Fix and test

kmath-core/src/commonMain/kotlin/space/kscience/kmath/expressions/MST.kt

@@ -76,7 +76,7 @@ public fun <T> Algebra<T>.evaluate(node: MST): T = when (node) {
     }
 }
 
-internal class InnerAlgebra<T : Any>(val algebra: Algebra<T>, val arguments: Map<Symbol, T>) : NumericAlgebra<T> {
+internal class InnerAlgebra<T>(val algebra: Algebra<T>, val arguments: Map<Symbol, T>) : NumericAlgebra<T> {
     override fun bindSymbolOrNull(value: String): T? = algebra.bindSymbolOrNull(value) ?: arguments[StringSymbol(value)]
 
     override fun unaryOperation(operation: String, arg: T): T =
@@ -101,7 +101,7 @@ internal class InnerAlgebra<T : Any>(val algebra: Algebra<T>, val arguments: Map
 /**
  * Interprets the [MST] node with this [Algebra] and optional [arguments]
  */
-public fun <T : Any> MST.interpret(algebra: Algebra<T>, arguments: Map<Symbol, T>): T =
+public fun <T> MST.interpret(algebra: Algebra<T>, arguments: Map<Symbol, T>): T =
     InnerAlgebra(algebra, arguments).evaluate(this)
 
 /**
@@ -111,7 +111,7 @@ public fun <T : Any> MST.interpret(algebra: Algebra<T>, arguments: Map<Symbol, T
  * @param algebra the algebra that provides operations.
  * @return the value of expression.
  */
-public fun <T : Any> MST.interpret(algebra: Algebra<T>, vararg arguments: Pair<Symbol, T>): T =
+public fun <T> MST.interpret(algebra: Algebra<T>, vararg arguments: Pair<Symbol, T>): T =
     interpret(algebra, mapOf(*arguments))
 
 /**

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

@@ -84,7 +84,7 @@ public interface Algebra<T> {
      * @return an operation.
      */
     public fun binaryOperationFunction(operation: String): (left: T, right: T) -> T =
-        error("Binary operation $operation not defined in $this")
+        error("Binary operation '$operation; not defined in $this")
 
     /**
      * Dynamically invokes a binary operation with the certain name.

kmath-core/src/commonMain/kotlin/space/kscience/kmath/operations/LogicAlgebra.kt

@@ -27,12 +27,18 @@ public interface LogicAlgebra<T : Any> : Algebra<T> {
         else -> super.unaryOperation(operation, arg)
     }
 
+    override fun unaryOperationFunction(operation: String): (arg: T) -> T = { unaryOperation(operation, it) }
+
     override fun binaryOperation(operation: String, left: T, right: T): T = when (operation) {
         Boolean::and.name -> left.and(right)
         Boolean::or.name -> left.or(right)
         else -> super.binaryOperation(operation, left, right)
     }
 
+    override fun binaryOperationFunction(operation: String): (left: T, right: T) -> T = { l, r ->
+        binaryOperation(operation, l, r)
+    }
+
     /**
      * Logic 'not'
      */

kmath-core/src/commonTest/kotlin/space/kscience/kmath/expressions/ExpressionFieldTest.kt

@@ -6,7 +6,6 @@
 package space.kscience.kmath.expressions
 
 import space.kscience.kmath.operations.DoubleField
-import space.kscience.kmath.operations.invoke
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFails
@@ -16,7 +15,7 @@ class ExpressionFieldTest {
 
     @Test
     fun testExpression() {
-        val expression = FunctionalExpressionField(DoubleField).invoke {
+        val expression = with(FunctionalExpressionField(DoubleField)) {
             val x by binding()
             x * x + 2 * x + one
         }

kmath-core/src/commonTest/kotlin/space/kscience/kmath/expressions/InterpretTest.kt

@@ -5,18 +5,32 @@
 
 package space.kscience.kmath.expressions
 
+import space.kscience.kmath.expressions.Symbol.Companion.x
+import space.kscience.kmath.misc.UnstableKMathAPI
+import space.kscience.kmath.operations.BooleanAlgebra
 import space.kscience.kmath.operations.DoubleField
-import space.kscience.kmath.operations.bindSymbol
 import space.kscience.kmath.operations.invoke
 import kotlin.test.Test
+import kotlin.test.assertEquals
+
 
 internal class InterpretTest {
     @Test
     fun interpretation() {
         val expr = MstField {
-            val x = bindSymbol(Symbol.x)
             x * 2.0 + number(2.0) / x - 16.0
         }.toExpression(DoubleField)
-        expr(Symbol.x to 2.2)
+        assertEquals(-10.69, expr(x to 2.2), 0.02)
+    }
+
+    @Test
+    @UnstableKMathAPI
+    fun booleanAlgebra() {
+        val expr = MstLogicAlgebra {
+            x and const(true)
+        }.toExpression(BooleanAlgebra)
+
+        assertEquals(true, expr(x to true))
+        assertEquals(false, expr(x to false))
     }
 }