Working on Formating DSL completion

src/myfasthtml/core/dsl/base.py

@@ -0,0 +1,84 @@
+"""
+Base class for DSL definitions.
+
+DSLDefinition provides the interface for defining domain-specific languages
+that can be used with the DslEditor control and CodeMirror.
+"""
+
+from abc import ABC, abstractmethod
+from functools import cached_property
+from typing import List, Dict, Any
+
+from myfasthtml.core.dsl.lark_to_lezer import (
+  lark_to_lezer_grammar,
+  extract_completions_from_grammar,
+)
+
+
+class DSLDefinition(ABC):
+  """
+  Base class for DSL definitions.
+
+  Subclasses must implement get_grammar() to provide the Lark grammar.
+  The Lezer grammar and completions are automatically derived.
+
+  Attributes:
+      name: Human-readable name of the DSL.
+  """
+  
+  name: str = "DSL"
+  
+  @abstractmethod
+  def get_grammar(self) -> str:
+    """
+    Return the Lark grammar string for this DSL.
+
+    Returns:
+        The Lark grammar as a string.
+    """
+    pass
+  
+  @cached_property
+  def lezer_grammar(self) -> str:
+    """
+    Return the Lezer grammar derived from the Lark grammar.
+
+    This is cached after first computation.
+
+    Returns:
+        The Lezer grammar as a string.
+    """
+    return lark_to_lezer_grammar(self.get_grammar())
+  
+  @cached_property
+  def completions(self) -> Dict[str, List[str]]:
+    """
+    Return completion items extracted from the grammar.
+
+    This is cached after first computation.
+
+    Returns:
+        Dictionary with completion categories:
+        - 'keywords': Language keywords (if, not, and, etc.)
+        - 'operators': Comparison and arithmetic operators
+        - 'functions': Function-like constructs (style, format, etc.)
+        - 'types': Type names (number, date, boolean, etc.)
+        - 'literals': Literal values (True, False, etc.)
+    """
+    return extract_completions_from_grammar(self.get_grammar())
+  
+  def get_editor_config(self) -> Dict[str, Any]:
+    """
+    Return the configuration for the DslEditor JavaScript initialization.
+
+    Returns:
+        Dictionary with:
+        - 'lezerGrammar': The Lezer grammar string
+        - 'completions': The completion items
+        - 'name': The DSL name
+    """
+    return {
+        "name": self.name,
+        "lezerGrammar": self.lezer_grammar,
+        "completions": self.completions,
+    }