Totally rework the Range class. Now the range is from [start, end)

to be consistent with the way that the stl works.  It also makes
lots of other stuff easier.  (Maybe those guys were smart?)
Overload the various comparison operators so that you can test
for overlapping of ranges, etc.

base/range.hh:
    Totally rework the Range class.  Now the range is from [start, end)
    to be consistent with the way that the stl works.  It also makes
    lots of other stuff easier.  (Maybe those guys were smart?)
    Overload the various comparison operators so that you can test
    for overlapping of ranges, etc.

    make parse function private and offer operator= instead
    isValid -> valid
    and for you erik, I add comments
test/Makefile:
    add range.o
test/rangetest.cc:
    better tests

--HG--
extra : convert_revision : dd58720aa3d02f20b03e933f2eaa3320c82bb27a

1 files changed, 263 insertions, 155 deletions

diff --git a/base/range.hh b/base/range.hh
index 3443bf246..34bd34136 100644
--- a/base/range.hh
+++ b/base/range.hh
@@ -29,232 +29,340 @@
 #ifndef __RANGE_HH__
 #define __RANGE_HH__
 
-#include <assert.h>
+#include <cassert>
+#include <string>
 
-#include "base/intmath.hh"
-#include "base/str.hh"
+template <class T>
+bool __parse_range(const std::string &s, T &start, T &end);
 
-template<class T>
-class Range
+template <class T>
+struct Range
 {
   private:
-    bool valid;
+    /**
+     * @param s range string
+     * Ranges are in the following format:
+     *    <range> := {<start_val>}:{<end>}
+     *    <end>   := <end_val> | +<delta>
+     */
+    void
+    parse(const std::string &s)
+    {
+        if (!__parse_range(s, start, end))
+            invalidate();
+    }
 
   public:
     T start;
     T end;
 
   public:
-    Range() {}
+    Range()
+    {
+        invalidate();
+    }
+
+    template <class U>
+    Range(const Range<U> &r)
+        : start(r.start), end(r.end)
+    {}
 
-    Range(const Range &r) { operator=(r); }
+    template <class U>
+    Range(const std::pair<U, U> &r)
+        : start(r.first), end(r.second)
+    {}
 
-    Range(const T &s, const T &e)
-        : start(s), end(e)
+    Range(const std::string &s)
     {
-        valid = (start <= end);
+        parse(s);
     }
 
-    Range(const std::string &s) { valid = parse(s); }
+    template <class U>
+    const Range<T> &operator=(const Range<U> &r)
+    {
+        start = r.start;
+        end = r.end;
+        return *this;
+    }
 
-    ~Range() {}
+    template <class U>
+    const Range<T> &operator=(const std::pair<U, U> &r)
+    {
+        start = r.first;
+        end = r.second;
+        return *this;
+    }
 
-    int compare(const T &p);
-    bool parse(const std::string &s);
-    const Range &operator=(const Range &r);
+    const Range &operator=(const std::string &s)
+    {
+        parse(s);
+        return *this;
+    }
 
-    bool isValid() const { return valid; }
+    void invalidate() { start = 0; end = 0; }
+    bool size() const { return end - start; }
+    bool valid() const { return start < end; }
 };
 
-
 template<class T>
-inline int
-Range<T>::compare(const T &p)
+inline std::ostream &
+operator<<(std::ostream &o, const Range<T> &r)
 {
-    assert(isValid());
-
-    if (p < start)
-        return -1;
-    else if (p > end)
-        return 1;
-    else
-        return 0;
+    // don't currently support output of invalid ranges
+    assert(r.valid());
+    o << r.start << ":" << r.end;
+    return o;
 }
 
-// Parse a range string
+////////////////////////////////////////////////////////////////////////
 //
-// Ranges are in the following format:
-//    <range> := {<start_val>}:{<end>}
-//    <end>   := <end_val> | +<delta>
-template<class T>
+// Range to Range Comparisons
+//
+
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 and range2 are identical.
+ */
+template<class T, class U>
 inline bool
-Range<T>::parse(const std::string &str)
+operator==(const Range<T> &range1, const Range<U> &range2)
 {
-    std::vector<std::string> values;
-    tokenize(values, str, ':');
-
-    T thestart, theend;
-
-    if (values.size() != 2)
-        return false;
-
-    std::string s = values[0];
-    std::string e = values[1];
-
-    if (!to_number(s, thestart))
-        return false;
-
-    bool increment = (e[0] == '+');
-    if (increment)
-        e = e.substr(1);
-
-    if (!to_number(e, theend))
-        return false;
-
-    if (increment)
-        theend += thestart;
-
-    start = thestart;
-    end = theend;
-
-    if (start > end)
-        return false;
-
-    return true;
+    assert(range1.valid() && range2.valid());
+    return range1.start == range2.start && range1.end == range2.end;
 }
 
-
-template<class T>
-inline const Range<T> &
-Range<T>::operator=(const Range<T> &r)
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 and range2 are not identical.
+ */
+template<class T, class U>
+inline bool
+operator!=(const Range<T> &range1, const Range<U> &range2)
 {
-    if (this != &r) {
-        start = r.start;
-        end = r.end;
-
-        valid = r.valid;
-    }
-    else {
-        valid = false;
-    }
+    assert(range1.valid() && range2.valid());
+    return range1.start != range2.start || range1.end != range2.end;
+}
 
-    return *this;
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 is less than range2 and does not overlap range1.
+ */
+template<class T, class U>
+inline bool
+operator<(const Range<T> &range1, const Range<U> &range2)
+{
+    assert(range1.valid() && range2.valid());
+    return range1.end <= range2.start;
 }
 
-template<class T>
-inline std::ostream &
-operator<<(std::ostream &o, const Range<T> &r)
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 is less than range2.  range1 may overlap range2,
+ * but not extend beyond the end of range2.
+ */
+template<class T, class U>
+inline bool
+operator<=(const Range<T> &range1, const Range<U> &range2)
 {
-    // don't currently support output of invalid ranges
-    assert(r.isValid());
-    o << r.start << ":" << r.end;
-    return o;
+    assert(range1.valid() && range2.valid());
+    return range1.start <= range2.start && range1.end <= range2.end;
 }
 
-//////////////////////////////////////////
-//
-// Compare two ranges
-//
-template<class T>
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 is greater than range2 and does not overlap range2.
+ */
+template<class T, class U>
 inline bool
-operator==(const Range<T> &l, const Range<T> &r)
+operator>(const Range<T> &range1, const Range<U> &range2)
 {
-    // ranges must both be valid to be equal
-    return (l.isValid() && r.isValid() &&
-            (l.start == r.start) && (l.end == r.end));
+    assert(range1.valid() && range2.valid());
+    return range1.start >= range2.end;
 }
 
-template<class T>
+/**
+ * @param range1 is a range.
+ * @param range2 is a range.
+ * @return if range1 is greater than range2.  range1 may overlap range2,
+ * but not extend beyond the beginning of range2.
+ */
+template<class T, class U>
 inline bool
-operator!=(const Range<T> &l, const Range<T> &r)
+operator>=(const Range<T> &range1, const Range<U> &range2)
 {
-    // for symmetry with ==, an invalid range is not equal to any other
-    return (!l.isValid() || !r.isValid() ||
-            (l.start != r.start) || (l.end != r.end));
+    assert(range1.valid() && range2.valid());
+    return range1.start >= range2.start && range1.end >= range2.end;
 }
 
-//////////////////////////////////////////
-//
-// Compare position to a range
-//
-// - 'pos == range' indicates that position pos is within the given range.
-//   This test always returns false if the range is invalid.
-//
-// - 'pos < range' and 'pos > range' indicate that the position is
-//   before the start of or after the end of the range, respectively.
-//   The range must be valid for these comparisons to be made.
-//
-// All other comparisons do the obvious thing based on these definitions.
+////////////////////////////////////////////////////////////////////////
 //
+// Position to Range Comparisons
 //
 
-//
-// Basic comparisons
-//
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is within the range.
+ */
+template<class T, class U>
 inline bool
-operator==(const T &pos, const Range<T> &range)
-{  return range.isValid() && pos >= range.start && pos <= range.end; }
+operator==(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos >= range.start && pos < range.end;
+}
 
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is not within the range.
+ */
+template<class T, class U>
 inline bool
-operator<(const T &pos, const Range<T> &range)
-{  assert(range.isValid()); return pos < range.start; }
+operator!=(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos < range.start || pos >= range.end;
+}
 
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is below the range.
+ */
+template<class T, class U>
 inline bool
-operator>(const T &pos, const Range<T> &range)
-{  assert(range.isValid()); return pos > range.end; }
+operator<(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos < range.start;
+}
 
-//
-// Derived comparisons
-//
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is below or in the range.
+ */
+template<class T, class U>
 inline bool
-operator<=(const T &pos, const Range<T> &range)
-{  assert(range.isValid()); return pos <= range.end; }
+operator<=(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos < range.end;
+}
 
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is above the range.
+ */
+template<class T, class U>
 inline bool
-operator>=(const T &pos, const Range<T> &range)
-{  assert(range.isValid()); return pos >= range.start; }
+operator>(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos >= range.end;
+}
 
-template<class T>
+/**
+ * @param pos position compared to the range.
+ * @param range range compared against.
+ * @return indicates that position pos is above or in the range.
+ */
+template<class T, class U>
 inline bool
-operator!=(const T &pos, const Range<T> &range)
-{  return !(pos == range); }
+operator>=(const T &pos, const Range<U> &range)
+{
+    assert(range.valid());
+    return pos >= range.start;
+}
 
+////////////////////////////////////////////////////////////////////////
 //
-// Define symmetric comparisons based on above
+// Range to Position Comparisons (for symmetry)
 //
-template<class T>
+
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * @return indicates that position pos is within the range.
+ */
+template<class T, class U>
 inline bool
-operator>(const Range<T> &range, const T &pos)
-{  return pos < range; }
+operator==(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return pos >= range.start && pos < range.end;
+}
 
-template<class T>
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * @return indicates that position pos is not within the range.
+ */
+template<class T, class U>
 inline bool
-operator<(const Range<T> &range, const T &pos)
-{  return pos > range; }
+operator!=(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return pos < range.start || pos >= range.end;
+}
 
-template<class T>
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * @return indicates that position pos is above the range.
+ */
+template<class T, class U>
 inline bool
-operator<=(const Range<T> &range, const T &pos)
-{  return pos >= range; }
+operator<(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return range.end <= pos;
+}
 
-template<class T>
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * @return indicates that position pos is above or in the range.
+ */
+template<class T, class U>
 inline bool
-operator>=(const Range<T> &range, const T &pos)
-{  return pos <= range; }
+operator<=(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return range.start <= pos;
+}
 
-template<class T>
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * 'range > pos' indicates that position pos is below the range.
+ */
+template<class T, class U>
 inline bool
-operator==(const Range<T> &range, const T &pos)
-{  return (pos == range); }
+operator>(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return range.start > pos;
+}
 
-template<class T>
+/**
+ * @param range range compared against.
+ * @param pos position compared to the range.
+ * 'range >= pos' indicates that position pos is below or in the range.
+ */
+template<class T, class U>
 inline bool
-operator!=(const Range<T> &range, const T &pos)
-{  return (pos != range); }
+operator>=(const Range<T> &range, const U &pos)
+{
+    assert(range.valid());
+    return range.end > pos;
+}
 
 #endif // __RANGE_HH__