feat: great user and handle exceptions in repl (#112)

.github/docker/monkey-github-builder-void-linux-musl-clang/Dockerfile

@@ -1,7 +1,7 @@
 FROM ghcr.io/void-linux/void-musl
 RUN xbps-install -Syu || xbps-install -yu xbps \
     && xbps-install -yu \
-    && xbps-install -y bash git cmake clang python3-codespell ninja clang clang-tools-extra cppcheck \
+    && xbps-install -y bash git cmake clang ninja clang clang-tools-extra cppcheck wget tar gzip jq \
     && xbps-remove -Ooy
 
 

.github/workflows/ci.yml

@@ -23,12 +23,12 @@ jobs:
       - name: Checkout
         uses: classabbyamp/treeless-checkout-action@v1
 
-      - name: Lint
+      - name: 📐 Check clang-format
         run: cmake -D FORMAT_COMMAND=clang-format -P cmake/lint.cmake
 
-      - name: Spell check
+      - name: 📝 Check spelling using typos-action
         if: always()
-        run: cmake -P cmake/spell.cmake
+        uses: crate-ci/typos@d1c850b2b5d502763520c25fb4a6a1128ad99bd9 # v1.28.3
 
   Build-And-Test:
     needs: [Lint]

HACKING.md

@@ -130,7 +130,7 @@ Runs the executable target `monkey_exe`.
 
 #### `spell-check` and `spell-fix`
 
-These targets run the codespell tool on the codebase to check errors and to fix
+These targets run the typos tool on the codebase to check errors and to fix
 them respectively. Customization available using the `SPELL_COMMAND` cache
 variable.
 

cmake/lint-targets.cmake

@@ -1,5 +1,5 @@
 set(FORMAT_PATTERNS
-    source/**/*.cpp source/**/*.hpp test/**/*.cpp test/**/*.hpp
+    source/*.cpp source/*.hpp test/*.cpp test/*.hpp
     CACHE STRING
           "; separated patterns relative to the project source dir to format")
 

cmake/lint.cmake

@@ -1,20 +1,20 @@
 cmake_minimum_required(VERSION 3.14)
 
 macro(default name)
-  if(NOT DEFINED "${name}")
-    set("${name}" "${ARGN}")
-  endif()
+    if(NOT DEFINED "${name}")
+        set("${name}" "${ARGN}")
+    endif()
 endmacro()
 
 default(FORMAT_COMMAND clang-format)
-default(PATTERNS source/**/*.cpp source/**/*.hpp test/**/*.cpp test/**/*.hpp)
+default(PATTERNS source/*.cpp source/*.hpp test/*.cpp test/*.hpp)
 default(FIX NO)
 
 set(flag --output-replacements-xml)
 set(args OUTPUT_VARIABLE output)
 if(FIX)
-  set(flag -i)
-  set(args "")
+    set(flag -i)
+    set(args "")
 endif()
 
 file(GLOB_RECURSE files ${PATTERNS})
@@ -23,22 +23,22 @@ set(output "")
 string(LENGTH "${CMAKE_SOURCE_DIR}/" path_prefix_length)
 
 foreach(file IN LISTS files)
-  execute_process(
+    execute_process(
     COMMAND "${FORMAT_COMMAND}" --style=file "${flag}" "${file}"
     WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
     RESULT_VARIABLE result ${args})
-  if(NOT result EQUAL "0")
-    message(FATAL_ERROR "'${file}': formatter returned with ${result}")
-  endif()
-  if(NOT FIX AND output MATCHES "\n<replacement offset")
-    string(SUBSTRING "${file}" "${path_prefix_length}" -1 relative_file)
-    list(APPEND badly_formatted "${relative_file}")
-  endif()
-  set(output "")
+    if(NOT result EQUAL "0")
+        message(FATAL_ERROR "'${file}': formatter returned with ${result}")
+    endif()
+    if(NOT FIX AND output MATCHES "\n<replacement offset")
+        string(SUBSTRING "${file}" "${path_prefix_length}" -1 relative_file)
+        list(APPEND badly_formatted "${relative_file}")
+    endif()
+    set(output "")
 endforeach()
 
 if(NOT badly_formatted STREQUAL "")
-  list(JOIN badly_formatted "\n" bad_list)
-  message("The following files are badly formatted:\n\n${bad_list}\n")
-  message(FATAL_ERROR "Run again with FIX=YES to fix these files.")
+    list(JOIN badly_formatted "\n" bad_list)
+    message("The following files are badly formatted:\n\n${bad_list}\n")
+    message(FATAL_ERROR "Run again with FIX=YES to fix these files.")
 endif()

cmake/spell-targets.cmake

@@ -1,4 +1,4 @@
-set(SPELL_COMMAND codespell CACHE STRING "Spell checker to use")
+set(SPELL_COMMAND typos CACHE STRING "Spell checker to use")
 
 add_custom_target(
     spell-check

cmake/spell.cmake

@@ -1,17 +1,17 @@
 cmake_minimum_required(VERSION 3.14)
 
 macro(default name)
-  if(NOT DEFINED "${name}")
-    set("${name}" "${ARGN}")
-  endif()
+    if(NOT DEFINED "${name}")
+        set("${name}" "${ARGN}")
+    endif()
 endmacro()
 
-default(SPELL_COMMAND codespell)
+default(SPELL_COMMAND typos)
 default(FIX NO)
 
 set(flag "")
 if(FIX)
-  set(flag -w)
+    set(flag --write-changes)
 endif()
 
 execute_process(
@@ -21,9 +21,9 @@ execute_process(
 )
 
 if(result EQUAL "65")
-  message(FATAL_ERROR "Run again with FIX=YES to fix these errors.")
+    message(FATAL_ERROR "Run again with FIX=YES to fix these errors.")
 elseif(result EQUAL "64")
-  message(FATAL_ERROR "Spell checker printed the usage info. Bad arguments?")
+    message(FATAL_ERROR "Spell checker printed the usage info. Bad arguments?")
 elseif(NOT result EQUAL "0")
-  message(FATAL_ERROR "Spell checker returned with ${result}")
+    message(FATAL_ERROR "Spell checker returned with ${result}")
 endif()

source/main.cpp

@@ -11,12 +11,12 @@
 #include <vector>
 
 #include <ast/builtin_function_expression.hpp>
-#include <gc.hpp>
 #include <compiler/compiler.hpp>
 #include <compiler/symbol_table.hpp>
 #include <eval/environment.hpp>
 #include <fmt/base.h>
 #include <fmt/format.h>
+#include <gc.hpp>
 #include <lexer/lexer.hpp>
 #include <parser/parser.hpp>
 #include <vm/vm.hpp>
@@ -44,24 +44,50 @@ constexpr auto monkey_face = R"r(
 auto monkey_business()
 {
     std::cerr << monkey_face;
-    std::cerr << "Woops! We ran into some monkey business here!\n";
+    std::cerr << "Woops! We ran into some monkey business here!\n  ";
 }
 
 auto print_parse_errors(const std::vector<std::string>& errors)
 {
     monkey_business();
     std::cerr << "  parser errors: \n";
     for (const auto& error : errors) {
-        std::cerr << "\t" << error << "\n";
+        std::cerr << "    " << error << '\n';
     }
 }
 
+auto show_error(std::string_view error_kind, std::string_view error_message)
+{
+    std::cerr << "Whoops! We ran into some " << error_kind << " error: \n  " << error_message << '\n';
+}
+
+auto print_compile_error(std::string_view error)
+{
+    show_error("compiler", error);
+}
+
+auto print_eval_error(std::string_view error)
+{
+    show_error("evaluation", error);
+}
+
 enum class engine : std::uint8_t
 {
     vm,
     eval,
 };
 
+auto operator<<(std::ostream& strm, engine en) -> std::ostream&
+{
+    switch (en) {
+        case engine::vm:
+            return strm << "vm";
+        case engine::eval:
+            return strm << "eval";
+    }
+    return strm << "unknown";
+}
+
 struct command_line_args
 {
     bool help {};
@@ -70,6 +96,19 @@ struct command_line_args
     std::string_view file;
 };
 
+auto get_logged_in_user() -> std::string
+{
+    // NOLINTBEGIN(concurrency-mt-unsafe)
+    const char* username = getenv("USER");
+
+    if (username == nullptr) {
+        username = getenv("USERNAME");
+    }
+    // NOLINTEND(concurrency-mt-unsafe)
+
+    return (username != nullptr) ? std::string(username) : "Unknown";
+}
+
 [[noreturn]] auto show_usage(std::string_view program, std::string_view error_msg = {})
 {
     auto exit_code = EXIT_SUCCESS;
@@ -120,7 +159,7 @@ auto run_file(const command_line_args& opts) -> int
 {
     std::ifstream ifs(std::string {opts.file});
     if (!ifs) {
-        std::cerr << "ERROR: could not open file: " << opts.file << "\n";
+        std::cerr << "ERROR: could not open file: " << opts.file << '\n';
         return 1;
     }
     const std::string contents {(std::istreambuf_iterator<char>(ifs)), (std::istreambuf_iterator<char>())};
@@ -138,7 +177,7 @@ auto run_file(const command_line_args& opts) -> int
         machine.run();
         const auto* result = machine.last_popped();
         if (!result->is(object::object_type::null)) {
-            std::cout << result->inspect() << "\n";
+            std::cout << result->inspect() << '\n';
         }
     } else {
         auto* global_env = make<environment>();
@@ -147,52 +186,69 @@ auto run_file(const command_line_args& opts) -> int
         }
         const auto* result = prgrm->eval(global_env);
         if (!result->is(object::object_type::null)) {
-            std::cout << result->inspect() << "\n";
+            std::cout << result->inspect() << '\n';
         }
     }
     return 0;
 }
 
 auto run_repl(const command_line_args& opts) -> int
 {
+    std::cout << "Hello " << get_logged_in_user() << ". This is the Monkey programming language using engine "
+              << opts.mode << ".\n";
+    std::cout << "Feel free to type in commands\n";
     auto* global_env = make<environment>();
     auto* symbols = symbol_table::create();
     constants consts;
     constants globals(globals_size);
     for (auto idx = 0UL; const auto& builtin : builtin_function_expression::builtins) {
-        global_env->set(builtin->name, make<function_object>(builtin, nullptr));
+        global_env->set(builtin->name, make<builtin_object>(builtin));
         symbols->define_builtin(idx, builtin->name);
         idx++;
     }
+    auto show_prompt = []() { std::cout << prompt; };
     auto input = std::string {};
-    std::cout << prompt;
+    show_prompt();
     while (getline(std::cin, input)) {
         auto lxr = lexer {input};
         auto prsr = parser {lxr};
         auto* prgrm = prsr.parse_program();
         if (!prsr.errors().empty()) {
             print_parse_errors(prsr.errors());
+            show_prompt();
             continue;
         }
         if (opts.mode == engine::vm) {
-            auto cmplr = compiler::create_with_state(&consts, symbols);
-            cmplr.compile(prgrm);
-            auto machine = vm::create_with_state(cmplr.byte_code(), &globals);
-            machine.run();
-            const auto* result = machine.last_popped();
-            if (result != nullptr && !result->is(object::object_type::null)) {
-                std::cout << result->inspect() << "\n";
+            try {
+                auto cmplr = compiler::create_with_state(&consts, symbols);
+                cmplr.compile(prgrm);
+                auto machine = vm::create_with_state(cmplr.byte_code(), &globals);
+                machine.run();
+                const auto* result = machine.last_popped();
+                if (result != nullptr && !result->is(object::object_type::null)) {
+                    std::cout << result->inspect() << '\n';
+                }
+            } catch (const std::exception& e) {
+                print_compile_error(e.what());
+                show_prompt();
+                continue;
             }
         } else {
-            const auto* result = prgrm->eval(global_env);
-            if (result != nullptr && !result->is(object::object_type::null)) {
-                std::cout << result->inspect() << "\n";
+            try {
+                const auto* result = prgrm->eval(global_env);
+                if (result != nullptr && !result->is(object::object_type::null)) {
+                    std::cout << result->inspect() << '\n';
+                }
+            } catch (const std::exception& e) {
+                print_eval_error(e.what());
+                show_prompt();
+                continue;
             }
         }
         if (opts.debug_env) {
             global_env->debug();
         }
-        std::cout << prompt;
+        show_prompt();
     }
     return 0;
 }
@@ -213,7 +269,7 @@ auto main(int argc, char* argv[]) -> int
 
     } catch (const std::exception& e) {
         monkey_business();
-        std::cerr << "Caught an exception: " << e.what() << "\n";
+        std::cerr << "Caught an exception: " << e.what() << '\n';
         return 1;
     }
 }

typos.toml

@@ -1,5 +1,7 @@
+[files]
+extend-exclude = ["test/doctest/doctest/doctest.h"]
+
 [default.extend-words]
-SEH = "SEH"
 fals = "fals"
 tru = "tru"
 thr = "thr"