quote eval define print read

.dir-locals.el

@@ -0,0 +1,36 @@
+((c-mode . ((eval . (company-clang-set-prefix "main.c"))
+            (eval . (flycheck-mode 0))
+            (eval . (rainbow-mode 0))))
+ (nil . ((eval . (progn
+                   (defvar context-mode-map (make-sparse-keymap)
+                     "Keymap while context-mode is active.")
+                   (define-minor-mode context-mode
+                     "A temporary minor mode to be activated only specific to a buffer."
+                     nil
+                     :lighter " Context"
+                     context-mode-map)
+                   (context-mode 1)
+
+                   ;; additional scripts
+                   (defun save-and-find-test-script-and-compile ()
+                     (interactive)
+                     (let ((build-script-name "test.bat"))
+                       (save-and-find-build-script-and-compile)))
+                   (defun save-and-find-run-script-and-compile ()
+                     (interactive)
+                     (let ((build-script-name "run.bat"))
+                       (save-and-find-build-script-and-compile)))
+                   (defun save-and-find-debug-script-and-compile ()
+                     (interactive)
+                     (let ((build-script-name "debug.bat"))
+                       (save-and-find-build-script-and-compile)))
+
+                   (defhydra hydra-context (context-mode-map "<f2>")
+                     "Context Actions:"
+                     ("b" save-and-find-build-script-and-compile "build" :color blue)
+                     ("r" save-and-find-run-script-and-compile   "run"   :color blue)
+                     ("d" save-and-find-debug-script-and-compile "debug" :color blue)
+                     ("t" save-and-find-test-script-and-compile  "test"  :color blue)
+                     ("q" nil                                    "quit"  :color blue))
+                   (define-key context-mode-map (kbd "<f2>") 'hydra-context/body)
+                   )))))

.gitignore

@@ -3,4 +3,6 @@
 /*.ilk
 /*.pdb
 /.vs/
-/vs/
+/vs/
+/*.exe
+*.exe

bin/test.lsp

@@ -1 +1,12 @@
-(/ (+ 1 (- 100 7 3)) 2)
+((lambda (x) (* x x)) 2)
+
+(setq a 3)
+
+(let ((a 10))
+  (let ((b 5))
+    (setq a 4))
+  a)
+
+
+a
+

build.bat

@@ -2,8 +2,6 @@
 @setlocal
 pushd %~dp0
 
-set start=%time%
-
 set exeName=lisp.exe
 set binDir=bin
 
@@ -17,11 +15,6 @@ if %errorlevel% == 0 (
    echo.
    if not exist ..\%binDir% mkdir ..\%binDir%
    move %exeName% ..\%binDir%\ > NUL
-   pushd ..\%binDir%
-   echo ---------- Running ----------
-   call timecmd %exeName% test.lsp
-   del %exeName% /S /Q > NUL
-   popd
 ) else (
   echo.
   echo Fucki'n 'ell

debug.bat

@@ -0,0 +1,3 @@
+pushd %~dp0\vs
+start lisp.sln
+popd

run.bat

@@ -0,0 +1,9 @@
+@echo off
+pushd %~dp0\bin
+
+call ..\build.bat
+if %errorlevel% == 0 (
+   echo ---------- Running ----------
+   call timecmd lisp.exe
+)
+popd

src/.dir-locals.el

@@ -1,3 +0,0 @@
-((c-mode . ((eval . (company-clang-set-prefix "main.c"))
-            (eval . (flycheck-mode 0))
-            (eval . (rainbow-mode 0)))))

src/env.c

@@ -1,7 +1,8 @@
 
 struct Environment {
     struct Environment* parent;
-    int       key_count;
+    int       capacity;
+    int       next_index;
     char**    keys;
     Ast_Node* values;
 };
@@ -11,16 +12,37 @@ typedef struct Environment Environment;
 Environment* create_empty_environment() {
     Environment* env = new(Environment);
 
-    env->parent    = nullptr;
-    env->key_count = 0;
-    env->keys      = nullptr;
-    env->values    = nullptr;
+    int start_capacity = 1;
+
+    env->parent     = nullptr;
+    env->capacity   = start_capacity;
+    env->next_index = 0;
+    env->keys       =    (char**)malloc(start_capacity * sizeof(char*));
+    env->values     = (Ast_Node*)malloc(start_capacity * sizeof(Ast_Node));
 
     return env;
 }
 
+void define_symbol(Ast_Node* symbol, Ast_Node* value, Environment* env) {
+    // NOTE(Felix): right now we are simmply adding the symol at the
+    // back of the list without checking if it already exists but are
+    // also searching for thesymbol from the back, so we will find the
+    // latest defined one first, but a bit messy. Later we should use
+    // a hashmap here. @refactor
+
+    if (env->next_index == env->capacity) {
+        env->capacity *= 2;
+        env->keys   =    (char**)realloc(env->keys, env->capacity * sizeof(char*));
+        env->values = (Ast_Node*)realloc(env->values, env->capacity * sizeof(Ast_Node));
+    }
+
+    env->keys  [env->next_index] = symbol->value.symbol->identifier;
+    env->values[env->next_index] = *value;
+    ++env->next_index;
+}
+
 Ast_Node* lookup_symbol(Symbol* sym, Environment* env) {
-    for (int i = 0; i < env->key_count; ++i)
+    for (int i = env->next_index - 1; i >= 0; --i)
         if (string_equal(env->keys[i], sym->identifier))
             return env->values+i;
 
@@ -30,19 +52,19 @@ Ast_Node* lookup_symbol(Symbol* sym, Environment* env) {
     char* built_in_names[] = {
         // Math stuff
         "+", "-", "*", "/",
-        ">", "<", "=",
+        ">", "<", "=", "<=", ">=",
         // Conditional stuff
         "if", "and", "or", "not",
         // Cons stuff
         "first", "rest", "pair",
         // rest
-        "load", "define",
+        "load",   "define",
         "lambda", "progn",
-        "eval", "quote",
-        "print", "read",
-        "help"
+        "eval",   "quote",
+        "print",  "read",
+        "help", "exit"
     };
-    int built_in_count = 23;
+    int built_in_count = 26;
 
     for (int i = 0; i < built_in_count; ++i) {
         if (string_equal(built_in_names[i], sym->identifier)) {

src/error.c

@@ -7,6 +7,8 @@ typedef enum {
     Error_Type_Not_Yet_Implemented,
     Error_Type_Syntax_Error,
     Error_Type_Unexpected_Eof,
+    Error_Type_Unbalanced_Parenthesis,
+    Error_Type_Trailing_Garbage,
     Error_Type_Unknown_Error,
 } Error_Type;
 
@@ -34,15 +36,16 @@ void create_error(Error_Type type, Ast_Node* location) {
 
 char* Error_Type_to_string(Error_Type type) {
     switch (type) {
-    case Error_Type_Ill_Formed_List:           return "Ill formed list";
-    case Error_Type_Not_A_Function:            return "Not a function";
-    case Error_Type_Symbol_Not_Defined:        return "Symbol not defined";
-    case Error_Type_Wrong_Number_Of_Arguments: return "Wrong number of arguments";
-    case Error_Type_Type_Missmatch:            return "Type Missmatch";
-    case Error_Type_Not_Yet_Implemented:       return "Not yet implemented";
+    case Error_Type_Ill_Formed_List:           return "Evaluation-error: Ill formed list";
+    case Error_Type_Not_A_Function:            return "Evaluation-error: Not a function";
+    case Error_Type_Symbol_Not_Defined:        return "Evaluation-error: Symbol not defined";
+    case Error_Type_Wrong_Number_Of_Arguments: return "Evaluation-error: Wrong number of arguments";
+    case Error_Type_Type_Missmatch:            return "Evaluation-error: Type Missmatch";
+    case Error_Type_Not_Yet_Implemented:       return "Evaluation-error: Not yet implemented";
+    case Error_Type_Trailing_Garbage:          return "Evaluation-error: Trailing garbage following expression";
     case Error_Type_Syntax_Error:              return "Syntax Error";
-    case Error_Type_Unexpected_Eof:            return "Unexpected EOF";
+    case Error_Type_Unexpected_Eof:            return "Parsing-error: Unexpected EOF";
+    case Error_Type_Unbalanced_Parenthesis:    return "Parsing-error: Unbalanced parenthesis";
     default:                                   return "Unknown Error";
     }
 }
-

src/eval.c

@@ -1,9 +1,5 @@
 /* Ast_Node* apply_to_lambda () {} */
 
-/* Ast_Node* apply_to_built_in (Ast_Node* function, Ast_Node* arguments) { */
-
-/* } */
-
 Ast_Node* eval_expr(Ast_Node* node, Environment* env);
 bool is_truthy (Ast_Node* expression, Environment* env);
 
@@ -43,10 +39,10 @@ void eval_operands(Ast_Node* operands, Environment* env) {
 Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
 #define report_error(_type) {                   \
         create_error(_type, node);              \
-        log_error();                            \
-        exit(1);                                \
         return nullptr;                         \
     }
+    if (error)
+        return nullptr;
 
     Ast_Node* ret = new(Ast_Node);
     switch (node->type) {
@@ -56,31 +52,112 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
     case Ast_Node_Type_Symbol:
         return lookup_symbol(node->value.symbol, env);
     case Ast_Node_Type_Number:
+    case Ast_Node_Type_Keyword:
     case Ast_Node_Type_String:
         return node;
     case Ast_Node_Type_Pair: {
         Ast_Node* operator = eval_expr(node->value.pair->first, env);
+        if (error) return nullptr;
+
         Ast_Node* operands = node->value.pair->rest;
 
         // check for built ins functions
         if (operator->type == Ast_Node_Type_Built_In_Function) {
             char* operator_name = operator->value.built_in_function->identifier;
             if (string_equal("quote", operator_name)) {
-                return node->value.pair->rest;
+                int operands_length = list_length(operands);
+                if (operands_length != 1) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+                return operands->value.pair->first;
+            } else if (string_equal("eval", operator_name)) {
+                int operands_length = list_length(operands);
+                if (operands_length != 1) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+                if (error) return nullptr;
+                return eval_expr(operands->value.pair->first, env);
             } else if (string_equal("+", operator_name)) {
                 eval_operands(operands, env);
+                if (error) return nullptr;
                 return built_in_add(operands);
             } else if (string_equal("-", operator_name)) {
                 eval_operands(operands, env);
+                if (error) return nullptr;
                 return built_in_substract(operands);
             } else if (string_equal("*", operator_name)) {
                 eval_operands(operands, env);
+                if (error) return nullptr;
                 return built_in_multiply(operands);
             } else if (string_equal("/", operator_name)) {
                 eval_operands(operands, env);
+                if (error) return nullptr;
                 return built_in_divide(operands);
+            } else if (string_equal("define", operator_name)) {
+                int operands_length = list_length(operands);
+                if (error) return nullptr;
+                if (operands_length != 2) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+
+                Ast_Node* symbol = operands->value.pair->first;
+                if (symbol->type != Ast_Node_Type_Symbol)
+                    report_error(Error_Type_Type_Missmatch);
+
+                Ast_Node* value = operands->value.pair->rest->value.pair->first;
+                value = eval_expr(value, env);
+
+                define_symbol(symbol, value, env);
+
+                return value;
+            } else if (string_equal("exit", operator_name)) {
+                int operands_length = list_length(operands);
+                if (error) return nullptr;
+                if (operands_length > 1) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+
+                if (operands_length == 1) {
+                    Ast_Node* error_code = operands->value.pair->first;
+                    if (error_code->type != Ast_Node_Type_Number)
+                        report_error(Error_Type_Type_Missmatch);
+
+                    exit((int)error_code->value.number->value);
+                }
+                exit(0);
+
+            } else if (string_equal("print", operator_name)) {
+                int operands_length = list_length(operands);
+                if (error) return nullptr;
+                if (operands_length != 1) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+                eval_operands(operands, env);
+                if (error) return nullptr;
+                print(operands->value.pair->first);
+                printf("\n");
+                return operands->value.pair->first;
+            } else if (string_equal("read", operator_name)) {
+                int operands_length = list_length(operands);
+                if (error) return nullptr;
+                if (operands_length > 1) {
+                    report_error(Error_Type_Wrong_Number_Of_Arguments);
+                }
+
+                if (operands_length == 1) {
+                    eval_operands(operands, env);
+                    if (error) return nullptr;
+                    Ast_Node* prompt = operands->value.pair->first;
+                    if (prompt->type == Ast_Node_Type_String)
+                        printf("%s", prompt->value.string->value);
+                    else
+                        print(operands->value.pair->first);
+                }
+                char* line = read_line();
+                return create_ast_node_string(line, (int)strlen(line));
             } else if (string_equal("if", operator_name)) {
                 int operands_length = list_length(operands);
+                if (error) return nullptr;
                 if (operands_length != 2 && operands_length != 3) {
                     report_error(Error_Type_Wrong_Number_Of_Arguments);
                 }
@@ -89,7 +166,9 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
                 Ast_Node* then_part = operands->value.pair->rest;
                 Ast_Node* else_part = then_part->value.pair->rest;
 
-                if (is_truthy(condition, env))
+                bool truthy = is_truthy(condition, env);
+                if (error) return nullptr;
+                if (truthy)
                     return eval_expr(then_part->value.pair->first, env);
                 else if (operands_length == 3)
                     return eval_expr(else_part->value.pair->first, env);
@@ -102,6 +181,7 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
                         report_error(Error_Type_Ill_Formed_List);
                     }
                     result &= is_truthy(operands->value.pair->first, env);
+                    if (error) return nullptr;
                     operands = operands->value.pair->rest;
 
                     if (!result) return create_ast_node_nil();
@@ -116,6 +196,7 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
                         report_error(Error_Type_Ill_Formed_List);
                     }
                     result |= is_truthy(operands->value.pair->first, env);
+                    if (error) return nullptr;
                     operands = operands->value.pair->rest;
 
                     if (result) return create_ast_node_number(1);;
@@ -129,6 +210,7 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
                     return nullptr;
                 }
                 bool truthy = is_truthy(operands->value.pair->first, env);
+                if (error) return nullptr;
                 if (truthy)
                     return create_ast_node_nil();
                 return create_ast_node_number(1);
@@ -150,6 +232,7 @@ Ast_Node* eval_expr(Ast_Node* node, Environment* env) {
 
 bool is_truthy (Ast_Node* expression, Environment* env) {
     Ast_Node* result = eval_expr(expression, env);
+    if (error) return false;
     switch (result->type) {
     case Ast_Node_Type_Nil:    return false;
     /* case Ast_Node_Type_Number: return result->value.number->value != 0; */

src/main.c

@@ -16,46 +16,66 @@
 #include "./eval.c"
 #include "./testing.c"
 
+int interprete_file (char* file_content) {
+    Ast_Node_Array_List* program = parse_program(file_content);
+    if (error) {
+        log_error();
+        return 1;
+    }
+    Environment* env = create_empty_environment();
+    Ast_Node* result = create_ast_node_nil();
+    for (int i = 0; i < program->next_index; ++i) {
+        result = eval_expr(program->data[i], env);
+        if (error) {
+            log_error();
+            return 1;
+        }
+    }
+    print(result);
+    printf("\n");
+    return 0;
+}
+
+int interprete_stdin () {
+    printf("Welcome to the lispy interpreter.\n");
+    char* line;
+    Environment* env = create_empty_environment();
+    Ast_Node* parsed, * evaluated;
+    while (true) {
+        printf(">");
+        line = read_line();
+        parsed = parse_single_expression(line);
+        if (error) {
+            log_error();
+            delete_error();
+            continue;
+        }
+        evaluated = eval_expr(parsed, env);
+        if (error) {
+            log_error();
+            delete_error();
+            continue;
+        }
+        print(evaluated);
+        printf("\n");
+    }
+    return 0;
+}
+
+
 int main (int argc, char *argv[]) {
     if (argc > 1) {
-        char* fileContent = read_entire_file(argv[1]);
-        if (fileContent) {
-            Ast_Node_Array_List* program = parse_program(fileContent);
-            if (error) {
-                log_error();
-                exit(1);
-            }
-            Environment* env = create_empty_environment();
-            Ast_Node* result = create_ast_node_nil();
-            for (int i = 0; i < program->next_index; ++i) {
-                result = eval_expr(program->data[i], env);
-                if (error) {
-                    log_error();
-                    exit(1);
-                }
-            }
-            print(result);
-            printf("\n");
+        char* file_content = read_entire_file(argv[1]);
+        if (file_content) {
+            return interprete_file(file_content);
         } else {
             printf("The file could not be read\n");
+            return 1;
         }
     } else {
         run_all_tests();
-
-        printf("Welcome to the lispy interpreter.\n");
-        char* line;
-        Environment* env = create_empty_environment();
-        Ast_Node* parsed, * evaluated;
-        while (true) {
-            printf(">");
-            line = read_line();
-            parsed = parse_single_expression(line);
-            evaluated = eval_expr(parsed, env);
-            print(evaluated);
-            printf("\n");
-        }
+        return interprete_stdin();
     }
 
-
     return 0;
 }

src/parse.c

@@ -18,10 +18,8 @@ Ast_Node_Array_List* create_Ast_Node_Array_List() {
 void append_to_Ast_Node_Array_List(Ast_Node_Array_List* list, Ast_Node* node) {
     if (list->next_index == list->length) {
         list->length *= 2;
-        list->data =
-            (Ast_Node**)realloc(list->data, list->length * sizeof(Ast_Node));
+        list->data = (Ast_Node**)realloc(list->data, list->length * sizeof(Ast_Node));
     }
-
     list->data[list->next_index++] = node;
 }
 
@@ -231,7 +229,17 @@ Ast_Node* parse_expression(char* text, int* index_in_text) {
 
 Ast_Node* parse_single_expression(char* text) {
     int index_in_text = 0;
-    return parse_expression(text, &index_in_text);
+    Ast_Node* result;
+    eat_until_code(text, &index_in_text);
+    if (text[(index_in_text)] == '(')
+        result = parse_expression(text, &index_in_text);
+    else
+        result = parse_atom(text, &index_in_text);
+    eat_until_code(text, &index_in_text);
+    if (text[(index_in_text)] == '\0')
+        return result;
+    create_error(Error_Type_Trailing_Garbage, create_ast_node_nil());
+    return nullptr;
 }
 
 Ast_Node_Array_List* parse_program(char* text) {
@@ -247,13 +255,11 @@ Ast_Node_Array_List* parse_program(char* text) {
                 return nullptr;
             append_to_Ast_Node_Array_List(program, parsed);
         } break;
-        case ';': {
-            eat_comment_line(text, &index_in_text);
-        } break;
+        case ';':
         case ' ':
         case '\t':
         case '\n': {
-            ++index_in_text;
+            eat_until_code(text, &index_in_text);
         } break;
         default:
             /* syntax error */

test.bat

@@ -0,0 +1,10 @@
+@echo off
+pushd %~dp0\bin
+
+call ..\build.bat
+if %errorlevel% == 0 (
+   echo ---------- Testing ----------
+   call timecmd lisp.exe test.lsp
+)
+
+popd