Move lazy datastructures to misc.lazyTools

Lib/fontTools/misc/lazyTools.py

@@ -0,0 +1,42 @@
+from collections import UserDict, UserList
+
+__all__ = ["LazyDict", "LazyList"]
+
+
+class LazyDict(UserDict):
+    def __init__(self, data):
+        super().__init__()
+        self.data = data
+
+    def __getitem__(self, k):
+        v = self.data[k]
+        if callable(v):
+            v = v(self, k)
+            self.data[k] = v
+        return v
+
+
+class LazyList(UserList):
+    def __getitem__(self, k):
+        if isinstance(k, slice):
+            indices = range(*k.indices(len(self)))
+            return [self[i] for i in indices]
+        v = self.data[k]
+        if callable(v):
+            v = v(self, k)
+            self.data[k] = v
+        return v
+
+    def __add__(self, other):
+        if isinstance(other, LazyList):
+            other = list(other)
+        elif isinstance(other, list):
+            pass
+        else:
+            return NotImplemented
+        return list(self) + other
+
+    def __radd__(self, other):
+        if not isinstance(other, list):
+            return NotImplemented
+        return other + list(self)

Lib/fontTools/ttLib/tables/_g_v_a_r.py

@@ -1,7 +1,8 @@
-from collections import UserDict, deque
+from collections import deque
 from functools import partial
 from fontTools.misc import sstruct
 from fontTools.misc.textTools import safeEval
+from fontTools.misc.lazyTools import LazyDict
 from . import DefaultTable
 import array
 import itertools
@@ -39,19 +40,6 @@ GVAR_HEADER_FORMAT = """
 GVAR_HEADER_SIZE = sstruct.calcsize(GVAR_HEADER_FORMAT)
 
 
-class _LazyDict(UserDict):
-    def __init__(self, data):
-        super().__init__()
-        self.data = data
-
-    def __getitem__(self, k):
-        v = self.data[k]
-        if callable(v):
-            v = v(self, k)
-            self.data[k] = v
-        return v
-
-
 def _decompileVarGlyph(self, glyphName):
     gid = self.reverseGlyphMap[glyphName]
     offsetSize = 2 if self.tableFormat == 0 else 4
@@ -143,7 +131,7 @@ class table__g_v_a_r(DefaultTable.DefaultTable):
         offsetToData = self.offsetToGlyphVariationData
         glyf = ttFont["glyf"]
 
-        l = _LazyDict(
+        l = LazyDict(
             {glyphs[gid]: _decompileVarGlyph for gid in range(self.glyphCount)}
         )
         l.reverseGlyphMap = ttFont.getReverseGlyphMap()

Lib/fontTools/ttLib/tables/otConverters.py

@@ -8,6 +8,7 @@ from fontTools.misc.fixedTools import (
 )
 from fontTools.misc.roundTools import nearestMultipleShortestRepr, otRound
 from fontTools.misc.textTools import bytesjoin, tobytes, tostr, pad, safeEval
+from fontTools.misc.lazyTools import LazyList
 from fontTools.ttLib import getSearchRange
 from .otBase import (
     CountReference,
@@ -108,38 +109,6 @@ def buildConverters(tableSpec, tableNamespace):
     return converters, convertersByName
 
 
-try:
-    from collections import UserList
-except ImportError:
-    from UserList import UserList
-
-
-class _LazyList(UserList):
-    def __getitem__(self, k):
-        if isinstance(k, slice):
-            indices = range(*k.indices(len(self)))
-            return [self[i] for i in indices]
-        v = self.data[k]
-        if callable(v):
-            v = v(self, k)
-            self.data[k] = v
-        return v
-
-    def __add__(self, other):
-        if isinstance(other, _LazyList):
-            other = list(other)
-        elif isinstance(other, list):
-            pass
-        else:
-            return NotImplemented
-        return list(self) + other
-
-    def __radd__(self, other):
-        if not isinstance(other, list):
-            return NotImplemented
-        return other + list(self)
-
-
 def _base_converter_read_item(self, i):
     self.reader.seek(self.pos + i * self.recordSize)
     return self.conv.read(self.reader, self.font, {})
@@ -192,7 +161,7 @@ class BaseConverter(object):
                 l.append(self.read(reader, font, tableDict))
             return l
         else:
-            l = _LazyList(_base_converter_read_item for i in range(count))
+            l = LazyList(_base_converter_read_item for i in range(count))
             l.reader = reader.copy()
             l.pos = l.reader.pos
             l.font = font
@@ -1893,7 +1862,7 @@ class CFF2Index(BaseConverter):
                 lastOffset = offset
             return items
         else:
-            l = _LazyList([cff2_index_read_item] * count)
+            l = LazyList([cff2_index_read_item] * count)
             l.reader = reader.copy()
             l.offset_pos = l.reader.pos
             l.data_pos = l.offset_pos + (count + 1) * offSize

Tests/ttLib/tables/otConverters_test.py

@@ -427,9 +427,12 @@ class AATLookupTest(unittest.TestCase):
         )
 
 
+from fontTools.misc.lazyTools import LazyList
+
+
 class LazyListTest(unittest.TestCase):
     def test_slice(self):
-        ll = otConverters._LazyList([10, 11, 12, 13])
+        ll = LazyList([10, 11, 12, 13])
         sl = ll[:]
 
         self.assertIsNot(sl, ll)
@@ -439,8 +442,8 @@ class LazyListTest(unittest.TestCase):
         self.assertEqual([11, 12], ll[1:3])
 
     def test_add_both_LazyList(self):
-        ll1 = otConverters._LazyList([1])
-        ll2 = otConverters._LazyList([2])
+        ll1 = LazyList([1])
+        ll2 = LazyList([2])
 
         l3 = ll1 + ll2
 
@@ -448,7 +451,7 @@ class LazyListTest(unittest.TestCase):
         self.assertEqual([1, 2], l3)
 
     def test_add_LazyList_and_list(self):
-        ll1 = otConverters._LazyList([1])
+        ll1 = LazyList([1])
         l2 = [2]
 
         l3 = ll1 + l2
@@ -458,13 +461,13 @@ class LazyListTest(unittest.TestCase):
 
     def test_add_not_implemented(self):
         with self.assertRaises(TypeError):
-            otConverters._LazyList() + 0
+            LazyList() + 0
         with self.assertRaises(TypeError):
-            otConverters._LazyList() + tuple()
+            LazyList() + tuple()
 
     def test_radd_list_and_LazyList(self):
         l1 = [1]
-        ll2 = otConverters._LazyList([2])
+        ll2 = LazyList([2])
 
         l3 = l1 + ll2
 
@@ -473,9 +476,9 @@ class LazyListTest(unittest.TestCase):
 
     def test_radd_not_implemented(self):
         with self.assertRaises(TypeError):
-            0 + otConverters._LazyList()
+            0 + LazyList()
         with self.assertRaises(TypeError):
-            tuple() + otConverters._LazyList()
+            tuple() + LazyList()
 
 
 if __name__ == "__main__":