diff --git a/src/vm/src/Compiler.cpp b/src/vm/src/Compiler.cpp
index b5c5d26..ef81f81 100644
--- a/src/vm/src/Compiler.cpp
+++ b/src/vm/src/Compiler.cpp
@@ -38,7 +38,7 @@ Handle Compiler::compile(const Handle &src, Handle fake_env, const Handle &suffi
         return out;
     };
 
-    std::function<Handle(Handle, Handle)> compileArgsList = [&](Handle args, Handle env) {
+    std::function<Handle(Handle, Handle)> compileArgsList = [&](Handle args, const Handle &env) {
         Handle out;
         out.append(make_cmd(NIL));
         std::stack<Handle> rev;
diff --git a/src/vm/src/VM.cpp b/src/vm/src/VM.cpp
index 85e4d8b..dc25b5e 100644
--- a/src/vm/src/VM.cpp
+++ b/src/vm/src/VM.cpp
@@ -23,10 +23,8 @@ void VM::run() {
 
 void VM::step() {
     Handle poppedH = _c.pop();
-    // as to not complicate parser for tests...
     CellValType poppedCmd = poppedH.type() == CellType::STRATOM ? str_to_cmd.at(poppedH.strval()) : poppedH.val();
 
-
     Logger::log(
             "VM",
             [&](std::ostream &out) {
@@ -37,216 +35,276 @@ void VM::step() {
                 if (!_d.null()) out << "d:" << _d << "\n";
             },
             Logger::TRACE);
-
-    if (poppedCmd == NIL) {
-        _s.push(nullptr);
-    } else if (poppedCmd == LDC) {
-        _s.push(_c.pop());
-    } else if (poppedCmd == ATOM) {
-        _s.push(_s.pop().atom() ? 1 : 0);
-    } else if (poppedCmd == NILC) {
-        _s.push(_s.pop().null() ? 1 : 0);
-    } else if (poppedCmd == LD) {
-        Handle poppedH2 = _c.pop();
-
-        int64_t frame = poppedH2.car().val();
-        int64_t arg = poppedH2.cdr().val();
-
-        assert(frame > 0);
-        assert(arg > 0);
-
-        Handle curFrame = _e;
-
-        for (int i = 1; i < frame; i++) { curFrame = curFrame.cdr(); }
-
-        Handle curArg = curFrame.car();
-
-        for (int i = 1; i < arg; i++) { curArg = curArg.cdr(); }
-
-        _s.push(curArg.car());
-    } else if (poppedCmd == SEL) {
-        Handle popped2H = _s.pop();
-
-        Handle ct = _c.pop();
-        Handle cf = _c.pop();
-
-        _d.push(_c);
-        if (popped2H.val() > 0) {
-            _c = ct;
-        } else {
-            _c = cf;
+    
+    switch (poppedCmd) {
+        case NIL: {
+            _s.push(nullptr);
+            break;
         }
-    } else if (poppedCmd == JOIN) {
-        _c = _d.pop();
-    } else if (poppedCmd == LDF) {
-        _s.push(Handle::cons(_c.pop(), _e));
-    } else if (poppedCmd == AP) {
-        Handle closureH = _s.pop();
-        Handle argsH = _s.pop();
-
-        _d.push(_s);
-        _d.push(_e);
-        _d.push(_c);
-
-        std::optional<std::string> name;
-        if (Logger::en_level("VM", Logger::DEBUG)) {
-            name = "unknown";
-            if (_globals_names_map.find(closureH) != _globals_names_map.end()) name = _globals_names_map.at(closureH);
-            _d.push(Handle(*name));
+        case LDC: {
+            _s.push(_c.pop());
+            break;
         }
-
-        _s = Handle::cons(nullptr, nullptr);
-        _c = closureH.car();
-        _e = closureH.cdr();
-
-        Logger::log(
-                "VM",
-                [&](std::ostream &out) {
-                    out << _cur_call_level;
-                    for (int i = 0; i < _cur_call_level; i++) out << "  ";
-                    out << " Applying " << *name;
-                    out << " with args " << argsH;
-                },
-                Logger::DEBUG);
-
-        _cur_call_level++;
-        _e.push(argsH);
-    } else if (poppedCmd == RET) {
-        _cur_call_level--;
-
-        Handle n;
-        if (Logger::en_level("VM", Logger::DEBUG)) n = _d.pop();
-
-        Handle c = _d.pop();
-        Handle e = _d.pop();
-        Handle s = _d.pop();
-
-        Handle ret = _s.pop();
-
-        _c = c;
-        _e = e;
-        _s = s;
-
-        Logger::log(
-                "VM",
-                [&](std::ostream &out) {
-                    out << _cur_call_level;
-                    for (int i = 0; i < _cur_call_level; i++) out << "  ";
-                    out << " Returning from " << n << " ";
-                    bool cons = !ret.atom();
-                    if (cons) out << "(";
-                    out << ret;
-                    if (cons) out << ")";
-                },
-                Logger::DEBUG);
-
-        _s.push(ret);
-    } else if (poppedCmd == DUM) {
-        _e.push(nullptr);
-    } else if (poppedCmd == RAP) {
-        Handle closureH = _s.pop();
-        Handle argsH = _s.pop();
-
-        Handle origE = _e.cdr();
-
-        _d.push(_s);
-        _d.push(origE);
-        _d.push(_c);
-
-        if (Logger::en_level("VM", Logger::DEBUG)) _d.push(Handle("rap"));
-
-        _s = Handle::cons(nullptr, nullptr);
-        _c = closureH.car();
-        _e = closureH.cdr();
-
-        Handle fnEnv = closureH.cdr();
-        assert(_e == fnEnv);
-
-        _cur_call_level++;
-
-        _e.push(argsH);
-        fnEnv.setcar(argsH);
-    } else if (poppedCmd == STOP) {
-        _stop = true;
-    } else if (poppedCmd == ADD) {
-        _s.push(_s.pop().val() + _s.pop().val());
-    } else if (poppedCmd == MULT) {
-        _s.push(_s.pop().val() * _s.pop().val());
-    } else if (poppedCmd == SUB) {
-        CellValType a1 = _s.pop().val();
-        CellValType a2 = _s.pop().val();
-        _s.push(a1 - a2);
-    } else if (poppedCmd == DIV) {
-        CellValType a1 = _s.pop().val();
-        CellValType a2 = _s.pop().val();
-        _s.push(a1 / a2);
-    } else if (poppedCmd == EQ) {
-        _s.push(_s.pop() == _s.pop() ? 1 : 0);
-    } else if (poppedCmd == LT) {
-        CellValType a1 = _s.pop().val();
-        CellValType a2 = _s.pop().val();
-        _s.push(a1 < a2 ? 1 : 0);
-    } else if (poppedCmd == GT) {
-        CellValType a1 = _s.pop().val();
-        CellValType a2 = _s.pop().val();
-        _s.push(a1 > a2 ? 1 : 0);
-    } else if (poppedCmd == CAR) {
-        _s.push(_s.pop().car());
-    } else if (poppedCmd == CDR) {
-        _s.push(_s.pop().cdr());
-    } else if (poppedCmd == CONS) {
-        Handle h1 = _s.pop();
-        Handle h2 = _s.pop();
-
-        _s.push(Handle::cons(h1, h2));
-    } else if (poppedCmd == READCHAR) {
-        char c;
-        _instream >> c;
-        _s.push(Handle::makeNumCell(c));
-    } else if (poppedCmd == PUTCHAR) {
-        _outstream << (char) _s.pop().val();
-    } else if (poppedCmd == PUTNUM) {
-        _outstream << _s.pop().val();
-    } else if (poppedCmd == EVAL) {
-        Handle code = _s.pop();
-        Handle newc = Compiler::compile(code, _globals_names);
-        Logger::log(
-                "Compiler",
-                [&](std::ostream &out) {
-                    out << "Compiled (" << code << ")";
-                    out << " to ";
-                    out << "(" << newc << ")";
-                },
-                Logger::DEBUG);
-        newc.splice(_c);
-        _c = newc;
-    } else if (poppedCmd == LDG) {
-        Handle newclosure = Handle::cons(_c.pop(), _e);
-
-        Handle curName = _globals_names.car();
-        for (int i = 0; i < _cur_global; i++) { curName = curName.cdr(); }
-        _globals_names_map.emplace(newclosure, curName.car().strval());
-        _cur_global++;
-
-        _globals_vals.append(newclosure);
-    } else if (poppedCmd == PRINT) {
-        if (!_s.null()) {
-            Handle val = _s.pop();
-            bool cons = !val.atom();
-            if (cons) _outstream << "(";
-            _outstream << val;
-            if (cons) _outstream << ")";
-            _outstream << std::endl;
+        case ATOM: {
+            _s.push(_s.pop().atom() ? 1 : 0);
+            break;
         }
-    } else if (poppedCmd == READ) {
-        std::string read;
-        std::getline(_instream, read);
-        _s.push(Parser::parse_str(read));
-    } else {
-        throw std::invalid_argument("Unexpected end of program");
+        case NILC: {
+            _s.push(_s.pop().null() ? 1 : 0);
+            break;
+        }
+        case LD: {
+            Handle poppedH2 = _c.pop();
+
+            int64_t frame = poppedH2.car().val();
+            int64_t arg = poppedH2.cdr().val();
+
+            assert(frame > 0);
+            assert(arg > 0);
+
+            Handle curFrame = _e;
+
+            for (int i = 1; i < frame; i++) { curFrame = curFrame.cdr(); }
+
+            Handle curArg = curFrame.car();
+
+            for (int i = 1; i < arg; i++) { curArg = curArg.cdr(); }
+
+            _s.push(curArg.car());
+            break;
+        }
+        case SEL: {
+            Handle popped2H = _s.pop();
+
+            Handle ct = _c.pop();
+            Handle cf = _c.pop();
+
+            _d.push(_c);
+            if (popped2H.val() > 0) {
+                _c = ct;
+            } else {
+                _c = cf;
+            }
+            break;
+        }
+        case JOIN: {
+            _c = _d.pop();
+            break;
+        }
+        case LDF: {
+            _s.push(Handle::cons(_c.pop(), _e));
+            break;
+        }
+        case AP: {
+            Handle closureH = _s.pop();
+            Handle argsH = _s.pop();
+
+            _d.push(_s);
+            _d.push(_e);
+            _d.push(_c);
+
+            std::optional<std::string> name;
+            if (Logger::en_level("VM", Logger::DEBUG)) {
+                name = "unknown";
+                if (_globals_names_map.find(closureH) != _globals_names_map.end())
+                    name = _globals_names_map.at(closureH);
+                _d.push(Handle(*name));
+            }
+
+            _s = Handle::cons(nullptr, nullptr);
+            _c = closureH.car();
+            _e = closureH.cdr();
+
+            Logger::log(
+                    "VM",
+                    [&](std::ostream &out) {
+                        out << _cur_call_level;
+                        for (int i = 0; i < _cur_call_level; i++) out << "  ";
+                        out << " Applying " << *name;
+                        out << " with args " << argsH;
+                    },
+                    Logger::DEBUG);
+
+            _cur_call_level++;
+            _e.push(argsH);
+            break;
+        }
+        case RET: {
+            _cur_call_level--;
+
+            Handle n;
+            if (Logger::en_level("VM", Logger::DEBUG)) n = _d.pop();
+
+            Handle c = _d.pop();
+            Handle e = _d.pop();
+            Handle s = _d.pop();
+
+            Handle ret = _s.pop();
+
+            _c = c;
+            _e = e;
+            _s = s;
+
+            Logger::log(
+                    "VM",
+                    [&](std::ostream &out) {
+                        out << _cur_call_level;
+                        for (int i = 0; i < _cur_call_level; i++) out << "  ";
+                        out << " Returning from " << n << " ";
+                        bool cons = !ret.atom();
+                        if (cons) out << "(";
+                        out << ret;
+                        if (cons) out << ")";
+                    },
+                    Logger::DEBUG);
+
+            _s.push(ret);
+            break;
+        }
+        case DUM: {
+            _e.push(nullptr);
+            break;
+        }
+        case RAP: {
+            Handle closureH = _s.pop();
+            Handle argsH = _s.pop();
+
+            Handle origE = _e.cdr();
+
+            _d.push(_s);
+            _d.push(origE);
+            _d.push(_c);
+
+            if (Logger::en_level("VM", Logger::DEBUG)) _d.push(Handle("rap"));
+
+            _s = Handle::cons(nullptr, nullptr);
+            _c = closureH.car();
+            _e = closureH.cdr();
+
+            Handle fnEnv = closureH.cdr();
+            assert(_e == fnEnv);
+
+            _cur_call_level++;
+
+            _e.push(argsH);
+            fnEnv.setcar(argsH);
+            break;
+        }
+        case STOP: {
+            _stop = true;
+            break;
+        }
+        case ADD: {
+            _s.push(_s.pop().val() + _s.pop().val());
+            break;
+        }
+        case MULT: {
+            _s.push(_s.pop().val() * _s.pop().val());
+            break;
+        }
+        case SUB: {
+            CellValType a1 = _s.pop().val();
+            CellValType a2 = _s.pop().val();
+            _s.push(a1 - a2);
+            break;
+        }
+        case DIV: {
+            CellValType a1 = _s.pop().val();
+            CellValType a2 = _s.pop().val();
+            _s.push(a1 / a2);
+            break;
+        }
+        case EQ: {
+            _s.push(_s.pop() == _s.pop() ? 1 : 0);
+            break;
+        }
+        case LT: {
+            CellValType a1 = _s.pop().val();
+            CellValType a2 = _s.pop().val();
+            _s.push(a1 < a2 ? 1 : 0);
+            break;
+        }
+        case GT: {
+            CellValType a1 = _s.pop().val();
+            CellValType a2 = _s.pop().val();
+            _s.push(a1 > a2 ? 1 : 0);
+            break;
+        }
+        case CAR: {
+            _s.push(_s.pop().car());
+            break;
+        }
+        case CDR: {
+            _s.push(_s.pop().cdr());
+            break;
+        }
+        case CONS: {
+            Handle h1 = _s.pop();
+            Handle h2 = _s.pop();
+
+            _s.push(Handle::cons(h1, h2));
+            break;
+        }
+        case READCHAR: {
+            char c;
+            _instream >> c;
+            _s.push(Handle::makeNumCell(c));
+            break;
+        }
+        case PUTCHAR: {
+            _outstream << (char) _s.pop().val();
+            break;
+        }
+        case PUTNUM: {
+            _outstream << _s.pop().val();
+            break;
+        }
+        case EVAL: {
+            Handle code = _s.pop();
+            Handle newc = Compiler::compile(code, _globals_names);
+            Logger::log(
+                    "Compiler",
+                    [&](std::ostream &out) {
+                        out << "Compiled (" << code << ")";
+                        out << " to ";
+                        out << "(" << newc << ")";
+                    },
+                    Logger::DEBUG);
+            newc.splice(_c);
+            _c = newc;
+            break;
+        }
+        case LDG: {
+            Handle newclosure = Handle::cons(_c.pop(), _e);
+
+            Handle curName = _globals_names.car();
+            for (int i = 0; i < _cur_global; i++) { curName = curName.cdr(); }
+            _globals_names_map.emplace(newclosure, curName.car().strval());
+            _cur_global++;
+
+            _globals_vals.append(newclosure);
+            break;
+        }
+        case PRINT: {
+            if (!_s.null()) {
+                Handle val = _s.pop();
+                bool cons = !val.atom();
+                if (cons) _outstream << "(";
+                _outstream << val;
+                if (cons) _outstream << ")";
+                _outstream << std::endl;
+            }
+            break;
+        }
+        case READ: {
+            std::string read;
+            std::getline(_instream, read);
+            _s.push(Parser::parse_str(read));
+        }
+        default:
+            throw std::invalid_argument("Unknown command: " + std::to_string(poppedCmd));
     }
 
-
     Logger::log(
             "VM",
             [&](std::ostream &out) {
diff --git a/test/vm/CompilerTest.cpp b/test/vm/CompilerTest.cpp
index 3f1556e..52fc1c2 100644
--- a/test/vm/CompilerTest.cpp
+++ b/test/vm/CompilerTest.cpp
@@ -13,6 +13,7 @@ public:
     ~Environment() override {}
 
     void SetUp() override {
+        Options::set<size_t>("cell_limit", 50000);
         Options::set<bool>("command_strs", true);
         Logger::set_level("VM", Logger::DEBUG);
         Logger::set_level("Compiler", Logger::DEBUG);
diff --git a/test/vm/VMTest.cpp b/test/vm/VMTest.cpp
index 1b09509..2ddfabe 100644
--- a/test/vm/VMTest.cpp
+++ b/test/vm/VMTest.cpp
@@ -7,7 +7,7 @@ public:
     ~Environment() override {}
 
     void SetUp() override {
-        Options::set<size_t>("cell_limit", 1000);
+        Options::set<size_t>("cell_limit", 5000);
         Logger::set_level("Compiler", Logger::DEBUG);
     }
 
diff --git a/test/vm/VMWithParserTest.cpp b/test/vm/VMWithParserTest.cpp
index 34c1139..4003e56 100644
--- a/test/vm/VMWithParserTest.cpp
+++ b/test/vm/VMWithParserTest.cpp
@@ -8,7 +8,7 @@ public:
     ~Environment() override {}
 
     void SetUp() override {
-        Options::set<size_t>("cell_limit", 2000);
+        Options::set<size_t>("cell_limit", 5000);
         Logger::set_level("Compiler", Logger::DEBUG);
     }