Add compare command to glyphsets CLI tool

Lib/glyphsets/__init__.py

@@ -498,6 +498,52 @@ def describe_glyphset(glyph_names):
     return md
 
 
+def compare_glyphsets(glyphsets):
+    """
+    Compare the contents of glyphsets to each other,
+    with the first glyphset being the reference.
+    Each consecutive glyphset gets compares to each former.
+    """
+
+    if len(list(set(glyphsets))) < 2:
+        raise ValueError("Please provide at least two glyphsets to compare.")
+
+    if len(list(set(glyphsets))) != len(glyphsets):
+        raise ValueError("Please provide unique glyphsets to compare.")
+
+    reference_glyphset = glyphsets[0]
+    reference_glyphs = set(glyphs_in_glyphset(reference_glyphset))
+
+    print(f"{reference_glyphset}:\n{'=' * len(reference_glyphset)}\n")
+    print(f"Total glyphs: {len(reference_glyphs)}\n")
+    print(describe_glyphset(reference_glyphs))
+
+    for i, glyphset in enumerate(glyphsets):
+        if i == 0:
+            continue
+
+        this_glyphs = set(glyphs_in_glyphset(glyphsets[i]))
+        previous_glyphs = set(glyphs_in_glyphset(glyphsets[i - 1]))
+
+        print(f"\n{glyphset}:\n{'=' * len(glyphset)}\n")
+        print(f"Total glyphs: {len(this_glyphs)}\n")
+
+        missing = previous_glyphs.difference(this_glyphs)
+        extra = this_glyphs.difference(previous_glyphs)
+
+        if missing:
+            print(
+                f"{glyphset} has {len(missing)} **missing** glyphs compared to {glyphsets[i - 1]}:\n"
+            )
+            print(describe_glyphset(missing))
+
+        if extra:
+            print(
+                f"{glyphset} has {len(extra)} **extra** glyphs compared to {glyphsets[i - 1]}:\n"
+            )
+            print(describe_glyphset(extra))
+
+
 def add_country(code):
     if code in regions:
         return f"{regions[code].name} ({code})"

Lib/glyphsets/__main__.py

@@ -1,5 +1,5 @@
 import argparse
-from glyphsets import build_glyphsapp_filter_list
+from glyphsets import build_glyphsapp_filter_list, compare_glyphsets
 
 
 def main():
@@ -28,6 +28,12 @@ def main():
     filter_lists_parser.add_argument("--prod-names", action="store_true", default=False)
     filter_lists_parser.add_argument("-o", "--out", required=True, help="output path")
 
+    filter_lists_parser = subparsers.add_parser(
+        "compare",
+        help="Compare two or more glyhsets to each other; with later glyphsets being compared to the former.",
+    )
+    filter_lists_parser.add_argument("glyphsets", nargs="+")
+
     # nam_file_parser = subparsers.add_parser(
     #     "nam-file", help="Ouput .nam file from given glyphset(s)."
     # )
@@ -52,6 +58,9 @@ def main():
     if args.command == "filter-list":
         build_glyphsapp_filter_list(args.glyphsets, args.out, args.prod_names)
 
+    if args.command == "compare":
+        compare_glyphsets(args.glyphsets)
+
     # elif args.command == "update-srcs":
     #     srcs = [load_source(src) for src in args.srcs]
     #     for src in srcs:

README.md

@@ -106,6 +106,11 @@ RESULTS:                        │
 Glyphsets Tool
 ==============
 
+> [!NOTE]  
+> Previously existing commands of the `glyphsets` tool are currently deactivated after the transition to the new database. These are: `update-srcs`, `nam-file`, `missing-in-font`. Please report if you need to use these.
+
+## Custom Filters
+
 You can create your own Glyphs.app _Custom Filters_ using the `glyphsets` tool.
 
 Install or update the tool with pip, if you haven’t already:
@@ -121,10 +126,42 @@ glyphsets filter-list -o myfilter.plist GF_Latin_Core GF_Latin_Plus
 ```
 Add this `.plist` file next to your Glyphs file and (after restart) you would be able to see it in the filters sidebar.
 
-> [!NOTE]  
-> Previously existing commands of the `glyphsets` tool are currently deactivated after the transition to the new database. These are: `update-srcs`, `nam-file`, `missing-in-font`. Please report if you need to use these.
+## Compare Glyphsets
+
+You can compare the contents of two or more glyphsets against each other. Each consecutive glyphset will be compared to the previous one.
+
+This command lists the complete contents of `GF_Latin_Kernel` first, and then lists only extra (or missing) glyphs for `GF_Latin_Core` when compared to `GF_Latin_Kernel`:
+```
+glyphsets compare GF_Latin_Kernel GF_Latin_Core
+```
+
+Output:
 
+```
+GF_Latin_Kernel:
+===============
+
+Total glyphs: 116
+
+Letter (52 glyphs): 
+`A B C D E F G H I J K L M N O P Q R S T U V W X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z`
+
+...
+
+
+GF_Latin_Core:
+=============
 
+Total glyphs: 324
+
+GF_Latin_Core has 208 **extra** glyphs compared to GF_Latin_Kernel:
+
+Letter (168 glyphs): 
+`ª º À Á Â Ã Ä Å Æ Ç È É Ê Ë Ì Í Î Ï Ð Ñ Ò Ó Ô Õ Ö Ø Ù Ú Û Ü Ý Þ ß à á â ã ä å æ ç è é ê ë ì í î ï ð ñ ò ó ô õ ö ø ù ú û ü ý þ ÿ Ā ā Ă ă Ą ą Ć ć Ċ ċ Č č Ď ď Đ đ Ē ē Ė ė Ę ę Ě ě Ğ ğ Ġ ġ Ģ ģ Ħ ħ Ī ī Į į İ ı Ķ ķ Ĺ ĺ Ļ ļ Ľ ľ Ł ł Ń ń Ņ ņ Ň ň Ő ő Œ œ Ŕ ŕ Ř ř Ś ś Ş ş Š š Ť ť Ū ū Ů ů Ű ű Ų ų Ŵ ŵ Ŷ ŷ Ÿ Ź ź Ż ż Ž ž Ș ș Ț ț ȷ Ẁ ẁ Ẃ ẃ Ẅ ẅ ẞ Ỳ ỳ /idotaccent`
+
+...
+
+```
 Acknowledgements
 ================
 

tests/test_glyphsets.py

@@ -4,6 +4,7 @@
     languages_per_glyphset,
     get_glyphsets_fulfilled,
     defined_glyphsets,
+    compare_glyphsets,
 )
 
 DATA_FP = os.path.join(os.path.dirname(__file__), "data")
@@ -31,3 +32,7 @@ def test_coverage():
 
     ttFont = TTFont(FONT_PATH)
     assert get_glyphsets_fulfilled(ttFont)["GF_Latin_Core"]["percentage"] > 0.99
+
+
+def test_compare():
+    compare_glyphsets(["GF_Latin_Kernel", "GF_Latin_Core", "GF_Latin_Plus"])