add case insensitive symbol lookup

adds feature described in issue #9

Author: amari-calipso

pylasu/model/naming.py

@@ -1,4 +1,5 @@
 from dataclasses import dataclass, field
+from itertools   import chain
 from typing import TypeVar, Generic, Optional, List, Dict
 
 
@@ -33,14 +34,14 @@ def __hash__(self):
     def resolved(self):
         return self.referred is not None
 
-    def resolve(self, scope: 'Scope') -> bool:
-        self.referred = scope.lookup(symbol_name=self.name)
+    def resolve(self, scope: 'Scope', case_insensitive: bool = False) -> bool:
+        self.referred = scope.lookup(symbol_name=self.name, case_insensitive=case_insensitive)
         return self.resolved()
 
     def try_to_resolve(self, candidates: List[T], case_insensitive: bool = False) -> bool:
         """
         Try to resolve the reference by finding a named element with a matching name.
-        The name match is performed in a case sensitive or insensitive way depending on the value of caseInsensitive.
+        The name match is performed in a case sensitive or insensitive way depending on the value of case_insensitive.
         """
 
         def check_name(candidate: T) -> bool:
@@ -60,10 +61,36 @@ class Symbol(PossiblyNamed):
 class Scope:
     symbols: Dict[str, List[Symbol]] = field(default_factory=list)
     parent: Optional['Scope'] = field(default=None)
+    insensitive_map: Optional[Dict[str, List[str]]] = field(default=None)
+
+    def lookup(self, symbol_name: str, symbol_type: type = Symbol, case_insensitive: bool = False) -> Optional[Symbol]:
+        if case_insensitive:
+            if self.insensitive_map is None:
+                self.insensitive_map = {}
+                for key in self.symbols.keys():
+                    key_lower: str = key.lower()
+                    self.insensitive_map[key_lower] = self.insensitive_map.get(key_lower, []) + [key]
+
+            symbol_name_lower: str = symbol_name.lower()
+
+            return next(
+                (
+                    symbol
+                    for symbol in chain.from_iterable(
+                        self.symbols.get(orig_symbol_name, [])
+                        for orig_symbol_name in self.insensitive_map[symbol_name_lower]
+                    )
+                    if isinstance(symbol, symbol_type)
+                ),
+                self.parent.lookup(symbol_name, symbol_type) if self.parent is not None else None
+            )
 
-    def lookup(self, symbol_name: str, symbol_type: type = Symbol) -> Optional[Symbol]:
         return next((symbol for symbol in self.symbols.get(symbol_name, []) if isinstance(symbol, symbol_type)),
                     self.parent.lookup(symbol_name, symbol_type) if self.parent is not None else None)
 
     def add(self, symbol: Symbol):
         self.symbols[symbol.name] = self.symbols.get(symbol.name, []) + [symbol]
+
+        if self.insensitive_map is not None:
+            symbol_name_lower: str = symbol.name.lower()
+            self.insensitive_map[symbol_name_lower] = self.insensitive_map.get(symbol_name_lower, []) + [symbol.name]

tests/model/test_model.py

@@ -136,6 +136,13 @@ def test_scope_lookup_7(self):
         result = scope.lookup(symbol_name='a', symbol_type=AnotherSymbol)
         self.assertIsNone(result)
 
+    def test_scope_case_insensitive_lookup(self):
+        local_symbol = SomeSymbol(name='a', index=0)
+        scope = Scope(symbols={'a': [local_symbol]}, parent=Scope(symbols={'a': [SomeSymbol(name='a', index=1)]}))
+        result = scope.lookup(symbol_name='A', case_insensitive=True)
+        self.assertEqual(result, local_symbol)
+        self.assertIsInstance(result, Symbol)
+
     def test_node_properties_meta(self):
         pds = [pd for pd in sorted(SomeNode.node_properties, key=lambda x: x.name)]
         self.assertEqual(5, len(pds))
@@ -149,4 +156,4 @@ def test_node_properties_meta(self):
         self.assertEqual("name", pds[3].name)
         self.assertFalse(pds[3].provides_nodes)
         self.assertEqual("ref", pds[4].name)
-        self.assertTrue(pds[4].provides_nodes)
+        self.assertTrue(pds[4].provides_nodes)