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lang: ast: implement for-loop parsing

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max 🍓
2024-12-06 10:02:31 +00:00
parent f3cd89c72a
commit d88d58be70
7 changed files with 347 additions and 5 deletions
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264
lang/ast/for.c Normal file
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@@ -0,0 +1,264 @@
#include "block.h"
#include "expr/expr.h"
#include "iterate.h"
struct for_parser_state {
struct parser_state s_base;
bool s_inline;
unsigned int s_prev_token;
struct ivy_ast_node *s_body, *s_iterator, *s_iterable;
struct ivy_ast_node *s_prev_node;
};
static void init_state(struct ivy_parser *ctx, struct parser_state *sp, uintptr_t arg)
{
struct for_parser_state *state = (struct for_parser_state *)sp;
state->s_prev_node = (struct ivy_ast_node *)arg;
}
struct token_parse_result parse_for(struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (state->s_prev_node) {
/* this is an inline for-loop */
state->s_inline = true;
state->s_body = state->s_prev_node;
state->s_prev_node = NULL;
} else {
state->s_inline = false;
}
struct expr_parser_state *expr
= (struct expr_parser_state *)parser_push_state(
ctx, IVY_AST_EXPR, 0);
state->s_prev_token = IVY_KW_FOR;
expr->s_terminator = IVY_KW_IN;
expr->s_subexpr_depth = 1;
return PARSE_RESULT(IVY_OK, 0);
}
static struct token_parse_result parse_in(
struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (state->s_prev_token != IVY_KW_FOR) {
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
/* previous component was the for iterator */
if (!state->s_prev_node) {
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
state->s_iterator = state->s_prev_node;
state->s_prev_node = NULL;
/* next component will be the for iterable. */
struct expr_parser_state *expr
= (struct expr_parser_state *)parser_push_state(
ctx, IVY_AST_EXPR, 0);
/* set the sub-expression depth to be non-zero so the expression parser doesn't consume the expression separator. */
expr->s_subexpr_depth = 1;
expr->s_terminator = IVY_KW_DO;
state->s_prev_token = IVY_KW_IN;
return PARSE_RESULT(IVY_OK, 0);
}
static struct token_parse_result parse_do(
struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (state->s_inline) {
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
if (state->s_prev_token != IVY_KW_IN) {
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
/* previous component was the for iterable. */
if (!state->s_prev_node) {
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
state->s_iterable = state->s_prev_node;
state->s_prev_node = NULL;
/* next component will be a block. */
struct block_parser_state *block
= (struct block_parser_state *)parser_push_state(
ctx, IVY_AST_BLOCK, 0);
block->s_terminator = IVY_KW_END;
state->s_prev_token = IVY_KW_DO;
return PARSE_RESULT(IVY_OK, 0);
}
static struct token_parse_result parse_expr_begin(
struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (state->s_prev_token != IVY_KW_DO) {
/* expression can only follow do keyword. */
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
struct block_parser_state *block
= (struct block_parser_state *)parser_push_state(
ctx, IVY_AST_BLOCK, 0);
block->s_terminator = IVY_KW_END;
return PARSE_RESULT(IVY_OK, PARSE_REPEAT_TOKEN);
}
static enum ivy_status finalise_for_loop(struct for_parser_state *state)
{
struct ivy_ast_for_loop_node *loop
= (struct ivy_ast_for_loop_node *)state->s_base.s_node;
if (state->s_inline) {
/* we have just reached the end of the for iterable. */
if (!state->s_prev_node) {
/* for condition is empty. */
return IVY_ERR_BAD_SYNTAX;
}
state->s_iterable = state->s_prev_node;
state->s_prev_node = NULL;
loop->n_iterator = state->s_iterator;
loop->n_iterable = state->s_iterable;
loop->n_body = state->s_body;
state->s_iterator = NULL;
state->s_iterable = NULL;
state->s_body = NULL;
return IVY_OK;
}
if (!state->s_prev_node) {
/* for body is empty. */
return IVY_ERR_BAD_SYNTAX;
}
state->s_body = state->s_prev_node;
state->s_prev_node = NULL;
loop->n_iterator = state->s_iterator;
loop->n_iterable = state->s_iterable;
loop->n_body = state->s_body;
state->s_iterator = NULL;
state->s_iterable = NULL;
state->s_body = NULL;
return IVY_OK;
}
static struct token_parse_result parse_punct_terminator(
struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (!state->s_inline) {
/* only inline for loop can be ended with punctuation. */
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
enum ivy_status status = finalise_for_loop(state);
if (status != IVY_OK) {
return PARSE_RESULT(status, 0);
}
parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);
return PARSE_RESULT(IVY_OK, PARSE_REPEAT_TOKEN);
}
static struct token_parse_result parse_end(
struct ivy_parser *ctx, struct ivy_token *tok)
{
struct for_parser_state *state
= parser_get_state(ctx, struct for_parser_state);
if (state->s_inline) {
/* inline for loop must be terminated with punctuation. */
return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}
enum ivy_status status = finalise_for_loop(state);
if (status != IVY_OK) {
return PARSE_RESULT(status, 0);
}
parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);
return PARSE_RESULT(IVY_OK, 0);
}
static enum ivy_status add_child(
struct parser_state *parent, struct ivy_ast_node *child)
{
struct for_parser_state *state = (struct for_parser_state *)parent;
if (state->s_prev_node) {
return IVY_ERR_BAD_SYNTAX;
}
state->s_prev_node = child;
return IVY_OK;
}
static void collect_children(
struct ivy_ast_node *node, struct ivy_ast_node_iterator *iterator)
{
struct ivy_ast_for_loop_node *loop = (struct ivy_ast_for_loop_node *)node;
if (loop->n_iterator) {
ast_node_iterator_enqueue_node(iterator, node, loop->n_iterator);
}
if (loop->n_iterable) {
ast_node_iterator_enqueue_node(iterator, node, loop->n_iterable);
}
if (loop->n_body) {
ast_node_iterator_enqueue_node(iterator, node, loop->n_body);
}
}
struct ast_node_type for_loop_node_ops = {
.n_init_state = init_state,
.n_add_child = add_child,
.n_collect_children = collect_children,
.n_state_size = sizeof(struct for_parser_state),
.n_node_size = sizeof(struct ivy_ast_for_loop_node),
.n_keyword_parsers = {
KW_PARSER(FOR, parse_for),
KW_PARSER(IN, parse_in),
KW_PARSER(DO, parse_do),
KW_PARSER(END, parse_end),
},
.n_symbol_parsers = {
SYM_PARSER(DOT, parse_punct_terminator),
SYM_PARSER(COMMA, parse_punct_terminator),
SYM_PARSER(RIGHT_PAREN, parse_punct_terminator),
SYM_PARSER(BANG, parse_punct_terminator),
},
.n_expr_parser = {
.expr_begin = parse_expr_begin,
},
};