Refactor/more refactoring (#4)

* Created "http" library, moved platform-dependent utilities to "utility" library

* fix: forgot to add building of platform.c

* Added "main" program - interprets the given .bas file
More refactoring of code

* Fixed build issue on linux due to fread/fread_s

* Added interactive shell, runs when no arguments are passed

* Added option in interactive mode (prefix $) to parse and display AST only

* refactor: split basic.h into various headers, move built-in basic functions to `basic_runtime_builtin_functions.c`

* Added explicitly ',' and ';' as expression delimiters and as "whitespace characters"
Added whitespace printing in lexer
Improved expression parsing logic

* fix used incorrect `exit` method for error case in interpreter

* Added example .bas files, updated readme

* forgot to add \n as expression delimiter

* moved tty io-related system calls to system.c/system.h

* fix indenting

Author: nb-programmer

CMakeLists.txt

@@ -11,42 +11,44 @@ project(
 add_subdirectory("lib/basic/")
 add_subdirectory("lib/basic_system_interface/")
 add_subdirectory("lib/data_structures/")
+add_subdirectory("lib/utility/")
+add_subdirectory("lib/http/")
 
 # Build the main project executable
-add_executable(server
-    "src/http_server_main.c"
+add_executable(${CMAKE_PROJECT_NAME}
+    "src/main.c"
+)
 
-    "src/http.c"
-    "src/http.h"
-    "src/tcpserver.c"
-    "src/tcpserver.h"
-    "src/utils.c"
-    "src/utils.h"
-    "src/platform/platform.c"
-    "src/platform/platform.h"
+add_dependencies(${CMAKE_PROJECT_NAME}
+    basic
+    data_structures
+    utility
 )
 
-# Add some preprocessor defines
-target_compile_definitions(server
-    PUBLIC "$<$<CONFIG:DEBUG>:DEBUG>"
+target_link_libraries(${CMAKE_PROJECT_NAME}
+    PRIVATE
+        basic::basic
+        data_structures::data_structures
+        utility::utility
 )
 
-add_dependencies(server
-    basic
-    data_structures
+# Server
+add_executable(server
+    "src/http_server_main.c"
 )
 
 target_link_libraries(server
     PRIVATE
         basic::basic
         data_structures::data_structures
+        utility::utility
+        http::http
 )
 
-# Build the main project executable
+# Build the test executables
+
 add_executable(${CMAKE_PROJECT_NAME}-test_ast
     "src/test_ast.c"
-    "src/utils.c"
-    "src/utils.h"
 )
 
 target_link_libraries(${CMAKE_PROJECT_NAME}-test_ast

README.md

@@ -155,7 +155,7 @@ while true then
     end
 
     if is_prime then
-    	print(i)
+        print(i)
     end
 
     i = i + 2
@@ -168,7 +168,8 @@ Some features I would like to implement in this project:
 
 - [ ] Refactor the whole thing :)
 - [ ] Add more built-in functions and constants
+  - [ ] Make constants actually constant
 - [ ] Add ability to create user-defined functions
-- [ ] Make use of WebSocket to allow real-time communication
-  - [ ] Remove the Web server entirely so that the Pages can be served by a real Web server. The BASIC interpreter will run using only WebSocket.
+- [ ] Allow `stdin`
+- [ ] Port to C++
 - [ ] Remove dependencies on Linux (it was made for Linux as that was the subject I wrote it for)

examples/condition.bas

@@ -0,0 +1,6 @@
+val = 5
+if val < 10 then
+    print("Success")
+else
+    print("Failure")
+end

examples/counting_up.bas

@@ -0,0 +1,5 @@
+val = 0
+while val < 10 then
+    print("Counting at", val)
+    val = val + 1
+end

examples/hello.bas

@@ -0,0 +1 @@
+print("Hello world!")

examples/primes.bas

@@ -0,0 +1,20 @@
+print(2)
+
+i = 3
+
+while true then
+    p_sub = 2
+    is_prime = true
+    while p_sub < i then
+        if (i % p_sub) = 0 then
+            is_prime = false
+        end
+        p_sub = p_sub + 1
+    end
+
+    if is_prime then
+        print(i)
+    end
+
+    i = i + 2
+end

lib/basic/CMakeLists.txt

@@ -15,21 +15,18 @@ add_library(${PROJECT_NAME}
     "src/basic_parser.c"
     "src/basic_program.c"
     "src/basic_runner.c"
-    "src/utils.c"
-    "src/utils.h"
+    "src/basic_runtime_builtin_functions.c"
 )
 
 add_library(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
 
-# Add some preprocessor defines
-target_compile_definitions(${PROJECT_NAME} PUBLIC "$<$<CONFIG:DEBUG>:DEBUG>")
-
-add_dependencies(${PROJECT_NAME} basic_system_interface data_structures)
+add_dependencies(${PROJECT_NAME} basic_system_interface data_structures utility)
 
 target_link_libraries(${PROJECT_NAME}
     PRIVATE
         basic_system_interface::basic_system_interface
         data_structures::data_structures
+        utility::utility
 )
 
 target_include_directories(${PROJECT_NAME} PUBLIC

lib/basic/include/basic/basic.h

@@ -10,149 +10,12 @@
  * 2. BASIC Parser (Tokens to AST)
  * 3. Execute AST sequentially (Program run)
  *
- * */
+ */
 
-#include "ast.h"
 #include <data_structures/stack.h>
 
-/* For printing Log messages */
-extern unsigned int log_print_mask;
-
-// Log level mask
-#define LOGTYPE_DEBUG (1 << 0)
-#define LOGTYPE_INFO (1 << 1)
-#define LOGTYPE_MESSAGE (1 << 2)
-#define LOGTYPE_ERROR (1 << 3)
-#define LOGMASK_ALL 0xffff
-
-// Printf modified to allow only selected messages
-void lprintf(const char *tag, unsigned int level_mask, const char *format, ...);
-
-/* AST parser (tokenizer) */
-
-typedef enum
-{
-	TOKEN_IDENTIFIER,
-	TOKEN_KEYWORD,
-	TOKEN_WHITESPACE,
-	TOKEN_OPERATOR,
-	TOKEN_SEPARATOR,
-	TOKEN_NUM,
-	TOKEN_BOOL,
-	TOKEN_STRING,
-	TOKEN_END
-} BASICTokenType;
-
-typedef struct
-{
-	StringLiteral token;
-	BASICTokenType token_type;
-	char *token_at;
-} BASICToken;
-
-// Structure with all the stuff needed to convert a BASIC program to an AST
-typedef struct
-{
-	// List of tokens
-	BASICToken *tokens;
-	int tokens_length;
-	// Stack for knowning current scope
-} BASICParseTree;
-
-typedef struct
-{
-	char *program_source;
-	BASICParseTree program_tokens;
-	ASTNode *program_sequence;
-	// Map between line number and which instruction to execute on that line. For non-linear control flow
-	// BASICLineNode program_line_instruction;
-} BASICProgram;
-
-BASICProgram *basic_create_program();
-void basic_clear_program(BASICProgram *program);
-void basic_destroy_program(BASICProgram *program);
-
-// Recognized tokens
-extern char *PARSE_KEYWORDS[];
-extern int PARSE_KW_COUNT;
-extern char *PARSE_BOOLEAN[];
-extern char PARSE_OPERATORS[];
-extern char PARSE_SEPARATOR[];
-extern char PARSE_WS_CHAR[];
-
-// Index of the keyword in the above PARSE_KEYWORDS array
-#define KEYWORD_IDX_WHILE 0
-#define KEYWORD_IDX_IF 1
-#define KEYWORD_IDX_THEN 2
-#define KEYWORD_IDX_ELSE 3
-#define KEYWORD_IDX_END 4
-#define KEYWORD_IDX_GOTO 5
-
-// Lexer
-int basic_tokenize(BASICProgram *program);
-
-// Parser
-int basic_parse_form_expression(BASICParseTree *ptree, ASTNode *root, int parse_from, int parse_to, int *parse_new_pos);
-int basic_parse_form_function(BASICParseTree *ptree, ASTNode *root, int parse_from, int parse_to, int *parse_new_pos);
-
-int basic_parse_to_ast_between_level(BASICParseTree *ptree, ASTNode *root, int from, int to, int level, int allow_keyword, int *next_ptr);
-int basic_parse_to_ast_between_onlyexpr(BASICParseTree *ptree, ASTNode *root, int from, int to);
-int basic_parse_to_ast_between(BASICParseTree *ptree, ASTNode *root, int from, int to);
-int basic_parse_to_ast(BASICProgram *program);
-
-/* BASIC interpreter */
-
-typedef enum
-{
-	KW_DO_NOTHING,
-	KW_JMP_ONLY,
-	KW_JMP_AND_RET_NEXT,
-	KW_JMP_AND_RET_CURR
-} KeywordAction;
-
-typedef struct
-{
-	ASTNodeData value;
-	StringLiteral name;
-} BASICVariable;
-
-typedef struct
-{
-	BASICProgram *program;
-	int halt;
-	BASICVariable *variables;
-	int var_count;
-	StackNode *traverse_stack;
-} BASICRuntime;
-
-typedef ASTNodeData (*basic_function)(BASICRuntime *runtime, ASTNode *args);
-
-/* Public functions */
-BASICRuntime *basic_create_runtime(BASICProgram *program);
-void basic_free_runtime(BASICRuntime *runtime);
-
-ASTNodeData basic_evaluate_node(BASICRuntime *runtime, ASTNode *node);
-ASTNodeData basic_execute(BASICRuntime *runtime, ASTNode *pc);
-
-/* Private functions */
-
-BASICVariable *basic_find_variable(BASICRuntime *runtime, char var_name[]);
-ASTNodeData basic_get_variable(BASICRuntime *runtime, char var_name[]);
-void basic_set_variable(BASICRuntime *runtime, char var_name[], ASTNodeData value);
-void basic_var_assignment(BASICRuntime *runtime, ASTNode *args);
-void basic_init_constants(BASICRuntime *runtime);
-KeywordAction basic_evaluate_keyword_block(BASICRuntime *runtime, ASTNode *pc, ASTNode **nextpc);
-
-// Keyword handlers
-KeywordAction basic_eval_kw_if(BASICRuntime *runtime, ASTNode *pc, ASTNode **nextpc);
-KeywordAction basic_eval_kw_while(BASICRuntime *runtime, ASTNode *pc, ASTNode **nextpc);
-
-// Built-in functions
-ASTNodeData _basic_fn_print(BASICRuntime *runtime, ASTNode *args);
-ASTNodeData _basic_fn_max(BASICRuntime *runtime, ASTNode *args);
-ASTNodeData _basic_fn_min(BASICRuntime *runtime, ASTNode *args);
-ASTNodeData _basic_fn_sleep(BASICRuntime *runtime, ASTNode *arg);
-ASTNodeData _basic_fn_toint(BASICRuntime *runtime, ASTNode *arg);
-ASTNodeData _basic_fn_toflt(BASICRuntime *runtime, ASTNode *arg);
-ASTNodeData _basic_fn_rand(BASICRuntime *runtime, ASTNode *arg);
-ASTNodeData _basic_fn_irand(BASICRuntime *runtime, ASTNode *arg);
+#include "ast.h"
+#include "basic_token.h"
+#include "basic_parser.h"
+#include "basic_program.h"
+#include "basic_runner.h"

lib/basic/include/basic/basic_parser.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "ast.h"
+#include "basic_token.h"
+#include "basic_program.h"
+
+// Recognized tokens
+extern char *PARSE_KEYWORDS[];
+extern int PARSE_KW_COUNT;
+extern char *PARSE_BOOLEAN[];
+extern char PARSE_OPERATORS[];
+extern char PARSE_SEPARATOR[];
+extern char PARSE_WS_CHAR[];
+
+// Index of the keyword in the above PARSE_KEYWORDS array
+#define KEYWORD_IDX_WHILE 0
+#define KEYWORD_IDX_IF 1
+#define KEYWORD_IDX_THEN 2
+#define KEYWORD_IDX_ELSE 3
+#define KEYWORD_IDX_END 4
+#define KEYWORD_IDX_GOTO 5
+
+// Parser
+int basic_parse_form_expression(BASICParseTree *ptree, ASTNode *root, int parse_from, int parse_to, int *parse_new_pos);
+int basic_parse_form_function(BASICParseTree *ptree, ASTNode *root, int parse_from, int parse_to, int *parse_new_pos);
+
+int basic_parse_to_ast_between_level(BASICParseTree *ptree, ASTNode *root, int from, int to, int level, int allow_keyword, int *next_ptr);
+int basic_parse_to_ast_between_onlyexpr(BASICParseTree *ptree, ASTNode *root, int from, int to);
+int basic_parse_to_ast_between(BASICParseTree *ptree, ASTNode *root, int from, int to);
+int basic_parse_to_ast(BASICProgram *program);

lib/basic/include/basic/basic_program.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "ast.h"
+#include "basic_token.h"
+
+/* Basic Program */
+
+typedef struct
+{
+	char *program_source;
+	BASICParseTree program_tokens;
+	ASTNode *program_sequence;
+	// Map between line number and which instruction to execute on that line. For non-linear control flow
+	// BASICLineNode program_line_instruction;
+} BASICProgram;
+
+BASICProgram *basic_create_program();
+void basic_clear_program(BASICProgram *program);
+void basic_destroy_program(BASICProgram *program);
+
+// Lexer
+int basic_tokenize(BASICProgram *program);