From aa4af2c36d5fbcc15e99250a1dc718b8c8e88a98 Mon Sep 17 00:00:00 2001
From: Robert Altena <Rob@ra-ai.com>
Date: Mon, 29 Jul 2019 21:20:16 +0900
Subject: [PATCH] refactor duplicate code from pad methods. (#86)

* refactor duplicate code from pad methods.

Signed-off-by: Robert Altena <Rob@Ra-ai.com>

* replace switch with if.

Signed-off-by: Robert Altena <Rob@Ra-ai.com>
---
 .../java/org/nd4j/linalg/factory/Nd4j.java    | 111 +++++++-----------
 1 file changed, 45 insertions(+), 66 deletions(-)

diff --git a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/factory/Nd4j.java b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/factory/Nd4j.java
index 82dd64337..b82a9e19e 100644
--- a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/factory/Nd4j.java
+++ b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/factory/Nd4j.java
@@ -225,85 +225,64 @@ public class Nd4j {
      * based on the specified mode
      */
     public static INDArray pad(INDArray toPad, int[][] padWidth, List<double[]> constantValues, PadMode padMode) {
-        switch (padMode) {
-            case CONSTANT:
-                if (padWidth.length < toPad.rank())
-                    throw new IllegalArgumentException("Please specify a pad width for each dimension");
+        if (padMode == PadMode.CONSTANT) {
+            if (padWidth.length < toPad.rank())
+                throw new IllegalArgumentException("Please specify a pad width for each dimension");
 
-                List<int[]> sizes = new ArrayList<>();
-                for (int i = 0; i < toPad.rank(); i++) {
-                    sizes.add(padWidth[i]);
-                }
-
-                INDArray ret = toPad;
-                for (int i = 0; i < toPad.rank(); i++) {
-                    int[] pad = sizes.get(i);
-                    double[] constant = constantValues.get(i);
-                    int padBefore = pad[0];
-                    int padAfter = pad[1];
-                    if (constant.length < 2) {
-                        double val = constant[0];
-                        constant = new double[2];
-                        constant[0] = val;
-                        constant[1] = val;
-                    }
-
-                    double beforeVal = constant[0];
-                    double afterVal = constant[1];
-                    ret = Nd4j.prepend(ret, padBefore, beforeVal, i);
-                    ret = Nd4j.append(ret, padAfter, afterVal, i);
-
-                }
-
-                return ret;
-
-            default:
-                throw new UnsupportedOperationException();
+            List<int[]> sizes = new ArrayList<>();
+            for (int i = 0; i < toPad.rank(); i++) {
+                sizes.add(padWidth[i]);
+            }
 
+            return padImpl(toPad, sizes, constantValues);
         }
+        throw new UnsupportedOperationException();
     }
 
     /**
      * See {@link #pad(INDArray, int[][], List, PadMode)} with a 1D int[] for padWidth.
      */
     public static INDArray pad(INDArray toPad, int[] padWidth, List<double[]> constantValues, PadMode padMode) {
-        switch (padMode) {
-            case CONSTANT:
-                if (padWidth.length < toPad.rank())
-                    throw new IllegalArgumentException("Please specify a pad width for each dimension");
+        if (padMode == PadMode.CONSTANT) {
+            if (padWidth.length < toPad.rank())
+                throw new IllegalArgumentException("Please specify a pad width for each dimension");
 
-                toPad = Nd4j.stripOnes(toPad);
+            toPad = Nd4j.stripOnes(toPad);
 
-                List<int[]> sizes = new ArrayList<>();
-                for (int i = 0; i < toPad.rank(); i++) {
-                    sizes.add(padWidth);
-                }
+            List<int[]> sizes = new ArrayList<>();
+            for (int i = 0; i < toPad.rank(); i++) {
+                sizes.add(padWidth);
+            }
 
-                INDArray ret = toPad;
-                //TODO: Remove duplicate code.
-                for (int i = 0; i < toPad.rank(); i++) {
-                    int[] pad = sizes.get(i);
-                    double[] constant = constantValues.get(i);
-                    int padBefore = pad[0];
-                    int padAfter = pad[1];
-                    if (constant.length < 2) {
-                        double val = constant[0];
-                        constant = new double[2];
-                        constant[0] = val;
-                        constant[1] = val;
-                    }
-
-                    double beforeVal = constant[0];
-                    double afterVal = constant[1];
-                    ret = Nd4j.prepend(ret, padBefore, beforeVal, i);
-                    ret = Nd4j.append(ret, padAfter, afterVal, i);
-
-                }
-                return ret;
-
-            default:
-                throw new UnsupportedOperationException();
+            return padImpl(toPad, sizes, constantValues);
         }
+        throw new UnsupportedOperationException();
+    }
+
+    // common code for pad(INDArray, int[],   List<double[]>, PadMode) and
+    //                 pad(INDArray, int[][], List<double[]>, PadMode)
+    private static INDArray padImpl(INDArray toPad, List<int[]> sizes, List<double[]> constantValues){
+
+        INDArray ret = toPad;
+        for (int i = 0; i < toPad.rank(); i++) {
+            int[] pad = sizes.get(i);
+            double[] constant = constantValues.get(i);
+            int padBefore = pad[0];
+            int padAfter = pad[1];
+            if (constant.length < 2) {
+                double val = constant[0];
+                constant = new double[2];
+                constant[0] = val;
+                constant[1] = val;
+            }
+
+            double beforeVal = constant[0];
+            double afterVal = constant[1];
+            ret = Nd4j.prepend(ret, padBefore, beforeVal, i);
+            ret = Nd4j.append(ret, padAfter, afterVal, i);
+
+        }
+        return ret;
     }
 
     /**