feat: yet another new parser architecture

src/main.c

@@ -73,6 +73,9 @@ int main(int argc, char **argv)
     // init lexer context
     struct lexer_context *ctx = calloc(1, sizeof(struct lexer_context));
 
+    // init parser
+    int parser_init();
+
     // Retrieve and build first AST
     struct ast *command_ast = get_ast(ctx);
 
@@ -107,6 +110,7 @@ int main(int argc, char **argv)
         return ERR_INPUT_PROCESSING;
 
     ast_free(&command_ast);
+    parser_close();
 
     return return_code;
 }

src/parser/grammar.c

@@ -0,0 +1,41 @@
+#define _POSIX_C_SOURCE 200809L
+
+// === Includes
+#include "grammar.h"
+
+#include "../utils/hash_map/hash_map.h"
+#include "grammar_basic.h"
+
+// === Static variables
+
+static struct hash_map *firsts_map = NULL;
+
+// === Static functions
+static enum token_type first(enum rule r)
+{
+    // TODO
+    return TOKEN_NULL;
+}
+
+// === Functions
+
+bool grammar_init(void)
+{
+    // Create firsts hashmap
+    // TODO
+
+    // Populate the hashmap
+    // TODO
+
+    return true;
+}
+
+void grammar_close(void)
+{
+    // TODO free hashmap
+}
+
+struct ast *parse_input(struct lexer_context *ctx)
+{
+    return parse_list(ctx);
+}

src/parser/grammar.h

@@ -0,0 +1,65 @@
+#ifndef GRAMMAR_H
+#define GRAMMAR_H
+
+#include <stdbool.h>
+
+#include "../lexer/lexer.h"
+
+// === Macros
+
+#define PEEK_TOKEN()                                                           \
+    peek_token(ctx);                                                           \
+    if (token == NULL)                                                         \
+    {                                                                          \
+        puts("Internal error: cannot get the following token");                \
+        return NULL;                                                           \
+    }
+
+#define POP_TOKEN()                                                            \
+    pop_token(ctx);                                                            \
+    if (token == NULL)                                                         \
+    {                                                                          \
+        puts("Internal error: cannot get the following token");                \
+        return NULL;                                                           \
+    }
+
+// === Structures
+
+enum rule {
+   RULE_NULL,
+   RULE_INPUT,
+   RULE_LIST,
+   RULE_AND_OR,
+   RULE_PIPELINE,
+   RULE_COMMAND,
+   RULE_SIMPLE_COMMAND,
+   RULE_SHELL_COMMAND,
+   RULE_IF,
+   RULE_COMPOUND_LIST,
+   RULE_ELSE_CLAUSE
+};
+
+// === Functions
+
+/* @brief Initializes the grammar submodule
+ * @return PARSER_INIT_SUCCESS on success PARSER_INIT_ERROR on error
+ * @warning Do not use outside the parser
+ */
+ bool grammar_init(void);
+
+/* @brief Closes the grammar submodule
+ * @warning Do not use outside the parser
+ */
+ void grammar_close(void);
+
+/* @brief Acts as the entry point of the parser, calls parse_list
+ *
+ * @code input = list '\n'
+ *             | list EOF
+ *             | '\n'
+ *             | EOF
+ *             ;
+ */
+struct ast *parse_input(struct lexer_context *ctx);
+
+#endif /* ! GRAMMAR_H */

src/parser/grammar_advanced.h

@@ -0,0 +1,4 @@
+#ifndef GRAMMAR_ADVANCED_H
+#define GRAMMAR_ADVANCED_H
+
+#endif /* ! GRAMMAR_ADVANCED_H */

src/parser/grammar_basic.c

@@ -1,64 +1,11 @@
-#define _POSIX_C_SOURCE 200809L
+#include "grammar_basic.h"
 
-// === Includes
-#include "parsing_utils.h"
-
-#include <stdbool.h>
-#include <stddef.h>
 #include <stdio.h>
 #include <string.h>
 
 #include "../lexer/lexer.h"
-#include "../utils/ast/ast.h"
-
-// === Static functions
-
-/* Returns true if c is a command terminator, false otherwise
-static bool isterminator(struct token *token)
-{
-    if (token == NULL)
-        return false;
-
-    switch (token->type)
-    {
-    case TOKEN_NEWLINE:
-    case TOKEN_SEMICOLON:
-    case TOKEN_EOF:
-        return true;
-    default:
-        return false;
-    }
-}
-
- */
-
-/* @brief: returns true if token is an end of list indicator.
- * @warning: not used
- */
-
-/*
-static bool is_end_of_list(struct token *token)
-{
-    if (token == NULL)
-        return false;
-
-    switch (token->type)
-    {
-        case TOKEN_NEWLINE:
-        case TOKEN_EOF:
-            return true;
-        default:
-            return false;
-    }
-}
-*/
-
-// === Functions
-
-struct ast *parse_input(struct lexer_context *ctx)
-{
-    return parse_list(ctx);
-}
+#include "../utils/lists/lists.h"
+#include "grammar.h"
 
 struct ast *parse_list(struct lexer_context *ctx)
 {
@@ -78,8 +25,6 @@ struct ast *parse_list(struct lexer_context *ctx)
     while (token->type == TOKEN_SEMICOLON)
     {
         token = POP_TOKEN();
-       // if (!isterminator(token)) // Follow(list)
-        // {
         current_node = parse_and_or(ctx);
         if (current_node == NULL)
         {
@@ -88,10 +33,8 @@ struct ast *parse_list(struct lexer_context *ctx)
             return NULL;
         }
         result_list = list_append(result_list, current_node);
-        // }
         token = PEEK_TOKEN();
     }
-    // result_list = list_append(result_list, current_node);
 
     return ast_create_list(result_list);
 }

src/parser/grammar_basic.h

@@ -1,35 +1,10 @@
-#ifndef PARSING_UTILS_H
-#define PARSING_UTILS_H
+#ifndef GRAMMAR_BASIC_H
+#define GRAMMAR_BASIC_H
 
+#include "../utils/ast/ast.h"
 #include "../lexer/lexer.h"
 
-// === Macros
-
-#define PEEK_TOKEN()                                                           \
-    peek_token(ctx);                                                           \
-    if (token == NULL)                                                         \
-    {                                                                          \
-        puts("Internal error: cannot get the following token");                \
-        return NULL;                                                           \
-    }
-
-#define POP_TOKEN()                                                            \
-    pop_token(ctx);                                                            \
-    if (token == NULL)                                                         \
-    {                                                                          \
-        puts("Internal error: cannot get the following token");                \
-        return NULL;                                                           \
-    }
-
-/* @brief Acts as the entry point of the parser, calls parse_list
- *
- * @code input = list '\n'
- *             | list EOF
- *             | '\n'
- *             | EOF
- *             ;
- */
-struct ast *parse_input(struct lexer_context *ctx);
+// === Functions
 
 /* @brief: parses a list of [and_or] rules separated by semicolons and that
  *         ends by a newline
@@ -97,4 +72,4 @@ struct ast *parse_compound_list(struct lexer_context *ctx);
  */
 struct ast *parse_else_clause(struct lexer_context *ctx);
 
-#endif /* ! PARSING_UTILS_H */
+#endif /* ! GRAMMAR_BASIC_H */

src/parser/parser.c

@@ -1,49 +1,52 @@
 #include "parser.h"
 
-#include <stdbool.h>
-#include <stddef.h>
 #include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 
-#include "../lexer/lexer.h"
-#include "../parser/parsing_utils.h"
-#include "../utils/lists/lists.h"
+#include "grammar.h"
 
-// === Static functions
-// ...
+// === Static variables
+
+static enum parser_state state = PARSER_STATE_NOT_INITIALIZED;
 
 // === Functions
 
-struct ast *get_ast(struct lexer_context *ctx)
+bool parser_init(void)
 {
-    struct token *token = PEEK_TOKEN();
-    struct ast *res;
-
-    if (token->type == TOKEN_EOF)
+    if (state == PARSER_STATE_READY)
     {
-        token = pop_token(ctx);
-        return ast_create_end();
-    }
-    else if (token->type == TOKEN_NEWLINE)
-    {
-        token = pop_token(ctx);
-        return ast_create_void();
-    }
-    else // TOKEN WORD
-    {
-        res = parse_list(ctx);
-    }
-
-    /*
-       if (token == NULL)
-       {
-       puts("Internal error: cannot get the following token");
-       puts("Hint: EOF might be missing");
+        puts("Internal error: tried to initialize the parser module twice.");
         return NULL;
     }
-       */
-    return res;
+    int success = grammar_init();
+    if (success == false)
+        return false;
+
+    state = PARSER_STATE_READY;
+    return true;
+}
+
+struct ast *get_ast(struct lexer_context *ctx)
+{
+    if (ctx == NULL)
+    {
+        puts("Internal error: called parser with no lexer context (NULL "
+             "pointer). Aborting.");
+        return NULL;
+    }
+    if (state == PARSER_STATE_NOT_INITIALIZED)
+    {
+        puts("Internal error: attempted to call parser without initializing "
+             "it. Aborting.");
+        return NULL;
+    }
+    if (state == PARSER_STATE_CLOSED)
+    {
+        puts("Internal error: attempted to call parser after closing it. "
+             "Aborting.");
+        return NULL;
+    }
+
+    return parse_input(ctx);
 }
 
 // TODO

src/parser/parser.h

@@ -1,9 +1,28 @@
 #ifndef PARSER_H
 #define PARSER_H
 
+#include <stdbool.h>
+
 #include "../lexer/lexer.h"
 #include "../utils/ast/ast.h"
 
+enum parser_state {
+    PARSER_STATE_NOT_INITIALIZED = 0,
+    PARSER_STATE_READY,
+    PARSER_STATE_CLOSED
+};
+
+/* @brief Initializes the parser module
+ * @warning parser needs to be closed after use with parser_close()
+ *
+ * @return Returns false on error and true on success
+ */
+bool parser_init(void);
+
+/* @brief Closes the parser module after use
+ */
+void parser_close(void);
+
 /* @brief Builds the AST representation of the next command to execute.
  *
  * @return Returns the AST representation of the next command to execute.