Uploading Assignment 4

1 files changed, 153 insertions, 0 deletions

diff --git a/dev/a4-dance/simple_parser.cc b/dev/a4-dance/simple_parser.cc
new file mode 100644
index 0000000..53eca6a
--- /dev/null
+++ b/dev/a4-dance/simple_parser.cc
@@ -0,0 +1,153 @@
+#include "simple_parser.h"
+#include <cctype>
+#include <sstream>
+
+SimpleParser::SimpleParser(std::istream *i) {
+  in_ = i;
+}
+
+bool SimpleParser::Expect(std::string s) {
+  SwallowWhitespace();
+  if (s.size() == 0) {
+    return true;
+  }
+  std::string swallowed;
+  char c;
+  in_->get(c);
+  swallowed += c;
+  while ((*in_) && swallowed.size() < s.size() && swallowed == s.substr(0, swallowed.size())) {
+    in_->get(c);
+    swallowed += c;
+  }
+  if (swallowed == s) {
+    return true;
+  }
+  else {
+    std::string::reverse_iterator it;
+    for (it = swallowed.rbegin(); it != swallowed.rend(); ++it) {
+      in_->putback(*it);
+    }
+    return false;
+  }
+}
+
+bool SimpleParser::Peek(std::string s) {
+  SwallowWhitespace();
+  bool retval = false;
+  if (s.size() == 0) {
+    return true;
+  }
+  std::string swallowed;
+  char c;
+  in_->get(c);
+  swallowed += c;
+  while ((*in_) && swallowed.size() < s.size() && swallowed == s.substr(0, swallowed.size())) {
+    in_->get(c);
+    swallowed += c;
+  }
+  if (swallowed == s) {
+    retval = true;
+  }
+  else {
+    retval = false;
+  }
+  std::string::reverse_iterator it;
+  for (it = swallowed.rbegin(); it != swallowed.rend(); ++it) {
+    in_->putback(*it);
+  }
+  return retval;
+}
+
+void SimpleParser::SwallowWhitespace() {
+  char c;
+  in_->get(c);
+  while ((*in_) && std::isspace(c)) {
+    in_->get(c);
+  }
+  in_->putback(c);
+}
+
+void SimpleParser::SwallowLine() {
+  std::string placeholder;
+  std::getline(*in_, placeholder);
+  SwallowWhitespace();
+}
+
+bool SimpleParser::ReadFloat(float &f) {
+  SwallowWhitespace();
+  std::string accum;
+  char c;
+  in_->get(c);
+  while ((*in_) && FloatChar(c)) {
+    accum += c;
+    in_->get(c);
+  }
+  in_->putback(c);
+  std::stringstream ss(accum);
+  ss >> f;
+  return true;
+}
+
+bool SimpleParser::ReadInt(int &i) {
+  SwallowWhitespace();
+  std::string accum;
+  char c;
+  in_->get(c);
+  while ((*in_) && IntChar(c)) {
+    accum += c;
+    in_->get(c);
+  }
+  in_->putback(c);
+  std::stringstream ss(accum);
+  ss >> i;
+  return true;
+  
+}
+
+bool SimpleParser::ReadToken(std::string &s) {
+  SwallowWhitespace();
+  std::string accum;
+  char c;
+  in_->get(c);
+  while ((*in_) && TokenChar(c)) {
+    accum += c;
+    in_->get(c);
+  }
+  in_->putback(c);
+  s = accum;
+  return true;
+}
+
+bool SimpleParser::Good() {
+  return (*in_).good();
+}
+
+bool SimpleParser::ReadLine(std::string &line) {
+  getline(*in_, line);
+  return true;
+}
+
+bool SimpleParser::UpcomingInt() {
+  SwallowWhitespace();
+  char c;
+  in_->get(c);
+  in_->putback(c);
+  return IntChar(c);
+}
+
+bool SimpleParser::FloatChar(char c) {
+  return ( c == 'e'
+          || (c >= '0' && c <= '9')
+          || c == '.'
+          || c == '+'
+          || c == '-'
+          );
+}
+
+bool SimpleParser::IntChar(char c) {
+  return ( (c >= '0' && c <= '9') || c == '-');
+}
+
+bool SimpleParser::TokenChar(char c) {
+  return !std::isspace(c);
+}