If working

src/ytdl_sub/script/functions/__init__.py

@@ -1,9 +1,8 @@
 from typing import Optional
 
-from ytdl_sub.script.functions.conditional_functions import ConditionalFunctions
 from ytdl_sub.script.functions.numeric_functions import NumericFunctions
 from ytdl_sub.script.functions.string_functions import StringFunctions
 
 
-class Functions(StringFunctions, NumericFunctions, ConditionalFunctions):
+class Functions(StringFunctions, NumericFunctions):
     pass

src/ytdl_sub/script/functions/conditional_functions.py

@@ -1,17 +0,0 @@
-from typing import TypeVar
-
-from ytdl_sub.script.types.resolvable import Boolean
-from ytdl_sub.script.types.resolvable import Resolvable
-
-ResolvableTrue = TypeVar("ResolvableTrue", bound=Resolvable)
-ResolvableFalse = TypeVar("ResolvableFalse", bound=Resolvable)
-
-
-class ConditionalFunctions:
-    @staticmethod
-    def iff(
-        condition: Boolean, true: ResolvableTrue, false: ResolvableFalse
-    ) -> ResolvableTrue | ResolvableFalse:
-        if condition.value:
-            return true
-        return false

src/ytdl_sub/script/functions/special_functions.py

@@ -0,0 +1,24 @@
+from ytdl_sub.entries.entry import Entry
+from ytdl_sub.script.types.resolvable import Boolean
+from ytdl_sub.script.types.resolvable import Resolvable
+from ytdl_sub.script.types.resolvable import String
+
+
+class SpecialFunctions:
+    @staticmethod
+    def if_(condition: Boolean, true: Resolvable, false: Resolvable) -> Resolvable:
+        if condition.value:
+            return true
+        return false
+
+    @staticmethod
+    def entry_contains(entry: Entry, key: String) -> Boolean:
+        return Boolean(entry.kwargs_contains(key=key.value))
+
+    @staticmethod
+    def entry(entry: Entry, key: String) -> Resolvable:
+        return entry.kwargs(key=key.value)
+
+    @staticmethod
+    def entry_get(entry: Entry, key: String, default: Resolvable) -> Resolvable:
+        return entry.kwargs_get(key=key.value, default=default.value)

src/ytdl_sub/script/parser.py

@@ -4,6 +4,7 @@ from typing import Optional
 from ytdl_sub.script.syntax_tree import SyntaxTree
 from ytdl_sub.script.types.function import ArgumentType
 from ytdl_sub.script.types.function import Function
+from ytdl_sub.script.types.function import IfFunction
 from ytdl_sub.script.types.resolvable import Boolean
 from ytdl_sub.script.types.resolvable import Float
 from ytdl_sub.script.types.resolvable import Integer
@@ -157,6 +158,10 @@ class _Parser:
 
         while ch := self._read():
             if ch == ")":
+                # Special case for If functions since it can return a Union based on input types
+                if function_name == "if":
+                    return IfFunction(name=function_name, args=function_args)
+
                 return Function(name=function_name, args=function_args)
 
             if ch != "(":

src/ytdl_sub/script/types/function.py

@@ -10,12 +10,12 @@ from typing import List
 from typing import Optional
 from typing import Set
 from typing import Type
-from typing import TypeVar
 from typing import Union
 from typing import final
 from typing import get_origin
 
 from ytdl_sub.script.functions import Functions
+from ytdl_sub.script.functions.special_functions import SpecialFunctions
 from ytdl_sub.script.types.resolvable import Boolean
 from ytdl_sub.script.types.resolvable import Float
 from ytdl_sub.script.types.resolvable import Integer
@@ -48,12 +48,8 @@ class VariableDependency(ABC):
         return self.variables.issubset(set(resolved_variables.keys()))
 
 
-def is_union(type: Type) -> bool:
-    return get_origin(type) is Union
-
-
-def is_generic(type: Type) -> bool:
-    return type.__class__ is TypeVar
+def is_union(arg_type: Type) -> bool:
+    return get_origin(arg_type) is Union
 
 
 @dataclass(frozen=True)
@@ -67,10 +63,15 @@ class FunctionInputSpec:
     @classmethod
     def _is_type_compatible(
         cls,
-        input_arg: Optional[Resolvable],
+        input_arg: ArgumentType,
         expected_arg_type: Type[Resolvable | Optional[Resolvable]],
     ) -> bool:
-        input_arg_type = input_arg.__class__
+        if isinstance(input_arg, Function):
+            input_arg_type = input_arg.output_type
+        elif isinstance(input_arg, Variable):
+            return True  # unresolved variables can be anything, so pass for now
+        else:
+            input_arg_type = input_arg.__class__
 
         if is_union(expected_arg_type):
             # See if the arg is a valid against the union
@@ -82,15 +83,12 @@ class FunctionInputSpec:
 
             if not valid_type:
                 return False
-        elif is_generic(expected_arg_type):
-            # TypeVars (generics) support any type of input
-            return True
         elif not issubclass(input_arg_type, expected_arg_type):
             return False
 
         return True
 
-    def _is_args_compatible(self, input_args: List[Resolvable | Optional[Resolvable]]) -> bool:
+    def _is_args_compatible(self, input_args: List[ArgumentType]) -> bool:
         assert self.args is not None
 
         if len(input_args) > len(self.args):
@@ -103,7 +101,7 @@ class FunctionInputSpec:
 
         return True
 
-    def _is_varargs_compatible(self, input_args: List[Resolvable | Optional[Resolvable]]) -> bool:
+    def _is_varargs_compatible(self, input_args: List[ArgumentType]) -> bool:
         assert self.varargs is not None
 
         for input_arg in input_args:
@@ -112,7 +110,7 @@ class FunctionInputSpec:
 
         return True
 
-    def is_compatible(self, input_args: List[Resolvable | Optional[Resolvable]]) -> bool:
+    def is_compatible(self, input_args: List[ArgumentType]) -> bool:
         if self.args is not None:
             return self._is_args_compatible(input_args=input_args)
         elif self.varargs is not None:
@@ -199,3 +197,18 @@ class Function(VariableDependency):
 
     def resolve(self, resolved_variables: Dict[Variable, Resolvable]) -> Resolvable:
         raise NotImplemented()
+
+
+@dataclass(frozen=True)
+class IfFunction(Function):
+    def __post_init__(self):
+        super().__post_init__()
+        assert len(self.args) == 3  # bool, true, false
+
+    @property
+    def callable(self) -> Callable[..., Resolvable]:
+        return SpecialFunctions.if_
+
+    @property
+    def output_type(self) -> Type[Resolvable]:
+        return Union[self.args[1].__class__, self.args[2].__class__]

src/ytdl_sub/script/types/resolvable.py

@@ -1,6 +1,7 @@
 from abc import ABC
 from abc import abstractmethod
 from dataclasses import dataclass
+from typing import Any
 from typing import Generic
 from typing import List
 from typing import TypeVar
@@ -11,6 +12,8 @@ NumericT = TypeVar("NumericT", bound=int | float)
 
 @dataclass(frozen=True)
 class Resolvable(ABC):
+    value: Any
+
     @abstractmethod
     def resolve(self) -> str:
         ...

tests/unit/script/test_parser.py

@@ -1,8 +1,11 @@
+from typing import Union
+
 import pytest
 
 from ytdl_sub.script.parser import parse
 from ytdl_sub.script.syntax_tree import SyntaxTree
 from ytdl_sub.script.types.function import Function
+from ytdl_sub.script.types.function import IfFunction
 from ytdl_sub.script.types.resolvable import Boolean
 from ytdl_sub.script.types.resolvable import Float
 from ytdl_sub.script.types.resolvable import Integer
@@ -27,16 +30,33 @@ class TestParser:
         )
 
     def test_conditional(self):
-        parsed = parse("hello {%iff(True, 'hi', 3.4)}")
+        parsed = parse("hello {%if(True, 'hi', 3.4)}")
+        assert parsed == SyntaxTree(
+            [
+                String("hello "),
+                IfFunction(
+                    name="if", args=[Boolean(value=True), String(value="hi"), Float(value=3.4)]
+                ),
+            ]
+        )
+        assert parsed.ast[1].output_type == Union[String, Float]
+
+    def test_conditional_as_input(self):
+        parsed = parse("hello {%concat(%if(True, 'hi', 'mom'), 'and dad')}")
         assert parsed == SyntaxTree(
             [
                 String("hello "),
                 Function(
-                    name="iff", args=[Boolean(value=True), String(value="hi"), Float(value=3.4)]
+                    name="concat",
+                    args=[
+                        IfFunction(
+                            name="if", args=[Boolean(value=True), String("hi"), String("mom")]
+                        ),
+                        String(value="and dad"),
+                    ],
                 ),
             ]
         )
-        assert parsed.ast[1].output_type
 
     def test_single_function_one_vararg(self):
         parsed = parse("hello {%concat('hi mom')}")