Добавлена функция functional::chain

Author: aNNiMON

src/com/annimon/ownlang/lib/modules/functional.java

@@ -18,6 +18,7 @@ public void init() {
         Functions.set("filter", new functional_filter());
         Functions.set("sortby", new functional_sortby());
 
+        Functions.set("chain", new functional_chain());
         Functions.set("combine", new functional_combine());
 
         Variables.set("IDENTITY", new FunctionValue(args -> args[0]));

src/com/annimon/ownlang/lib/modules/functions/functional_chain.java

@@ -0,0 +1,24 @@
+package com.annimon.ownlang.lib.modules.functions;
+
+import com.annimon.ownlang.exceptions.TypeException;
+import com.annimon.ownlang.lib.*;
+
+public final class functional_chain implements Function {
+
+    @Override
+    public Value execute(Value... args) {
+        Arguments.checkAtLeast(2, args.length);
+
+        Value result = args[0];
+        for (int i = 1; i < args.length; i += 2) {
+            final Value arg = args[i];
+            if (arg.type() != Types.FUNCTION) {
+                throw new TypeException(arg.toString() + " is not a function");
+            }
+            final Function function = ((FunctionValue) arg).getValue();
+            result = function.execute(result, args[i+1]);
+        }
+        return result;
+    }
+    
+}

tests.own

@@ -1,4 +1,5 @@
 use "ounit"
+use "functional"
 
 def testAdditionOnNumbers() {
   assertEquals(6, 0 + 1 + 2 + 3)
@@ -56,4 +57,14 @@ def testFibonacci() {
   assertEquals(21, fib(8))
 }
 
+def testFunctionalChain() {
+  data = [1,2,3,4,5,6,7]
+  result = chain(data,
+    ::filter, def(x) = x <= 4,
+    ::sortby, def(x) = -x,
+    ::map,    def(x) = x * 2,
+  )
+  assertEquals([8,6,4,2], result)
+}
+
 println runTests()