@sema-agent/core/dist/core/surrogate-safe-slice.js

Stateless, task-oriented AI agent core

export const isHighSurrogate = (c) => c >= 0xd800 && c <= 0xdbff;
export const isLowSurrogate = (c) => c >= 0xdc00 && c <= 0xdfff;
export function sliceHeadSafe(s, keep) {
    if (keep <= 0)
        return "";
    if (s.length <= keep)
        return s;
    const head = s.slice(0, keep);
    return keep > 0 && isHighSurrogate(head.charCodeAt(keep - 1)) ? head.slice(0, -1) : head;
}
export function sliceTailSafe(s, keep) {
    if (keep <= 0)
        return "";
    if (s.length <= keep)
        return s;
    const tail = s.slice(-keep);
    return keep > 0 && isLowSurrogate(tail.charCodeAt(0)) ? tail.slice(1) : tail;
}