Refactor: rename rmSpace to remove_redundant_spaces (#10796)

### What problem does this PR solve?

- rename rmSpace to remove_redundant_spaces
- move clean_markdown_block to common module
- add unit tests for remove_redundant_spaces and clean_markdown_block

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

common/__init__.py

@@ -0,0 +1,15 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#

common/float_utils.py

@@ -0,0 +1,46 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+def get_float(v):
+    """
+    Convert a value to float, handling None and exceptions gracefully.
+
+    Attempts to convert the input value to a float. If the value is None or
+    cannot be converted to float, returns negative infinity as a default value.
+
+    Args:
+        v: The value to convert to float. Can be any type that float() accepts,
+           or None.
+
+    Returns:
+        float: The converted float value if successful, otherwise float('-inf').
+
+    Examples:
+        >>> get_float("3.14")
+        3.14
+        >>> get_float(None)
+        -inf
+        >>> get_float("invalid")
+        -inf
+        >>> get_float(42)
+        42.0
+    """
+    if v is None:
+        return float('-inf')
+    try:
+        return float(v)
+    except Exception:
+        return float('-inf')

common/string_utils.py

@@ -0,0 +1,73 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+import re
+
+
+def remove_redundant_spaces(txt: str):
+    """
+    Remove redundant spaces around punctuation marks while preserving meaningful spaces.
+
+    This function performs two main operations:
+    1. Remove spaces after left-boundary characters (opening brackets, etc.)
+    2. Remove spaces before right-boundary characters (closing brackets, punctuation, etc.)
+
+    Args:
+        txt (str): Input text to process
+
+    Returns:
+        str: Text with redundant spaces removed
+    """
+    # First pass: Remove spaces after left-boundary characters
+    # Matches: [non-alphanumeric-and-specific-right-punctuation] + [non-space]
+    # Removes spaces after characters like '(', '<', and other non-alphanumeric chars
+    # Examples:
+    #   "( test" → "(test"
+    txt = re.sub(r"([^a-z0-9.,\)>]) +([^ ])", r"\1\2", txt, flags=re.IGNORECASE)
+
+    # Second pass: Remove spaces before right-boundary characters
+    # Matches: [non-space] + [non-alphanumeric-and-specific-left-punctuation]
+    # Removes spaces before characters like non-')', non-',', non-'.', and non-alphanumeric chars
+    # Examples:
+    #   "world !" → "world!"
+    return re.sub(r"([^ ]) +([^a-z0-9.,\(<])", r"\1\2", txt, flags=re.IGNORECASE)
+
+
+def clean_markdown_block(text):
+    """
+    Remove Markdown code block syntax from the beginning and end of text.
+
+    This function cleans Markdown code blocks by removing:
+    - Opening ```Markdown tags (with optional whitespace and newlines)
+    - Closing ``` tags (with optional whitespace and newlines)
+
+    Args:
+        text (str): Input text that may be wrapped in Markdown code blocks
+
+    Returns:
+        str: Cleaned text with Markdown code block syntax removed, and stripped of surrounding whitespace
+
+    """
+    # Remove opening ```markdown tag with optional whitespace and newlines
+    # Matches: optional whitespace + ```markdown + optional whitespace + optional newline
+    text = re.sub(r'^\s*```markdown\s*\n?', '', text)
+
+    # Remove closing ``` tag with optional whitespace and newlines
+    # Matches: optional newline + optional whitespace + ``` + optional whitespace at end
+    text = re.sub(r'\n?\s*```\s*$', '', text)
+
+    # Return text with surrounding whitespace removed
+    return text.strip()