lang: ast: implement parsing of match statements

lang/ast/expr/arith.c

@@ -50,7 +50,7 @@ static void print_operand(struct ivy_ast_node *node)
 	}
 }
 
-void arith_push_operand(struct expr_parser_state *state, struct ivy_token *tok)
+enum ivy_status arith_push_operand(struct expr_parser_state *state, struct ivy_token *tok)
 {
 	switch (tok->t_type) {
 	case IVY_TOK_IDENT: {
@@ -84,9 +84,20 @@ void arith_push_operand(struct expr_parser_state *state, struct ivy_token *tok)
 		b_queue_push_back(&state->s_output_queue, &v->n_base.n_entry);
 		break;
 	}
-	default:
+	case IVY_TOK_SYMBOL: {
+		if (tok->t_symbol != IVY_SYM_UNDERSCORE) {
+			return IVY_ERR_BAD_SYNTAX;
+		}
+
+		struct ivy_ast_node *v = ast_node_create(IVY_AST_DISCARD);
+		b_queue_push_back(&state->s_output_queue, &v->n_entry);
 		break;
 	}
+	default:
+		return IVY_ERR_BAD_SYNTAX;
+	}
+
+	return IVY_OK;
 }
 
 static const struct ivy_operator *get_operator_from_token(struct ivy_token *tok)
@@ -448,6 +459,20 @@ struct token_parse_result arith_parse_operator(
 	return PARSE_RESULT(IVY_OK, 0);
 }
 
+struct token_parse_result arith_parse_in(
+	struct ivy_parser *ctx, struct ivy_token *tok)
+{
+	struct expr_parser_state *state
+		= parser_get_state(ctx, struct expr_parser_state);
+
+	if (state->s_terminator == IVY_KW_IN) {
+		state->s_prev_token = IVY_KW_IN;
+		return expr_finalise_and_return(ctx, state);
+	}
+
+	return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
+}
+
 struct token_parse_result arith_parse_ident(
 	struct ivy_parser *ctx, struct ivy_token *tok)
 {
@@ -790,21 +815,21 @@ struct token_parse_result expr_finalise(
 		struct ivy_ast_cascade_node *cascade
 			= expr_finalise_cascade(state);
 
-		*result = cascade;
+		*result = (struct ivy_ast_node *)cascade;
 		return PARSE_RESULT(IVY_OK, flags);
 	}
 
 	if (state->s_sub_type == EXPR_SUBTYPE_COMPLEX_MSG) {
 		/* this is the end of a keyword-message */
 		struct ivy_ast_msg_node *msg = expr_finalise_complex_msg(state);
-		*result = msg;
+		*result = (struct ivy_ast_node *)msg;
 		return PARSE_RESULT(IVY_OK, 0);
 	}
 
 	if (state->s_sub_type == EXPR_SUBTYPE_KEYWORD_MSG) {
 		/* this is the end of a keyword-message */
 		struct ivy_ast_msg_node *msg = expr_finalise_keyword_msg(state);
-		*result = msg;
+		*result = (struct ivy_ast_node *)msg;
 		return PARSE_RESULT(IVY_OK, flags);
 	}
 
@@ -854,6 +879,38 @@ struct token_parse_result arith_parse_dot(
 	return expr_finalise_and_return(ctx, state);
 }
 
+struct token_parse_result arith_parse_comma(
+	struct ivy_parser *ctx, struct ivy_token *tok)
+{
+	struct expr_parser_state *state
+		= parser_get_state(ctx, struct expr_parser_state);
+	
+	if (state->s_type != EXPR_TYPE_ARITH) {
+		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
+	}
+
+	if (state->s_paren_depth > 0 && (state->s_prev_component == EXPR_CMP_OPERAND || state->s_prev_component == EXPR_CMP_MSG)) {
+		/* tuple. */
+		return PARSE_RESULT(IVY_ERR_NOT_SUPPORTED, 0);
+	}
+
+	state->s_prev_token = IVY_SYM_DOT;
+	return expr_finalise_and_return(ctx, state);
+}
+
+extern struct token_parse_result arith_parse_equal_right_angle(
+	struct ivy_parser *ctx, struct ivy_token *tok)
+{
+	struct expr_parser_state *state
+		= parser_get_state(ctx, struct expr_parser_state);
+
+	state->s_prev_token = IVY_SYM_EQUAL_RIGHT_ANGLE;
+	struct token_parse_result result = expr_finalise_and_return(ctx, state);
+
+	result.r_flags |= PARSE_REPEAT_TOKEN;
+	return result;
+}
+
 struct token_parse_result arith_parse_label(
 	struct ivy_parser *ctx, struct ivy_token *tok)
 {