Setup the minimal semantic analysis foundation

include/serene/errors/constants.h

@@ -34,7 +34,7 @@ namespace errors {
 enum ErrID {
   E0000,
   E0001,
-
+  E0002,
 };
 
 struct ErrorVariant {
@@ -52,8 +52,13 @@ static ErrorVariant
     DefExpectSymbol(E0001, "The first argument to 'def' has to be a Symbol.",
                     "");
 
-static std::map<ErrID, ErrorVariant *> ErrDesc = {{E0000, &UnknownError},
-                                                  {E0001, &DefExpectSymbol}};
+static ErrorVariant DefWrongNumberOfArgs(
+    E0002, "Wrong number of arguments is passed to the 'def' form.", "");
+
+static std::map<ErrID, ErrorVariant *> ErrDesc = {
+    {E0000, &UnknownError},
+    {E0001, &DefExpectSymbol},
+    {E0002, &DefWrongNumberOfArgs}};
 
 } // namespace errors
 } // namespace serene

include/serene/exprs/def.h

@@ -53,7 +53,7 @@ public:
   maybe_node analyze(reader::SemanticContext &);
 
   static bool classof(const Expression *e);
-  static std::shared_ptr<errors::Error> isValid(const List *);
+  static std::shared_ptr<errors::Error> isValid(List *);
 
   ~Def() = default;
 };

include/serene/exprs/expression.h

@@ -107,6 +107,7 @@ std::shared_ptr<T> makeAndCast(Args &&...args) {
   return std::make_shared<T>(std::forward<Args>(args)...);
 };
 
+std::string toString(ast &);
 void dump(ast &);
 
 } // namespace exprs

src/serene/errors/error.cpp

@@ -33,9 +33,7 @@ serene::exprs::ExprType Error::getType() const {
 };
 
 std::string Error::toString() const {
-  return llvm::formatv(
-      "<Error [loc: {0} | {1}]: E{2}: {3}>", this->location.start.toString(),
-      this->location.end.toString(), this->variant->id, this->message);
+  return llvm::formatv("<Error E{0}: {1}>", this->variant->id, this->message);
 }
 
 serene::exprs::maybe_node Error::analyze(reader::SemanticContext &ctx) {

src/serene/exprs/def.cpp

@@ -23,7 +23,9 @@
  */
 
 #include "serene/exprs/def.h"
+#include "serene/errors/error.h"
 #include "serene/exprs/list.h"
+#include "serene/exprs/symbol.h"
 #include "llvm/Support/FormatVariadic.h"
 
 namespace serene {
@@ -44,7 +46,21 @@ bool Def::classof(const Expression *e) {
   return e->getType() == ExprType::Def;
 };
 
-std::shared_ptr<errors::Error> Def::isValid(const List *list) {
+std::shared_ptr<errors::Error> Def::isValid(List *list) {
+  // TODO: Add support for docstring as the 3rd argument (4th element)
+  if (list->count() != 3) {
+    std::string msg = llvm::formatv("Expected 3 got {}", list->count());
+    return makeAndCast<errors::Error>(&errors::DefWrongNumberOfArgs,
+                                      list->elements[0], msg);
+  }
+
+  Symbol *binding = llvm::dyn_cast<Symbol>(list->elements[1].get());
+
+  if (!binding) {
+    return makeAndCast<errors::Error>(&errors::DefExpectSymbol,
+                                      list->elements[1], "");
+  }
+
   return nullptr;
 };
 } // namespace exprs

src/serene/exprs/expression.cpp

@@ -28,16 +28,22 @@
 namespace serene {
 namespace exprs {
 
-/// Dump the given AST tree to the standard out
-void dump(ast &tree) {
-  std::string result = "";
-
-  for (auto &node : tree) {
-    result = llvm::formatv("{0} {1}", result, node->toString());
+std::string toString(ast &tree) {
+  if (tree.size() == 0) {
+    return "";
   }
 
-  llvm::outs() << result << "\n";
-};
+  std::string result = tree.at(0)->toString();
+
+  for (unsigned int i = 1; i < tree.size(); i++) {
+    result = llvm::formatv("{0} {1}", result, tree.at(i)->toString());
+  }
+
+  return result;
+}
+
+/// Dump the given AST tree to the standard out
+void dump(ast &tree) { llvm::outs() << toString(tree) << "\n"; };
 
 } // namespace exprs
 } // namespace serene

src/tests/errors/error_tests.cpp.inc

@@ -41,7 +41,7 @@ TEST_CASE("Error Expression", "[expression]") {
   exprs::node err = exprs::make<Error>(&DefExpectSymbol, sym, "Something Failed");
 
   REQUIRE(err->getType() == exprs::ExprType::Error);
-  CHECK(err->toString() == "<Error [loc: 2:20:40 | 3:30:80]: E1: Something Failed>");
+  CHECK(err->toString() == "<Error E1: Something Failed>");
 
   auto error = llvm::dyn_cast<Error>(err.get());
   CHECK(error->target == sym);

src/tests/exprs/list_tests.cpp.inc

@@ -23,7 +23,10 @@
  */
 
 #include "../test_helpers.cpp.inc"
+#include "serene/exprs/expression.h"
 #include "serene/exprs/list.h"
+#include "serene/reader/reader.h"
+#include "serene/reader/semantics.h"
 #include "serene/exprs/symbol.h"
 #include <catch2/catch.hpp>
 
@@ -75,5 +78,19 @@ TEST_CASE("List Expression", "[expression]") {
   }
 };
 
+
+  TEST_CASE("List semantic analysis", "[semantic]") {
+    reader::Semantics analyzer;
+    auto r = new reader::Reader("(def (a b) 4)");
+    auto ast = r->read().getValue();
+
+    //auto &ast = maybeAst.getValue();
+    auto afterAst = analyzer.analyze(ast);
+
+
+    REQUIRE(afterAst);
+    CHECK(toString(afterAst.getValue()) == "<Error E1: >");
+    delete r;
+  }
 } // namespace exprs
 } // namespace serene