Use recommended lib loading; accept negative numbers (#4)

* Use recommended way of loading language lib

* grammar.js: allow negative numbers

Author: elifarley

grammar.js

@@ -457,7 +457,7 @@ in the target code file.
       )
     ),
 
-    number: $ => /\d+/,
+    number: $ => seq(optional('-'), /\d+/),
 
     comment: $ => token(prec(-1, seq(
       '--',

src/cedarscript_grammar/__init__.py

@@ -1,6 +1,8 @@
 import logging
 import sys
 from pathlib import Path
+from ctypes import cdll, c_void_p
+from os import fspath
 
 from tree_sitter import Language
 
@@ -25,5 +27,8 @@ def language() -> Language:
         raise OSError(f"Unsupported platform: {sys.platform}")
 
     language_path = str((_ROOT_DIR / lib_name).absolute())
-    logger.warning(f"[{__name__}] Loading native CEDARScript parsing library from {language_path}")
-    return Language(language_path, "CEDARScript")
+    logger.warning(f"[{__name__}] Loading native CEDARScript parsing lib from {language_path}")
+    lang_name = 'CEDARScript'
+    language_function = getattr(cdll.LoadLibrary(fspath(language_path)), f"tree_sitter_{lang_name}")
+    language_function.restype = c_void_p
+    return Language(language_function(), name=lang_name)