merge LRA

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/util/lp/iterator_on_row.h

@@ -0,0 +1,37 @@
+/*
+  Copyright (c) 2017 Microsoft Corporation
+  Author: Lev Nachmanson
+*/
+#pragma once
+#include "util/lp/linear_combination_iterator.h"
+namespace lean {
+template <typename T>
+struct iterator_on_row:linear_combination_iterator<T> {
+    const vector<row_cell<T>> & m_row;
+    unsigned m_i= 0; // offset
+    iterator_on_row(const vector<row_cell<T>> & row) : m_row(row)
+    {}
+    unsigned size() const { return m_row.size(); }
+    bool next(T & a, unsigned & i) {
+        if (m_i == m_row.size())
+            return false;
+        auto &c = m_row[m_i++];
+        i = c.m_j;
+        a = c.get_val();
+        return true;
+    }
+    bool next(unsigned & i) {
+        if (m_i == m_row.size())
+            return false;
+        auto &c = m_row[m_i++];
+        i = c.m_j;
+        return true;
+    }
+    void reset() {
+        m_i = 0;
+    }
+    linear_combination_iterator<T>* clone() {
+        return new iterator_on_row(m_row);
+    }
+};
+}