WIP top-level parsing and keyword tokens

parser.c

@@ -3,30 +3,6 @@ typedef struct Parser {
     Token *end;
 } Parser;
 
-typedef enum Ast_Kind {
-    AST_NONE,
-    AST_ERROR,
-    AST_INT,
-    AST_UNARY,
-    AST_BINARY,
-} Ast_Kind;
-
-typedef struct Ast Ast;
-struct Ast {
-    Ast_Kind kind;
-    Token *pos;
-
-    union {
-        uint64_t u;
-        struct {
-            Token_Kind op;
-            Ast *l;
-            Ast *r;
-        };
-        char *error;
-    };
-};
-
 Token *next_token(Parser *p) {
     if (p->at < p->end) {
         return p->at++;
@@ -41,6 +17,18 @@ Token *match_token(Parser *p, Token_Kind kind) {
     return NULL;
 }
 
+bool is_keyword(Token *token) {
+    bool result = (token->kind >= TOK_FIRST_KEYWORD && token->kind <= TOK_LAST_KEYWORD);
+    return result;
+}
+
+Token *match_keyword(Parser *p, char *keyword) {
+    if (is_keyword(p->at) && p->at->intern == keyword) {
+        return next_token(p);
+    }
+    return NULL;
+}
+
 Token *expect_token(Parser *p, Token_Kind kind) {
     if (p->at->kind == kind) {
         return next_token(p);
@@ -48,21 +36,6 @@ Token *expect_token(Parser *p, Token_Kind kind) {
     panicf("expected token kind: %s, got instead: %s", token_to_name(p->at->kind), token_to_name(kind));
 }
 
-Ast *create_ast(Token *token, Ast_Kind kind) {
-    Ast *result = calloc(1, sizeof(Ast));
-    result->pos = token;
-    result->kind = kind;
-    return result;
-}
-
-Ast *create_binary_expr(Token *token, Token_Kind op, Ast *left, Ast *right) {
-    Ast *result = create_ast(token, AST_BINARY);
-    result->op = op;
-    result->l = left;
-    result->r = right;
-    return result;
-}
-
 Ast *parse_expr(Parser *p, int power_of_binding_to_right);
 
 Ast *parse_atom(Parser *p) {
@@ -118,6 +91,20 @@ Ast *parse_expr(Parser *p, int power_of_binding_to_right) {
     return n;
 }
 
+Ast *parse_program(Parser *p) {
+    for (;;) {
+        if (match_keyword(p, keyword_int)) {
+            Token *ident = expect_token(p, TOK_IDENT);
+            expect_token(p, TOK_LPAREN);
+            expect_token(p, TOK_RPAREN);
+        } else {
+            Token *token = next_token(p);
+            panicf("invalid token");
+        }
+    }
+    return result;
+}
+
 int64_t eval_expr(Ast *n) {
     switch (n->kind) {
         case AST_INT: return (int64_t)n->u;