Add glyphs finder for feature porting

requirements.txt

@@ -2,6 +2,6 @@ fontmake==3.5.1
 cu2qu==1.6.7
 gftools==0.9.27
 glyphsLib==6.2.1
-arrrgs==0.0.5
+arrrgs==2.0.0
 ruff==0.0.259
 pylint==2.17.1

scripts/find.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""Utility script for feature porting.
+Finds glyphs in the .fea file
+and checks which of them are present in the source font file.
+
+Usage: find.py ../features/calt/hyphen-arrows.fea missing
+"""
+from re import sub
+from typing import List
+
+from arrrgs import arg, command, global_args, run
+from glyphsLib import GSFont
+
+FONT_FILE = "Lilex.glyphs"
+
+global_args(
+    arg("--file", "-f", required=True, help="Input .fea file")
+)
+
+@command()
+def missing(_, gls: List[str]):
+    """Finds missing glyphs"""
+    font = GSFont(FONT_FILE)
+    missing_glyphs = []
+    for glyph in gls:
+        if glyph not in font.glyphs:
+            missing_glyphs.append(glyph)
+    print("Missing glyphs:")
+    print("\n".join(missing_glyphs))
+
+    stock = len(gls) - len(missing_glyphs)
+    percent = stock / len(gls)
+    print(f"\nGlyphs coverage: {(percent * 100):.1f}% ({stock}/{len(gls)})")
+
+
+
+@command()
+def glyphs(_, gls: List[str]):
+    print("\n".join(gls))
+
+KEYWORDS = [
+    "ignore", "sub", "by"
+]
+
+def _is_glyph_name(word: str) -> bool:
+    return len(word) > 0 and word not in KEYWORDS
+
+def glyphs_from_fea(path: str) -> List[str]:
+    with open(path, mode="r", encoding="utf-8") as file:
+        content = file.read()
+    # Remove comments
+    content = sub(r"\#(.*)", "", content)
+    # Remove lookups
+    content = sub(r"lookup(.*){", "", content)
+    content = sub(r"}(.*);", "", content)
+    # Remove symbols
+    content = sub(r"[';\[\]]", "", content)
+    # Remove newlines and duplicated spaces
+    content = content.replace("\n", " ")
+    content = sub(" +", " ", content)
+    # Filter keywords
+    words = content.split(" ")
+    return list(filter(_is_glyph_name, words))
+
+def load_words(args):
+    words = glyphs_from_fea(args.file)
+    return args, words
+
+if __name__ == "__main__":
+    run(prepare=load_words)