From d1c4106bba1fa02bd4cb5bc8f777919565cc7aa1 Mon Sep 17 00:00:00 2001
From: Bob Polis <rpb.polis@avans.nl>
Date: Tue, 22 Sep 2020 13:13:50 +0200
Subject: [PATCH] renamed _stack to _values, to make a clearer distinction
 between value and call stacks

---
 interpreter.cpp | 234 ++++++++++++++++++++++++------------------------
 interpreter.hpp |   2 +-
 2 files changed, 118 insertions(+), 118 deletions(-)

diff --git a/interpreter.cpp b/interpreter.cpp
index aa91e31..5599ccb 100644
--- a/interpreter.cpp
+++ b/interpreter.cpp
@@ -20,7 +20,7 @@ int to_int(const std::string& val) {
 
 void interpreter::reset() {
     _prog.clear();
-    _stack.clear();
+    _values.clear();
     _labels.clear();
     _vars.clear();
     _calls.clear();
@@ -52,36 +52,36 @@ std::string interpreter::eval(std::istream& in, bool& done) {
 
         // check literal int
         if (std::isdigit(code[0])) {
-            _stack.push_back(code);
+            _values.push_back(code);
             _pc++;
             continue;
         }
 
         // check literal string
         if (code[0] == '\\') {
-            _stack.push_back(code.substr(1));
+            _values.push_back(code.substr(1));
             _pc++;
             continue;
         }
 
         // check label ref
         if (code[0] == '>') {
-            _stack.push_back(code.substr(1));
+            _values.push_back(code.substr(1));
             _pc++;
             continue;
         }
 
         // check var assignment
         if (code[0] == '=') {
-            _vars[code.substr(1)] = _stack.back();
-            _stack.pop_back();
+            _vars[code.substr(1)] = _values.back();
+            _values.pop_back();
             _pc++;
             continue;
         }
 
         // check var ref
         if (code[0] == '$') {
-            _stack.push_back(_vars[code.substr(1)]);
+            _values.push_back(_vars[code.substr(1)]);
             _pc++;
             continue;
         }
@@ -90,8 +90,8 @@ std::string interpreter::eval(std::istream& in, bool& done) {
         exec_instruction(code, done);
     }
 
-    if (_stack.size()) {
-        result = _stack.back();
+    if (_values.size()) {
+        result = _values.back();
     }
     return result;
 }
@@ -137,136 +137,136 @@ void interpreter::exec_instruction(const std::string& code, bool& done) {
 // integer operations -----------------------------------------------------
 
 void interpreter::add() {
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val1 + val2));
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val1 + val2));
     _pc++;
 }
 
 void interpreter::sub() {
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val1 - val2));
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val1 - val2));
     _pc++;
 }
 
 void interpreter::mul() {
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val1 * val2));
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val1 * val2));
     _pc++;
 }
 
 void interpreter::div() {
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val1 / val2));
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val1 / val2));
     _pc++;
 }
 
 void interpreter::mod() {
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val1 % val2));
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val1 % val2));
     _pc++;
 }
 
 void interpreter::abs() {
-    int val {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val < 0 ? -val : val));
+    int val {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(val < 0 ? -val : val));
     _pc++;
 }
 
 void interpreter::neg() {
-    int val {to_int(_stack.back())};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(-val));
+    int val {to_int(_values.back())};
+    _values.pop_back();
+    _values.push_back(std::to_string(-val));
     _pc++;
 }
 
 void interpreter::inc() {
-    int val {to_int(_stack.back()) + 1};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val));
+    int val {to_int(_values.back()) + 1};
+    _values.pop_back();
+    _values.push_back(std::to_string(val));
     _pc++;
 }
 
 void interpreter::dec() {
-    int val {to_int(_stack.back()) - 1};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val));
+    int val {to_int(_values.back()) - 1};
+    _values.pop_back();
+    _values.push_back(std::to_string(val));
     _pc++;
 }
 
 // string operations ------------------------------------------------------
 
 void interpreter::dup() {
-    _stack.push_back(_stack.back());
+    _values.push_back(_values.back());
     _pc++;
 }
 
 void interpreter::rev() {
-    std::string val {_stack.back()};
-    _stack.pop_back();
+    std::string val {_values.back()};
+    _values.pop_back();
     std::string result;
     for (auto it = val.rbegin(); it != val.rend(); ++it) {
         result += *it;
     }
-    _stack.push_back(result);
+    _values.push_back(result);
     _pc++;
 }
 
 void interpreter::slc() {
-    int to {to_int(_stack.back())};
-    _stack.pop_back();
-    int from {to_int(_stack.back())};
-    _stack.pop_back();
-    std::string val {_stack.back()};
-    _stack.pop_back();
-    _stack.push_back(val.substr(from, to - from));
+    int to {to_int(_values.back())};
+    _values.pop_back();
+    int from {to_int(_values.back())};
+    _values.pop_back();
+    std::string val {_values.back()};
+    _values.pop_back();
+    _values.push_back(val.substr(from, to - from));
     _pc++;
 }
 
 void interpreter::idx() {
-    int idx {to_int(_stack.back())};
-    _stack.pop_back();
-    std::string val {_stack.back()};
-    _stack.pop_back();
+    int idx {to_int(_values.back())};
+    _values.pop_back();
+    std::string val {_values.back()};
+    _values.pop_back();
     val = val[idx];
-    _stack.emplace_back(val);
+    _values.emplace_back(val);
     _pc++;
 }
 
 void interpreter::cat() {
-    std::string val2 {_stack.back()};
-    _stack.pop_back();
-    std::string val1 {_stack.back()};
-    _stack.pop_back();
-    _stack.emplace_back(val1 + val2);
+    std::string val2 {_values.back()};
+    _values.pop_back();
+    std::string val1 {_values.back()};
+    _values.pop_back();
+    _values.emplace_back(val1 + val2);
     _pc++;
 }
 
 void interpreter::len() {
-    std::string val {_stack.back()};
-    _stack.pop_back();
-    _stack.push_back(std::to_string(val.size()));
+    std::string val {_values.back()};
+    _values.pop_back();
+    _values.push_back(std::to_string(val.size()));
     _pc++;
 }
 
 void interpreter::rot() {
-    std::string val {_stack.back()};
-    _stack.pop_back();
+    std::string val {_values.back()};
+    _values.pop_back();
     std::transform(val.begin(), val.end(), val.begin(), [](char ch) -> char {
         if (ch >= 'a' && ch <= 'm') {
             return ch + 13;
@@ -279,32 +279,32 @@ void interpreter::rot() {
         }
         return ch;
     });
-    _stack.push_back(val);
+    _values.push_back(val);
     _pc++;
 }
 
 void interpreter::enl() {
-    std::string val {_stack.back()};
-    _stack.pop_back();
+    std::string val {_values.back()};
+    _values.pop_back();
     val += '\n';
-    _stack.push_back(val);
+    _values.push_back(val);
     _pc++;
 }
 
 // tests & jumps ----------------------------------------------------------
 
 void interpreter::gto() {
-    _pc = _labels[_stack.back()];
-    _stack.pop_back();
+    _pc = _labels[_values.back()];
+    _values.pop_back();
 }
 
 void interpreter::geq() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    std::string val2 {_stack.back()};
-    _stack.pop_back();
-    std::string val1 {_stack.back()};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    std::string val2 {_values.back()};
+    _values.pop_back();
+    std::string val1 {_values.back()};
+    _values.pop_back();
     if (val1 == val2) {
         _pc = _labels[label];
     } else {
@@ -313,12 +313,12 @@ void interpreter::geq() {
 }
 
 void interpreter::gne() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    std::string val2 {_stack.back()};
-    _stack.pop_back();
-    std::string val1 {_stack.back()};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    std::string val2 {_values.back()};
+    _values.pop_back();
+    std::string val1 {_values.back()};
+    _values.pop_back();
     if (val1 != val2) {
         _pc = _labels[label];
     } else {
@@ -327,12 +327,12 @@ void interpreter::gne() {
 }
 
 void interpreter::glt() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
     if (val1 < val2) {
         _pc = _labels[label];
     } else {
@@ -341,12 +341,12 @@ void interpreter::glt() {
 }
 
 void interpreter::gle() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
     if (val1 <= val2) {
         _pc = _labels[label];
     } else {
@@ -355,12 +355,12 @@ void interpreter::gle() {
 }
 
 void interpreter::ggt() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
     if (val1 > val2) {
         _pc = _labels[label];
     } else {
@@ -369,12 +369,12 @@ void interpreter::ggt() {
 }
 
 void interpreter::gge() {
-    std::string label {_stack.back()};
-    _stack.pop_back();
-    int val2 {to_int(_stack.back())};
-    _stack.pop_back();
-    int val1 {to_int(_stack.back())};
-    _stack.pop_back();
+    std::string label {_values.back()};
+    _values.pop_back();
+    int val2 {to_int(_values.back())};
+    _values.pop_back();
+    int val1 {to_int(_values.back())};
+    _values.pop_back();
     if (val1 >= val2) {
         _pc = _labels[label];
     } else {
@@ -399,16 +399,16 @@ void interpreter::ret() {
 void interpreter::inp() {
     std::string val;
     std::cin >> val;
-    _stack.push_back(val);
+    _values.push_back(val);
     _pc++;
 }
 
 void interpreter::out() {
-    std::cout << _stack.back() << '\n';
+    std::cout << _values.back() << '\n';
     _pc++;
 }
 
 void interpreter::err() {
-    std::cerr << _stack.back() << '\n';
+    std::cerr << _values.back() << '\n';
     _pc++;
 }
diff --git a/interpreter.hpp b/interpreter.hpp
index ad0049a..3415dfb 100644
--- a/interpreter.hpp
+++ b/interpreter.hpp
@@ -33,7 +33,7 @@ class interpreter {
 
     private:
         std::vector<std::string> _prog; // program lines without label defs or comments
-        std::vector<std::string> _stack; // value stack
+        std::vector<std::string> _values; // value stack
         std::map<std::string, size_t> _labels; // label name => prog line index
         std::map<std::string, std::string> _vars; // var name => string value
         std::vector<size_t> _calls; // call stack