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[toc] / antlr4-cpp-runtime-4.9.2-source / runtime / src / ANTLRInputStream.cpp

diff --git a/antlr4-cpp-runtime-4.9.2-source/runtime/src/ANTLRInputStream.cpp b/antlr4-cpp-runtime-4.9.2-source/runtime/src/ANTLRInputStream.cpp
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+++ b/antlr4-cpp-runtime-4.9.2-source/runtime/src/ANTLRInputStream.cpp
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+/* 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 <string.h>
+
+#include "Exceptions.h"
+#include "misc/Interval.h"
+#include "IntStream.h"
+
+#include "support/StringUtils.h"
+#include "support/CPPUtils.h"
+
+#include "ANTLRInputStream.h"
+
+using namespace antlr4;
+using namespace antlrcpp;
+
+using misc::Interval;
+
+ANTLRInputStream::ANTLRInputStream() {
+  InitializeInstanceFields();
+}
+
+#if __cplusplus >= 201703L
+ANTLRInputStream::ANTLRInputStream(const std::string_view &input): ANTLRInputStream() {
+  load(input.data(), input.length());
+}
+#endif
+
+ANTLRInputStream::ANTLRInputStream(const std::string &input): ANTLRInputStream() {
+  load(input.data(), input.size());
+}
+
+ANTLRInputStream::ANTLRInputStream(const char *data, size_t length) {
+  load(data, length);
+}
+
+ANTLRInputStream::ANTLRInputStream(std::istream &stream): ANTLRInputStream() {
+  load(stream);
+}
+
+void ANTLRInputStream::load(const std::string &input) {
+  load(input.data(), input.size());
+}
+
+void ANTLRInputStream::load(const char *data, size_t length) {
+  // Remove the UTF-8 BOM if present.
+  const char *bom = "\xef\xbb\xbf";
+  if (length >= 3 && strncmp(data, bom, 3) == 0)
+    _data = antlrcpp::utf8_to_utf32(data + 3, data + length);
+  else
+    _data = antlrcpp::utf8_to_utf32(data, data + length);
+  p = 0;
+}
+
+void ANTLRInputStream::load(std::istream &stream) {
+  if (!stream.good() || stream.eof()) // No fail, bad or EOF.
+    return;
+
+  _data.clear();
+
+  std::string s((std::istreambuf_iterator<char>(stream)), std::istreambuf_iterator<char>());
+  load(s.data(), s.length());
+}
+
+void ANTLRInputStream::reset() {
+  p = 0;
+}
+
+void ANTLRInputStream::consume() {
+  if (p >= _data.size()) {
+    assert(LA(1) == IntStream::EOF);
+    throw IllegalStateException("cannot consume EOF");
+  }
+
+  if (p < _data.size()) {
+    p++;
+  }
+}
+
+size_t ANTLRInputStream::LA(ssize_t i) {
+  if (i == 0) {
+    return 0; // undefined
+  }
+
+  ssize_t position = static_cast<ssize_t>(p);
+  if (i < 0) {
+    i++; // e.g., translate LA(-1) to use offset i=0; then _data[p+0-1]
+    if ((position + i - 1) < 0) {
+      return IntStream::EOF; // invalid; no char before first char
+    }
+  }
+
+  if ((position + i - 1) >= static_cast<ssize_t>(_data.size())) {
+    return IntStream::EOF;
+  }
+
+  return _data[static_cast<size_t>((position + i - 1))];
+}
+
+size_t ANTLRInputStream::LT(ssize_t i) {
+  return LA(i);
+}
+
+size_t ANTLRInputStream::index() {
+  return p;
+}
+
+size_t ANTLRInputStream::size() {
+  return _data.size();
+}
+
+// Mark/release do nothing. We have entire buffer.
+ssize_t ANTLRInputStream::mark() {
+  return -1;
+}
+
+void ANTLRInputStream::release(ssize_t /* marker */) {
+}
+
+void ANTLRInputStream::seek(size_t index) {
+  if (index <= p) {
+    p = index; // just jump; don't update stream state (line, ...)
+    return;
+  }
+  // seek forward, consume until p hits index or n (whichever comes first)
+  index = std::min(index, _data.size());
+  while (p < index) {
+    consume();
+  }
+}
+
+std::string ANTLRInputStream::getText(const Interval &interval) {
+  if (interval.a < 0 || interval.b < 0) {
+    return "";
+  }
+
+  size_t start = static_cast<size_t>(interval.a);
+  size_t stop = static_cast<size_t>(interval.b);
+
+
+  if (stop >= _data.size()) {
+    stop = _data.size() - 1;
+  }
+
+  size_t count = stop - start + 1;
+  if (start >= _data.size()) {
+    return "";
+  }
+
+  return antlrcpp::utf32_to_utf8(_data.substr(start, count));
+}
+
+std::string ANTLRInputStream::getSourceName() const {
+  if (name.empty()) {
+    return IntStream::UNKNOWN_SOURCE_NAME;
+  }
+  return name;
+}
+
+std::string ANTLRInputStream::toString() const {
+  return antlrcpp::utf32_to_utf8(_data);
+}
+
+void ANTLRInputStream::InitializeInstanceFields() {
+  p = 0;
+}