Merge pull request #55 from javecs/feature/environment

ユーザー関数が実行中に他のユーザー関数を呼び出せる環境を作成しました。

Author: javecs

build.gradle

@@ -16,7 +16,7 @@ plugins {
 }
 
 group 'xyz.javecs.tools'
-version '0.2.1'
+version '0.2.2'
 
 apply plugin: 'kotlin'
 apply plugin: 'antlr'

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

@@ -6,21 +6,19 @@ 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 environment = Environment()
     var value: Number = expression.value
         get() = expression.getValue()
 
     init {
         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)
-        }
+    private fun callFunction(name: String, args: Array<Double>) = if (environment.isRegistered(name)) {
+        environment.invoke(name, args)
+    } else {
+        invoke(name.toLowerCase(), args)
     }
 
     fun eval(expr: String = ""): Calculator {
@@ -35,15 +33,16 @@ class Calculator(expressions: Array<String> = emptyArray()) : EvalContext {
         return this
     }
 
+    fun plugin(f: Function): Calculator {
+        environment.register(f)
+        return this
+    }
+
     fun clear() {
         variables.clear()
         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: Array<Double>) = callFunction(name, args)

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

@@ -0,0 +1,11 @@
+package xyz.javecs.tools.expr
+
+class Environment {
+    private val functions: HashMap<String, Function> = HashMap()
+    fun register(f: Function) {
+        functions.put(f.name, f)
+        f.setEnvironment(this)
+    }
+    fun isRegistered(name: String) = functions.containsKey(name)
+    fun invoke(name: String, args: Array<Double>) = functions[name]!!.call(args)
+}

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

@@ -17,6 +17,9 @@ class Function(signature: String, val codes: Array<String>) {
     private val calc = Calculator()
     val name = validate(signature).first
     val params = validate(signature).second
+    fun setEnvironment(environment: Environment) {
+        calc.environment = environment
+    }
     fun call(args: Array<Double>): Double {
         if (params.size != args.size) return Double.NaN
         calc.clear()

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

@@ -11,4 +11,11 @@ class CalculatorPluginTest {
         calc.plugin(Function("f(x,y)", arrayOf("x + y")))
         assertEquals(3, calc.eval("f(1,2)").value)
     }
+
+    @Test fun plugin2() {
+        val calc = Calculator()
+                .plugin(Function("f(x,y)", arrayOf("x + y")))
+                .plugin(Function("g(x,y,z)", arrayOf("f(x,y) + z")))
+        assertEquals(6, calc.eval("g(1,2,3)").value)
+    }
 }