ENH: Remove all references and uses of PERL

Author: hjmjohnson

Latex/doubleWordCheck.pl

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+"""
+Search for doubled words in text
+
+Behavior:
+- Reads one or more files (or stdin if none).
+- Processes input in "records" delimited by ".\n" (Perl: $/ = ".\n").
+- In each record, highlights a repeated word (case-insensitive) where the two
+  occurrences are separated by whitespace and/or simple HTML tags.
+- Removes any leading lines that contain no escape characters.
+- Prefixes each remaining line with "<filename>: ".
+"""
+
+from __future__ import annotations
+
+import argparse
+import re
+import sys
+from pathlib import Path
+
+
+ESC = "\x1b"
+
+# Perl: s/\b([a-z]+)((\s|<[^>]+>)+)(\1\b)/\e[7m$1\e[m$2\e[7m$4\e[m/ig
+DOUBLE_WORD_RE = re.compile(
+    r"\b([a-z]+)((?:\s|<[^>]+>)+)(\1\b)",
+    re.IGNORECASE,
+)
+
+# Perl: s/^([^\e]*\n)+//mg
+# Interpreted as: drop initial consecutive lines that contain no ESC.
+LEADING_NO_ESC_LINES_RE = re.compile(r"^(?:[^\x1b]*\n)+", re.MULTILINE)
+
+
+def highlight_double_words(record: str) -> str | None:
+    """
+    Return transformed record if a double-word pattern is found; otherwise None.
+    """
+
+    def repl(m: re.Match[str]) -> str:
+        w1 = m.group(1)
+        sep = m.group(2)
+        w2 = m.group(3)  # same text as group(1) as matched
+        return f"{ESC}[7m{w1}{ESC}[m{sep}{ESC}[7m{w2}{ESC}[m"
+
+    new_record, n = DOUBLE_WORD_RE.subn(repl, record, count=1)
+    if n == 0:
+        return None
+
+    new_record = LEADING_NO_ESC_LINES_RE.sub("", new_record, count=1)
+    return new_record
+
+
+def iter_records(text: str, sep: str = ".\n"):
+    """
+    Yield records split by the exact separator, including the separator (like Perl $/).
+    """
+    start = 0
+    while True:
+        idx = text.find(sep, start)
+        if idx == -1:
+            if start < len(text):
+                yield text[start:]
+            break
+        end = idx + len(sep)
+        yield text[start:end]
+        start = end
+
+
+def process_stream(name: str, data: str, out) -> None:
+    for record in iter_records(data, sep=".\n"):
+        transformed = highlight_double_words(record)
+        if transformed is None:
+            continue
+
+        # Perl: s/^/$ARGV: /mg  => prefix each line
+        prefixed = re.sub(r"^", f"{name}: ", transformed, flags=re.MULTILINE)
+        out.write(prefixed)
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("files", nargs="*", help="Files to scan; if empty, read stdin.")
+    args = ap.parse_args()
+
+    if not args.files:
+        data = sys.stdin.read()
+        process_stream("<stdin>", data, sys.stdout)
+        return 0
+
+    for f in args.files:
+        p = Path(f)
+        data = p.read_text(encoding="utf-8", errors="replace")
+        process_stream(f, data, sys.stdout)
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

Latex/doubleWordCheck.py

@@ -1,4 +1,3 @@
-Remove all references to perl PERL
 Get output images only produced in BINARY_DIR.
 
 -- (DONE) Have python code line extractor throw warning when lines are too long to print.