Resolve alternate language names through fromname

babelfish/converters/name.py

@@ -6,6 +6,7 @@
 
 from typing import ClassVar
 
+from babelfish.compat import resource_stream
 from babelfish.language import LANGUAGE_MATRIX
 
 from . import LanguageEquivalenceConverter
@@ -18,3 +19,35 @@ class NameConverter(LanguageEquivalenceConverter):
     for iso_language in LANGUAGE_MATRIX:
         if iso_language.name:
             SYMBOLS[iso_language.alpha3] = iso_language.name
+
+    #: Common/colloquial names that no ISO 639-3 data source provides but that
+    #: users routinely expect to resolve. Keyed by alpha3 -> list of names.
+    COMMON_NAMES: ClassVar[dict[str, list[str]]] = {
+        'ell': ['Greek'],  # SIL only lists 'Modern Greek (1453-)'
+    }
+
+    def __init__(self) -> None:
+        # The base class builds the forward map (alpha3 -> ISO 639-3 reference
+        # name) and seeds the reverse map with those reference names.
+        super().__init__()
+
+        # Register the additional ISO 639-3 print names as reverse-only aliases,
+        # so e.g. both 'Pashto' and 'Pushto' resolve to 'pus' while the forward
+        # name (Language('pus').name) stays the canonical reference name.
+        with resource_stream('babelfish', 'data/iso-639-3_Name_Index.tab') as f:
+            f.readline()
+            for line in f:
+                alpha3, print_name, _inverted_name = line.decode('utf-8').rstrip('\r\n').split('\t')
+                self._add_name(alpha3, print_name)
+
+        for alpha3, names in self.COMMON_NAMES.items():
+            for name in names:
+                self._add_name(alpha3, name)
+
+    def _add_name(self, alpha3: str, name: str) -> None:
+        # Skip names whose language is not in the loaded matrix (e.g. codes the
+        # Name Index knows but the bundled iso-639-3.tab does not), and never
+        # let an alias override a reference name already claimed by a language.
+        if name and alpha3 in self.to_symbol and name not in self.from_symbol:
+            self.from_symbol[name] = (alpha3, None, None)
+            self.codes.add(name)