Function build_deopts

scripts/generate_opcode_metadata.py:75–118

(contents: str)

def build_deopts(contents: str) -> dict[str, list[str]]:
    raw_body = re.search(
        r"fn deopt\(self\) -> Option<Self>(.*)", contents, re.DOTALL
    ).group(1)
    body = "\n".join(
        itertools.takewhile(
            lambda l: not l.startswith("_ =>"),  # Take until reaching fallback
            filter(
                lambda l: (
                    not l.startswith(
                        ("//", "Some(match")
                    )  # Skip comments or start of match
                ),
                map(str.strip, raw_body.splitlines()),
            ),
        )
    ).removeprefix("{")

    depth = 0
    arms = []
    buf = []
    for char in body:
        if char == "{":
            depth += 1
        elif char == "}":
            depth -= 1

        if depth == 0 and (char in ("}", ",")):
            arm = "".join(buf).strip()
            arms.append(arm)
            buf = []
        else:
            buf.append(char)

    # last arm
    arms.append("".join(buf))
    arms = [arm for arm in arms if arm]

    deopts = {}
    for arm in arms:
        *specialized, deopt = map(to_pascal_case, re.findall(r"Self::(\w*)\b", arm))
        deopts[deopt] = specialized

    return deopts


contents = BYTECODE_FILE.read_text(encoding="utf-8")