diff --git a/orx-expression-evaluator/build.gradle.kts b/orx-expression-evaluator/build.gradle.kts
index 8c28caef..4f59af37 100644
--- a/orx-expression-evaluator/build.gradle.kts
+++ b/orx-expression-evaluator/build.gradle.kts
@@ -1,5 +1,5 @@
 import com.strumenta.antlrkotlin.gradle.AntlrKotlinTask
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.dsl.KotlinCompile
 
 plugins {
     org.openrndr.extra.convention.`kotlin-multiplatform`
@@ -29,9 +29,6 @@ val generateKotlinGrammarSource = tasks.register<AntlrKotlinTask>("generateKotli
     outputDirectory = layout.buildDirectory.dir(outDir).get().asFile
 }
 
-tasks.withType<KotlinCompile> {
-    kotlinOptions.freeCompilerArgs = listOf("-opt-in=kotlin.RequiresOptIn")
-}
 
 kotlin {
     sourceSets {
@@ -61,6 +58,6 @@ kotlin {
     }
 }
 
-tasks.withType<KotlinCompile> {
+tasks.withType<KotlinCompile<*>> {
     dependsOn(generateKotlinGrammarSource)
 }
diff --git a/orx-expression-evaluator/src/commonMain/kotlin/Expressions.kt b/orx-expression-evaluator/src/commonMain/kotlin/Expressions.kt
index 7178cae7..2796b703 100644
--- a/orx-expression-evaluator/src/commonMain/kotlin/Expressions.kt
+++ b/orx-expression-evaluator/src/commonMain/kotlin/Expressions.kt
@@ -5,13 +5,14 @@ package org.openrndr.extra.expressions
 import org.antlr.v4.kotlinruntime.*
 import org.antlr.v4.kotlinruntime.tree.ParseTreeWalker
 import org.antlr.v4.kotlinruntime.tree.TerminalNode
+import org.openrndr.collections.pop
+import org.openrndr.collections.push
 import org.openrndr.expressions.parser.KeyLangLexer
 import org.openrndr.expressions.parser.KeyLangParser
 import org.openrndr.expressions.parser.KeyLangParserBaseListener
 
 import org.openrndr.extra.noise.uniform
 import org.openrndr.math.*
-import java.util.*
 import kotlin.math.*
 
 typealias Function0 = () -> Double
@@ -49,14 +50,14 @@ internal class ExpressionListener(
     val constants: Map<String, Double> = mapOf()
 ) :
     KeyLangParserBaseListener() {
-    val doubleStack = Stack<Double>()
-    val functionStack = Stack<(DoubleArray) -> Double>()
+    val doubleStack = ArrayDeque<Double>()
+    val functionStack = ArrayDeque<(DoubleArray) -> Double>()
 
 
-    val idTypeStack = Stack<IDType>()
+    val idTypeStack = ArrayDeque<IDType>()
     var lastExpressionResult: Double? = null
 
-    val exceptionStack = Stack<ExpressionException>()
+    val exceptionStack = ArrayDeque<ExpressionException>()
 
 
     override fun exitExpressionStatement(ctx: KeyLangParser.ExpressionStatementContext) {
@@ -280,8 +281,8 @@ internal class ExpressionListener(
                     val function: (DoubleArray) -> Double =
                         when (name) {
                             "sqrt" -> { x -> sqrt(x[0]) }
-                            "radians" -> { x -> Math.toRadians(x[0]) }
-                            "degrees" -> { x -> Math.toDegrees(x[0]) }
+                            "radians" -> { x -> x[0].asRadians }
+                            "degrees" -> { x -> x[0].asDegrees }
                             "cos" -> { x -> cos(x[0]) }
                             "sin" -> { x -> sin(x[0]) }
                             "tan" -> { x -> tan(x[0]) }