1, X//=1, A |= 0, A ^= 0, A<<=0, etc etc
                         // A = A <operator> B
                         val vardeclDt = (target.identifier?.targetVarDecl(program.namespace))?.type