refactoring example, to create readable reusable code

Author: rdoetjes

function_pointers/switch_alternative.cpp

@@ -29,8 +29,7 @@ int main(){
 
   std::cout << "an example of using fuction pointers in an array, as order of execution" << std::endl;
   int ins[] = {1, 1, 2, 0, 1};
-  for(int i=0; i<sizeof(ins)/sizeof(ins[0]); i++)
-    (*p[ ins[i] ])(i);
+  for(int i=0; i<sizeof(ins)/sizeof(ins[0]); i++) (*p[ ins[i] ])(i);
 
   //declare a map (hash) of 3 function pointers that take int as argument. C++ as std::function which would be a cleaner more c++ approach for prototyping def.
   std::map<std::string, void (*)(int)> t;

modulo_2_must_go/Makefile

@@ -7,7 +7,7 @@
 CC = g++                        # compiler to use
 
 LINKERFLAG = 
-CXXFLAGS = -g -O3 -std=c++17
+CXXFLAGS = -O3 -g -std=c++17
 
 SRCS := $(wildcard *.cpp)
 BINS := $(SRCS:%.cpp=%)

modulo_2_must_go/fast_odd_even.cpp

@@ -25,6 +25,7 @@ void moduloMethod(const int ITS) {
       temp++;
     }
   }
+
   std::cout << temp << endl;
 }
 
@@ -45,19 +46,19 @@ int main() {
   vector<long> aC;
   vector<long> bC;
 
-  std::chrono::time_point<std::chrono::system_clock> startTime;
-  std::chrono::time_point<std::chrono::system_clock> endTime;
+  std::chrono::time_point<std::chrono::system_clock> sTime;
+  std::chrono::time_point<std::chrono::system_clock> eTime;
 
   for (int i = 0; i < 100; i++) {
-    startTime = high_resolution_clock::now();
+    sTime = high_resolution_clock::now();
     andMethod(ITS);
-    endTime = high_resolution_clock::now();
-    aC.push_back(duration_cast<microseconds>(endTime - startTime).count());
+    eTime = high_resolution_clock::now();
+    aC.push_back(duration_cast<microseconds>(eTime - sTime).count());
 
-    startTime = high_resolution_clock::now();
+    sTime = high_resolution_clock::now();
     moduloMethod(ITS);
-    endTime = high_resolution_clock::now();
-    bC.push_back(duration_cast<microseconds>(endTime - startTime).count());
+    eTime = high_resolution_clock::now();
+    bC.push_back(duration_cast<microseconds>(eTime - sTime).count());
   }
 
   float aCA = accumulate(aC.begin(), aC.end(), 0.0) / aC.size();

modulo_2_must_go/fast_odd_even.py

@@ -28,7 +28,7 @@ def Average(lst):
 
 ITS = 10000000
 
-for i in range(0, 3):
+for i in range(0, 100):
     start = time.time_ns()
     andMethod(ITS)
     stop = time.time_ns()

reusable_code/.write_to_file_v5.py.swp

@@ -0,0 +1 @@
+Hi write me to the file please

reusable_code/okay.txt

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+import os
+
+def writeDataToFile(fileName, data):
+    try:
+        f = open(fileName, "a+")
+        f.write(data)
+        f.close()
+    except IOError:
+        raise IOError
+
+#Main program
+data = "Hi write me to the file please"
+okayFile = "okay.txt"
+
+try:
+    writeDataToFile(okayFile, data)
+except IOError as  e:
+    print("Error %s occured, program halted" % {e.strerror})
+    exit(1)
+

reusable_code/write_to_file.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+import os
+
+def writeDataToFile(fileName, data):
+    try:
+        f = open(fileName, "w+")
+        f.write(data)
+    except IOError:
+        raise IOError
+    finally:
+        f.close()
+
+#Main program
+data = "Hi write me to the file please"
+okayFile = "okay.txt"
+
+try:
+    writeDataToFile(okayFile, data)
+except IOError as  e:
+    print("Error %s occured, program halted" % {e.strerror})
+    exit(1)
+

reusable_code/write_to_file_v1.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python3
+import os
+
+def writeDataToFile(fileName, data):
+    try:
+        f = open(fileName, "w+")
+        if f is None:
+            raise TypeError
+        f.write(data)
+    except IOError:
+        raise IOError
+    finally:
+        f.close()
+
+#Main program
+data = "Hi write me to the file please"
+okayFile = "okay.txt"
+
+try:
+    writeDataToFile(okayFile, data)
+except IOError as  e:
+    print("Error %s occured, program halted" % {e.strerror})
+    exit(1)
+

reusable_code/write_to_file_v2.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+import os
+
+def ThrowErrorIfObjectIsNull(obj):
+    if not obj:
+        raise TypeError("Object is set to Null")
+
+def writeDataToFile(fileName, data):
+    try:
+        f = open(fileName, "w+")
+        f = None
+        ThrowErrorIfObjectIsNull(f)
+        f.write(data)
+        f.close()
+    except Exception as e:
+        raise e
+
+#Main program
+data = "Hi write me to the file please"
+okayFile = "okay.txt"
+
+try:
+    writeDataToFile(okayFile, data)
+except Exception as e:
+    print("Uncaught exception %s" % (e))
+    exit(1)
+

reusable_code/write_to_file_v3.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+import os
+
+def ThrowErrorIfObjectIsNull(obj):
+    if not obj:
+        raise TypeError("Object is set to null")
+
+def writeToFileAndClose(fileDesc, data):
+    ThrowErrorIfObjectIsNull(fileDesc)
+    fileDesc.write(data)
+    fileDesc.close()
+
+def writeDataToFile(fileName, data):
+    try:
+        f = open(fileName, "w+")
+        writeToFileAndClose(f, data)
+    except IOError as e:
+        raise e
+
+#Main program
+data = "Hi write me to the file please"
+okayFile = "okay.txt"
+
+try:
+    writeDataToFile(okayFile, data)
+except Exception as e:
+    print("Uncaught exception %s" % (e))
+    exit(1)
+

reusable_code/write_to_file_v4.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+import os
+
+class ErrorCheck:
+    @staticmethod
+    def ThrowTypeErrorIfObjectIsNull(obj):
+        if not obj:
+            raise TypeError("ErrorCheck object is set to null ")
+    
+class File:
+    @staticmethod
+    def __writeDataToFileObjectAndClose(fileDesc, data):
+        ErrorCheck.ThrowTypeErrorIfObjectIsNull(fileDesc)
+        fileDesc.write(data)
+        fileDesc.close()
+     
+    @staticmethod
+    def writeText(fileName, text, mode):
+        try:
+            f = open(fileName, mode)
+            ErrorCheck.ThrowTypeErrorIfObjectIsNull(f)
+            File.__writeDataToFileObjectAndClose(f, text)
+        except TypeError as e:
+            raise TypeError("the file %s could not be open, fileObject is None" % (fileName) )
+        except IOError as e:
+            raise e
+
+    @staticmethod
+    def createFileOrAppendWithText(fileName, text):
+        try:
+            File.writeText(fileName,text, "a+")
+        except IOError as e:
+            raise e
+
+    @staticmethod
+    def createFileWithText(fileName, text):
+        try:
+            File.writeText(fileName,text, "w+")
+        except IOError as e:
+            raise e
+
+#Main program
+textToSave = "Hi write me to the file please\n"
+okayFile = "okay.txt"
+
+try:
+    File.createFileOrAppendWithText(okayFile, textToSave)
+except Exception as e:
+    print("Uncaught exception %s" % (e))
+    exit(1)
+