Utilities

This page documents the utility functions and classes used in LeanInteract.

Installation and Cache Management

install_lean

install_lean()

Install Lean 4 version manager (elan) in a cross-platform compatible way. Uses platform-specific methods for Windows, macOS, and Linux.

Source code in src/lean_interact/utils.py

def install_lean():
    """
    Install Lean 4 version manager (elan) in a cross-platform compatible way.
    Uses platform-specific methods for Windows, macOS, and Linux.
    """
    try:
        os_name = platform.system()
        logger.info("Detected operating system: %s", os_name)

        if os_name == "Windows":
            # Check long path support on Windows before installing Lean
            check_windows_long_paths()

            # Windows installation - use PowerShell with proper error handling
            logger.info("Installing elan for Windows...")

            # Download the PowerShell script
            dl_cmd = "curl -O --location https://raw.githubusercontent.com/leanprover/elan/master/elan-init.ps1"
            subprocess.run(dl_cmd, shell=True, check=True)

            ps_cmd = "powershell -ExecutionPolicy Bypass -Command \"& './elan-init.ps1' -NoPrompt $true -DefaultToolchain stable\""
            subprocess.run(ps_cmd, shell=True, check=True)

            cleanup_cmd = "del elan-init.ps1"
            subprocess.run(cleanup_cmd, shell=True, check=True)

            logger.info(
                "Elan has been installed. You may need to restart your terminal for the PATH changes to take effect."
            )

        else:  # Unix-like systems
            if os_name in ["Linux", "Darwin"]:
                command = "curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh -s -- -y --default-toolchain stable"
            else:
                raise RuntimeError(
                    f"Unsupported operating system: {os_name}. Please install elan manually: "
                    "https://leanprover-community.github.io/get_started.html"
                )

            subprocess.run(command, shell=True, check=True)

            # Add to PATH in common shell config files
            user_home = Path.home()
            shell_configs = [".bashrc", ".zshrc", ".bash_profile", ".profile"]
            for config_name in shell_configs:
                config_path = user_home / config_name
                if config_path.exists():
                    try:
                        with open(config_path, "a", encoding="utf-8") as file:
                            file.write('\nexport PATH="$HOME/.elan/bin:$PATH"\n')
                        logger.info("Added elan to PATH in %s", config_path)
                    except Exception as e:
                        logger.warning("Could not modify %s: %s", config_path, e)

            logger.info("Please restart your terminal or run 'source ~/.profile' to update your PATH")

        logger.info("Lean installation completed successfully.")

    except subprocess.CalledProcessError as e:
        logger.warning(
            "An error occurred during Lean installation: %s\n"
            "Please check https://leanprover-community.github.io/get_started.html for more information.",
            e,
        )
        raise e
    except Exception as e:
        logger.warning(
            "Unexpected error during Lean installation: %s\nPlease try installing manually: https://leanprover-community.github.io/get_started.html",
            e,
        )
        raise e

clear_cache

clear_cache()

Source code in src/lean_interact/utils.py

def clear_cache():
    shutil.rmtree(DEFAULT_CACHE_DIR, ignore_errors=True)

Project Utilities

get_project_lean_version

get_project_lean_version(
    project_dir: str | PathLike,
) -> str | None

Get the Lean version used in a project.

Source code in src/lean_interact/utils.py

def get_project_lean_version(project_dir: str | PathLike) -> str | None:
    """
    Get the Lean version used in a project.
    """
    project_dir = Path(project_dir)
    toolchain_file = project_dir / "lean-toolchain"
    if toolchain_file.is_file():
        with open(toolchain_file, "r", encoding="utf-8") as f:
            content = f.read().strip()
            try:
                return parse_lean_version(content)
            except ValueError:
                return None
    return None

Windows Path Utilities

check_windows_long_paths

check_windows_long_paths()

Check if long paths are enabled if running on Windows.

Source code in src/lean_interact/utils.py

def check_windows_long_paths():
    """Check if long paths are enabled if running on Windows."""
    if platform.system() != "Windows":
        return

    # Try to check if long paths are enabled via registry key
    try:
        import winreg

        key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, r"SYSTEM\CurrentControlSet\Control\FileSystem")  # type: ignore
        value, _ = winreg.QueryValueEx(key, "LongPathsEnabled")  # type: ignore
        if value == 1:
            logger.info("Windows long paths already enabled")
        else:
            logger.info("For optimal use on Windows, enable long paths by running this command as administrator:")
            logger.info(
                'New-ItemProperty -Path "HKLM:\\SYSTEM\\CurrentControlSet\\Control\\FileSystem" -Name LongPathsEnabled -Value 1 -PropertyType DWord -Force'
            )
    except Exception as e:
        logger.warning(f"Could not check Windows long path setting: {e}")

    # Check if git core.longpaths is already configured
    result = subprocess.run(
        ["git", "config", "--get", "core.longpaths"],
        check=False,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True,
    )

    if result.returncode == 0 and result.stdout.strip() == "true":
        logger.info("Git already configured for long paths")
    else:
        logger.info("For optimal use on Windows, configure git for long paths by running:")
        logger.info("git config --global core.longpaths true")

Memory Management

get_total_memory_usage

get_total_memory_usage(proc: Process)

Get total resident memory usage of a process and its children (in bytes).

Source code in src/lean_interact/utils.py

def get_total_memory_usage(proc: psutil.Process):
    """Get total resident memory usage of a process and its children (in bytes)."""
    try:
        return proc.memory_info().rss + sum(child.memory_info().rss for child in proc.children(recursive=True))
    except psutil.NoSuchProcess:
        return 0

Code Processing Utilities

indent_code

indent_code(code: str, nb_spaces: int = 2) -> str

Source code in src/lean_interact/utils.py

def indent_code(code: str, nb_spaces: int = 2) -> str:
    return "\n".join(" " * nb_spaces + line for line in code.split("\n"))

compress_newlines

compress_newlines(lean_code: str)

Source code in src/lean_interact/utils.py

def compress_newlines(lean_code: str):
    # compress lines containing only whitespaces
    lean_code = re.sub(r"^\s+$", "", lean_code, flags=re.MULTILINE)
    # Compress multiple consecutive newlines
    lean_code = re.sub(r"\n\n+", "\n\n", lean_code)
    lean_code = lean_code.lstrip()
    if lean_code.endswith("\n"):
        lean_code = lean_code.rstrip() + "\n"
    return lean_code

lean_comments_ranges

lean_comments_ranges(
    lean_code: str,
    multiline_comment_suffix: str = "",
    remove_single_line_comments: bool = True,
) -> list[tuple[int, int]]

Extract the ranges of Lean comments from a Lean code snippet.

Source code in src/lean_interact/utils.py

def lean_comments_ranges(
    lean_code: str, multiline_comment_suffix: str = "", remove_single_line_comments: bool = True
) -> list[tuple[int, int]]:
    """Extract the ranges of Lean comments from a Lean code snippet."""
    # multiline comments
    open_comment_indices = [m.start() for m in re.finditer(r"/-" + multiline_comment_suffix, lean_code)]
    close_comment_indices = [
        m.start() + len(multiline_comment_suffix) + 2 for m in re.finditer(multiline_comment_suffix + r"-/", lean_code)
    ]

    if len(open_comment_indices) == len(close_comment_indices) + 1:
        # the last comment has probably not been closed due to partial code
        close_comment_indices.append(len(lean_code))

    elif len(open_comment_indices) + 1 == len(close_comment_indices):
        # the first comment has probably been opened before the code snippet
        open_comment_indices.insert(0, 0)

    elif len(open_comment_indices) != len(close_comment_indices):
        raise ValueError("Mismatched open and close comment indices.")

    # trick to handle nested comments in a simple way
    multiline_comment_ranges = list(zip(open_comment_indices, close_comment_indices))

    if remove_single_line_comments:
        # single line comments
        single_line_comment_ranges = [
            (m.start(), lean_code.find("\n", m.start())) for m in re.finditer(r"--", lean_code)
        ]
        multiline_comment_ranges += single_line_comment_ranges

    # merge potential overlapping ranges
    comment_ranges = sorted(multiline_comment_ranges, key=lambda x: x[0])
    merged_comment_ranges: list[tuple[int, int]] = []
    for start, end in comment_ranges:
        if merged_comment_ranges and start <= merged_comment_ranges[-1][1]:
            merged_comment_ranges[-1] = (merged_comment_ranges[-1][0], max(merged_comment_ranges[-1][1], end))
        else:
            merged_comment_ranges.append((start, end))

    return merged_comment_ranges

remove_lean_comments

remove_lean_comments(lean_code: str) -> str | None

Source code in src/lean_interact/utils.py

def remove_lean_comments(lean_code: str) -> str | None:
    try:
        comment_ranges = lean_comments_ranges(lean_code)

        new_lean_code = ""
        prev_start = 0
        for start, end in comment_ranges:
            new_lean_code += lean_code[prev_start:start]
            prev_start = end

        new_lean_code += lean_code[prev_start:]
        return new_lean_code

    except Exception:
        return None

split_implementation

split_implementation(declaration: str, start: int = 0)

Source code in src/lean_interact/utils.py

def split_implementation(declaration: str, start: int = 0):
    # for a theorem, an implementation is the proof
    if ":=" in declaration:
        # we have to be careful here as ":=" can be used inside the declaration itself
        indices = set([m.start() for m in re.finditer(r":=", declaration)])

        # we remove the ones related to "let", "haveI", ... declarations
        for keyword in ["let", "haveI"]:
            regex = rf"{keyword}\s+\S*?\s*(:=)"
            decl_indices = set([m.start(1) for m in re.finditer(regex, declaration)])
            indices = indices - decl_indices

        # implementation using pcre2 blows up the memory, and it turns out it is faster to use a python loop
        counters = {"(": 0, "{": 0, "[": 0}
        closing = {")": "(", "}": "{", "]": "["}
        for i, c in enumerate(declaration[start:]):
            if c in counters:
                counters[c] += 1
            elif c in [")", "}", "]"]:
                counters[closing[c]] -= 1
            if all([v == 0 for v in counters.values()]) and (i + start) in indices:
                return i + start
    return None

split_conclusion

split_conclusion(
    declaration: str, start: int = 0
) -> int | None

Source code in src/lean_interact/utils.py

def split_conclusion(declaration: str, start: int = 0) -> int | None:
    counters = {"(": 0, "{": 0, "[": 0}
    closing = {")": "(", "}": "{", "]": "["}
    for i, c in enumerate(declaration[start:]):
        if c in counters:
            counters[c] += 1
        elif c in [")", "}", "]"]:
            counters[closing[c]] -= 1
        if all([v == 0 for v in counters.values()]) and c == ":":
            return i + start
    return None

clean_theorem_string

clean_theorem_string(
    theorem_string: str,
    new_theorem_name: str = "dummy",
    add_sorry: bool = True,
) -> str | None

Clean a theorem string by removing the proof, comments, and updating the theorem name. This method assumes that no other declarations are present in the theorem string.

Source code in src/lean_interact/utils.py

def clean_theorem_string(theorem_string: str, new_theorem_name: str = "dummy", add_sorry: bool = True) -> str | None:
    """Clean a theorem string by removing the proof, comments, and updating the theorem name.
    This method assumes that no other declarations are present in the theorem string."""
    try:
        # clean the theorem string
        clean_formal = remove_lean_comments(theorem_string)
        if clean_formal is None:
            raise ValueError("Comment removal failed.")
        clean_formal = clean_formal.strip()

        # we remove the first part of the string until the first "theorem" or "lemma" keyword
        theorem_decl_keywords = "|".join(["theorem", "lemma", "example"])
        re_match = re.search(rf"\b{theorem_decl_keywords}\s", clean_formal)
        if re_match is None:
            raise ValueError("Theorem declaration keyword not found.")
        idx_theorem = re_match.start()
        clean_formal = clean_formal[idx_theorem:]

        # if a proof is provided we remove it
        idx_implement = split_implementation(clean_formal)
        if idx_implement is not None:
            clean_formal = clean_formal[:idx_implement].strip()

        # remove "theorem" and the theorem name
        if clean_formal.strip().startswith("example"):
            clean_formal = re.sub(r"^[^\s]+", "", clean_formal).strip()
        else:
            clean_formal = re.sub(r"^[^\s]+", "", clean_formal).strip()
            clean_formal = re.sub(r"^[^\s:({\[]+", "", clean_formal).strip()
        clean_formal = f"theorem {new_theorem_name} " + clean_formal
        if add_sorry:
            clean_formal += " := by sorry"
        return clean_formal
    except Exception:
        return None

extract_last_theorem

extract_last_theorem(lean_code: str) -> int

Extract the last theorem from a Lean code snippet. It assumes that the Lean code snippet ends with a theorem.

Source code in src/lean_interact/utils.py

def extract_last_theorem(lean_code: str) -> int:
    """Extract the last theorem from a Lean code snippet. It assumes that the Lean code snippet ends with a theorem."""
    comments_ranges = lean_comments_ranges(lean_code)

    # find last theorem by looking for `theorem` keyword surrounded by whitespaces, or by being at the beginning of the string
    theorem_decl_keywords = ["theorem", "lemma", "example"]
    theorem_indices = []
    for keyword in theorem_decl_keywords:
        theorem_indices += [m.start() for m in re.finditer(rf"\b{keyword}\s", lean_code)]

    # remove matches that are inside comments
    theorem_indices = [idx for idx in theorem_indices if not any(start <= idx <= end for start, end in comments_ranges)]

    if not theorem_indices:
        raise ValueError(f"No theorem found in the provided Lean code:\n{lean_code}")

    return theorem_indices[-1]

clean_last_theorem_string

clean_last_theorem_string(
    lean_code: str,
    new_theorem_name: str = "dummy",
    add_sorry: bool = False,
) -> str

Clean the last theorem string from a Lean code snippet. It assumes that the Lean code snippet ends with a theorem.

Source code in src/lean_interact/utils.py

def clean_last_theorem_string(lean_code: str, new_theorem_name: str = "dummy", add_sorry: bool = False) -> str:
    """Clean the last theorem string from a Lean code snippet. It assumes that the Lean code snippet ends with a theorem."""
    idx_last_theorem = extract_last_theorem(lean_code)
    clean_thm = clean_theorem_string(lean_code[idx_last_theorem:], new_theorem_name, add_sorry=add_sorry)
    if clean_thm is not None:
        return lean_code[:idx_last_theorem] + clean_thm

    raise ValueError(f"Theorem extraction failed for the following Lean code:\n{lean_code}")