Add a very basic Error Expression to be used in semantic analysis

include/serene/exprs/error.h

@@ -0,0 +1,73 @@
+/* -*- C++ -*-
+ * Serene programming language.
+ *
+ *  Copyright (c) 2019-2021 Sameer Rahmani <lxsameer@gnu.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef EXPRS_ERROR_H
+#define EXPRS_ERROR_H
+
+#include "serene/exprs/expression.h"
+#include "llvm/ADT/StringRef.h"
+#include <string>
+
+namespace serene {
+
+namespace exprs {
+
+/// This enum represent the expression type and **not** the value type.
+enum class ErrType {
+  Syntax,
+  Semantic,
+  Compile,
+};
+
+/// This data structure represent the Lisp error. This type of expression
+/// doesn't show up in the AST but the compiler might rewrite the AST
+/// to contains error expressions
+class Error : public Expression {
+
+public:
+  ErrType errorType;
+  node target;
+  std::string message;
+
+  Error(ErrType err, node &t, llvm::StringRef msg)
+      : Expression(t->location), errorType(err), target(t), message(msg){};
+
+  // Error(reader::LocationRange &loc, ErrType err, node &t, llvm::StringRef
+  // msg)
+  //   : Expression(loc), errorType(err), target(t),  message(msg) {};
+
+  ExprType getType() const;
+  std::string toString() const;
+
+  static bool classof(const Expression *e);
+
+  maybe_node analyze(reader::SemanticContext &);
+
+  ~Error() = default;
+};
+
+} // namespace exprs
+} // namespace serene
+
+#endif

include/serene/exprs/expression.h

@@ -45,6 +45,7 @@ enum class ExprType {
   List,
   Number,
   Def,
+  Error,
 };
 
 class Expression;

include/serene/exprs/symbol.h

@@ -37,9 +37,6 @@ namespace exprs {
 /// in the context of the AST and nothing else.
 class Symbol : public Expression {
 
-  // private:
-  //   using Expression::analyze;
-
 public:
   std::string name;
 

src/serene/CMakeLists.txt

@@ -7,6 +7,7 @@ set(HEADER_LIST
   "${INCLUDE_DIR}/serene/exprs/list.h"
   "${INCLUDE_DIR}/serene/exprs/number.h"
   "${INCLUDE_DIR}/serene/exprs/def.h"
+  "${INCLUDE_DIR}/serene/exprs/error.h"
 
   # Reader
   "${INCLUDE_DIR}/serene/reader/reader.h"
@@ -41,6 +42,7 @@ add_library(serene
   exprs/number.cpp
   exprs/expression.cpp
   exprs/def.cpp
+  exprs/error.cpp
 
   serene.cpp
   symbol.cpp

src/serene/exprs/error.cpp

@@ -0,0 +1,48 @@
+/*
+ * Serene programming language.
+ *
+ *  Copyright (c) 2019-2021 Sameer Rahmani <lxsameer@gnu.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "serene/exprs/error.h"
+#include "llvm/Support/FormatVariadic.h"
+
+namespace serene {
+namespace exprs {
+
+ExprType Error::getType() const { return ExprType::Error; };
+
+std::string Error::toString() const {
+  return llvm::formatv("<Error [loc: {0} | {1}]: {2}>",
+                       this->location.start.toString(),
+                       this->location.end.toString(), this->message);
+}
+
+maybe_node Error::analyze(reader::SemanticContext &ctx) {
+  return Result<node>::Success(nullptr);
+};
+
+bool Error::classof(const Expression *e) {
+  return e->getType() == ExprType::Error;
+};
+
+} // namespace exprs
+} // namespace serene

src/tests/exprs/error_tests.cpp.inc

@@ -0,0 +1,49 @@
+/* -*- C++ -*-
+ * Serene programming language.
+ *
+ *  Copyright (c) 2019-2021 Sameer Rahmani <lxsameer@gnu.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "../test_helpers.cpp.inc"
+#include "serene/exprs/symbol.h"
+#include "serene/exprs/error.h"
+#include "llvm/Support/Casting.h"
+#include <catch2/catch.hpp>
+
+namespace serene {
+namespace exprs {
+
+TEST_CASE("Error Expression", "[expression]") {
+  std::unique_ptr<reader::LocationRange> range(dummyLocation());
+
+  node sym = make<Symbol>(*range.get(), llvm::StringRef("example"));
+  node err = make<Error>(ErrType::Semantic, sym, "Something Failed");
+
+  REQUIRE(err->getType() == ExprType::Error);
+  CHECK(err->toString() == "<Error [loc: 2:20:40 | 3:30:80]: Something Failed>");
+
+  auto error = llvm::dyn_cast<Error>(err.get());
+  CHECK(error->errorType == ErrType::Semantic);
+  CHECK(error->target == sym);
+};
+
+} // namespace exprs
+} // namespace serene

src/tests/serenetests.cpp

@@ -23,6 +23,7 @@
  */
 
 #define CATCH_CONFIG_MAIN
+#include "./exprs/error_tests.cpp.inc"
 #include "./exprs/expression_tests.cpp.inc"
 #include "./exprs/list_tests.cpp.inc"
 #include "./exprs/number_tests.cpp.inc"