tree-sitter/src/runtime/get_changed_ranges.c
2017-08-07 10:35:06 -07:00

345 lines
10 KiB
C

#include "runtime/get_changed_ranges.h"
#include "runtime/tree.h"
#include "runtime/language.h"
#include "runtime/error_costs.h"
#include <assert.h>
typedef Array(TSRange) RangeArray;
static void range_array_add(RangeArray *results, TSPoint start, TSPoint end) {
if (results->size > 0) {
TSRange *last_range = array_back(results);
if (point_lte(start, last_range->end)) {
last_range->end = end;
return;
}
}
if (point_lt(start, end)) {
TSRange range = { start, end };
array_push(results, range);
}
}
typedef struct {
TreePath path;
const TSLanguage *language;
unsigned visible_depth;
bool in_padding;
} Iterator;
static Iterator iterator_new(TreePath *path, Tree *tree, const TSLanguage *language) {
array_clear(path);
array_push(path, ((TreePathEntry){
.tree = tree,
.position = length_zero(),
.child_index = 0,
.structural_child_index = 0,
}));
return (Iterator) {
.path = *path,
.language = language,
.visible_depth = 1,
.in_padding = false,
};
}
static bool iterator_done(Iterator *self) {
return self->path.size == 0;
}
Length iterator_start_position(Iterator *self) {
TreePathEntry entry = *array_back(&self->path);
if (self->in_padding) {
return entry.position;
} else {
return length_add(entry.position, entry.tree->padding);
}
}
Length iterator_end_position(Iterator *self) {
TreePathEntry entry = *array_back(&self->path);
Length result = length_add(entry.position, entry.tree->padding);
if (self->in_padding) {
return result;
} else {
return length_add(result, entry.tree->size);
}
}
static bool iterator_tree_is_visible(const Iterator *self) {
TreePathEntry entry = *array_back(&self->path);
if (entry.tree->visible) return true;
if (self->path.size > 1) {
Tree *parent = self->path.contents[self->path.size - 2].tree;
const TSSymbol *alias_sequence = ts_language_alias_sequence(self->language, parent->alias_sequence_id);
return alias_sequence && alias_sequence[entry.structural_child_index] != 0;
}
return false;
}
static void iterator_get_visible_state(const Iterator *self, Tree **tree,
TSSymbol *alias_symbol, uint32_t *start_byte) {
uint32_t i = self->path.size - 1;
if (self->in_padding) {
while (self->path.contents[i].child_index == 0) i--;
}
for (; i + 1 > 0; i--) {
TreePathEntry entry = self->path.contents[i];
if (i > 0) {
Tree *parent = self->path.contents[i - 1].tree;
const TSSymbol *alias_sequence = ts_language_alias_sequence(
self->language,
parent->alias_sequence_id
);
if (alias_sequence) {
*alias_symbol = alias_sequence[entry.structural_child_index];
}
}
if (entry.tree->visible || *alias_symbol) {
*tree = entry.tree;
*start_byte = entry.position.bytes;
break;
}
}
}
static void iterator_ascend(Iterator *self) {
if (iterator_done(self)) return;
if (iterator_tree_is_visible(self) && !self->in_padding) self->visible_depth--;
if (array_back(&self->path)->child_index > 0) self->in_padding = false;
self->path.size--;
}
static bool iterator_descend(Iterator *self, uint32_t goal_position) {
if (self->in_padding) return false;
bool did_descend;
do {
did_descend = false;
TreePathEntry entry = *array_back(&self->path);
Length position = entry.position;
uint32_t structural_child_index = 0;
for (uint32_t i = 0; i < entry.tree->child_count; i++) {
Tree *child = entry.tree->children[i];
Length child_left = length_add(position, child->padding);
Length child_right = length_add(child_left, child->size);
if (child_right.bytes > goal_position) {
array_push(&self->path, ((TreePathEntry){
.tree = child,
.position = position,
.child_index = i,
.structural_child_index = structural_child_index,
}));
if (iterator_tree_is_visible(self)) {
if (child_left.bytes > goal_position) {
self->in_padding = true;
} else {
self->visible_depth++;
}
return true;
}
did_descend = true;
break;
}
position = child_right;
if (!child->extra) structural_child_index++;
}
} while (did_descend);
return false;
}
static void iterator_advance(Iterator *self) {
if (self->in_padding) {
self->in_padding = false;
if (iterator_tree_is_visible(self)) {
self->visible_depth++;
} else {
iterator_descend(self, 0);
}
return;
}
for (;;) {
if (iterator_tree_is_visible(self)) self->visible_depth--;
TreePathEntry entry = array_pop(&self->path);
if (iterator_done(self)) return;
Tree *parent = array_back(&self->path)->tree;
uint32_t child_index = entry.child_index + 1;
if (parent->child_count > child_index) {
Length position = length_add(entry.position, ts_tree_total_size(entry.tree));
uint32_t structural_child_index = entry.structural_child_index;
if (!entry.tree->extra) structural_child_index++;
Tree *next_child = parent->children[child_index];
array_push(&self->path, ((TreePathEntry){
.tree = next_child,
.position = position,
.child_index = child_index,
.structural_child_index = structural_child_index,
}));
if (iterator_tree_is_visible(self)) {
if (next_child->padding.bytes > 0) {
self->in_padding = true;
} else {
self->visible_depth++;
}
} else {
iterator_descend(self, 0);
}
break;
}
}
}
typedef enum {
IteratorDiffers,
IteratorMayDiffer,
IteratorMatches,
} IteratorComparison;
IteratorComparison iterator_compare(const Iterator *old_iter, const Iterator *new_iter) {
Tree *old_tree = NULL, *new_tree = NULL;
uint32_t old_start = 0, new_start = 0;
TSSymbol old_alias_symbol = 0, new_alias_symbol = 0;
iterator_get_visible_state(old_iter, &old_tree, &old_alias_symbol, &old_start);
iterator_get_visible_state(new_iter, &new_tree, &new_alias_symbol, &new_start);
assert(old_tree && new_tree);
if (old_alias_symbol == new_alias_symbol) {
if (old_start == new_start) {
if (!old_tree->has_changes &&
old_tree->symbol == new_tree->symbol &&
old_tree->symbol != ts_builtin_sym_error &&
old_tree->size.bytes == new_tree->size.bytes &&
old_tree->parse_state != TS_TREE_STATE_NONE &&
new_tree->parse_state != TS_TREE_STATE_NONE &&
(old_tree->parse_state == ERROR_STATE) ==
(new_tree->parse_state == ERROR_STATE)) {
return IteratorMatches;
}
}
if (old_tree->symbol == new_tree->symbol) {
return IteratorMayDiffer;
}
}
return IteratorDiffers;
}
// static inline void iterator_print_state(Iterator *self) {
// TreePathEntry entry = *array_back(&self->path);
// TSPoint start = iterator_start_position(self).extent;
// TSPoint end = iterator_end_position(self).extent;
// const char *name = ts_language_symbol_name(self->language, entry.tree->symbol);
// printf(
// "(%-25s %s\t depth:%u [%u, %u] - [%u, %u])",
// name, self->in_padding ? "(p)" : " ",
// self->visible_depth,
// start.row, start.column,
// end.row, end.column
// );
// }
unsigned ts_tree_get_changed_ranges(Tree *old_tree, Tree *new_tree,
TreePath *path1, TreePath *path2,
const TSLanguage *language, TSRange **ranges) {
RangeArray results = array_new();
Iterator old_iter = iterator_new(path1, old_tree, language);
Iterator new_iter = iterator_new(path2, new_tree, language);
Length position = iterator_start_position(&old_iter);
Length next_position = iterator_start_position(&new_iter);
if (position.bytes < next_position.bytes) {
range_array_add(&results, position.extent, next_position.extent);
position = next_position;
} else if (position.bytes > next_position.bytes) {
range_array_add(&results, next_position.extent, position.extent);
next_position = position;
}
do {
// printf("At [%-2u, %-2u] Compare ", position.extent.row, position.extent.column);
// iterator_print_state(&old_iter);
// printf("\tvs\t");
// iterator_print_state(&new_iter);
// puts("");
bool is_changed = false;
switch (iterator_compare(&old_iter, &new_iter)) {
case IteratorMatches:
next_position = iterator_end_position(&old_iter);
break;
case IteratorMayDiffer:
if (iterator_descend(&old_iter, position.bytes)) {
if (!iterator_descend(&new_iter, position.bytes)) {
is_changed = true;
next_position = iterator_end_position(&old_iter);
}
} else if (iterator_descend(&new_iter, position.bytes)) {
is_changed = true;
next_position = iterator_end_position(&new_iter);
} else {
next_position = length_min(
iterator_end_position(&old_iter),
iterator_end_position(&new_iter)
);
}
break;
case IteratorDiffers:
is_changed = true;
next_position = length_min(
iterator_end_position(&old_iter),
iterator_end_position(&new_iter)
);
break;
}
while (
!iterator_done(&old_iter) &&
iterator_end_position(&old_iter).bytes <= next_position.bytes
) iterator_advance(&old_iter);
while (
!iterator_done(&new_iter) &&
iterator_end_position(&new_iter).bytes <= next_position.bytes
) iterator_advance(&new_iter);
while (old_iter.visible_depth > new_iter.visible_depth) iterator_ascend(&old_iter);
while (new_iter.visible_depth > old_iter.visible_depth) iterator_ascend(&new_iter);
if (is_changed) {
// printf(
// " change: [[%u, %u] - [%u, %u]]\n",
// position.extent.row, position.extent.column,
// next_position.extent.row, next_position.extent.column
// );
range_array_add(&results, position.extent, next_position.extent);
}
position = next_position;
} while (!iterator_done(&old_iter) && !iterator_done(&new_iter));
*path1 = old_iter.path;
*path2 = new_iter.path;
*ranges = results.contents;
return results.size;
}