leftover

hls4ml/utils/dependency.py

@@ -0,0 +1,55 @@
+import sys
+from functools import wraps
+from importlib.metadata import metadata
+from inspect import ismethod
+
+extra_requires: dict[str, list[str]] = {}
+subpackage = None
+for k, v in metadata('hls4ml')._headers:  # type: ignore
+    if k != 'Requires-Dist':
+        continue
+    if '; extra == ' not in v:
+        continue
+
+    req, pkg = v.split('; extra == ')
+    pkg = pkg.strip('"')
+
+    extra_requires.setdefault(pkg, []).append(req)
+
+
+def requires(pkg: str):
+    """Mark a function or method as requiring a package to be installed.
+    'name': requires hls4ml[name] to be installed.
+    '_name': requires name to be installed.
+
+    Parameters
+    ----------
+    pkg : str
+        The package to require.
+    """
+
+    def deco(f):
+        if ismethod(f):
+            qualifier = f"Method {f.__self__.__class__.__name__}.{f.__name__}"
+        else:
+            qualifier = f"Function {f.__name__}"
+
+        if not pkg.startswith("_"):
+            reqs = ", ".join(extra_requires[pkg])
+            msg = f"{qualifier} requires {reqs}, but package {{ename}} is missing"
+            "Please consider install it with `pip install hls4ml[{pkg}]` for full functionality with {pkg}."
+        else:
+            msg = f"{qualifier} requires {pkg[1:]}, but package {{ename}} is missing."
+            "Consider install it with `pip install {pkg}`."
+
+        @wraps(f)
+        def inner(*args, **kwargs):
+            try:
+                return f(*args, **kwargs)
+            except ImportError as e:
+                print(msg.format(ename=e.name), file=sys.stderr)
+                raise e
+
+        return inner
+
+    return deco