1 files changed, 109 insertions, 0 deletions
diff --git a/src/hydrilla/util/_util.py b/src/hydrilla/util/_util.py
new file mode 100644
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+++ b/src/hydrilla/util/_util.py
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+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# Building Hydrilla packages.
+#
+# This file is part of Hydrilla
+#
+# Copyright (C) 2021, 2022 Wojtek Kosior
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+#
+# I, Wojtek Kosior, thereby promise not to sue for violation of this
+# file's license. Although I request that you do not make use this code
+# in a proprietary program, I am not going to enforce this in court.
+
+import re
+import json
+
+from pathlib import Path
+from typing import Optional
+
+here = Path(__file__).resolve().parent
+
+_strip_comment_re = re.compile(r'''
+^ # match from the beginning of each line
+( # catch the part before '//' comment
+  (?: # this group matches either a string or a single out-of-string character
+    [^"/] |
+    "
+    (?: # this group matches any in-a-string character
+      [^"\\] |          # match any normal character
+      \\[^u] |          # match any escaped character like '\f' or '\n'
+      \\u[a-fA-F0-9]{4} # match an escape
+    )*
+    "
+  )*
+)
+# expect either end-of-line or a comment:
+# * unterminated strings will cause matching to fail
+# * bad comment (with '/' instead of '//') will be indicated by second group
+#   having length 1 instead of 2 or 0
+(//?|$)
+''', re.VERBOSE)
+
+def strip_json_comments(text: str) -> str:
+    """
+    Accept JSON text with optional C++-style ('//') comments and return the text
+    with comments removed. Consecutive slashes inside strings are handled
+    properly. A spurious single slash ('/') shall generate an error. Errors in
+    JSON itself shall be ignored.
+    """
+    processed = 0
+    stripped_text = []
+    for line in text.split('\n'):
+        match = _strip_comment_re.match(line)
+
+        if match is None: # unterminated string
+            # ignore this error, let json module report it
+            stripped = line
+        elif len(match[2]) == 1:
+            raise json.JSONDecodeError('bad comment', text,
+                                       processed + len(match[1]))
+        else:
+            stripped = match[1]
+
+        stripped_text.append(stripped)
+        processed += len(line) + 1
+
+    return '\n'.join(stripped_text)
+
+def normalize_version(ver: list[int]) -> list[int]:
+    """Strip right-most zeroes from 'ver'. The original list is not modified."""
+    new_len = 0
+    for i, num in enumerate(ver):
+        if num != 0:
+            new_len = i + 1
+
+    return ver[:new_len]
+
+def parse_version(ver_str: str) -> list[int]:
+    """
+    Convert 'ver_str' into an array representation, e.g. for ver_str="4.6.13.0"
+    return [4, 6, 13, 0].
+    """
+    return [int(num) for num in ver_str.split('.')]
+
+def version_string(ver: list[int], rev: Optional[int]=None) -> str:
+    """
+    Produce version's string representation (optionally with revision), like:
+        1.2.3-5
+    No version normalization is performed.
+    """
+    return '.'.join([str(n) for n in ver]) + ('' if rev is None else f'-{rev}')
+
+def load_schema(schema_filename: str) -> dict:
+    """Find schema JSON file in '../schemas' and json.load() it."""
+    with open(here.parent / 'schemas' / schema_filename, 'rt') as file_handle:
+        return json.load(file_handle)