From e0d8dc01719a5645a7114ee495976d7c1e82ed7d Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Thu, 8 Feb 2018 08:38:06 -0800
Subject: [PATCH] More chapter 2 work.

---
 ods/notes/chapter2.txt    |  8 +++++++-
 ods/src/Makefile.am       | 31 ++++++-------------------------
 ods/src/array_test.cc     | 14 ++++++++++++++
 ods/src/build.yaml        |  1 +
 ods/src/ods/array.h       | 37 +++++++++++++++++++++++++++++++++++--
 ods/src/ods/array_stack.h | 18 ++++++++++++++++++
 6 files changed, 81 insertions(+), 28 deletions(-)
 create mode 100644 ods/src/array_test.cc
 create mode 100644 ods/src/ods/array_stack.h

diff --git a/ods/notes/chapter2.txt b/ods/notes/chapter2.txt
index f996518..9ef8889 100644
--- a/ods/notes/chapter2.txt
+++ b/ods/notes/chapter2.txt
@@ -12,4 +12,10 @@ These data structures have common advantages and limitations:
   array requires shifting all the following elements.
 
 With some careful management, the additional *amortised* complexity added by
-resizing isn't too bad.
\ No newline at end of file
+resizing isn't too bad.
+
+## Array stack
+
+* Uses backing array *a*.
+* Typically, the array will be larger than necessary, so an element *n* is
+  used to track the actual number of elements stored in the stack.
diff --git a/ods/src/Makefile.am b/ods/src/Makefile.am
index b1f2881..0a6e850 100644
--- a/ods/src/Makefile.am
+++ b/ods/src/Makefile.am
@@ -1,27 +1,8 @@
-AM_CPPFLAGS  =  -Wall -Wextra -pedantic -Wshadow -Wpointer-arith -Wcast-align
-AM_CPPFLAGS +=  -Wwrite-strings -Wmissing-declarations -Wno-long-long -Werror
-AM_CPPFLAGS +=  -Wunused-variable -std=c++17 -D_XOPEN_SOURCE -O0 -g -I.
-AM_CPPFLAGS +=  -fno-elide-constructors -Weffc++ -fPIC
+all: build.ninja
+	ninja
 
-bin_PROGRAMS :=		ch01ex01 ch01ex03 ch01ex04 ch01ex05 ch01ex06 \
-			list_bench uset_bench sset_bench
-ch01ex01_SOURCES :=	ch01ex01.cc
-ch01ex03_SOURCES :=	ch01ex03.cc
-ch01ex04_SOURCES :=	ch01ex04.cc
-ch01ex05_SOURCES :=	ch01ex05.cc
-ch01ex06_SOURCES :=	ch01ex06.cc
-list_bench_SOURCES :=	list_bench.cc
-uset_bench_SOURCES :=	uset_bench.cc
-sset_bench_SOURCES :=	sset_bench.cc
+build.ninja: build.yaml
+	ng -f build.yaml $@
 
-BENCH_OPS ?=	1000000
-
-benchmarks: list_bench uset_bench sset_bench
-	@echo "LIST BENCHMARKS"
-	@./list_bench $(BENCH_OPS) > /dev/null
-	@echo
-	@echo "USET BENCHMARKS"
-	@./uset_bench $(BENCH_OPS) > /dev/null
-	@echo
-	@echo "SSET BENCHMARKS"
-	@./sset_bench $(BENCH_OPS) > /dev/null
\ No newline at end of file
+clean:
+	ninja -t clean
diff --git a/ods/src/array_test.cc b/ods/src/array_test.cc
new file mode 100644
index 0000000..54db1c5
--- /dev/null
+++ b/ods/src/array_test.cc
@@ -0,0 +1,14 @@
+#include <iostream>
+#include <ods/array.h>
+using namespace std;
+
+int
+main(void)
+{
+	Array<int>	a(2);
+	Array<int>	b(5);;
+	cout << "a[0] " << a[0] << endl;
+	
+	b = a;
+	cout << "a[0] " << a[0] << endl;
+}
\ No newline at end of file
diff --git a/ods/src/build.yaml b/ods/src/build.yaml
index 89b0527..6b6abd1 100644
--- a/ods/src/build.yaml
+++ b/ods/src/build.yaml
@@ -8,6 +8,7 @@ targets:
     ch01ex03: []
     ch01ex04: []
     ch01ex05: []
+    array_test: []
 
     # disabled due to flakey C++17 support.
     # ch01ex06: []
diff --git a/ods/src/ods/array.h b/ods/src/ods/array.h
index f1cb844..fe1a55b 100644
--- a/ods/src/ods/array.h
+++ b/ods/src/ods/array.h
@@ -1,9 +1,42 @@
 #ifndef __ODS_ODS_ARRAY__
 #define __ODS_ODS_ARRAY__
 
+#include <cstdint>
 
-class array {
+namespace ods {
+
+template<typename T>
+class Array {
+public:
+	Array(int len) : length(len) { a = new T[length]; }
+	T& operator[](int i) {
+		assert(i >= 0 && static_cast<std::size_t>(i) < length);
+		return a[i];
+	}
+	Array<T>& operator=(Array<T> &rhs) {
+		if (a != nullptr) {
+			delete a;
+		}
+		
+		a = rhs.a;
+		
+		// I don't understand why this is done, but it's how the book defines it.
+		rhs.a = nullptr;
+		
+		// I put this in to prevent segfaults.
+		rhs.length = 0;
+
+
+		length = rhs.length;
+		return *this;
+	}
 	
+	std::size_t	size(void) { return length; }
+private:
+	T		*a;
+	std::size_t	 length;
 };
 
-#endif __ODS_ODS_ARRAY__
\ No newline at end of file
+} // namespace ods
+
+#endif // __ODS_ODS_ARRAY__
\ No newline at end of file
diff --git a/ods/src/ods/array_stack.h b/ods/src/ods/array_stack.h
new file mode 100644
index 0000000..0b4931b
--- /dev/null
+++ b/ods/src/ods/array_stack.h
@@ -0,0 +1,18 @@
+#ifndef __ODS_ODS_ARRAY_STACK__
+#define __ODS_ODS_ARRAY_STACK__
+
+
+namespace ods {
+
+
+template<typename T>
+class ArrayStack {
+	int size(void) { return static_cast<int>(this->a->size()); }
+private:
+	Array<T>	a;
+	int		n;
+}
+
+} // namespace ods
+
+#endif // __ODS_ODS_ARRAY_STACK__
\ No newline at end of file