From e87b32d72aca15a8c13d7ed5bfb205fc9736f2c0 Mon Sep 17 00:00:00 2001
From: Bob Polis <rpb.polis@avans.nl>
Date: Tue, 22 Sep 2020 15:03:00 +0200
Subject: [PATCH] moved to_int into pop_int; compacted second pass by removing
 continues and changing to else-if

---
 interpreter.cpp | 50 +++++++++++--------------------------------------
 1 file changed, 11 insertions(+), 39 deletions(-)

diff --git a/interpreter.cpp b/interpreter.cpp
index 52adab9..2da3be1 100644
--- a/interpreter.cpp
+++ b/interpreter.cpp
@@ -11,13 +11,6 @@
 #include <algorithm>
 #include <sstream>
 
-int to_int(const std::string& val) {
-    std::istringstream iss {val};
-    int result;
-    iss >> result;
-    return result;
-}
-
 void interpreter::reset() {
     _prog.clear();
     _values.clear();
@@ -50,44 +43,22 @@ std::string interpreter::eval(std::istream& in, bool& done) {
         // fetch next instruction
         std::string code {_prog[_pc]};
 
-        // check literal int
-        if (std::isdigit(code[0])) {
+        if (std::isdigit(code[0])) { // check literal int
             _values.push_back(code);
             _pc++;
-            continue;
-        }
-
-        // check literal string
-        if (code[0] == '\\') {
+        } else if (code[0] == '\\' || code[0] == '>') { // check literal string or label ref
             _values.push_back(code.substr(1));
             _pc++;
-            continue;
-        }
-
-        // check label ref
-        if (code[0] == '>') {
-            _values.push_back(code.substr(1));
-            _pc++;
-            continue;
-        }
-
-        // check var assignment
-        if (code[0] == '=') {
+        } else if (code[0] == '=') { // check var assignment
             _vars[code.substr(1)] = _values.back();
             _values.pop_back();
             _pc++;
-            continue;
-        }
-
-        // check var ref
-        if (code[0] == '$') {
+        } else if (code[0] == '$') { // check var ref
             _values.push_back(_vars[code.substr(1)]);
             _pc++;
-            continue;
+        } else {
+            exec_instruction(code, done);
         }
-        
-        // exec instruction
-        exec_instruction(code, done);
     }
 
     if (_values.size()) {
@@ -136,9 +107,10 @@ void interpreter::exec_instruction(const std::string& code, bool& done) {
 }
 
 inline int interpreter::pop_int() {
-    int val {to_int(_values.back())};
-    _values.pop_back();
-    return val;
+    std::istringstream iss {pop_str()};
+    int result;
+    iss >> result;
+    return result;
 }
 
 inline std::string interpreter::pop_str() {
@@ -362,7 +334,7 @@ void interpreter::ret() {
     _calls.pop_back();
 }
 
-// debugging --------------------------------------------------------------
+// I/O --------------------------------------------------------------------
 
 void interpreter::inp() {
     std::string val;