--- /dev/null
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#include "misc/Interval.h"
+
+using namespace antlr4::misc;
+
+size_t antlr4::misc::numericToSymbol(ssize_t v) {
+ return static_cast<size_t>(v);
+}
+
+ssize_t antlr4::misc::symbolToNumeric(size_t v) {
+ return static_cast<ssize_t>(v);
+}
+
+Interval const Interval::INVALID;
+
+Interval::Interval() : Interval(static_cast<ssize_t>(-1), -2) { // Need an explicit cast here for VS.
+}
+
+Interval::Interval(size_t a_, size_t b_) : Interval(symbolToNumeric(a_), symbolToNumeric(b_)) {
+}
+
+Interval::Interval(ssize_t a_, ssize_t b_) : a(a_), b(b_) {
+}
+
+size_t Interval::length() const {
+ if (b < a) {
+ return 0;
+ }
+ return size_t(b - a + 1);
+}
+
+bool Interval::operator == (const Interval &other) const {
+ return a == other.a && b == other.b;
+}
+
+size_t Interval::hashCode() const {
+ size_t hash = 23;
+ hash = hash * 31 + static_cast<size_t>(a);
+ hash = hash * 31 + static_cast<size_t>(b);
+ return hash;
+}
+
+bool Interval::startsBeforeDisjoint(const Interval &other) const {
+ return a < other.a && b < other.a;
+}
+
+bool Interval::startsBeforeNonDisjoint(const Interval &other) const {
+ return a <= other.a && b >= other.a;
+}
+
+bool Interval::startsAfter(const Interval &other) const {
+ return a > other.a;
+}
+
+bool Interval::startsAfterDisjoint(const Interval &other) const {
+ return a > other.b;
+}
+
+bool Interval::startsAfterNonDisjoint(const Interval &other) const {
+ return a > other.a && a <= other.b; // b >= other.b implied
+}
+
+bool Interval::disjoint(const Interval &other) const {
+ return startsBeforeDisjoint(other) || startsAfterDisjoint(other);
+}
+
+bool Interval::adjacent(const Interval &other) const {
+ return a == other.b + 1 || b == other.a - 1;
+}
+
+bool Interval::properlyContains(const Interval &other) const {
+ return other.a >= a && other.b <= b;
+}
+
+Interval Interval::Union(const Interval &other) const {
+ return Interval(std::min(a, other.a), std::max(b, other.b));
+}
+
+Interval Interval::intersection(const Interval &other) const {
+ return Interval(std::max(a, other.a), std::min(b, other.b));
+}
+
+std::string Interval::toString() const {
+ return std::to_string(a) + ".." + std::to_string(b);
+}