refactor(parse): add base html and json parsers

gallery/sketch/parse/core.py

@@ -1,13 +1,49 @@
-from typing import Generic, TypeVar
-
-D = TypeVar("D")
-R = TypeVar("R")
+from abc import ABC, abstractmethod
+from typing import Generic, NamedTuple, Protocol, TypeVar
 
 
 class ParseError(Exception):
     pass
 
 
-class Parser(Generic[D, R]):
+D = TypeVar("D")
+R = TypeVar("R")
+
+
+class Parser[D, R](Protocol):
+    def parse(self, data: D) -> R: ...
+
+
+P = TypeVar("P")
+
+
+class PrepareParser(ABC, Parser[D, R], Generic[D, P, R]):
+
+    @abstractmethod
+    def prepare(self, data: D) -> P: ...
+
+    @abstractmethod
+    def extract(self, data: P) -> R: ...
+
     def parse(self, data: D) -> R:
-        raise NotImplementedError
+        return self.extract(self.prepare(data))
+
+
+class Context(Protocol):
+    data: str
+
+
+C = TypeVar("C", bound=Context)
+
+
+class ParsedContext(NamedTuple, Generic[C, D]):
+    context: C
+    data: D
+
+
+class ContextParser(PrepareParser[C, ParsedContext[C, P], R], Generic[C, P, R]):
+    @abstractmethod
+    def prepare_context(self, data: str) -> P: ...
+
+    def prepare(self, data: C) -> ParsedContext[C, P]:
+        return ParsedContext(context=data, data=self.prepare_context(data.data))