import re

_SEMVER_RE = re.compile(
    r'^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)'
    r'(?:-((?:0|[1-9]\d*|\d*[A-Za-z-][0-9A-Za-z-]*)(?:\.(?:0|[1-9]\d*|\d*[A-Za-z-][0-9A-Za-z-]*))*))?'
    r'(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$'
)


def parse_semver(s):
    if not isinstance(s, str):
        return None
    m = _SEMVER_RE.match(s)
    if not m:
        return None
    return {
        "major": int(m.group(1)),
        "minor": int(m.group(2)),
        "patch": int(m.group(3)),
        "prerelease": m.group(4),
        "build": m.group(5),
    }