Better docs

Author: lemire

README.md

@@ -122,6 +122,27 @@ Versions 0.5 and above assume that the compiler supports the C++11 standard.
     make example
     ./example
 
+# Quick code sample
+
+```C++
+  #include "ewah.h"
+
+  typedef EWAHBoolArray<uint32_t> bitmap;
+
+  bitmap bitset1 =
+      bitmap::bitmapOf(9, 1, 2, 1000, 1001, 1002, 1003, 1007, 1009, 100000);
+  std::cout << "first bitset : " << bitset1 << std::endl;
+  bitmap bitset2 = bitmap::bitmapOf(5, 1, 3, 1000, 1007, 100000);
+  std::cout << "second bitset : " << bitset2 << std::endl;
+  bitmap bitset3 = bitmap::bitmapOf(3, 10, 11, 12);
+  std::cout << "third  bitset : " << bitset3 << std::endl;
+  bitmap orbitset = bitset1 | bitset2;
+  bitmap andbitset = bitset1 & bitset2;
+  bitmap xorbitset = bitset1 ^ bitset2;
+  bitmap andnotbitset = bitset1 - bitset2;
+```
+
+
 # Example
 
 Please see example.cpp.

example.cpp

@@ -7,6 +7,40 @@
 #include <stdlib.h>
 #include "ewah.h"
 
+void easydemo() {
+  typedef EWAHBoolArray<uint32_t> bitmap;
+  bitmap bitset1 =
+      bitmap::bitmapOf(9, 1, 2, 1000, 1001, 1002, 1003, 1007, 1009, 100000);
+  std::cout << "first bitset : " << bitset1 << std::endl;
+  bitmap bitset2 = bitmap::bitmapOf(5, 1, 3, 1000, 1007, 100000);
+  std::cout << "second bitset : " << bitset2 << std::endl;
+  bitmap bitset3 = bitmap::bitmapOf(3, 10, 11, 12);
+  std::cout << "third  bitset : " << bitset3 << std::endl;
+  bitmap orbitset = bitset1 | bitset2;
+  bitmap andbitset = bitset1 & bitset2;
+  bitmap xorbitset = bitset1 ^ bitset2;
+  bitmap andnotbitset = bitset1 - bitset2;
+
+  std::cout << "logical and: " << andbitset << std::endl;
+  std::cout << "memory usage of compressed bitset = " << andbitset.sizeInBytes()
+            << " bytes" << std::endl;
+  // we will display the and
+  std::cout << "logical or: " << orbitset << std::endl;
+  std::cout << "memory usage of compressed bitset = " << orbitset.sizeInBytes()
+            << " bytes" << std::endl;
+  // we will display the xor
+  std::cout << "logical xor: " << xorbitset << std::endl;
+  std::cout << "memory usage of compressed bitset = " << xorbitset.sizeInBytes()
+            << " bytes" << std::endl;
+  std::cout << "union of all three bitsets = " << (orbitset | bitset3)
+            << std::endl;
+  const bitmap *mybitmaps[] = {&bitset1, &bitset2, &bitset3};
+  std::cout << "fast union of all three bitsets = "
+            << fast_logicalor(3, mybitmaps) << std::endl;
+
+  std::cout << std::endl;
+}
+
 template <class bitmap> void demo() {
   bitmap bitset1 =
       bitmap::bitmapOf(9, 1, 2, 1000, 1001, 1002, 1003, 1007, 1009, 100000);
@@ -109,6 +143,8 @@ int main(void) {
   std::cout << std::endl;
   std::cout << "====compressed example====" << std::endl;
   std::cout << std::endl;
+  easydemo();
+
   demo<EWAHBoolArray<uint32_t>>();
   demoSerialization<EWAHBoolArray<uint32_t>>();
   std::cout << "==== benchmark intersecs === " << std::endl;

src/unit.cpp

@@ -186,7 +186,7 @@ template <class uword> bool testCardinalityEWAHBoolArray() {
 template <class uword> bool testLargeDirty() {
   cout << "[testing LargeDirty] sizeof(uword)=" << sizeof(uword)
        << endl;
-  size_t N = 8000000;
+  size_t N = 200000000;
   vector<uint32_t> bigarray1(N);
   vector<uint32_t> bigarray2(N);
   for(size_t k = 0; k < N; k++) {
@@ -195,36 +195,36 @@ template <class uword> bool testLargeDirty() {
   }
   EWAHBoolArray<uword> b1 = EWAHBoolArray<uword>();
   EWAHBoolArray<uword> b2 = EWAHBoolArray<uword>();
-  for(size_t k = 0; k < N; k++) {
+  for(size_t k = 0; (8*k) < N; k++) {
     b1.set(8 * k);
-    b2.set(64 * k);
+  }
+  for(size_t k = 0; (64*k) < N; k++) {
+    b1.set(64 * k);
   }
 
-  EWAHBoolArray<uword> b3 = EWAHBoolArray<uword>::bitmapOf(3,1,10,1000);
-  EWAHBoolArray<uword> b4 = EWAHBoolArray<uword>::bitmapOf(3,1,10,1000);
+  EWAHBoolArray<uword> b3 = EWAHBoolArray<uword>::bitmapOf(3,1,10,1001);
+  EWAHBoolArray<uword> b4 = EWAHBoolArray<uword>::bitmapOf(3,1,10,1001);
 
-  if (b1.numberOfOnes() != N) {
-    return false;
-  }
-  if (b2.numberOfOnes() != N) {
-    return false;
-  }
   if (b3.numberOfOnes() != 3) {
+    std::cout<< "bad b3 count" << b4.numberOfOnes()<<std::endl;
     return false;
   }
   b3 = b3 | b1;
   b4 = b4 | b2;
   b3 = b3 | b2;
   b4 = b4 | b1;
   if( b3 != b4 ) {
+    std::cout<< "b3 != b4"<<std::endl;
     return false;
   }
   b4 = b4 - b1;
   if (b4.numberOfOnes() != 3) {
+    std::cout<< "bad b4 count" << b4.numberOfOnes()<<std::endl;
     return false;
   }
   b3 = b3 ^ b4;
   if( b3 != b1 ) {
+    std::cout<< "b3 != b1"<<std::endl;
     return false;
   }