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-rw-r--r--src/tree_sitter/stack.c846
1 files changed, 846 insertions, 0 deletions
diff --git a/src/tree_sitter/stack.c b/src/tree_sitter/stack.c
new file mode 100644
index 0000000000..3e842c99c3
--- /dev/null
+++ b/src/tree_sitter/stack.c
@@ -0,0 +1,846 @@
+#include "./alloc.h"
+#include "./language.h"
+#include "./subtree.h"
+#include "./array.h"
+#include "./stack.h"
+#include "./length.h"
+#include <assert.h>
+#include <stdio.h>
+
+#define MAX_LINK_COUNT 8
+#define MAX_NODE_POOL_SIZE 50
+#define MAX_ITERATOR_COUNT 64
+
+#ifdef _WIN32
+#define inline __forceinline
+#else
+#define inline static inline __attribute__((always_inline))
+#endif
+
+typedef struct StackNode StackNode;
+
+typedef struct {
+ StackNode *node;
+ Subtree subtree;
+ bool is_pending;
+} StackLink;
+
+struct StackNode {
+ TSStateId state;
+ Length position;
+ StackLink links[MAX_LINK_COUNT];
+ short unsigned int link_count;
+ uint32_t ref_count;
+ unsigned error_cost;
+ unsigned node_count;
+ int dynamic_precedence;
+};
+
+typedef struct {
+ StackNode *node;
+ SubtreeArray subtrees;
+ uint32_t subtree_count;
+ bool is_pending;
+} StackIterator;
+
+typedef struct {
+ void *payload;
+ StackIterateCallback callback;
+} StackIterateSession;
+
+typedef Array(StackNode *) StackNodeArray;
+
+typedef enum {
+ StackStatusActive,
+ StackStatusPaused,
+ StackStatusHalted,
+} StackStatus;
+
+typedef struct {
+ StackNode *node;
+ Subtree last_external_token;
+ StackSummary *summary;
+ unsigned node_count_at_last_error;
+ TSSymbol lookahead_when_paused;
+ StackStatus status;
+} StackHead;
+
+struct Stack {
+ Array(StackHead) heads;
+ StackSliceArray slices;
+ Array(StackIterator) iterators;
+ StackNodeArray node_pool;
+ StackNode *base_node;
+ SubtreePool *subtree_pool;
+};
+
+typedef unsigned StackAction;
+enum {
+ StackActionNone,
+ StackActionStop = 1,
+ StackActionPop = 2,
+};
+
+typedef StackAction (*StackCallback)(void *, const StackIterator *);
+
+static void stack_node_retain(StackNode *self) {
+ if (!self)
+ return;
+ assert(self->ref_count > 0);
+ self->ref_count++;
+ assert(self->ref_count != 0);
+}
+
+static void stack_node_release(StackNode *self, StackNodeArray *pool, SubtreePool *subtree_pool) {
+recur:
+ assert(self->ref_count != 0);
+ self->ref_count--;
+ if (self->ref_count > 0) return;
+
+ StackNode *first_predecessor = NULL;
+ if (self->link_count > 0) {
+ for (unsigned i = self->link_count - 1; i > 0; i--) {
+ StackLink link = self->links[i];
+ if (link.subtree.ptr) ts_subtree_release(subtree_pool, link.subtree);
+ stack_node_release(link.node, pool, subtree_pool);
+ }
+ StackLink link = self->links[0];
+ if (link.subtree.ptr) ts_subtree_release(subtree_pool, link.subtree);
+ first_predecessor = self->links[0].node;
+ }
+
+ if (pool->size < MAX_NODE_POOL_SIZE) {
+ array_push(pool, self);
+ } else {
+ ts_free(self);
+ }
+
+ if (first_predecessor) {
+ self = first_predecessor;
+ goto recur;
+ }
+}
+
+static StackNode *stack_node_new(StackNode *previous_node, Subtree subtree,
+ bool is_pending, TSStateId state, StackNodeArray *pool) {
+ StackNode *node = pool->size > 0 ?
+ array_pop(pool) :
+ ts_malloc(sizeof(StackNode));
+ *node = (StackNode){.ref_count = 1, .link_count = 0, .state = state};
+
+ if (previous_node) {
+ node->link_count = 1;
+ node->links[0] = (StackLink){
+ .node = previous_node,
+ .subtree = subtree,
+ .is_pending = is_pending,
+ };
+
+ node->position = previous_node->position;
+ node->error_cost = previous_node->error_cost;
+ node->dynamic_precedence = previous_node->dynamic_precedence;
+ node->node_count = previous_node->node_count;
+
+ if (subtree.ptr) {
+ node->error_cost += ts_subtree_error_cost(subtree);
+ node->position = length_add(node->position, ts_subtree_total_size(subtree));
+ node->node_count += ts_subtree_node_count(subtree);
+ node->dynamic_precedence += ts_subtree_dynamic_precedence(subtree);
+ }
+ } else {
+ node->position = length_zero();
+ node->error_cost = 0;
+ }
+
+ return node;
+}
+
+static bool stack__subtree_is_equivalent(Subtree left, Subtree right) {
+ return
+ left.ptr == right.ptr ||
+ (left.ptr && right.ptr &&
+ ts_subtree_symbol(left) == ts_subtree_symbol(right) &&
+ ((ts_subtree_error_cost(left) > 0 && ts_subtree_error_cost(right) > 0) ||
+ (ts_subtree_padding(left).bytes == ts_subtree_padding(right).bytes &&
+ ts_subtree_size(left).bytes == ts_subtree_size(right).bytes &&
+ ts_subtree_child_count(left) == ts_subtree_child_count(right) &&
+ ts_subtree_extra(left) == ts_subtree_extra(right) &&
+ ts_subtree_external_scanner_state_eq(left, right))));
+}
+
+static void stack_node_add_link(StackNode *self, StackLink link, SubtreePool *subtree_pool) {
+ if (link.node == self) return;
+
+ for (int i = 0; i < self->link_count; i++) {
+ StackLink *existing_link = &self->links[i];
+ if (stack__subtree_is_equivalent(existing_link->subtree, link.subtree)) {
+ // In general, we preserve ambiguities until they are removed from the stack
+ // during a pop operation where multiple paths lead to the same node. But in
+ // the special case where two links directly connect the same pair of nodes,
+ // we can safely remove the ambiguity ahead of time without changing behavior.
+ if (existing_link->node == link.node) {
+ if (
+ ts_subtree_dynamic_precedence(link.subtree) >
+ ts_subtree_dynamic_precedence(existing_link->subtree)
+ ) {
+ ts_subtree_retain(link.subtree);
+ ts_subtree_release(subtree_pool, existing_link->subtree);
+ existing_link->subtree = link.subtree;
+ self->dynamic_precedence =
+ link.node->dynamic_precedence + ts_subtree_dynamic_precedence(link.subtree);
+ }
+ return;
+ }
+
+ // If the previous nodes are mergeable, merge them recursively.
+ if (existing_link->node->state == link.node->state &&
+ existing_link->node->position.bytes == link.node->position.bytes) {
+ for (int j = 0; j < link.node->link_count; j++) {
+ stack_node_add_link(existing_link->node, link.node->links[j], subtree_pool);
+ }
+ int32_t dynamic_precedence = link.node->dynamic_precedence;
+ if (link.subtree.ptr) {
+ dynamic_precedence += ts_subtree_dynamic_precedence(link.subtree);
+ }
+ if (dynamic_precedence > self->dynamic_precedence) {
+ self->dynamic_precedence = dynamic_precedence;
+ }
+ return;
+ }
+ }
+ }
+
+ if (self->link_count == MAX_LINK_COUNT) return;
+
+ stack_node_retain(link.node);
+ unsigned node_count = link.node->node_count;
+ int dynamic_precedence = link.node->dynamic_precedence;
+ self->links[self->link_count++] = link;
+
+ if (link.subtree.ptr) {
+ ts_subtree_retain(link.subtree);
+ node_count += ts_subtree_node_count(link.subtree);
+ dynamic_precedence += ts_subtree_dynamic_precedence(link.subtree);
+ }
+
+ if (node_count > self->node_count) self->node_count = node_count;
+ if (dynamic_precedence > self->dynamic_precedence) self->dynamic_precedence = dynamic_precedence;
+}
+
+static void stack_head_delete(StackHead *self, StackNodeArray *pool, SubtreePool *subtree_pool) {
+ if (self->node) {
+ if (self->last_external_token.ptr) {
+ ts_subtree_release(subtree_pool, self->last_external_token);
+ }
+ if (self->summary) {
+ array_delete(self->summary);
+ ts_free(self->summary);
+ }
+ stack_node_release(self->node, pool, subtree_pool);
+ }
+}
+
+static StackVersion ts_stack__add_version(Stack *self, StackVersion original_version,
+ StackNode *node) {
+ StackHead head = {
+ .node = node,
+ .node_count_at_last_error = self->heads.contents[original_version].node_count_at_last_error,
+ .last_external_token = self->heads.contents[original_version].last_external_token,
+ .status = StackStatusActive,
+ .lookahead_when_paused = 0,
+ };
+ array_push(&self->heads, head);
+ stack_node_retain(node);
+ if (head.last_external_token.ptr) ts_subtree_retain(head.last_external_token);
+ return (StackVersion)(self->heads.size - 1);
+}
+
+static void ts_stack__add_slice(Stack *self, StackVersion original_version,
+ StackNode *node, SubtreeArray *subtrees) {
+ for (uint32_t i = self->slices.size - 1; i + 1 > 0; i--) {
+ StackVersion version = self->slices.contents[i].version;
+ if (self->heads.contents[version].node == node) {
+ StackSlice slice = {*subtrees, version};
+ array_insert(&self->slices, i + 1, slice);
+ return;
+ }
+ }
+
+ StackVersion version = ts_stack__add_version(self, original_version, node);
+ StackSlice slice = { *subtrees, version };
+ array_push(&self->slices, slice);
+}
+
+inline StackSliceArray stack__iter(Stack *self, StackVersion version,
+ StackCallback callback, void *payload,
+ int goal_subtree_count) {
+ array_clear(&self->slices);
+ array_clear(&self->iterators);
+
+ StackHead *head = array_get(&self->heads, version);
+ StackIterator iterator = {
+ .node = head->node,
+ .subtrees = array_new(),
+ .subtree_count = 0,
+ .is_pending = true,
+ };
+
+ bool include_subtrees = false;
+ if (goal_subtree_count >= 0) {
+ include_subtrees = true;
+ array_reserve(&iterator.subtrees, goal_subtree_count);
+ }
+
+ array_push(&self->iterators, iterator);
+
+ while (self->iterators.size > 0) {
+ for (uint32_t i = 0, size = self->iterators.size; i < size; i++) {
+ StackIterator *iterator = &self->iterators.contents[i];
+ StackNode *node = iterator->node;
+
+ StackAction action = callback(payload, iterator);
+ bool should_pop = action & StackActionPop;
+ bool should_stop = action & StackActionStop || node->link_count == 0;
+
+ if (should_pop) {
+ SubtreeArray subtrees = iterator->subtrees;
+ if (!should_stop)
+ ts_subtree_array_copy(subtrees, &subtrees);
+ ts_subtree_array_reverse(&subtrees);
+ ts_stack__add_slice(
+ self,
+ version,
+ node,
+ &subtrees
+ );
+ }
+
+ if (should_stop) {
+ if (!should_pop)
+ ts_subtree_array_delete(self->subtree_pool, &iterator->subtrees);
+ array_erase(&self->iterators, i);
+ i--, size--;
+ continue;
+ }
+
+ for (uint32_t j = 1; j <= node->link_count; j++) {
+ StackIterator *next_iterator;
+ StackLink link;
+ if (j == node->link_count) {
+ link = node->links[0];
+ next_iterator = &self->iterators.contents[i];
+ } else {
+ if (self->iterators.size >= MAX_ITERATOR_COUNT) continue;
+ link = node->links[j];
+ StackIterator current_iterator = self->iterators.contents[i];
+ array_push(&self->iterators, current_iterator);
+ next_iterator = array_back(&self->iterators);
+ ts_subtree_array_copy(next_iterator->subtrees, &next_iterator->subtrees);
+ }
+
+ next_iterator->node = link.node;
+ if (link.subtree.ptr) {
+ if (include_subtrees) {
+ array_push(&next_iterator->subtrees, link.subtree);
+ ts_subtree_retain(link.subtree);
+ }
+
+ if (!ts_subtree_extra(link.subtree)) {
+ next_iterator->subtree_count++;
+ if (!link.is_pending) {
+ next_iterator->is_pending = false;
+ }
+ }
+ } else {
+ next_iterator->subtree_count++;
+ next_iterator->is_pending = false;
+ }
+ }
+ }
+ }
+
+ return self->slices;
+}
+
+Stack *ts_stack_new(SubtreePool *subtree_pool) {
+ Stack *self = ts_calloc(1, sizeof(Stack));
+
+ array_init(&self->heads);
+ array_init(&self->slices);
+ array_init(&self->iterators);
+ array_init(&self->node_pool);
+ array_reserve(&self->heads, 4);
+ array_reserve(&self->slices, 4);
+ array_reserve(&self->iterators, 4);
+ array_reserve(&self->node_pool, MAX_NODE_POOL_SIZE);
+
+ self->subtree_pool = subtree_pool;
+ self->base_node = stack_node_new(NULL, NULL_SUBTREE, false, 1, &self->node_pool);
+ ts_stack_clear(self);
+
+ return self;
+}
+
+void ts_stack_delete(Stack *self) {
+ if (self->slices.contents)
+ array_delete(&self->slices);
+ if (self->iterators.contents)
+ array_delete(&self->iterators);
+ stack_node_release(self->base_node, &self->node_pool, self->subtree_pool);
+ for (uint32_t i = 0; i < self->heads.size; i++) {
+ stack_head_delete(&self->heads.contents[i], &self->node_pool, self->subtree_pool);
+ }
+ array_clear(&self->heads);
+ if (self->node_pool.contents) {
+ for (uint32_t i = 0; i < self->node_pool.size; i++)
+ ts_free(self->node_pool.contents[i]);
+ array_delete(&self->node_pool);
+ }
+ array_delete(&self->heads);
+ ts_free(self);
+}
+
+uint32_t ts_stack_version_count(const Stack *self) {
+ return self->heads.size;
+}
+
+TSStateId ts_stack_state(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->node->state;
+}
+
+Length ts_stack_position(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->node->position;
+}
+
+Subtree ts_stack_last_external_token(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->last_external_token;
+}
+
+void ts_stack_set_last_external_token(Stack *self, StackVersion version, Subtree token) {
+ StackHead *head = array_get(&self->heads, version);
+ if (token.ptr) ts_subtree_retain(token);
+ if (head->last_external_token.ptr) ts_subtree_release(self->subtree_pool, head->last_external_token);
+ head->last_external_token = token;
+}
+
+unsigned ts_stack_error_cost(const Stack *self, StackVersion version) {
+ StackHead *head = array_get(&self->heads, version);
+ unsigned result = head->node->error_cost;
+ if (
+ head->status == StackStatusPaused ||
+ (head->node->state == ERROR_STATE && !head->node->links[0].subtree.ptr)) {
+ result += ERROR_COST_PER_RECOVERY;
+ }
+ return result;
+}
+
+unsigned ts_stack_node_count_since_error(const Stack *self, StackVersion version) {
+ StackHead *head = array_get(&self->heads, version);
+ if (head->node->node_count < head->node_count_at_last_error) {
+ head->node_count_at_last_error = head->node->node_count;
+ }
+ return head->node->node_count - head->node_count_at_last_error;
+}
+
+void ts_stack_push(Stack *self, StackVersion version, Subtree subtree,
+ bool pending, TSStateId state) {
+ StackHead *head = array_get(&self->heads, version);
+ StackNode *new_node = stack_node_new(head->node, subtree, pending, state, &self->node_pool);
+ if (!subtree.ptr) head->node_count_at_last_error = new_node->node_count;
+ head->node = new_node;
+}
+
+inline StackAction iterate_callback(void *payload, const StackIterator *iterator) {
+ StackIterateSession *session = payload;
+ session->callback(
+ session->payload,
+ iterator->node->state,
+ iterator->subtree_count
+ );
+ return StackActionNone;
+}
+
+void ts_stack_iterate(Stack *self, StackVersion version,
+ StackIterateCallback callback, void *payload) {
+ StackIterateSession session = {payload, callback};
+ stack__iter(self, version, iterate_callback, &session, -1);
+}
+
+inline StackAction pop_count_callback(void *payload, const StackIterator *iterator) {
+ unsigned *goal_subtree_count = payload;
+ if (iterator->subtree_count == *goal_subtree_count) {
+ return StackActionPop | StackActionStop;
+ } else {
+ return StackActionNone;
+ }
+}
+
+StackSliceArray ts_stack_pop_count(Stack *self, StackVersion version, uint32_t count) {
+ return stack__iter(self, version, pop_count_callback, &count, count);
+}
+
+inline StackAction pop_pending_callback(void *payload, const StackIterator *iterator) {
+ if (iterator->subtree_count >= 1) {
+ if (iterator->is_pending) {
+ return StackActionPop | StackActionStop;
+ } else {
+ return StackActionStop;
+ }
+ } else {
+ return StackActionNone;
+ }
+}
+
+StackSliceArray ts_stack_pop_pending(Stack *self, StackVersion version) {
+ StackSliceArray pop = stack__iter(self, version, pop_pending_callback, NULL, 0);
+ if (pop.size > 0) {
+ ts_stack_renumber_version(self, pop.contents[0].version, version);
+ pop.contents[0].version = version;
+ }
+ return pop;
+}
+
+inline StackAction pop_error_callback(void *payload, const StackIterator *iterator) {
+ if (iterator->subtrees.size > 0) {
+ bool *found_error = payload;
+ if (!*found_error && ts_subtree_is_error(iterator->subtrees.contents[0])) {
+ *found_error = true;
+ return StackActionPop | StackActionStop;
+ } else {
+ return StackActionStop;
+ }
+ } else {
+ return StackActionNone;
+ }
+}
+
+SubtreeArray ts_stack_pop_error(Stack *self, StackVersion version) {
+ StackNode *node = array_get(&self->heads, version)->node;
+ for (unsigned i = 0; i < node->link_count; i++) {
+ if (node->links[i].subtree.ptr && ts_subtree_is_error(node->links[i].subtree)) {
+ bool found_error = false;
+ StackSliceArray pop = stack__iter(self, version, pop_error_callback, &found_error, 1);
+ if (pop.size > 0) {
+ assert(pop.size == 1);
+ ts_stack_renumber_version(self, pop.contents[0].version, version);
+ return pop.contents[0].subtrees;
+ }
+ break;
+ }
+ }
+ return (SubtreeArray){.size = 0};
+}
+
+inline StackAction pop_all_callback(void *payload, const StackIterator *iterator) {
+ return iterator->node->link_count == 0 ? StackActionPop : StackActionNone;
+}
+
+StackSliceArray ts_stack_pop_all(Stack *self, StackVersion version) {
+ return stack__iter(self, version, pop_all_callback, NULL, 0);
+}
+
+typedef struct {
+ StackSummary *summary;
+ unsigned max_depth;
+} SummarizeStackSession;
+
+inline StackAction summarize_stack_callback(void *payload, const StackIterator *iterator) {
+ SummarizeStackSession *session = payload;
+ TSStateId state = iterator->node->state;
+ unsigned depth = iterator->subtree_count;
+ if (depth > session->max_depth) return StackActionStop;
+ for (unsigned i = session->summary->size - 1; i + 1 > 0; i--) {
+ StackSummaryEntry entry = session->summary->contents[i];
+ if (entry.depth < depth) break;
+ if (entry.depth == depth && entry.state == state) return StackActionNone;
+ }
+ array_push(session->summary, ((StackSummaryEntry){
+ .position = iterator->node->position,
+ .depth = depth,
+ .state = state,
+ }));
+ return StackActionNone;
+}
+
+void ts_stack_record_summary(Stack *self, StackVersion version, unsigned max_depth) {
+ SummarizeStackSession session = {
+ .summary = ts_malloc(sizeof(StackSummary)),
+ .max_depth = max_depth
+ };
+ array_init(session.summary);
+ stack__iter(self, version, summarize_stack_callback, &session, -1);
+ self->heads.contents[version].summary = session.summary;
+}
+
+StackSummary *ts_stack_get_summary(Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->summary;
+}
+
+int ts_stack_dynamic_precedence(Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->node->dynamic_precedence;
+}
+
+bool ts_stack_has_advanced_since_error(const Stack *self, StackVersion version) {
+ const StackHead *head = array_get(&self->heads, version);
+ const StackNode *node = head->node;
+ if (node->error_cost == 0) return true;
+ while (node) {
+ if (node->link_count > 0) {
+ Subtree subtree = node->links[0].subtree;
+ if (subtree.ptr) {
+ if (ts_subtree_total_bytes(subtree) > 0) {
+ return true;
+ } else if (
+ node->node_count > head->node_count_at_last_error &&
+ ts_subtree_error_cost(subtree) == 0
+ ) {
+ node = node->links[0].node;
+ continue;
+ }
+ }
+ }
+ break;
+ }
+ return false;
+}
+
+void ts_stack_remove_version(Stack *self, StackVersion version) {
+ stack_head_delete(array_get(&self->heads, version), &self->node_pool, self->subtree_pool);
+ array_erase(&self->heads, version);
+}
+
+void ts_stack_renumber_version(Stack *self, StackVersion v1, StackVersion v2) {
+ if (v1 == v2) return;
+ assert(v2 < v1);
+ assert((uint32_t)v1 < self->heads.size);
+ StackHead *source_head = &self->heads.contents[v1];
+ StackHead *target_head = &self->heads.contents[v2];
+ if (target_head->summary && !source_head->summary) {
+ source_head->summary = target_head->summary;
+ target_head->summary = NULL;
+ }
+ stack_head_delete(target_head, &self->node_pool, self->subtree_pool);
+ *target_head = *source_head;
+ array_erase(&self->heads, v1);
+}
+
+void ts_stack_swap_versions(Stack *self, StackVersion v1, StackVersion v2) {
+ StackHead temporary_head = self->heads.contents[v1];
+ self->heads.contents[v1] = self->heads.contents[v2];
+ self->heads.contents[v2] = temporary_head;
+}
+
+StackVersion ts_stack_copy_version(Stack *self, StackVersion version) {
+ assert(version < self->heads.size);
+ array_push(&self->heads, self->heads.contents[version]);
+ StackHead *head = array_back(&self->heads);
+ stack_node_retain(head->node);
+ if (head->last_external_token.ptr) ts_subtree_retain(head->last_external_token);
+ head->summary = NULL;
+ return self->heads.size - 1;
+}
+
+bool ts_stack_merge(Stack *self, StackVersion version1, StackVersion version2) {
+ if (!ts_stack_can_merge(self, version1, version2)) return false;
+ StackHead *head1 = &self->heads.contents[version1];
+ StackHead *head2 = &self->heads.contents[version2];
+ for (uint32_t i = 0; i < head2->node->link_count; i++) {
+ stack_node_add_link(head1->node, head2->node->links[i], self->subtree_pool);
+ }
+ if (head1->node->state == ERROR_STATE) {
+ head1->node_count_at_last_error = head1->node->node_count;
+ }
+ ts_stack_remove_version(self, version2);
+ return true;
+}
+
+bool ts_stack_can_merge(Stack *self, StackVersion version1, StackVersion version2) {
+ StackHead *head1 = &self->heads.contents[version1];
+ StackHead *head2 = &self->heads.contents[version2];
+ return
+ head1->status == StackStatusActive &&
+ head2->status == StackStatusActive &&
+ head1->node->state == head2->node->state &&
+ head1->node->position.bytes == head2->node->position.bytes &&
+ head1->node->error_cost == head2->node->error_cost &&
+ ts_subtree_external_scanner_state_eq(head1->last_external_token, head2->last_external_token);
+}
+
+void ts_stack_halt(Stack *self, StackVersion version) {
+ array_get(&self->heads, version)->status = StackStatusHalted;
+}
+
+void ts_stack_pause(Stack *self, StackVersion version, TSSymbol lookahead) {
+ StackHead *head = array_get(&self->heads, version);
+ head->status = StackStatusPaused;
+ head->lookahead_when_paused = lookahead;
+ head->node_count_at_last_error = head->node->node_count;
+}
+
+bool ts_stack_is_active(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->status == StackStatusActive;
+}
+
+bool ts_stack_is_halted(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->status == StackStatusHalted;
+}
+
+bool ts_stack_is_paused(const Stack *self, StackVersion version) {
+ return array_get(&self->heads, version)->status == StackStatusPaused;
+}
+
+TSSymbol ts_stack_resume(Stack *self, StackVersion version) {
+ StackHead *head = array_get(&self->heads, version);
+ assert(head->status == StackStatusPaused);
+ TSSymbol result = head->lookahead_when_paused;
+ head->status = StackStatusActive;
+ head->lookahead_when_paused = 0;
+ return result;
+}
+
+void ts_stack_clear(Stack *self) {
+ stack_node_retain(self->base_node);
+ for (uint32_t i = 0; i < self->heads.size; i++) {
+ stack_head_delete(&self->heads.contents[i], &self->node_pool, self->subtree_pool);
+ }
+ array_clear(&self->heads);
+ array_push(&self->heads, ((StackHead){
+ .node = self->base_node,
+ .last_external_token = NULL_SUBTREE,
+ .status = StackStatusActive,
+ .lookahead_when_paused = 0,
+ }));
+}
+
+bool ts_stack_print_dot_graph(Stack *self, const TSLanguage *language, FILE *f) {
+ array_reserve(&self->iterators, 32);
+ bool was_recording_allocations = ts_toggle_allocation_recording(false);
+ if (!f) f = stderr;
+
+ fprintf(f, "digraph stack {\n");
+ fprintf(f, "rankdir=\"RL\";\n");
+ fprintf(f, "edge [arrowhead=none]\n");
+
+ Array(StackNode *) visited_nodes = array_new();
+
+ array_clear(&self->iterators);
+ for (uint32_t i = 0; i < self->heads.size; i++) {
+ StackHead *head = &self->heads.contents[i];
+ if (head->status == StackStatusHalted) continue;
+
+ fprintf(f, "node_head_%u [shape=none, label=\"\"]\n", i);
+ fprintf(f, "node_head_%u -> node_%p [", i, head->node);
+
+ if (head->status == StackStatusPaused) {
+ fprintf(f, "color=red ");
+ }
+ fprintf(f,
+ "label=%u, fontcolor=blue, weight=10000, labeltooltip=\"node_count: %u\nerror_cost: %u",
+ i,
+ ts_stack_node_count_since_error(self, i),
+ ts_stack_error_cost(self, i)
+ );
+
+ if (head->last_external_token.ptr) {
+ const ExternalScannerState *state = &head->last_external_token.ptr->external_scanner_state;
+ const char *data = ts_external_scanner_state_data(state);
+ fprintf(f, "\nexternal_scanner_state:");
+ for (uint32_t j = 0; j < state->length; j++) fprintf(f, " %2X", data[j]);
+ }
+
+ fprintf(f, "\"]\n");
+ array_push(&self->iterators, ((StackIterator){.node = head->node }));
+ }
+
+ bool all_iterators_done = false;
+ while (!all_iterators_done) {
+ all_iterators_done = true;
+
+ for (uint32_t i = 0; i < self->iterators.size; i++) {
+ StackIterator iterator = self->iterators.contents[i];
+ StackNode *node = iterator.node;
+
+ for (uint32_t j = 0; j < visited_nodes.size; j++) {
+ if (visited_nodes.contents[j] == node) {
+ node = NULL;
+ break;
+ }
+ }
+
+ if (!node) continue;
+ all_iterators_done = false;
+
+ fprintf(f, "node_%p [", node);
+ if (node->state == ERROR_STATE) {
+ fprintf(f, "label=\"?\"");
+ } else if (
+ node->link_count == 1 &&
+ node->links[0].subtree.ptr &&
+ ts_subtree_extra(node->links[0].subtree)
+ ) {
+ fprintf(f, "shape=point margin=0 label=\"\"");
+ } else {
+ fprintf(f, "label=\"%d\"", node->state);
+ }
+
+ fprintf(
+ f,
+ " tooltip=\"position: %u,%u\nnode_count:%u\nerror_cost: %u\ndynamic_precedence: %d\"];\n",
+ node->position.extent.row + 1,
+ node->position.extent.column,
+ node->node_count,
+ node->error_cost,
+ node->dynamic_precedence
+ );
+
+ for (int j = 0; j < node->link_count; j++) {
+ StackLink link = node->links[j];
+ fprintf(f, "node_%p -> node_%p [", node, link.node);
+ if (link.is_pending) fprintf(f, "style=dashed ");
+ if (link.subtree.ptr && ts_subtree_extra(link.subtree)) fprintf(f, "fontcolor=gray ");
+
+ if (!link.subtree.ptr) {
+ fprintf(f, "color=red");
+ } else {
+ fprintf(f, "label=\"");
+ bool quoted = ts_subtree_visible(link.subtree) && !ts_subtree_named(link.subtree);
+ if (quoted) fprintf(f, "'");
+ const char *name = ts_language_symbol_name(language, ts_subtree_symbol(link.subtree));
+ for (const char *c = name; *c; c++) {
+ if (*c == '\"' || *c == '\\') fprintf(f, "\\");
+ fprintf(f, "%c", *c);
+ }
+ if (quoted) fprintf(f, "'");
+ fprintf(f, "\"");
+ fprintf(
+ f,
+ "labeltooltip=\"error_cost: %u\ndynamic_precedence: %u\"",
+ ts_subtree_error_cost(link.subtree),
+ ts_subtree_dynamic_precedence(link.subtree)
+ );
+ }
+
+ fprintf(f, "];\n");
+
+ StackIterator *next_iterator;
+ if (j == 0) {
+ next_iterator = &self->iterators.contents[i];
+ } else {
+ array_push(&self->iterators, iterator);
+ next_iterator = array_back(&self->iterators);
+ }
+ next_iterator->node = link.node;
+ }
+
+ array_push(&visited_nodes, node);
+ }
+ }
+
+ fprintf(f, "}\n");
+
+ array_delete(&visited_nodes);
+ ts_toggle_allocation_recording(was_recording_allocations);
+ return true;
+}
+
+#undef inline