Repository Rules

Performance-critical iteration

This is a low-level library. Changes MUST NOT impose avoidable allocation or iteration overhead on user code.

Array traversal MUST use an indexed for loop (for (let index = 0; index < array.length; index++)).
for...of, for...in, iterator helpers, and generators MUST NOT be used in performance-sensitive library code.
Array higher-order methods that allocate or invoke callbacks—such as map, filter, reduce, flatMap, forEach, find, findIndex, and some—MUST NOT be used in library code.
A non-indexed traversal is allowed only when an indexed loop cannot implement the operation. The reason MUST be documented next to that code.
Avoid transient lookup arrays such as ["A", "B"].includes(value) in hot paths; use direct comparisons or switch.

Known properties of intermediate objects—including ColumnInfo, Column, ConstColumn, Col, rows, parameters, and canonical wire objects—MUST be initialized together when the object is created.
Optional known properties MUST be initialized to undefined rather than added later.
Dynamic property addition is allowed only for schema-defined record keys that cannot be known in advance.
When dynamic object keys must be enumerated, collect the keys once and traverse that key array with an indexed for loop.