lang: implement elif keyword for more complex if-statements
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@@ -160,6 +160,7 @@ struct ast_node_type block_node_ops = {
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KW_PARSER(VAR, parse_var),
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KW_PARSER(END, parse_end),
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KW_PARSER(ELSE, parse_else),
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KW_PARSER(ELIF, parse_else), /* same behaviour as ELSE */
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KW_PARSER_FALLBACK(parse_keyword),
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},
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.n_symbol_parsers = {
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@@ -20,6 +20,24 @@ static void init_state(struct ivy_parser *ctx, struct parser_state *sp, uintptr_
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state->s_prev_node = (struct ivy_ast_node *)arg;
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}
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static enum ivy_status flush_current_branch(struct cond_group_parser_state *state)
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{
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if (!state->s_cur_branch) {
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return IVY_ERR_INTERNAL_FAILURE;
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}
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b_queue_push_back(&state->s_branches, &state->s_cur_branch->n_base.n_entry);
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state->s_cur_branch
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= (struct ivy_ast_cond_node *)ast_node_create(IVY_AST_COND);
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if (!state->s_cur_branch) {
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return IVY_ERR_NO_MEMORY;
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}
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return IVY_OK;
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}
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struct token_parse_result parse_if(struct ivy_parser *ctx, struct ivy_token *tok)
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{
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struct cond_group_parser_state *state
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@@ -54,22 +72,45 @@ struct token_parse_result parse_if(struct ivy_parser *ctx, struct ivy_token *tok
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return PARSE_RESULT(IVY_OK, 0);
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}
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static enum ivy_status flush_current_branch(struct cond_group_parser_state *state)
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struct token_parse_result parse_elif(struct ivy_parser *ctx, struct ivy_token *tok)
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{
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struct cond_group_parser_state *state
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= parser_get_state(ctx, struct cond_group_parser_state);
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if (!state->s_cur_branch) {
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return IVY_ERR_INTERNAL_FAILURE;
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return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
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}
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b_queue_push_back(&state->s_branches, &state->s_cur_branch->n_base.n_entry);
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if (state->s_inline) {
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return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
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}
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if (state->s_prev_token != IVY_KW_THEN) {
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return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
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}
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state->s_cur_branch->n_body = state->s_prev_node;
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state->s_prev_node = NULL;
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enum ivy_status status = flush_current_branch(state);
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if (status != IVY_OK) {
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return PARSE_RESULT(status, 0);
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}
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state->s_cur_branch
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= (struct ivy_ast_cond_node *)ast_node_create(IVY_AST_COND);
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if (!state->s_cur_branch) {
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return IVY_ERR_NO_MEMORY;
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return PARSE_RESULT(IVY_ERR_NO_MEMORY, 0);
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}
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return IVY_OK;
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struct expr_parser_state *expr
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= (struct expr_parser_state *)parser_push_state(
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ctx, IVY_AST_EXPR, 0);
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state->s_prev_token = IVY_KW_ELIF;
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expr->s_subexpr_depth = 1;
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return PARSE_RESULT(IVY_OK, 0);
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}
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static struct token_parse_result parse_then(
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@@ -86,7 +127,7 @@ static struct token_parse_result parse_then(
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return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
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}
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if (state->s_prev_token != IVY_KW_IF) {
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if (state->s_prev_token != IVY_KW_IF && state->s_prev_token != IVY_KW_ELIF) {
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return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
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}
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@@ -103,6 +144,8 @@ static struct token_parse_result parse_then(
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= (struct block_parser_state *)parser_push_state(
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ctx, IVY_AST_BLOCK, 0);
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/* set the sub-expression depth to be non-zero so the expression parser doesn't consume the expression separator. */
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block_add_terminator(block, IVY_KW_ELIF);
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block_add_terminator(block, IVY_KW_ELSE);
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block_add_terminator(block, IVY_KW_END);
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state->s_prev_token = IVY_KW_THEN;
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@@ -138,7 +181,7 @@ static struct token_parse_result parse_else(
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return PARSE_RESULT(status, 0);
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}
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/* next component should either be an if keyword or a block. */
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/* next component should be a block. */
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} else {
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/* previous component was the if-condition. */
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if (!state->s_prev_node) {
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@@ -332,6 +375,7 @@ struct ast_node_type cond_group_node_ops = {
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.n_keyword_parsers = {
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KW_PARSER(IF, parse_if),
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KW_PARSER(THEN, parse_then),
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KW_PARSER(ELIF, parse_elif),
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KW_PARSER(ELSE, parse_else),
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KW_PARSER(END, parse_end),
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},
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@@ -84,6 +84,7 @@ struct ast_node_type expr_node_ops = {
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KW_PARSER(IF, stmt_parse_if),
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KW_PARSER(THEN, stmt_parse_end),
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KW_PARSER(ELSE, stmt_parse_end),
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KW_PARSER(ELIF, stmt_parse_end),
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KW_PARSER(CATCH, stmt_parse_end),
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KW_PARSER(FINALLY, stmt_parse_end),
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KW_PARSER(END, stmt_parse_end),
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@@ -34,13 +34,14 @@ enum ivy_keyword {
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IVY_KW_THROW,
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IVY_KW_CATCH,
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IVY_KW_FINALLY,
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IVY_KW_IF,
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IVY_KW_THEN,
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IVY_KW_AND,
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IVY_KW_OR,
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IVY_KW_UNDERSTANDS,
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IVY_KW_IS,
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IVY_KW_NOT,
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IVY_KW_IF,
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IVY_KW_THEN,
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IVY_KW_ELIF,
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IVY_KW_ELSE,
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IVY_KW_WHILE,
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IVY_KW_FOR,
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@@ -31,12 +31,13 @@ static struct lex_token_def keywords[] = {
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LEX_TOKEN_DEF(IVY_KW_FINALLY, "finally"),
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LEX_TOKEN_DEF(IVY_KW_UNDERSTANDS, "understands"),
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LEX_TOKEN_DEF(IVY_KW_IF, "if"),
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LEX_TOKEN_DEF(IVY_KW_ELIF, "elif"),
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LEX_TOKEN_DEF(IVY_KW_ELSE, "else"),
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LEX_TOKEN_DEF(IVY_KW_THEN, "then"),
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LEX_TOKEN_DEF(IVY_KW_AND, "and"),
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LEX_TOKEN_DEF(IVY_KW_OR, "or"),
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LEX_TOKEN_DEF(IVY_KW_IS, "is"),
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LEX_TOKEN_DEF(IVY_KW_NOT, "not"),
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LEX_TOKEN_DEF(IVY_KW_ELSE, "else"),
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LEX_TOKEN_DEF(IVY_KW_WHILE, "while"),
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LEX_TOKEN_DEF(IVY_KW_FOR, "for"),
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LEX_TOKEN_DEF(IVY_KW_MATCH, "match"),
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@@ -1140,6 +1141,7 @@ const char *ivy_keyword_to_string(enum ivy_keyword keyword)
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ENUM_STR(IVY_KW_CATCH);
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ENUM_STR(IVY_KW_FINALLY);
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ENUM_STR(IVY_KW_IF);
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ENUM_STR(IVY_KW_ELIF);
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ENUM_STR(IVY_KW_THEN);
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ENUM_STR(IVY_KW_AND);
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ENUM_STR(IVY_KW_OR);
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