Merge pull request #53 from javecs/feature/plugin

ユーザー関数をプラグインして、実行する機能を追加しました。

Author: javecs

build.gradle

@@ -16,7 +16,7 @@ plugins {
 }
 
 group 'xyz.javecs.tools'
-version '0.1.11'
+version '0.2.1'
 
 apply plugin: 'kotlin'
 apply plugin: 'antlr'

src/main/kotlin/xyz/javecs/tools/expr/BuiltIn.kt

@@ -5,7 +5,7 @@ internal fun constant() = HashMap<String, Double>().apply {
     put("e", Math.E)
 }
 
-internal fun invoke(name: String, args: ArrayList<Double>) = when (name) {
+internal fun invoke(name: String, args: Array<Double>) = when (name) {
     "sin" -> Math.sin(args[0])
     "cos" -> Math.cos(args[0])
     "tan" -> Math.tan(args[0])

src/main/kotlin/xyz/javecs/tools/expr/Calculator.kt

@@ -6,6 +6,7 @@ class Calculator(expressions: Array<String> = emptyArray()) : EvalContext {
     private val evaluator = EvalVisitor(this)
     private val variables = HashMap<String, Double>()
     private val constants = constant()
+    private val functions = HashMap<String, Function>()
     private var expression = Expression()
     var value: Number = expression.value
         get() = expression.getValue()
@@ -14,6 +15,14 @@ class Calculator(expressions: Array<String> = emptyArray()) : EvalContext {
         expressions.forEach { eval(it) }
     }
 
+    private fun callFunction(name: String, args: Array<Double>): Double {
+        return if (functions.containsKey(name)) {
+            functions[name]!!.call(args)
+        } else {
+            invoke(name.toLowerCase(), args)
+        }
+    }
+
     fun eval(expr: String = ""): Calculator {
         expression = when (expr.isEmpty()) {
             true -> expression
@@ -31,9 +40,13 @@ class Calculator(expressions: Array<String> = emptyArray()) : EvalContext {
         expression = Expression()
     }
 
+    fun plugin(function: Function) {
+        functions.put(function.name, function)
+    }
+
     override fun toString() = expression.toString()
     override fun isConstant(name: String) = constants.contains(name.toLowerCase())
-    override fun call(name: String, args: ArrayList<Double>) = invoke(name.toLowerCase(), args)
+    override fun call(name: String, args: Array<Double>) = callFunction(name, args)
     override fun get(name: String) = constants.getOrDefault(name.toLowerCase(), variables.getOrDefault(name, Double.NaN))
     override fun put(name:String, value: Double) = when (isConstant(name)) {
         true -> Double.NaN

src/main/kotlin/xyz/javecs/tools/expr/EvalContext.kt

@@ -3,6 +3,6 @@ package xyz.javecs.tools.expr
 internal interface EvalContext {
     fun get(name: String): Double
     fun put(name:String, value: Double): Double
-    fun call(name: String, args: ArrayList<Double>): Double
+    fun call(name: String, args: Array<Double>): Double
     fun isConstant(name: String): Boolean
 }

src/main/kotlin/xyz/javecs/tools/expr/EvalVisitor.kt

@@ -40,7 +40,7 @@ internal class EvalVisitor(val context: EvalContext) : ExprBaseVisitor<Expressio
         val func = ctx!!.ID().text
         val args = ArrayList<Double>()
         ctx.expr().mapTo(args) { visit(it).value }
-        return Expression(value = context.call(func, args))
+        return Expression(value = context.call(func, args.toTypedArray()))
     }
 
     override fun visitConstant(ctx: ExprParser.ConstantContext?): Expression {

src/test/kotlin/xyz/javecs/tools/expr/test/kotlin/CalculatorPluginTest.kt

@@ -0,0 +1,14 @@
+package xyz.javecs.tools.expr.test.kotlin
+
+import kotlin.test.assertEquals
+import org.junit.Test
+import xyz.javecs.tools.expr.Calculator
+import xyz.javecs.tools.expr.Function
+
+class CalculatorPluginTest {
+    @Test fun plugin1() {
+        val calc = Calculator()
+        calc.plugin(Function("f(x,y)", arrayOf("x + y")))
+        assertEquals(3, calc.eval("f(1,2)").value)
+    }
+}