Reduce along all possible parse-stack paths

src/runtime/tree_vector.h

@@ -0,0 +1,59 @@
+#ifndef RUNTIME_TREE_VECTOR_H_
+#define RUNTIME_TREE_VECTOR_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <string.h>
+#include "./tree.h"
+
+typedef struct {
+  TSTree **contents;
+  size_t capacity;
+  size_t size;
+} TreeVector;
+
+static inline TreeVector tree_vector_new(size_t size) {
+  return (TreeVector) {
+    .contents = malloc(size * sizeof(TSTree *)),
+    .capacity = size,
+    .size = 0,
+  };
+}
+
+static inline void tree_vector_push(TreeVector *this, TSTree *tree) {
+  if (this->size == this->capacity) {
+    this->capacity += 4;
+    this->contents = realloc(this->contents, this->capacity * sizeof(TSTree *));
+  }
+  this->contents[this->size++] = tree;
+}
+
+static inline void tree_vector_reverse(TreeVector *this) {
+  TSTree *swap;
+  size_t limit = this->size / 2;
+  for (size_t i = 0; i < limit; i++) {
+    swap = this->contents[i];
+    this->contents[i] = this->contents[this->size - 1 - i];
+    this->contents[this->size - 1 - i] = swap;
+  }
+}
+
+static inline TreeVector tree_vector_copy(TreeVector *this) {
+  return (TreeVector) {
+    .contents = memcpy(
+      malloc(this->capacity * sizeof(TSTree *)),
+      this->contents,
+      this->size * sizeof(TSTree *)
+    ),
+    .capacity = this->capacity,
+    .size = this->size,
+  };
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // RUNTIME_TREE_VECTOR_H_