minor changes for

include/ast_util.h

@@ -0,0 +1,3 @@
+#include "globals.h"
+
+ASTNode *ast_node_new(NodeKind kind, Token token);

include/globals.h

@@ -6,6 +6,8 @@
  * Token Definitions
  */
 typedef enum {
+    PROGRAM, /* use for syntax */
+
     LBRACK,
     RBRACK,
     LCURLY,
@@ -48,8 +50,29 @@ typedef struct {
 /**
  * AST Node Definitions
  */
+
+typedef enum NodeKind {
+    NODE_PROGRAM,
+    NODE_DEFN,
+    NODE_TYPE,
+    NODE_EXPR,
+    NODE_ATOM,
+    NODE_STMT,
+    NODE_BLOCK,
+    NODE_LAMBDA,
+    NODE_COMPOUND,
+    NODE_PARAMS
+
+    
+} NodeKind;
+
 typedef struct ASTNode {
+    NodeKind kind;
+
     Token token;
     struct ASTNode **children;
     size_t child_count;
+    size_t capacity;
+
+    
 } ASTNode;

src/ast_util.c

@@ -0,0 +1,96 @@
+#include "ast_util.h"
+
+#include <stdlib.h>
+
+ASTNode *ast_node_new(NodeKind kind, Token token) {
+    ASTNode *node = malloc(sizeof(ASTNode));
+    if (node == NULL) {
+        return NULL;
+    }
+
+    node->kind = kind;
+    node->token = token;
+    node->children = NULL;
+    node->capacity = 0;
+    node->child_count = 0;
+
+    return node;
+}
+
+ASTNode *ast_node_new_with_child(NodeKind kind, Token token, int child_count) {
+    ASTNode *node = ast_node_new(kind, token);
+    if (node == NULL) {
+        return NULL;
+    }
+
+    node->child_count = child_count;
+    node->capacity = child_count;
+    node->children = calloc(child_count, sizeof(ASTNode *));
+    if (node->children == NULL) {
+        free(node);
+        return NULL;
+    }
+
+    return node;
+}
+
+void ast_node_add_child(ASTNode *parent, ASTNode *child) {
+    if (parent->child_count >= parent->capacity) {
+        size_t new_capacity = parent->capacity == 0 ? 2 : parent->capacity * 2;
+        ASTNode **new_children = realloc(parent->children, new_capacity * sizeof(ASTNode *));
+        if (new_children == NULL) {
+            return;
+        }
+        parent->children = new_children;
+        parent->capacity = new_capacity;
+    }
+    parent->children[parent->child_count++] = child;
+}
+
+void ast_node_free(ASTNode *node) {
+    if (node == NULL) {
+        return;
+    }
+
+    for (size_t i = 0; i < node->child_count; i++) {
+        ast_node_free(node->children[i]);
+    }
+    free(node->children);
+    free(node);
+}
+
+ASTNode *ast_node_new_program() {
+    ASTNode *node = ast_node_new(NODE_PROGRAM, (Token) {PROGRAM, 0, {0, NULL}});
+    return node;
+}
+
+ASTNode *ast_node_new_defn(Token token, ASTNode *type_node, ASTNode *expr_node /* nullable */) {
+
+    ASTNode *node;
+
+    if (expr_node == NULL) {
+        node = ast_node_new_with_child(NODE_DEFN, token, 1);
+    } else {
+        node = ast_node_new_with_child(NODE_DEFN, token, 2);
+    }
+
+    if (node == NULL) {
+        return NULL;
+    }
+
+    node->children[0] = type_node;
+    if (expr_node != NULL) {
+        node->children[1] = expr_node;
+    }
+
+    return node;
+}
+
+ASTNode *ast_node_new_type_simple(Token token) {
+    ASTNode *node = ast_node_new(NODE_TYPE, token);
+}
+
+ASTNode *ast_node_new_type_functional(Token token, ASTNode *type_node_from, ASTNode *type_node_to) {
+    ASTNode *node = ast_node_new_with_child(
+            NODE_TYPE, token, 2);
+}

src/parse.c

@@ -29,10 +29,30 @@ static void parser_expect(Parser *parser, TokenType type) {
     if (parser->current.type == type) {
         parser_next(parser);
     } else {
-        parser->flag_error = 1;
+        parser->flag_error = 1; // TODO: 실패했을 떄, 예외전파
     }
 }
 
 /*
     IMPL. PARSER PARSE FUNCTIONS 
 */
+
+ASTNode *parser_parse_defn(Parser *parser) {
+    parser_expect(parser, ID);
+
+    Token id_token = parser->current;
+
+    ASTNode *type_node = parser_parse_type(parser);
+
+    Token id = parser->current;
+    parser_expect(parser, ID);
+
+    ASTNode *expr = NULL;
+    if (parser->current.type != SEMI) {
+        expr = parser_parse_expr(parser);
+    }
+
+    parser_expect(parser, SEMI);
+
+    return NULL;
+}