diff --git a/CMakeLists.txt b/CMakeLists.txt
index 86a9430..eb76ade 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.7)
 
-project(dpro)
+project(dbuild)
 
 set(THIRD_PARTY_INCLUDE_DIRS third_party)
 set(SRC_DIRS src)
diff --git a/default.nix b/default.nix
index 84b3888..dea883a 100644
--- a/default.nix
+++ b/default.nix
@@ -1,6 +1,6 @@
 { pkgs ? import <nixpkgs> { } }:
 pkgs.stdenv.mkDerivation rec {
-  pname = "dpro";
+  pname = "dbuild";
   version = "0.1.0";
 
   src = ./.;
@@ -20,6 +20,6 @@ pkgs.stdenv.mkDerivation rec {
 
   installPhase = ''
     mkdir -p $out/bin
-    mv dpro $out/bin
+    mv dbuild $out/bin
   '';
 }
diff --git a/src/context.cpp b/src/context.cpp
index 97b8b91..91d20a5 100644
--- a/src/context.cpp
+++ b/src/context.cpp
@@ -4,4 +4,180 @@
 
 void Context::error(std::string_view msg) {
     std::cout << "Error! " << msg << std::endl;
+}
+
+using std::any_cast;
+
+std::any Context::readIdentifier(std::any val) {
+  assert(val.type() == typeid(Identifier));
+  return currentScope->getVar(*this, any_cast<Identifier>(val).identifier);
+}
+
+/**
+ * Returns the value of the input (reads the value if it is a refers to a variable)
+ */
+std::any Context::getValue(std::any input) {
+  if (input.type() == typeid(Identifier))
+    return readIdentifier(input);
+  else
+    return input;
+}
+
+std::any Context::eval(peg::Ast& ast) {
+  const auto &nodes = ast.nodes;
+  if (ast.name == "Root") {
+    for (int i=0; i<ast.nodes.size(); i++) {
+      eval(*nodes[i]);
+    }
+    return Nil();
+  } else if (ast.name == "VarDecl") {
+    auto identifier = any_cast<Identifier>(eval(*nodes[0]));
+    auto value = eval(*nodes[1]);
+    currentScope->writeVar(*this, identifier.identifier, value);
+    return Nil();
+  } else if (ast.name == "IDENTIFIER" || ast.name == "BUILTINIDENTIFIER") {
+    return Identifier(std::string(ast.token_to_string()));
+  } else if (ast.name == "INTEGER") {
+    // TODO parse hex, oct, and binary
+    return ast.token_to_number<long>();
+  } else if (ast.name == "BUILTINCALL" ) {
+    auto identifier = any_cast<Identifier>(eval(*nodes[0]));
+    auto args = Args::toArgs(*this, eval(*nodes[1]));
+    builtins.at(identifier.identifier).execute(*this, args);
+    // TODO: handle returns
+    return Nil();
+  } else if (ast.name == "STRINGLITERALSINGLE")
+  {
+    return ast.token_to_string();
+  } else if (ast.name == "ExprList") {
+    std::vector<std::any> exprs;
+    for (int i=0; i<ast.nodes.size(); i++) {
+      exprs.push_back(getValue(eval(*nodes[i])));
+    }
+    return exprs;
+  } else if (ast.name == "AdditionExpr") {
+    auto value = getValue(eval(*nodes[0]));
+    for (int i=1; i<nodes.size(); i+=2) {
+      int op = (*nodes[i]).choice;
+      auto v2 = getValue(eval(*nodes[i+1]));
+      // TODO: floats
+      if (op == 0) {
+        value = any_cast<long>(value) + any_cast<long>(v2);
+      } else {
+        value = any_cast<long>(value) - any_cast<long>(v2);
+      }
+    }
+    return value;
+  } else if (ast.name == "MultiplyExpr") {
+    auto value = getValue(eval(*nodes[0]));
+    for (int i=1; i<nodes.size(); i+=2) {
+      int op = (*nodes[i]).choice;
+      auto v2 = getValue(eval(*nodes[i+1]));
+      // TODO: floats
+      if (op == 0) {
+        value = any_cast<long>(value) * any_cast<long>(v2);
+      } else {
+        value = any_cast<long>(value) / any_cast<long>(v2);
+      }
+    }
+    return value;
+  } else if (ast.name == "AssignExpr") {
+    std::string name = any_cast<Identifier>(eval(*nodes[0])).identifier;
+    // TODO arrays, dot operator, etc.
+    auto v1 = currentScope->getVar(*this, name);
+    int op = (*nodes[1]).choice;
+    auto v2 = getValue(eval(*nodes[2]));
+    std::any result;
+    // TODO: floats
+    if (op == 0) {
+      result = any_cast<long>(v1) * any_cast<long>(v2);
+    } else if (op == 1) {
+      result = any_cast<long>(v1) % any_cast<long>(v2);
+    } else if (op == 2) {
+      result = any_cast<long>(v1) + any_cast<long>(v2);
+    } else if (op == 3) {
+      result = any_cast<long>(v1) - any_cast<long>(v2);
+    } else if (op == 4) {
+      result = any_cast<long>(v1) & any_cast<long>(v2);
+    } else if (op == 5) {
+      result = any_cast<long>(v1) ^ any_cast<long>(v2);
+    } else if (op == 6) {
+      result = any_cast<long>(v1) | any_cast<long>(v2);
+    } else if (op == 7) {
+      result = v2;
+    }
+    currentScope->writeVar(*this, name, result);
+    return result;
+  } else if (ast.name == "PrimaryTypeExpr") {
+    int op = ast.choice;
+    if (op == 8) {
+      return false;
+    } else if (op == 9) {
+      return Nil();
+    } else if (op == 10) {
+      return true;
+    }
+  } else if (ast.name == "CompareExpr") {
+    auto v1 = getValue(eval(*nodes[0]));
+    int op = (*nodes[1]).choice;
+    auto v2 = getValue(eval(*nodes[2]));
+    // TODO: floats, bool, etc.
+    if (op == 0) {
+      return (bool)(any_cast<long>(v1) == any_cast<long>(v2));
+    } else if (op == 1) {
+      return (bool)(any_cast<long>(v1) != any_cast<long>(v2));
+    } else if (op == 2) {
+      return (bool)(any_cast<long>(v1) < any_cast<long>(v2));
+    } else if (op == 3) {
+      return (bool)(any_cast<long>(v1) > any_cast<long>(v2));
+    } else if (op == 4) {
+      return (bool)(any_cast<long>(v1) <= any_cast<long>(v2));
+    } else if (op == 5) {
+      return (bool)(any_cast<long>(v1) >= any_cast<long>(v2));
+    }
+  } else if (ast.name == "IfStatement") {
+    auto val = getValue(eval(*nodes[0]));
+    if (any_cast<bool>(val)) {
+      return eval(*nodes[1]);
+    } else {
+      return eval(*nodes[2]);
+    }
+  } else if (ast.name == "Block") {
+    // TODO create new scope
+    std::any result = Nil();
+    for (int i=0; i<ast.nodes.size(); i++) {
+      result = eval(*nodes[i]);
+    }
+    return result;
+  } else if (ast.name == "WhileStatement") {
+    std::any result = Nil();
+    while (any_cast<bool>(getValue(eval(*nodes[0])))) {
+      result = eval(*nodes[1]);
+    }
+    return result;
+  } else if (ast.name == "Fn") {
+    auto identifiers = any_cast<std::vector<Identifier>>(eval(*nodes[0]));
+    return Func(nodes[1], identifiers);
+  } else if (ast.name == "ParamDeclList") {
+    std::vector<Identifier> identifiers;
+    for (int i=0; i<nodes.size(); i++) {
+      identifiers.push_back(any_cast<Identifier>(eval(*nodes[i])));
+    }
+    return identifiers;
+  } else if (ast.name == "SuffixExpr") {
+    // TODO handle other PrimaryTypeExpr types
+    auto val = getValue(eval(*nodes[0]));
+    auto func = any_cast<Func>(val);
+    for (int i=1; i<nodes.size(); i++) {
+      auto args = Args::toArgs(*this, eval(*nodes[i]));
+      return func.execute(*this, args);
+    }
+  }
+
+  std::cout << "AST Name: " << ast.name << std::endl;
+  for (int i=0; i<ast.nodes.size(); i++) {
+    std::cout << "AST child: " << ast.name << " : ";
+    eval(*nodes[i]);
+  }
+  return Nil();
 }
\ No newline at end of file
diff --git a/src/context.h b/src/context.h
index 5d1aabd..c23d839 100644
--- a/src/context.h
+++ b/src/context.h
@@ -13,4 +13,8 @@ public:
   std::shared_ptr<Scope> currentScope;
 public:
   void error(std::string_view msg);
+  std::any eval(peg::Ast& ast);
+protected:
+  std::any readIdentifier(std::any val);
+  std::any getValue(std::any input);
 };
\ No newline at end of file
diff --git a/src/grammar.peg b/src/grammar.peg
index 317d427..c5a92b7 100644
--- a/src/grammar.peg
+++ b/src/grammar.peg
@@ -13,23 +13,15 @@ Statement
      / LabeledStatement
      / AssignExpr SEMICOLON
 
-IfStatement
-    <- IfPrefix BlockExpr ( KEYWORD_else Payload? Statement )?
-     / IfPrefix AssignExpr ( SEMICOLON / KEYWORD_else Payload? Statement )
+IfStatement <- IfPrefix Block ( KEYWORD_else Payload? Block )?
 
 LabeledStatement <- BlockLabel? (Block / LoopStatement)
 
 LoopStatement <- ForStatement / WhileStatement
 
-ForStatement
-    <- ForPrefix BlockExpr ( KEYWORD_else Statement )?
-     / ForPrefix AssignExpr ( SEMICOLON / KEYWORD_else Statement )
+ForStatement <- ForPrefix Block
 
-WhileStatement
-    <- WhilePrefix BlockExpr ( KEYWORD_else Payload? Statement )?
-     / WhilePrefix AssignExpr ( SEMICOLON / KEYWORD_else Payload? Statement )
-
-BlockExpr <- BlockLabel? Block
+WhileStatement <- WhilePrefix Block
 
 # *** Expression Level ***
 AssignExpr <- Expr (AssignOp Expr)?
@@ -71,8 +63,7 @@ ForExpr <- ForPrefix Expr (KEYWORD_else Expr)?
 
 WhileExpr <- WhilePrefix Expr (KEYWORD_else Payload? Expr)?
 
-SuffixExpr
-    <- PrimaryTypeExpr (SuffixOp / FnCallArguments)*
+SuffixExpr <- PrimaryTypeExpr (SuffixOp / FnCallArguments)*
 
 PrimaryTypeExpr
     <- BUILTINCALL
@@ -120,7 +111,6 @@ AssignOp
      / AMPERSANDEQUAL
      / CARETEQUAL
      / PIPEEQUAL
-     / ASTERISKPERCENTEQUAL
      / EQUAL
 
 CompareOp
@@ -148,8 +138,6 @@ MultiplyOp
     <- ASTERISK
      / SLASH
      / PERCENT
-     / ASTERISK2
-     / ASTERISKPERCENT
 
 PrefixOp
     <- EXCLAMATIONMARK
@@ -163,9 +151,9 @@ SuffixOp
 FnCallArguments <- LPAREN ExprList RPAREN
 
 # Lists
-ExprList <- (Expr COMMA)* Expr?
+ExprList <- (Expr COMMA)* Expr? { no_ast_opt }
 
-ParamDeclList <- (IDENTIFIER COMMA)* IDENTIFIER?
+ParamDeclList <- (IDENTIFIER COMMA)* IDENTIFIER? { no_ast_opt }
 
 # *** Tokens ***
 INTEGER
@@ -253,10 +241,7 @@ STRINGLITERALSINGLE <- "\"" < string_char* > "\"" skip
 ~AMPERSAND            <- '&'      ![=]      skip
 ~AMPERSANDEQUAL       <- '&='               skip
 ~ASTERISK             <- '*'      ![*%=]    skip
-~ASTERISK2            <- '**'               skip
 ~ASTERISKEQUAL        <- '*='               skip
-~ASTERISKPERCENT      <- '*%'     ![=]      skip
-~ASTERISKPERCENTEQUAL <- '*%='              skip
 ~CARET                <- '^'      ![=]      skip
 ~CARETEQUAL           <- '^='               skip
 ~COLON                <- ':'                skip
diff --git a/src/main.cpp b/src/main.cpp
index a4d64f0..fe1f1c8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -7,139 +7,6 @@
 #include "context.h"
 #include "util.h"
 
-using peg::SemanticValues;
-using std::any_cast;
-
-int main_old(void) {
-  // (2) Make a parser
-  peg::parser parser(R"(
-    # Grammar for Calculator...
-    Additive    <- Multitive '+' Additive / Multitive
-    Multitive   <- Primary '*' Multitive / Primary
-    Primary     <- '(' Additive ')' / Number
-    Number      <- < [0-9]+ >
-    %whitespace <- [ \t]*
-  )");
-
-  assert(static_cast<bool>(parser) == true);
-
-  // (3) Setup actions
-  parser["Additive"] = [](const SemanticValues &vs) {
-    switch (vs.choice()) {
-    case 0: // "Multitive '+' Additive"
-      return any_cast<int>(vs[0]) + any_cast<int>(vs[1]);
-    default: // "Multitive"
-      return any_cast<int>(vs[0]);
-    }
-  };
-
-  parser["Multitive"] = [](const SemanticValues &vs) {
-    switch (vs.choice()) {
-    case 0: // "Primary '*' Multitive"
-      return any_cast<int>(vs[0]) * any_cast<int>(vs[1]);
-    default: // "Primary"
-      return any_cast<int>(vs[0]);
-    }
-  };
-
-  parser["Number"] = [](const SemanticValues &vs) {
-    return vs.token_to_number<int>();
-  };
-
-  // (4) Parse
-  parser.enable_packrat_parsing(); // Enable packrat parsing.
-
-  int val;
-  parser.parse(" (1 + 2) * 3 ", val);
-
-  assert(val == 9);
-
-  return 0;
-}
-
-std::any readIdentifier(Context &cxt, std::any val) {
-  assert(val.type() == typeid(Identifier));
-  return cxt.currentScope->getVar(cxt, any_cast<Identifier>(val).identifier);
-}
-
-/**
- * Returns the value of the input (reads the value if it is a refers to a variable)
- */
-std::any getValue(Context& cxt, std::any input) {
-  if (input.type() == typeid(Identifier))
-    return readIdentifier(cxt, input);
-  else
-    return input;
-}
-
-std::any eval(Context &cxt, peg::Ast& ast) {
-  const auto &nodes = ast.nodes;
-  if (ast.name == "Root") {
-    for (int i=0; i<ast.nodes.size(); i++) {
-      eval(cxt, *nodes[i]);
-    }
-    return Nil();
-  } else if (ast.name == "VarDecl") {
-    auto identifier = any_cast<Identifier>(eval(cxt, *nodes[0]));
-    auto value = eval(cxt, *nodes[1]);
-    cxt.currentScope->writeVar(cxt, identifier.identifier, value);
-    return Nil();
-  } else if (ast.name == "IDENTIFIER" || ast.name == "BUILTINIDENTIFIER") {
-    return Identifier(std::string(ast.token_to_string()));
-  } else if (ast.name == "INTEGER") {
-    // TODO parse hex, oct, and binary
-    return ast.token_to_number<long>();
-  } else if (ast.name == "BUILTINCALL" ) {
-    auto identifier = any_cast<Identifier>(eval(cxt, *nodes[0]));
-    auto args = Args::toArgs(cxt, eval(cxt, *nodes[1]));
-    cxt.builtins.at(identifier.identifier).execute(cxt, args);
-    // TODO: handle returns
-    return Nil();
-  } else if (ast.name == "STRINGLITERALSINGLE")
-  {
-    return ast.token_to_string();
-  } else if (ast.name == "ExprList") {
-    std::vector<std::any> exprs;
-    for (int i=0; i<ast.nodes.size(); i++) {
-      exprs.push_back(getValue(cxt, eval(cxt, *nodes[i])));
-    }
-    return exprs;
-  } else if (ast.name == "AdditionExpr") {
-    auto value = getValue(cxt, eval(cxt, *nodes[0]));
-    for (int i=1; i<nodes.size(); i+=2) {
-      int op = (*nodes[i]).choice;
-      auto v2 = getValue(cxt, eval(cxt, *nodes[i+1]));
-      // TODO: floats
-      if (op == 0) {
-        value = any_cast<long>(value) + any_cast<long>(v2);
-      } else {
-        value = any_cast<long>(value) - any_cast<long>(v2);
-      }
-    }
-    return value;
-  } else if (ast.name == "MultiplyExpr") {
-    auto value = getValue(cxt, eval(cxt, *nodes[0]));
-    for (int i=1; i<nodes.size(); i+=2) {
-      int op = (*nodes[i]).choice;
-      auto v2 = getValue(cxt, eval(cxt, *nodes[i+1]));
-      // TODO: floats
-      if (op == 0) {
-        value = any_cast<long>(value) * any_cast<long>(v2);
-      } else {
-        value = any_cast<long>(value) / any_cast<long>(v2);
-      }
-    }
-    return value;
-  }
-
-  std::cout << "AST Name: " << ast.name << std::endl;
-  for (int i=0; i<ast.nodes.size(); i++) {
-    std::cout << "AST child: " << ast.name << " : ";
-    eval(cxt, *nodes[i]);
-  }
-  return Nil();
-}
-
 int main(void) {
   peg::parser parser(
     #include "grammar.peg"
@@ -147,7 +14,27 @@ int main(void) {
   std::string s = R"(
     var a = "hello world";
     var b = 20 + 10 + 5 - 10 * 2 / 2;
+    b *= 2;
+    @print("hello world");
     @print(a,b);
+    b = 2;
+    @print(b);
+    a = b != 2;
+    @print(a);
+    if (a) {
+      @print("yay");
+    } else {
+      @print("neigh");
+    }
+    a = 10;
+    while(a > 0) {
+      a -= 1;
+      @print(a);
+    }
+    var hello = fn(abc) {
+      @print(abc);
+    };
+    hello("world");
   )";
 
   parser.enable_ast();
@@ -166,7 +53,7 @@ int main(void) {
     cxt.builtins.emplace("print", Func(BuiltinFunctions::print));
     cxt.currentScope = scope;
 
-    eval(cxt, *ast);
+    cxt.eval(*ast);
 
     return 0;
   }
diff --git a/src/util.cpp b/src/util.cpp
index 7b11b02..e26b036 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -6,11 +6,7 @@
 
 Args Args::toArgs(Context& cxt, std::any input) {
   Args args;
-  if (input.type() == typeid(Identifier)) {
-    auto id = std::any_cast<Identifier>(input);
-    auto value = cxt.currentScope->getVar(cxt, id.identifier);
-    args.args.push_back(value);
-  } else if (input.type() == typeid(std::vector<std::any>)) {
+  if (input.type() == typeid(std::vector<std::any>)) {
     args.args = std::any_cast<std::vector<std::any>>(input);
   } else {
     cxt.error("Unimplemented toArgs");
@@ -18,16 +14,40 @@ Args Args::toArgs(Context& cxt, std::any input) {
   return args;
 }
 
-void BuiltinFunctions::print(Context& cxt, Args& args) {
+std::any Func::execute(Context& cxt, Args& args) {
+  if (ast == nullptr) {
+    return nativeFunction(cxt, args);
+  } else {
+    // TODO create scope
+    std::any result;
+    for (int i=0; i<args.args.size(); i++) {
+      cxt.currentScope->writeVar(cxt, argNames[i].identifier, args.args[i]);
+    }
+    result = cxt.eval(*ast);
+    // TODO tear down scope
+    return result;
+  }
+}
+
+std::any BuiltinFunctions::print(Context& cxt, Args& args) {
   for (int i=0; i<args.args.size(); i++) {
     std::any var = args.args[i];
     if (var.type() == typeid(long)) {
       std::cout << std::any_cast<long>(var) << '\t';
     } else if (var.type() == typeid(std::string)) {
       std::cout << std::any_cast<std::string>(var) << '\t';
+    } else if (var.type() == typeid(bool)) {
+      bool v = std::any_cast<bool>(var);
+      if (v)
+        std::cout << "true" << '\t';
+      else
+        std::cout << "false" << '\t';
+    } else if (var.type() == typeid(Nil)) {
+      std::cout << "nil" << '\t';
     } else {
       cxt.error("Attempt to print unsupported type");
     }
   }
   std::cout << std::endl;
+  return Nil();
 }
\ No newline at end of file
diff --git a/src/util.h b/src/util.h
index 9f6d364..2caf4e4 100644
--- a/src/util.h
+++ b/src/util.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cpp-peglib/peglib.h>
+
 #include <string>
 #include <any>
 #include <vector>
@@ -33,20 +35,29 @@ public:
 class Func {
 public:
   std::shared_ptr<Scope> capturedScope;
-  // ast ptr
-  std::function<void(Context&,Args&)> nativeFunction;
+  
+  std::shared_ptr<peg::Ast> ast = nullptr;
+  std::vector<Identifier> argNames;
+
+  std::function<std::any(Context&,Args&)> nativeFunction;
 
 public:
-  Func(std::function<void(Context&,Args&)> nativeFunction) 
+  /**
+   * Create a native function
+   */
+  Func(std::function<std::any(Context&,Args&)> nativeFunction) 
     : capturedScope(nullptr), nativeFunction(nativeFunction) {}
 
-  void execute(Context& cxt, Args& args) {
-    // TODO implement AST executer
-    nativeFunction(cxt, args);
-  }
+  /**
+   * Create an interpreted function
+   */
+  Func(std::shared_ptr<peg::Ast> ast, std::vector<Identifier> argNames)
+    : ast(ast), argNames(argNames) {}
+
+  std::any execute(Context& cxt, Args& args);
 };
 
 class BuiltinFunctions {
 public:
-  static void print(Context& cxt, Args& args);
+  static std::any print(Context& cxt, Args& args);
 };
\ No newline at end of file