slick script class

src/ytdl_sub/script/script.py

@@ -11,6 +11,7 @@ from ytdl_sub.script.types.variable import Variable
 from ytdl_sub.script.utils.exceptions import UNREACHABLE
 from ytdl_sub.script.utils.exceptions import CycleDetected
 from ytdl_sub.script.utils.exceptions import InvalidCustomFunctionArguments
+from ytdl_sub.script.utils.exceptions import RuntimeException
 from ytdl_sub.script.utils.name_validation import validate_variable_name
 
 # pylint: disable=missing-raises-doc
@@ -143,6 +144,12 @@ class Script:
                         f"{nested_custom_function.num_input_args}"
                     )
 
+    def _validate(self) -> None:
+        self._ensure_no_custom_function_cycles()
+        self._ensure_custom_function_arguments_valid()
+        self._ensure_no_variable_cycles()
+        self._ensure_custom_function_usage_num_input_arguments_valid()
+
     def __init__(self, script: Dict[str, str]):
         function_names: Set[str] = {
             self._function_name(name) for name in script.keys() if self._is_function(name)
@@ -174,25 +181,29 @@ class Script:
             for variable_key, variable_value in script.items()
             if not self._is_function(variable_key)
         }
+        self._validate()
 
-        self._ensure_no_custom_function_cycles()
+    def _update_internally(self, resolved_variables: Dict[str, Resolvable]) -> None:
-        self._ensure_custom_function_arguments_valid()
+        for variable_name, resolved in resolved_variables.items():
-        self._ensure_no_variable_cycles()
+            self._variables[variable_name] = SyntaxTree(ast=[resolved])
-        self._ensure_custom_function_usage_num_input_arguments_valid()
 
     def resolve(
         self,
         resolved: Optional[Dict[str, Resolvable]] = None,
         unresolvable: Optional[Set[str]] = None,
+        update: bool = False,
     ) -> Dict[str, Resolvable]:
         """
         Parameters
         ----------
         resolved
-            Optional variables that have been resolved elsewhere and could be used in this script
+            Optional. Variables that have been resolved elsewhere and could be used in this script
         unresolvable
-            Variables that cannot be resolved, forcing any variable that depends on it to not be
+            Optional. Variables that cannot be resolved, forcing any variable that depends on it
-            resolved.
+            to not be resolved.
+        update
+            Optional. Whether to update the internal representation of variables with their
+            resolved value (if they get resolved).
 
         Returns
         -------
@@ -232,4 +243,32 @@ class Script:
                 # since cycles are detected in __init__
                 raise UNREACHABLE
 
-        return {variable.name: resolvable for variable, resolvable in resolved.items()}
+        resolved_variables = {
+            variable.name: resolvable for variable, resolvable in resolved.items()
+        }
+        if update:
+            self._update_internally(resolved_variables=resolved_variables)
+
+        return resolved_variables
+
+    def add(self, variables: Dict[str, str]) -> "Script":
+        for variable_name, variable_definition in variables.items():
+            self._variables[variable_name] = parse(
+                text=variable_definition,
+                name=variable_name,
+                custom_function_names=set(self._functions.keys()),
+                variable_names=set(self._variables.keys()).union(variables.keys()),
+            )
+        self._validate()
+        return self
+
+    def get(self, variable_name: str) -> Resolvable:
+        if variable_name not in self._variables:
+            raise RuntimeException(
+                f"Tried to get resolved variable {variable_name}, but it does not exist"
+            )
+
+        if (resolvable := self._variables[variable_name].resolvable) is not None:
+            return resolvable
+
+        raise RuntimeException(f"Tried to get unresolved variable {variable_name}")

src/ytdl_sub/script/types/syntax_tree.py

@@ -1,6 +1,7 @@
 from dataclasses import dataclass
 from typing import Dict
 from typing import List
+from typing import Optional
 
 from ytdl_sub.script.types.resolvable import Argument
 from ytdl_sub.script.types.resolvable import Resolvable
@@ -38,3 +39,9 @@ class SyntaxTree(VariableDependency):
 
         # Otherwise, to concat multiple resolved outputs, we must concat as strings
         return String("".join([str(res) for res in resolved]))
+
+    @property
+    def resolvable(self) -> Optional[Resolvable]:
+        if len(self.ast) == 1 and isinstance(self.ast[0], Resolvable):
+            return self.ast[0]
+        return None

src/ytdl_sub/script/utils/exceptions.py

@@ -7,6 +7,10 @@ class UserException(ValidationException, ABC):
     """It's the user's fault!"""
 
 
+class RuntimeException(ValueError, ABC):
+    """Exception thrown at runtime during resolution"""
+
+
 class InvalidSyntaxException(UserException):
     """Syntax is incorrect"""
 
@@ -43,10 +47,6 @@ class CycleDetected(UserException):
     """A cycle exists within a user's script"""
 
 
-class RuntimeException(ValueError, ABC):
-    """Exception thrown at runtime during resolution"""
-
-
 class FunctionRuntimeException(RuntimeException):
     """Exception thrown when a ytdl-sub function has an error occur at runtime"""
 

tests/unit/script/test_script.py

@@ -34,16 +34,23 @@ class TestScript:
                 "entry": "{%throw('entry has not been populated yet')}",
                 "title": "{%map_get(entry, 'title')}",
                 "override": "hi",
+                "resolved_override": "{override} mom",
             }
         )
 
-        overrides = script.resolve(unresolvable={"entry"})
+        script.resolve(unresolvable={"entry"}, update=True)
-        assert overrides == {"override": String("hi")}
+        assert script.get("override") == String("hi")
+        assert script.get("resolved_override") == String("hi mom")
 
-        entry_map = ResolvedMap({String("title"): String("the title")})
+        script.add(
-        entry_output = script.resolve(resolved=dict(overrides, **{"entry": entry_map}))
+            {
-        assert entry_output == {
+                "new_variable": "{resolved_override} {title}",
-            "override": String("hi"),
+                "new_variable_upper": "{%upper(new_variable)}",
-            "entry": entry_map,
-            "title": String("the title"),
             }
+        ).resolve(
+            resolved={"entry": ResolvedMap({String("title"): String("the title")})}, update=True
+        )
+
+        assert script.get("title") == String("the title")
+        assert script.get("new_variable") == String("hi mom the title")
+        assert script.get("new_variable_upper") == String("HI MOM THE TITLE")