[BACKEND] Recreate regex plugin using functions

src/ytdl_sub/entries/script/function_scripts.py

@@ -6,6 +6,8 @@ from ytdl_sub.entries.script.variable_definitions import VariableDefinitions
 v: VariableDefinitions = VARIABLES
 
 CUSTOM_FUNCTION_SCRIPTS: Dict[str, str] = {
+    #############################################################################################
+    # SIBLING GETTER
     "%extract_field_from_metadata_array_getter": """{
         %map_get( %map(%array_at($0, 0)), %array_at($0, 1) )
     }""",
@@ -34,4 +36,33 @@ CUSTOM_FUNCTION_SCRIPTS: Dict[str, str] = {
             []
         )
     }}""",
+    #############################################################################################
+    # REGEX PLUGIN
+    #   $0 - input variable
+    #   $1 - regex array
+    #   $2 - defaults
+    "%regex_capture": """{
+        %assert_then(
+            %array_reduce(
+                %array_apply_fixed(
+                    %array_apply(
+                        $1,
+                        %regex_capture_groups
+                    ),
+                    %array_size($2),
+                    %eq
+                ),
+                %and
+            ),
+            %array_first(
+                %array_apply_fixed(
+                    %array($1),
+                    %string($0),
+                    %regex_search
+                ),
+                %array_extend( ['dummy'], $2 )
+            ),
+            'Number of regex capture groups must be the same for every input regex'
+        )
+    }""",
 }

src/ytdl_sub/script/functions/array_functions.py

@@ -57,6 +57,18 @@ class ArrayFunctions:
         """
         return array.value[idx.value]
 
+    @staticmethod
+    def array_first(array: Array, fallback: AnyArgument) -> AnyArgument:
+        """
+        Returns the first element whose boolean conversion is True. Returns fallback
+        if all elements evaluate to False.
+        """
+        for val in array.value:
+            if bool(val.value):
+                return val
+
+        return fallback
+
     @staticmethod
     def array_contains(array: Array, value: AnyArgument) -> Boolean:
         """
@@ -130,6 +142,16 @@ class ArrayFunctions:
         """
         return Array([Array([val]) for val in array.value])
 
+    @staticmethod
+    def array_apply_fixed(
+        array: Array, fixed_argument: AnyArgument, lambda2_function: LambdaTwo
+    ) -> Array:
+        """
+        Apply a lambda function on every element in the Array, with ``fixed_argument``
+        passed as a second argument to every invocation.
+        """
+        return Array([Array([val, fixed_argument]) for val in array.value])
+
     @staticmethod
     def array_enumerate(array: Array, lambda_function: LambdaTwo) -> Array:
         """

src/ytdl_sub/script/functions/error_functions.py

@@ -21,3 +21,15 @@ class ErrorFunctions:
         if not bool(value.value):
             raise UserThrownRuntimeError(assert_message)
         return value
+
+    @staticmethod
+    def assert_then(
+        value: AnyArgument, ret: ReturnableArgument, assert_message: String
+    ) -> ReturnableArgument:
+        """
+        Explicitly throw an error with the provided assert message if ``value`` evaluates to False.
+        If it evaluates to True, it will return ``ret``.
+        """
+        if not bool(value.value):
+            raise UserThrownRuntimeError(assert_message)
+        return ret

src/ytdl_sub/script/functions/regex_functions.py

@@ -3,6 +3,7 @@ from typing import AnyStr
 from typing import Match
 
 from ytdl_sub.script.types.array import Array
+from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 
 
@@ -40,3 +41,10 @@ class RegexFunctions:
         group as a subsequent element in the Array.
         """
         return _re_output_to_array(re.fullmatch(regex.value, string.value))
+
+    @staticmethod
+    def regex_capture_groups(regex: String) -> Integer:
+        """
+        Returns number of capture groups in regex
+        """
+        return Integer(re.compile(regex.value).groups)

tests/e2e/plugins/test_regex.py

@@ -76,6 +76,21 @@ def regex_subscription_dict(regex_subscription_dict_base, output_directory):
                 }
             },
             "overrides": {
+                "title_capture_list": f"""{{
+                    %regex_capture(
+                        title,
+                        [
+                            "should not cap (.+) - (.+)",
+                            ".*\\[(.+) - (Feb.+)]"
+                        ],
+                        [
+                            "ack",
+                            "ack"
+                        ]
+                    )
+                }}""",
+                "title_capture_list_1": "{%array_at(title_capture_list, 1)}",
+                "title_capture_list_2": "{%array_at(title_capture_list, 2)}",
                 "contains_regex_default": "contains {title_type}",
                 "contains_regex_sanitized_default": "contains {title_type_sanitized}",
             },