transformer overhaul

Author: kkozik-amplify

hcl2/api.py

@@ -3,7 +3,7 @@
 
 from lark.tree import Tree as AST
 from hcl2.parser import parser
-from hcl2.transformer import DictTransformer
+from hcl2.dict_transformer import DictTransformer
 
 
 def load(file: TextIO, with_meta=False) -> dict:

hcl2/transformer.py renamed to hcl2/dict_transformer.py

@@ -257,6 +257,10 @@ def heredoc_template_trim(self, args: List) -> str:
     def new_line_or_comment(self, args: List) -> _DiscardType:
         return Discard
 
+    # def EQ(self, args: List):
+    #     print("EQ", args)
+    #     return args
+
     def for_tuple_expr(self, args: List) -> str:
         args = self.strip_new_line_tokens(args)
         for_expr = " ".join([self.to_tf_inline(arg) for arg in args[1:-1]])

hcl2/rule_transformer.py

@@ -0,0 +1,101 @@
+# pylint: disable=missing-function-docstring,unused-argument
+from typing import List, Union
+
+from lark import Transformer, Tree, Token
+from lark.visitors import _Leaf_T, _Return_T, Discard
+
+from hcl2.serialization import (
+    LarkRule,
+    LarkToken,
+    StartRule,
+    BodyRule,
+    BlockRule,
+    IdentifierRule,
+    IntLitRule,
+    FloatLitRule,
+    StringLitRule,
+    ExprTermRule,
+    ConditionalRule,
+    BinaryOpRule,
+    BinaryOperatorRule,
+    BinaryTermRule,
+    UnaryOpRule,
+    AttributeRule,
+    NewLineOrCommentRule,
+)
+
+ArgsType = List[Union[Token, Tree]]
+
+
+class RuleTransformer(Transformer):
+    """Takes a syntax tree generated by the parser and
+    transforms it to a tree of LarkRule instances
+    """
+
+    with_meta: bool
+
+    @staticmethod
+    def is_type_keyword(value: str) -> bool:
+        return value in {"bool", "number", "string"}
+
+    def __init__(self, with_meta: bool = False, with_comments: bool = True):
+        """
+        :param with_meta: If set to true then adds `__start_line__` and `__end_line__`
+        parameters to the output dict. Default to false.
+        """
+        self._with_meta = with_meta
+        self._with_comments = with_comments
+        super().__init__()
+
+    def start(self, args: ArgsType) -> StartRule:
+        return StartRule(args)
+
+    def body(self, args: ArgsType) -> BodyRule:
+        return BodyRule(args)
+
+    def block(self, args: ArgsType) -> BlockRule:
+        return BlockRule(args)
+
+    def identifier(self, args: ArgsType) -> IdentifierRule:
+        return IdentifierRule(args)
+
+    def int_lit(self, args: ArgsType) -> IntLitRule:
+        return IntLitRule(args)
+
+    def float_lit(self, args: ArgsType) -> FloatLitRule:
+        return FloatLitRule(args)
+
+    def string_lit(self, args: ArgsType) -> StringLitRule:
+        return StringLitRule(args)
+
+    def expr_term(self, args: ArgsType) -> ExprTermRule:
+        return ExprTermRule(args)
+
+    def conditional(self, args: ArgsType) -> ConditionalRule:
+        return ConditionalRule(args)
+
+    def binary_operator(self, args: ArgsType) -> BinaryOperatorRule:
+        return BinaryOperatorRule(args)
+
+    def binary_term(self, args: ArgsType) -> BinaryTermRule:
+        return BinaryTermRule(args)
+
+    def unary_op(self, args: ArgsType) -> UnaryOpRule:
+        return UnaryOpRule(args)
+
+    def binary_op(self, args: ArgsType) -> BinaryOpRule:
+        return BinaryOpRule(args)
+
+    def attribute(self, args: ArgsType) -> AttributeRule:
+        return AttributeRule(args)
+
+    def new_line_or_comment(self, args: ArgsType) -> NewLineOrCommentRule:
+        if self._with_comments:
+            return NewLineOrCommentRule(args)
+        return Discard
+
+    def transform(self, tree: Tree[_Leaf_T]) -> LarkRule:
+        return super().transform(tree)
+
+    def __default_token__(self, token: Token) -> LarkToken:
+        return LarkToken(token.type, token.value)