kmath-ast/README.md

@@ -38,7 +38,9 @@ This subproject implements the following features:
 > ```
 >
 
-## Dynamic Expression Code Generation with ObjectWeb ASM
+## Dynamic expression code generation
+
+### On JVM
 
 `kmath-ast` JVM module supports runtime code generation to eliminate overhead of tree traversal. Code generator builds 
 a special implementation of `Expression<T>` with implemented `invoke` function. 
@@ -55,19 +57,20 @@ RealField.mstInField { symbol("x") + 2 }.compile()
 package kscience.kmath.asm.generated;
 
 import java.util.Map;
+import kotlin.jvm.functions.Function2;
 import kscience.kmath.asm.internal.MapIntrinsics;
 import kscience.kmath.expressions.Expression;
-import kscience.kmath.operations.RealField;
+import kscience.kmath.expressions.Symbol;
 
-public final class AsmCompiledExpression_1073786867_0 implements Expression<Double> {
+public final class AsmCompiledExpression_45045_0 implements Expression<Double> {
-    private final RealField algebra;
+    private final Object[] constants;
 
-    public final Double invoke(Map<String, ? extends Double> arguments) {
+    public final Double invoke(Map<Symbol, Double> arguments) {
-        return (Double)this.algebra.add(((Double)MapIntrinsics.getOrFail(arguments, "x")).doubleValue(), 2.0D);
+        return (Double)((Function2)this.constants[0]).invoke((Double)MapIntrinsics.getOrFail(arguments, "x"), 2);
     }
 
-    public AsmCompiledExpression_1073786867_0(RealField algebra) {
+    public AsmCompiledExpression_45045_0(Object[] constants) {
-        this.algebra = algebra;
+        this.constants = constants;
     }
 }
 
@@ -82,10 +85,30 @@ RealField.mstInField { symbol("x") + 2 }.compile()
 RealField.expression("x+2".parseMath())
 ```
 
-### Known issues
+#### Known issues
 
 - The same classes may be generated and loaded twice, so it is recommended to cache compiled expressions to avoid
 class loading overhead. 
 - This API is not supported by non-dynamic JVM implementations (like TeaVM and GraalVM) because of using class loaders.
 
 Contributed by [Iaroslav Postovalov](https://github.com/CommanderTvis).
+
+### On JS
+
+A similar feature is also available on JS.
+
+```kotlin
+RealField.mstInField { symbol("x") + 2 }.compile()
+``` 
+
+The code above returns expression implemented with such a JS function:
+
+```js
+var executable = function (constants, arguments) {
+  return constants[1](constants[0](arguments, "x"), 2);
+};
+```
+
+#### Known issues
+
+- This feature uses `eval` which can be unavailable in several environments.

kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt

@@ -27,7 +27,9 @@ public object MstSpace : Space<MST>, NumericAlgebra<MST> {
     public override fun add(a: MST, b: MST): MST.Binary = binaryOperation(SpaceOperations.PLUS_OPERATION)(a, b)
     public override operator fun MST.unaryPlus(): MST.Unary = unaryOperation(SpaceOperations.PLUS_OPERATION)(this)
     public override operator fun MST.unaryMinus(): MST.Unary = unaryOperation(SpaceOperations.MINUS_OPERATION)(this)
-    public override operator fun MST.minus(b: MST): MST.Binary = binaryOperation(SpaceOperations.MINUS_OPERATION)(this, b)
+
+    public override operator fun MST.minus(b: MST): MST.Binary =
+        binaryOperation(SpaceOperations.MINUS_OPERATION)(this, b)
 
     public override fun multiply(a: MST, k: Number): MST.Binary =
         binaryOperation(RingOperations.TIMES_OPERATION)(a, number(k))

kmath-ast/src/jvmMain/kotlin/kscience/kmath/asm/internal/AsmBuilder.kt

@@ -2,13 +2,16 @@ package kscience.kmath.asm.internal
 
 import kscience.kmath.asm.internal.AsmBuilder.ClassLoader
 import kscience.kmath.ast.MST
+import kscience.kmath.ast.mstInField
 import kscience.kmath.expressions.Expression
+import kscience.kmath.operations.RealField
 import org.objectweb.asm.*
 import org.objectweb.asm.Opcodes.*
 import org.objectweb.asm.Type.*
 import org.objectweb.asm.commons.InstructionAdapter
 import java.lang.invoke.MethodHandles
 import java.lang.invoke.MethodType
+import java.lang.reflect.Modifier
 import java.util.stream.Collectors.toMap
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
@@ -82,7 +85,7 @@ internal class AsmBuilder<T>(
                 ACC_PUBLIC or ACC_FINAL,
                 "invoke",
                 getMethodDescriptor(tType, MAP_TYPE),
-                "(L${MAP_TYPE.internalName}<${STRING_TYPE.descriptor}+${tType.descriptor}>;)${tType.descriptor}",
+                "(L${MAP_TYPE.internalName}<${SYMBOL_TYPE.descriptor}${if (Modifier.isFinal(classOfT.modifiers)) "" else "+"}${tType.descriptor}>;)${tType.descriptor}",
                 null,
             ).instructionAdapter {
                 invokeMethodVisitor = this
@@ -159,7 +162,7 @@ internal class AsmBuilder<T>(
                 "<init>",
                 getMethodDescriptor(VOID_TYPE, *OBJECT_ARRAY_TYPE.wrapToArrayIf { hasConstants }),
                 null,
-                null
+                null,
             ).instructionAdapter {
                 val l0 = label()
                 load(0, classType)
@@ -190,6 +193,7 @@ internal class AsmBuilder<T>(
         }
 
         val cls = classLoader.defineClass(className, classWriter.toByteArray())
+        java.io.File("dump.class").writeBytes(classWriter.toByteArray())
         val l = MethodHandles.publicLookup()
 
         if (hasConstants)
@@ -334,5 +338,10 @@ internal class AsmBuilder<T>(
          * ASM type for MapIntrinsics.
          */
         val MAP_INTRINSICS_TYPE: Type by lazy { getObjectType("kscience/kmath/asm/internal/MapIntrinsics") }
+
+        /**
+         * ASM Type for [kscience.kmath.expressions.Symbol].
+         */
+        val SYMBOL_TYPE: Type by lazy { getObjectType("kscience/kmath/expressions/Symbol") }
     }
 }

kmath-ast/src/jvmTest/kotlin/kscience/kmath/ast/AsmTest.kt

@@ -2,8 +2,6 @@ package kscience.kmath.ast
 
 import kscience.kmath.asm.compile
 import kscience.kmath.asm.expression
-import kscience.kmath.ast.mstInField
-import kscience.kmath.ast.parseMath
 import kscience.kmath.expressions.invoke
 import kscience.kmath.operations.Complex
 import kscience.kmath.operations.ComplexField

kmath-ast/src/jvmTest/kotlin/kscience/kmath/ast/ParserPrecedenceTest.kt

@@ -1,7 +1,5 @@
 package kscience.kmath.ast
 
-import kscience.kmath.ast.evaluate
-import kscience.kmath.ast.parseMath
 import kscience.kmath.operations.Field
 import kscience.kmath.operations.RealField
 import kotlin.test.Test

kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Algebra.kt

@@ -275,12 +275,12 @@ public interface SpaceOperations<T> : Algebra<T> {
 
     public companion object {
         /**
-         * The identifier of addition and unary positive.
+         * The identifier of addition and unary positive operator.
          */
         public const val PLUS_OPERATION: String = "+"
 
         /**
-         * The identifier of subtraction and unary negation.
+         * The identifier of subtraction and unary negative operator.
          */
         public const val MINUS_OPERATION: String = "-"
     }