simple repl!

src/main.cpp

@@ -1,6 +1,25 @@
-#include "VM.h"
 #include <iostream>
 
+#include "MemoryContext.h"
+#include "Parser.h"
+#include "VM.h"
+
 int main() {
+    MemoryContext mc;
+    Handle repl;
+    {
+        Parser parser;
+        parser.loadStr("(READ EVAL PRINT STOP)");
+        repl = parser.parseExpr();
+    }
+
+    while (true) {
+        VM vm;
+        std::cout << std::endl;
+        vm.loadControl(repl);
+        vm.run();
+        std::cout << std::endl;
+    }
+
     return 0;
 }

src/vm/includes/VM.h

@@ -55,6 +55,7 @@ private:
 
     Handle EVAL = Handle::makeStrCell("EVAL");
     Handle PRINT = Handle::makeStrCell("PRINT");
+    Handle READ = Handle::makeStrCell("READ");
 
     Handle CONS = Handle::makeStrCell("CONS");
 };

src/vm/src/Compiler.cpp

@@ -54,6 +54,8 @@ Handle Compiler::compile(Handle src, Handle fake_env, Handle suffix) {
             if (car.strval() == "+") {
                 out.splice(compileArgsRaw(cdr));
                 out.append(Handle("ADD"));
+            } else if (car.strval() == "read") {
+                out.append(Handle("READ"));
             } else if (car.strval() == "lambda") {
                 out.append(Handle("LDF"));
                 out.append(compile(cdr.cdr().car(), Handle::cons(cdr.car(), fake_env), Handle("RET")));

src/vm/src/Parser.cpp

@@ -69,6 +69,7 @@ void Parser::Tokenizer::load(std::string_view input) {
     while (curpos != std::string_view::npos) {
         if (alnum.find(input.at(curpos)) != std::string::npos) {
             std::string_view::size_type end = input.find_first_not_of(alnum, curpos);
+            if (end == std::string_view ::npos) end = input.size();
             _tokens.emplace(input.cbegin() + curpos, input.cbegin() + end);
             curpos = end;
         } else if (special.find(input.at(curpos)) != std::string::npos) {

src/vm/src/VM.cpp

@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "Compiler.h"
+#include "Parser.h"
 #include "VM.h"
 
 
@@ -136,7 +137,13 @@ void VM::step() {
         newc.splice(_c);
         _c = newc;
     } else if (poppedH == PRINT) {
-        _outstream << _s.pop().val();
+        _outstream << _s.pop();
+    } else if (poppedH == READ) {
+        std::string read;
+        std::getline(_instream, read);
+        Parser parser;
+        parser.loadStr(read);
+        _s.push(parser.parseExpr());
     } else {
         assert(false);
     }