Re-implement _symbol_ident

pyk/src/pyk/k2lean4/k2lean4.py

@@ -1,18 +1,27 @@
 from __future__ import annotations
 
+import re
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
 
+from ..konvert import unmunge
 from ..kore.internal import CollectionKind
 from ..kore.syntax import SortApp
 from ..utils import check_type
 from .model import Abbrev, Ctor, ExplBinder, Inductive, Module, Signature, Term
 
 if TYPE_CHECKING:
+    from typing import Final
+
     from ..kore.internal import KoreDefn
     from .model import Command
 
 
+_VALID_LEAN_IDENT: Final = re.compile(
+    "_[a-zA-Z0-9_?!']+|[a-zA-Z][a-zA-Z0-9_?!']*"
+)  # Simplified to characters permitted in KORE in the first place
+
+
 @dataclass(frozen=True)
 class K2Lean4:
     defn: KoreDefn
@@ -52,7 +61,12 @@ def _symbol_ctor(self, sort: str, symbol: str) -> Ctor:
 
     @staticmethod
     def _symbol_ident(symbol: str) -> str:
-        return symbol.replace('-', '_')
+        if symbol.startswith('Lbl'):
+            symbol = symbol[3:]
+        symbol = unmunge(symbol)
+        if not _VALID_LEAN_IDENT.fullmatch(symbol):
+            symbol = f'«{symbol}»'
+        return symbol
 
     def _collections(self) -> list[Command]:
         return [self._collection(sort) for sort in sorted(self.defn.collections)]