let done

CMakeLists.txt

@@ -30,6 +30,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 # sets targets
 include(Options.mk)
+include(FindReadline.mk)
 
 # "#includes"
 include_directories(${CMAKE_SOURCE_DIR}/include)
@@ -49,4 +50,11 @@ include_directories(${gmock_SOURCE_DIR}/include ${gmock_SOURCE_DIR})
 # add_subdirectory(external/abseil)
 # find_package(absl REQUIRED)
 # include_directories(${abseil_SOURCE_DIR})
-# target_link_libraries(riftlang absl::base absl::synchronization absl::strings)
+# target_link_libraries(riftlang absl::base absl::synchronization absl::strings)
+
+#readline library for interpreter
+# find_package(Readline REQUIRED)
+# if READLINE_FOUND is false then fail
+if(NOT READLINE_FOUND)
+    message(FATAL_ERROR "Readline not found")
+endif()

FindReadline.mk

@@ -0,0 +1,49 @@
+# Code copied from sethhall@github
+#
+# - Try to find readline include dirs and libraries 
+#
+# Usage of this module as follows:
+#
+#     find_package(Readline)
+#
+# Variables used by this module, they can change the default behaviour and need
+# to be set before calling find_package:
+#
+#  Readline_ROOT_DIR         Set this variable to the root installation of
+#                            readline if the module has problems finding the
+#                            proper installation path.
+#
+# Variables defined by this module:
+#
+#  READLINE_FOUND            System has readline, include and lib dirs found
+#  Readline_INCLUDE_DIR      The readline include directories. 
+#  Readline_LIBRARY          The readline library.
+
+find_path(Readline_ROOT_DIR
+    NAMES include/readline/readline.h
+)
+
+find_path(Readline_INCLUDE_DIR
+    NAMES readline/readline.h
+    HINTS ${Readline_ROOT_DIR}/include
+)
+
+find_library(Readline_LIBRARY
+    NAMES readline
+    HINTS ${Readline_ROOT_DIR}/lib
+)
+
+if(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+  set(READLINE_FOUND TRUE)
+else(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+  FIND_LIBRARY(Readline_LIBRARY NAMES readline)
+  include(FindPackageHandleStandardArgs)
+  FIND_PACKAGE_HANDLE_STANDARD_ARGS(Readline DEFAULT_MSG Readline_INCLUDE_DIR Readline_LIBRARY )
+  MARK_AS_ADVANCED(Readline_INCLUDE_DIR Readline_LIBRARY)
+endif(Readline_INCLUDE_DIR AND Readline_LIBRARY AND Ncurses_LIBRARY)
+
+mark_as_advanced(
+    Readline_ROOT_DIR
+    Readline_INCLUDE_DIR
+    Readline_LIBRARY
+)

include/ast/env.hh

@@ -36,6 +36,7 @@ namespace rift
                 }
                 Token getEnv(const str_t& name) const;
                 void setEnv(const str_t& name, const Token& value);
+                void printState();
             protected:
                 // absl::flat_hash_map<str_t, rift::scanner::Token> values;
                 std::unordered_map<str_t, rift::scanner::Token> values = {};

include/reader/reader.hh

@@ -50,7 +50,9 @@ namespace rift
                 // inline typename std::enable_if<!std::is_same<T, char>::value, T>::type advance() { return (!atEnd()) ? source->at(curr++) : nullptr; }
 
                 /// @brief Peeks at the current character 
-                inline bool peek(T expected) { return !atEnd() && source->at(curr) == expected; };
+                inline bool peek(T expected) {
+                    return !atEnd() && source->at(curr) == expected; 
+                };
                 /// @brief Peeks at the current character with an offset
                 inline bool peek_off(T expected, int offset) { return curr+offset<source->size() && source->at(curr+offset) == expected; };
                 /// @brief Peeks at the current character

include/scanner/scanner.hh

@@ -67,7 +67,8 @@ namespace rift
 
             inline bool isDigit(char c) { return c>='0' && c<='9'; }
             inline bool isAlpha(char c) { return (c!=' ') && ( (c>='a' && c<='z') || (c>='A' && c<='Z') || c=='_'); }
-            inline bool isAlphaNumeric(char c) { return isAlpha(c) || isDigit(c); }
+            inline bool isAlphaNumeric(char c) { return std::isalnum(c); }
+            inline bool isIdentifier(char c) { return std::isalnum(c) || c == '_'; }
 
             #pragma mark - Token Scanners
 

lib/CMakeLists.txt

@@ -46,6 +46,7 @@ add_executable(
 target_compile_options(riftlang PRIVATE -Wno-gcc-compat)
 target_compile_definitions(riftlang PRIVATE ABSL_USES_STD_ANY=1)
 
+target_link_libraries(riftlang PRIVATE Readline)
 # target_link_libraries(riftlang absl::base absl::strings absl::hash absl::algorithm absl::memory absl::flat_hash_map absl::container_common absl::container_memory)
 
 add_library(riftlib STATIC ${SOURCES})

lib/ast/env.cc

@@ -24,9 +24,6 @@ namespace rift
             // if(tok == Token())
             //     rift::error::runTimeError("🛑 Undefined variable '" + name + "'");
             // }
-            for (const auto& [key, value] : values) {
-                std::cout << key << " => " << value.to_string() << std::endl;
-            }
             if (!values.contains(name)) {
                 return Token();
             }
@@ -37,5 +34,12 @@ namespace rift
         {
             values[name] = value;
         }
+
+        void Environment::printState()
+        {
+            for (const auto& [key, value] : values) {
+                std::cout << key << " => " << value.to_string() << std::endl;
+            }
+        }
     }
 }

lib/ast/parser.cc

@@ -57,10 +57,11 @@ namespace rift
             if (match({Token(TokenType::IDENTIFIER, "", "", line)})) {
                 /// @note rhs identifier undeclared
                 auto idt = peekPrev(1);
-                if (rift::ast::Environment::getInstance().getEnv(castString(idt)) == Token()) {
+                auto val  = rift::ast::Environment::getInstance().getEnv(castString(idt));
+                if (val == Token()) {
                     rift::error::report(line, "primary", "🛑 Undefined variable '" + castString(idt) + "' at line: " + castNumberString(idt.line), idt, ParserException("Undefined variable '" + castString(idt) + "'"));
                 }
-                return std::unique_ptr<Literal>(new Literal(Token(peekPrev(1))));
+                return std::unique_ptr<Literal>(new Literal(Token(val)));
             }
 
             if (match({Token(TokenType::LEFT_PAREN, "(", "", line)})) { 
@@ -154,6 +155,10 @@ namespace rift
         std::unique_ptr<Expr> Parser::assignment()
         {
             if (match({Token(TokenType::IDENTIFIER, "", "", line)})) {
+                if (peek(Token(TokenType::SEMICOLON, ";", "", line))) {
+                    prevance();
+                    return equality();
+                }
                 auto idt = peekPrev();
                 consume(Token(TokenType::EQUAL, "=", "", line), std::unique_ptr<ParserException>(new ParserException("Expected '=' after variable name")));
                 auto expr = assignment();

lib/driver/driver.cc

@@ -27,6 +27,9 @@
 #include <ast/eval.hh>
 #include <string>
 
+#include <readline/readline.h>
+#include <readline/history.h>
+
 using namespace rift::error;
 using namespace rift::scanner;
 using namespace rift::ast;
@@ -51,6 +54,7 @@ namespace rift
 
             Eval riftEvaluator;
             riftEvaluator.evaluate(*statements);
+            rift::ast::Environment::getInstance().printState();
         }
 
         void Driver::runFile()
@@ -85,14 +89,17 @@ namespace rift
 
         void Driver::runPrompt()
         {
-            while(true)
-            {
-                std::string input = "";
-                std::cout << "🦊 ＞ ";
-                std::getline(std::cin >> std::ws, input);
-                if (input.empty()) break;
+            rl_bind_key('\t', rl_complete);
+            while(true) {
+                char* input = readline("🦊 ＞ ");
+                if (input == nullptr) break;
+                add_history(input);
+
                 run(input);
-                errorOccured = false; // reset error
+
+                // reset
+                errorOccured = false;
+                free(input);
             }
         }
 

lib/scanner/scanner.cc

@@ -46,7 +46,7 @@ namespace rift
             keywords["super"] = Type::SUPER;
             keywords["this"] = Type::THIS;
             keywords["true"] = Type::TRUE;
-            keywords["var"] = Type::VAR;
+            keywords["let"] = Type::VAR;
             keywords["while"] = Type::WHILE;
         }
 
@@ -94,7 +94,7 @@ namespace rift
         }
 
         void Scanner::identifier() {
-            while (isAlphaNumeric(advance()));
+            while (isIdentifier(peek())) advance();
             std::string text = std::string(source->begin()+start, source->begin()+curr);
             text.erase(std::remove_if(text.begin(), text.end(), ::isspace), text.end());
             if (keywords.find(text)!= keywords.end()) {