elipl/test1.exs
Kacper Marzecki 7d02481d9f checkpoint
2025-06-17 10:31:39 +02:00

1547 lines
64 KiB
Elixir

doc = """
# Ternary Decision Diagram (TDD) for Set-Theoretic Types in Elixir
## 1. Introduction
This document outlines the design and implementation of a Ternary Decision Diagram (TDD) based system for representing and manipulating set-theoretic types, inspired by systems like CDuce. The goal is to create a robust way to perform type checking, type inference, and other type-level computations for a rich set of datatypes, similar to those found in Elixir.
A TDD is a directed acyclic graph (DAG) used to represent a function `f(v1, v2, ..., vn) -> {true, false, dont_care}`. In our context, it represents a characteristic function for a type: given a value, the TDD determines if the value belongs to the type (`true`), does not belong (`false`), or if the specific predicates tested so far are insufficient or irrelevant for this particular type operation (`dont_care`).
The TDDs are kept **ordered** and **reduced** to ensure a canonical representation for each type, making type equivalence checks (and other operations) efficient.
- **Ordered**: Variables (predicates) appear in the same fixed global order on all paths from the root to a terminal.
- **Reduced**: Isomorphic subgraphs are merged (shared), and nodes whose children would make the test redundant under certain TDD algebra rules are eliminated or simplified.
## 2. Core TDD Structure and Operations
### 2.1. Nodes
There are two kinds of nodes:
1. **Terminal Nodes**:
* `TRUE_TERMINAL` (ID: `1`): Represents the universal set (type `any`). A path ending here means the value (or part of it) satisfies the type constraints along that path.
* `FALSE_TERMINAL` (ID: `0`): Represents the empty set (type `none`). A path ending here means the value fails the type constraints.
2. **Variable Nodes**:
* Represented as a tuple: `{variable_identifier, yes_child_id, no_child_id, dc_child_id}`.
* `variable_identifier`: A unique, globally ordered term identifying the predicate being tested at this node (e.g., "is the value an atom?", "is the integer value < 10?").
* `yes_child_id`: The ID of the next TDD node if the predicate is true.
* `no_child_id`: The ID of the next TDD node if the predicate is false.
* `dc_child_id` (Don't Care): The ID of the next TDD node if the predicate is irrelevant for the current type or operation. The semantic interpretation of `dc` is crucial and aligns with common TDD usage (e.g., for a union operation, `dc(A | B) = dc(A) | dc(B)`).
### 2.2. Node Management (`Tdd` module state)
The `Tdd` module maintains global state (currently via `Process.put/get` for simplicity, ideally a `GenServer`):
* `@nodes`: A map from `node_tuple ({variable, yes_id, no_id, dc_id})` to `node_id`. This ensures that structurally identical nodes are shared (part of the "reduced" property).
* `@node_by_id`: A map from `node_id` to its `node_tuple` or a terminal symbol (`:true_terminal`, `:false_terminal`).
* `@next_id`: The next available integer ID for a new node.
* `@op_cache`: A map for memoizing results of operations like `apply` (binary ops), `negate`, and `simplify_with_constraints`. Keys are typically `{{op_name, id1, id2}, result_id}` or `{{op_name, id1}, result_id}`.
### 2.3. Variable Ordering
A strict global total order of all possible `variable_identifier`s is essential. This is achieved by defining variable identifiers as Elixir tuples, which have a natural sort order.
The proposed structure for variable identifiers is:
`{category_integer, predicate_type_atom, specific_value_or_nested_id}`
Example categories:
* `0`: Primary type discriminators (e.g., `is_atom`, `is_integer`, `is_list`).
* `1`: Atom-specific predicates (e.g., `value == :foo`).
* `2`: Integer-specific predicates (e.g., `value < 10`).
* `4`: Tuple-specific predicates (e.g., `size == 2`, `element 0 has_type X`).
* And so on for other types.
### 2.4. Core Operations
1. **`make_node_raw(variable, yes_id, no_id, dc_id)`**:
* The fundamental private function for creating or retrieving unique structural nodes.
* Implements structural sharing via the `@nodes` table.
* Implements a basic reduction rule: if `yes_id == no_id == dc_id`, the node is redundant, and that common child ID is returned.
2. **`check_assumptions_consistency(assumptions_map)`**:
* A private helper function crucial for semantic reduction.
* Takes a map `%{variable_id => value (true/false/:dc)}` representing current path assumptions.
* Returns `:consistent` or `:contradiction` based on predefined semantic rules of the type system (e.g., `is_atom=true` AND `is_tuple=true` is a contradiction).
* This function will be expanded as more types and predicates are added.
3. **`simplify_with_constraints(tdd_id, assumptions_map)`**:
* A private, memoized, recursive function that takes a `tdd_id` and an `assumptions_map`.
* It produces a new `tdd_id` that is semantically equivalent to the input `tdd_id` under the given assumptions, but potentially simpler.
* **Crucial Behavior**: If `check_assumptions_consistency(assumptions_map)` returns `:contradiction` at any point, `simplify_with_constraints` immediately returns `@false_node_id`.
* If the TDD's variable is already in `assumptions_map`, it follows the constrained path.
* Otherwise, it recursively simplifies children, adding the current node's variable assignment to the assumptions for those deeper calls, and rebuilds the node using `make_node_raw`.
4. **`apply_raw(op_name, op_lambda, u1_id, u2_id)`**:
* The private, memoized, recursive Shannon expansion algorithm for binary set operations (union, intersection).
* `op_lambda` defines the operation on terminal nodes.
* It selects the `top_var` based on the global variable order.
* Recursively calls `apply_raw` on the children.
* Uses `make_node_raw` to construct result nodes.
* This function computes the *structural* result of the operation.
5. **Public API Operations (`sum/2`, `intersect/2`, `negate/1`)**:
* These functions orchestrate the operation:
1. Call the respective `_raw` version (e.g., `apply_raw` for `sum`/`intersect`, `negate_raw` for `negate`).
2. Take the `raw_result_id` from step 1.
3. Return `simplify_with_constraints(raw_result_id, %{})`. This final step ensures that all TDDs exposed through the public API are not only structurally canonical (via `make_node_raw` and `apply_raw`) but also *semantically canonical* (i.e., known impossible paths or contradictions are resolved to `@false_node_id`).
6. **Type Constructors (e.g., `type_atom()`, `type_atom_literal(:foo)`)**:
* These public functions build the TDD for a specific type.
* They use `make_node_raw` to define the basic structure.
* They then return `simplify_with_constraints(raw_id, %{})` to ensure the constructed type is in its simplest semantic form.
7. **`is_subtype(sub_id, super_id)`**:
* Defined as `simplify_with_constraints(intersect(sub_id, negate(super_id)), %{}) == @false_node_id`.
* Since `intersect` and `negate` now return semantically simplified TDDs, if `A ∩ ¬B` represents an empty set, the result of the intersection will be `@false_node_id`.
## 3. Datatype Representation Details
This section outlines how various Elixir-like datatypes are (or will be) represented using TDD variables and constructors. All constructors ensure the final TDD is passed through `simplify_with_constraints(raw_id, %{})`.
### 3.1. Atoms
* **Variables**:
* `@v_is_atom = {0, :is_atom}`: Primary type check.
* `v_atom_eq_A = {1, :value, A}`: Checks if the atom's value is `A`. Order by `A`.
* **Constructors**:
* `type_atom()`: Represents any atom. TDD: `make_node_raw(@v_is_atom, @true_node_id, @false_node_id, @false_node_id)`.
* `type_atom_literal(val)`: Represents a specific atom. TDD: `make_node_raw(@v_is_atom, node_for_val_eq, @false_node_id, @false_node_id)` where `node_for_val_eq = make_node_raw(v_atom_eq_A, @true_node_id, @false_node_id, @false_node_id)`.
* **Semantic Constraints for `check_assumptions_consistency`**:
* If `assumptions_map` contains `{{0, :is_atom}, true}` and `{{0, other_primary_type}, true}` -> contradiction.
* If `assumptions_map` contains `{{1, :value, A}, true}` and `{{1, :value, B}, true}` where `A != B` -> contradiction.
### 3.2. Tuples
* **Variables**:
* `@v_is_tuple = {0, :is_tuple}`: Primary type check.
* `v_tuple_size_eq_N = {4, :size, N}`: Checks if tuple size is `N`. Order by `N`.
* `v_tuple_elem_I_PRED = {4, :element, Index_I, NESTED_PREDICATE_ID}`: Predicate for element at `Index_I`. `NESTED_PREDICATE_ID` is a variable from the global order, applied to the element. (e.g., `{4, :element, 0, {0, :is_atom}}` checks if element 0 is an atom). Order by `Index_I`, then by `NESTED_PREDICATE_ID`.
* **Constructors**:
* `type_tuple()`: Any tuple.
* `type_empty_tuple()`: The tuple `{}`.
* `type_tuple_sized_any(size)`: Any tuple of a given size.
* `type_tuple_specific(element_type_ids_list)`: e.g., for `{atom(), integer()}`. This will involve creating nodes for size, then for each element, applying the TDD for that element's type.
* **Semantic Constraints**:
* `is_tuple=true` vs. other primary types.
* If `{{4, :size, N}, true}` and `{{4, :size, M}, true}` where `N != M` -> contradiction.
* If `{{4, :size, N}, true}` and a predicate `{{4, :element, I, _}, _}` exists where `I >= N` -> potential contradiction or path simplification (element doesn't exist).
### 3.3. Integers (Next to Implement)
* **Variables**:
* `@v_is_integer = {0, :is_integer}` (or a new category, e.g., `2` for integer properties).
* INT_CAT variables (names of variables prefixed with `a b c` to force ordering
* `v_int_lt_N = {INT_CAT, :alt, N}` (value < N).
* `v_int_eq_N = {INT_CAT, :beq, N}`.
* `v_int_gt_N = {INT_CAT, :cgt, N}` (value > N).
* *(Consider also: `lte` (less than or equal), `gte` (greater than or equal) to simplify some range logic, or derive them).*
* **Constructors**:
* `type_integer()`: Any integer.
* `type_int_eq(n)`: A specific integer value.
* `type_int_lt(n)`, `type_int_gt(n)`.
* `type_int_range(min, max, min_inclusive, max_inclusive)`: Integers within a specific range.
* **Semantic Constraints**:
* `is_integer=true` vs. other primary types.
* `eq(N)` and `eq(M)` with `N != M` -> contradiction.
* `eq(N)` and `lt(M)` if `N >= M` -> contradiction.
* `eq(N)` and `gt(M)` if `N <= M` -> contradiction.
* `lt(N)` and `gt(M)` if `N <= M+1` (or `N <= M` if `gt` means `>=`) -> contradiction. (e.g., `x < 5` and `x > 4` has no integer solution).
* *Strategy for complex integer constraints*: Maintain a "current allowed interval" `[min_assumed, max_assumed]` based on `assumptions_map`. If this interval becomes empty or invalid, it's a contradiction. Each new integer assumption (`lt, gt, eq`) refines this interval.
### 3.4. Lists (Implemented)
* **Variables**:
* `@v_is_list = {0, :is_list}`.
* `v_list_is_empty = {5, :is_empty}`.
* *If not empty*:
* `v_list_head_pred = {5, :head, NESTED_PREDICATE_ID}`: Applies a global predicate to the head.
* `v_list_tail_pred = {5, :tail, NESTED_PREDICATE_ID_FOR_TAIL}`: Applies a global predicate (usually list predicates) to the tail.
* **Constructors**:
* `type_list()`: Represents any list.
* `type_empty_list()`: Represents the empty list `[]`.
* `type_cons(head_type_id, tail_type_id)`: Represents a non-empty list `[H|T]` where `H` is of type `head_type_id` and `T` is of type `tail_type_id`.
* **Semantic Constraints**:
* `is_list=true` vs. other primary types.
* If `is_empty=true`, any predicate on the `head` or `tail` is a contradiction.
* Recursive consistency checks on `head` and `tail` sub-types.
### 3.5. Strings & Binaries (Planned)
* **Variables**:
* `@v_is_binary = {0, :is_binary}`.
* `@v_is_string = {0, :is_string}` (can be a check after `is_binary` or a distinct primary type if model demands).
* Size/length predicates: `v_binary_size_eq_N`, `v_string_length_eq_N`.
* Content predicates: `v_string_eq_S`, `v_string_prefix_P`, `v_string_suffix_S`, `v_string_matches_regex_R`.
* **Semantic Constraints**: Size vs content (e.g., `size=1` and `prefix="foo"` is a contradiction). `eq(S1)` and `eq(S2)` if `S1 != S2`.
### 3.6. Maps (Planned - Complex)
* **Variables**:
* `@v_is_map = {0, :is_map}`.
* `v_map_size_eq_N`.
* `v_map_has_key_K`: (K is a canonical representation of an Elixir term).
* *If `has_key_K` is true*:
* `v_map_key_K_value_VAR = {MAP_CAT, :key_value, K, NESTED_PREDICATE_ID}`: Applies a global predicate to the value associated with key K.
* For `%{pattern_key => pattern_value}` types:
* This requires careful thought. Might involve predicates like `v_map_all_keys_matching_TYPE_X_have_values_matching_TYPE_Y`.
* **Semantic Constraints**: `is_map` vs. others. Size vs. `has_key` interactions. Contradictory type requirements for the same key's value.
### 3.7. Functions (Planned - Very Complex)
* Representation of function types (`fun((Arg1Type, Arg2Type, ...) -> ReturnType)`) is a significant challenge for TDDs.
* **Variables (Tentative)**:
* `@v_is_function = {0, :is_function}`.
* `v_fun_arity_eq_A`.
* Predicates for argument types at specific positions (e.g., `v_fun_arg_I_type_VAR`).
* Predicates for return type (e.g., `v_fun_return_type_VAR`).
* Intersection and union of function types involve concepts like contravariance of arguments and covariance of return types. This may require specialized logic beyond simple TDD operations or a very elaborate variable scheme. Often, function types are handled with auxiliary structures in type systems.
## 4. Current Status & Next Steps
* **Implemented**: Atoms, basic Tuples (any, empty, sized_any). Core TDD operations (`sum`, `intersect`, `negate`, `is_subtype`) with semantic simplification framework (`simplify_with_constraints` and `check_assumptions_consistency`).
* **Passing Tests**: A suite of tests for atom/tuple interactions, unions, intersections, negations, and subtyping, including resolution of contradictions like `atom & tuple == none`.
* **Next Immediate Step**: Implement **Integer types** as outlined in section 3.3. This will involve:
1. Defining integer-specific predicates and their global order.
2. Creating integer type constructors.
3. Significantly expanding `check_assumptions_consistency` to handle integer comparisons (`eq`, `lt`, `gt`) and their interactions.
4. Adding comprehensive tests for integers.
## 5. Future Considerations
* **Performance**: For very large TDDs or complex types, the number of nodes and cache sizes can grow. Investigate optimizations if needed.
* **Generality of `check_assumptions_consistency`**: Designing this to be easily extensible and correct for many interacting predicates is challenging. A rule-based system or a more abstract way to define predicate interactions might be beneficial.
* **"Don't Care" (`dc`) branch semantics**: Ensure the `dc` branch is consistently and correctly handled in all operations, especially `simplify_with_constraints` if assumptions can make a variable "don't care". Currently, `simplify_with_constraints` assumes `true/false/:dc` values in the `assumptions_map` if a variable is already constrained.
* **Type Inference**: Using the TDD operations to infer types or solve type constraints.
* **Polymorphism**: Representing and operating on types with free type variables. Typically, free variables are treated as `any` or involve substitution before TDD construction.
This document provides a snapshot of the current TDD system and a roadmap for its extension. The core principle is the combination of structurally canonical ROBDDs (via `make_node_raw` and `apply_raw`) with a semantic simplification layer (`simplify_with_constraints`) that embeds knowledge of the type system's rules.
"""
defmodule Tdd.Core do
@moduledoc """
The core, semantically-unaware TDD graph engine.
It supports three kinds of nodes:
- Terminals (true/false)
- Test Nodes: {variable, yes_id, no_id, dc_id}
- Applicator Nodes: {{:all_elements}, element_type_id}
"""
# --- Terminal Node IDs ---
@false_node_id 0
@true_node_id 1
def true_id, do: @true_node_id
def false_id, do: @false_node_id
defguard is_terminal_id(id) when id == @false_node_id or id == @true_node_id
def terminal_id?(id) when is_terminal_id(id), do: true
def terminal_id?(_), do: false
# --- State Management ---
def init do
Process.put(:tdd_test_nodes, %{})
Process.put(:tdd_applicator_nodes, %{})
Process.put(:tdd_node_by_id, %{@false_node_id => false, @true_node_id => true})
Process.put(:tdd_next_id, 2)
Process.put(:tdd_op_cache, %{})
:ok
end
defp get_state do
%{
test_nodes: Process.get(:tdd_test_nodes, %{}),
applicator_nodes: Process.get(:tdd_applicator_nodes, %{}),
node_by_id: Process.get(:tdd_node_by_id, %{@false_node_id => false, @true_node_id => true}),
next_id: Process.get(:tdd_next_id, 2),
op_cache: Process.get(:tdd_op_cache, %{})
}
end
defp update_state(changes) do
current_state = get_state()
new_state = Map.merge(current_state, changes)
Process.put(:tdd_test_nodes, new_state.test_nodes)
Process.put(:tdd_applicator_nodes, new_state.applicator_nodes)
Process.put(:tdd_node_by_id, new_state.node_by_id)
Process.put(:tdd_next_id, new_state.next_id)
Process.put(:tdd_op_cache, new_state.op_cache)
end
def clear_op_cache, do: Process.put(:tdd_op_cache, %{})
def get_node(id) when is_terminal_id(id), do: if(id == @true_node_id, do: true, else: false)
def get_node(id), do: get_state().node_by_id[id]
def get_op_cache(key), do: get_state().op_cache[key]
def put_op_cache(key, value),
do: update_state(%{op_cache: Map.put(get_state().op_cache, key, value)})
def make_node(variable, yes_id, no_id, dc_id) do
cond do
yes_id == no_id && yes_id == dc_id ->
yes_id
true ->
state = get_state()
node_tuple = {variable, yes_id, no_id, dc_id}
if Map.has_key?(state.test_nodes, node_tuple) do
state.test_nodes[node_tuple]
else
new_id = state.next_id
update_state(%{
test_nodes: Map.put(state.test_nodes, node_tuple, new_id),
node_by_id: Map.put(state.node_by_id, new_id, node_tuple),
next_id: new_id + 1
})
new_id
end
end
end
def make_applicator_node(element_type_id) do
state = get_state()
node_tuple = {{:all_elements}, element_type_id}
if Map.has_key?(state.applicator_nodes, node_tuple) do
state.applicator_nodes[node_tuple]
else
new_id = state.next_id
update_state(%{
applicator_nodes: Map.put(state.applicator_nodes, node_tuple, new_id),
node_by_id: Map.put(state.node_by_id, new_id, node_tuple),
next_id: new_id + 1
})
new_id
end
end
end
defmodule Tdd.PredicateLogic do
@moduledoc "Reasons about base predicates within a single context."
alias Tdd.Variables, as: V
@primary_types [:is_atom, :is_tuple, :is_integer, :is_list]
@primary_type_exclusivity_rules (for type <- @primary_types, into: %{} do
antecedent = {{0, type}, true}
consequents =
for other_type <- @primary_types, other_type != type do
{{{0, other_type}, false}}
end
{antecedent, consequents}
end)
@rules @primary_type_exclusivity_rules
def saturate(assumptions) do
case apply_static_rules(assumptions) do
{:ok, saturated_facts} -> final_check(saturated_facts)
:contradiction -> :contradiction
{:contradiction, _} -> :contradiction
end
end
defp apply_static_rules(facts) do
Enum.reduce(facts, {:ok, facts}, fn {var, val}, {status, acc_facts} ->
if status == :contradiction do
{:contradiction, %{}}
else
rules_for_fact = Map.get(@rules, {var, val}, [])
Enum.reduce_while(rules_for_fact, {:ok, acc_facts}, fn {{consequent_var, consequent_val}},
{_st, inner_facts} ->
case Map.get(inner_facts, consequent_var) do
nil -> {:cont, {:ok, Map.put(inner_facts, consequent_var, consequent_val)}}
^consequent_val -> {:cont, {:ok, inner_facts}}
_ -> {:halt, {:contradiction, %{}}}
end
end)
end
end)
end
defp final_check(facts) do
cond do
check_atom_values(facts) == :contradiction -> :contradiction
check_tuple_values(facts) == :contradiction -> :contradiction
check_list_structure(facts) == :contradiction -> :contradiction
check_integer_ranges(facts) == :contradiction -> :contradiction
true -> {:ok, facts}
end
end
def check_implication(predicate, constraints) do
case saturate(Map.put(constraints, predicate, true)) do
:contradiction ->
false
_ ->
case saturate(Map.put(constraints, predicate, false)) do
:contradiction -> true
_ -> :unknown
end
end
end
# --- PRIVATE HELPERS ---
defp check_atom_values(facts) do
trues =
Enum.reduce(facts, MapSet.new(), fn
{{1, :value, v}, true}, acc -> MapSet.put(acc, v)
_, acc -> acc
end)
if MapSet.size(trues) > 1, do: :contradiction, else: :ok
end
defp check_tuple_values(facts) do
trues =
Enum.reduce(facts, MapSet.new(), fn
{{4, :size, v}, true}, acc -> MapSet.put(acc, v)
_, acc -> acc
end)
if MapSet.size(trues) > 1, do: :contradiction, else: :ok
end
defp check_list_structure(facts) do
is_empty = Map.get(facts, V.v_list_is_empty()) == true
has_head_tail =
Enum.any?(facts, fn {var, _} -> match?({5, :head, _}, var) or match?({5, :tail, _}, var) end)
if is_empty and has_head_tail, do: :contradiction, else: :ok
end
defp check_integer_ranges(facts) do
if facts[V.v_is_integer()] != true do
:ok
else
if calculate_integer_interval(facts) == :contradiction, do: :contradiction, else: :ok
end
end
defp calculate_integer_interval(facts) do
bounds =
Enum.reduce(facts, %{eq: nil, min: nil, max: nil}, fn
{var, true}, acc ->
case var do
{2, :beq, n} ->
if(is_nil(acc.eq) or acc.eq == n, do: %{acc | eq: n}, else: %{acc | eq: :conflict})
{2, :alt, n} ->
%{acc | max: min_opt(acc.max, n - 1)}
{2, :cgt, n} ->
%{acc | min: max_opt(acc.min, n + 1)}
_ ->
acc
end
{var, false}, acc ->
case var do
{2, :alt, n} -> %{acc | min: max_opt(acc.min, n)}
{2, :cgt, n} -> %{acc | max: min_opt(acc.max, n)}
_ -> acc
end
_, acc ->
acc
end)
cond do
bounds.eq == :conflict ->
:contradiction
is_integer(bounds.eq) ->
if (is_nil(bounds.min) or bounds.eq >= bounds.min) and
(is_nil(bounds.max) or bounds.eq <= bounds.max) do
{bounds.eq, bounds.eq}
else
:contradiction
end
is_integer(bounds.min) and is_integer(bounds.max) and bounds.min > bounds.max ->
:contradiction
true ->
{bounds.min, bounds.max}
end
end
defp min_opt(nil, x), do: x
defp min_opt(x, nil), do: x
defp min_opt(x, y), do: min(x, y)
defp max_opt(nil, x), do: x
defp max_opt(x, nil), do: x
defp max_opt(x, y), do: max(x, y)
end
defmodule Tdd do
alias Tdd.Core
alias Tdd.PredicateLogic
alias Tdd.Variables, as: V
def init_tdd_system, do: Core.init()
defmodule Variables do
def v_is_atom, do: {0, :is_atom}
def v_is_tuple, do: {0, :is_tuple}
def v_is_integer, do: {0, :is_integer}
def v_is_list, do: {0, :is_list}
def v_atom_eq(v), do: {1, :value, v}
def v_int_eq(n), do: {2, :beq, n}
def v_int_lt(n), do: {2, :alt, n}
def v_int_gt(n), do: {2, :cgt, n}
def v_tuple_size_eq(n), do: {4, :size, n}
def v_tuple_elem(i, base_var), do: {4, :element, i, base_var}
def v_list_is_empty, do: {5, :is_empty}
def v_list_head(base_var), do: {5, :head, base_var}
def v_list_tail(base_var), do: {5, :tail, base_var}
end
# --- Type Constructors ---
def type_any, do: Core.true_id()
def type_none, do: Core.false_id()
def type_atom, do: Core.make_node(V.v_is_atom(), type_any(), type_none(), type_none())
def type_tuple, do: Core.make_node(V.v_is_tuple(), type_any(), type_none(), type_none())
def type_integer, do: Core.make_node(V.v_is_integer(), type_any(), type_none(), type_none())
def type_list, do: Core.make_node(V.v_is_list(), type_any(), type_none(), type_none())
def type_atom_literal(val), do: intersect(type_atom(), Core.make_node(V.v_atom_eq(val), type_any(), type_none(), type_none()))
def type_int_eq(n), do: intersect(type_integer(), Core.make_node(V.v_int_eq(n), type_any(), type_none(), type_none()))
def type_int_lt(n), do: intersect(type_integer(), Core.make_node(V.v_int_lt(n), type_any(), type_none(), type_none()))
def type_int_gt(n), do: intersect(type_integer(), Core.make_node(V.v_int_gt(n), type_any(), type_none(), type_none()))
def type_empty_tuple, do: intersect(type_tuple(), Core.make_node(V.v_tuple_size_eq(0), type_any(), type_none(), type_none()))
def type_tuple_sized_any(size), do: intersect(type_tuple(), Core.make_node(V.v_tuple_size_eq(size), type_any(), type_none(), type_none()))
def type_tuple(element_type_ids) when is_list(element_type_ids) do
base_type = type_tuple_sized_any(length(element_type_ids))
Enum.reduce(Enum.with_index(element_type_ids), base_type, fn {elem_type_id, index}, acc_tdd ->
elem_constraint_tdd = prefix_tdd_vars(elem_type_id, &V.v_tuple_elem(index, &1))
intersect(acc_tdd, elem_constraint_tdd)
end)
end
def type_empty_list, do: intersect(type_list(), Core.make_node(V.v_list_is_empty(), type_any(), type_none(), type_none()))
def type_cons(head_type_id, tail_type_id) do
non_empty_list = intersect(type_list(), negate(type_empty_list()))
head_constraint = prefix_tdd_vars(head_type_id, &V.v_list_head/1)
tail_constraint = prefix_tdd_vars(tail_type_id, &V.v_list_tail/1)
non_empty_list |> intersect(head_constraint) |> intersect(tail_constraint)
end
def type_list_of(element_type_id) do
if element_type_id == type_any() do
type_list()
else
applicator_node = Core.make_applicator_node(element_type_id)
# A `list_of(T)` is a list that is also constrained by this applicator.
intersect(type_list(), applicator_node)
end
end
# --- High-Level Operations ---
def intersect(u1_id, u2_id), do: do_op(:intersect, u1_id, u2_id)
def sum(u1_id, u2_id), do: do_op(:sum, u1_id, u2_id)
def negate(u_id), do: negate_recursive(u_id, %{})
def is_subtype(sub_id, super_id), do: intersect(sub_id, negate(super_id)) == type_none()
# --- Core Recursive Operation Logic ---
defp do_op(op_name, u1_id, u2_id) do
cache_key = {op_name, Enum.sort([u1_id, u2_id])}
if cached = Core.get_op_cache(cache_key) do
cached
else
# Final simplification is now part of the operation itself
res = dispatch_op(op_name, u1_id, u2_id, %{}) |> simplify(%{})
Core.put_op_cache(cache_key, res)
res
end
end
defp dispatch_op(op_name, u1_id, u2_id, constraints) do
s1_id = simplify(u1_id, constraints)
s2_id = simplify(u2_id, constraints)
cond do
s1_id == s2_id -> s1_id
op_name == :intersect and (s1_id == type_none() or s2_id == type_none()) -> type_none()
op_name == :intersect and s1_id == type_any() -> s2_id
op_name == :intersect and s2_id == type_any() -> s1_id
op_name == :sum and (s1_id == type_any() or s2_id == type_any()) -> type_any()
op_name == :sum and s1_id == type_none() -> s2_id
op_name == :sum and s2_id == type_none() -> s1_id
true ->
n1 = Core.get_node(s1_id)
n2 = Core.get_node(s2_id)
handle_op(op_name, s1_id, n1, s2_id, n2, constraints)
end
end
# --- RENAMED AND CORRECTED DISPATCHER ---
defp handle_op(op_name, s1_id, n1, s2_id, n2, constraints) do
# IO.inspect({op_name, s1_id, s2_id}, label: "HANDLE_OP")
case {n1, n2} do
# Case 1: The key logic for two `list_of` types. This is a terminal case for the recursion.
{{{_app = :all_elements}, t1_id}, {{_app, _}, t2_id}} ->
op_fun = if op_name == :intersect, do: &intersect/2, else: &sum/2
result_element_type = op_fun.(t1_id, t2_id)
# We must return the *full* `list_of` type, which is `list & applicator`
if result_element_type == type_none() do
type_empty_list()
else
type_list_of(result_element_type)
end
# Case 2: Any other combination falls through to the robust Shannon expansion.
_ ->
shannon_expand(op_name, s1_id, n1, s2_id, n2, constraints)
end
end
defp handle_applicators_or_expand(op_name, s1_id, n1, s2_id, n2, constraints) do
case {n1, n2} do
{{{_app = :all_elements}, t1_id}, {{_app, _}, t2_id}} ->
op_fun = if op_name == :intersect, do: &intersect/2, else: &sum/2
result_element_type = op_fun.(t1_id, t2_id)
type_list_of(result_element_type)
# All other combinations (Test/Test, App/Test, Test/App) fall through to expansion.
_ ->
shannon_expand(op_name, s1_id, n1, s2_id, n2, constraints)
end
end
defp get_var_from_node({var, _, _, _}), do: var
defp get_var_from_node(other_node) do
IO.inspect(other_node,label: "GET_VAR_FROM_OTHER_NODE")
:infinity # Terminals and applicators sort last
end
defp shannon_expand(op_name, s1_id, n1, s2_id, n2, constraints) do
var1 = get_var_from_node(n1)
var2 = get_var_from_node(n2)
top_var = Enum.min_by([var1, var2], fn
:infinity -> {1, nil}
var -> {0, var}
end)
if top_var == :infinity, do: raise("shannon_expand called with two non-test nodes")
{_, y1, n1_child, d1} = if var1 == top_var, do: n1, else: {nil, s1_id, s1_id, s1_id}
{_, y2, n2_child, d2} = if var2 == top_var, do: n2, else: {nil, s1_id, s1_id, s1_id}
res_y = dispatch_op(op_name, y1, y2, Map.put(constraints, top_var, true))
res_n = dispatch_op(op_name, n1_child, n2_child, Map.put(constraints, top_var, false))
res_d = dispatch_op(op_name, d1, d2, Map.put(constraints, top_var, :dc))
Core.make_node(top_var, res_y, res_n, res_d)
end
defp negate_recursive(id, constraints) do
cache_key = {:negate, id, Map.to_list(constraints) |> Enum.sort()}
if cached = Core.get_op_cache(cache_key) do
cached
else
s_id = simplify(id, constraints)
res =
case Core.get_node(s_id) do
true -> type_none()
false -> type_any()
{{:all_elements}, t_id} ->
sum(negate(type_list()), type_list_of(negate(t_id)))
{var, y, n, d} ->
res_y = negate_recursive(y, Map.put(constraints, var, true))
res_n = negate_recursive(n, Map.put(constraints, var, false))
res_d = negate_recursive(d, Map.put(constraints, var, :dc))
Core.make_node(var, res_y, res_n, res_d)
end
Core.put_op_cache(cache_key, res)
res
end
end
def simplify(id, constraints) do
cache_key = {:simplify, id, Map.to_list(constraints) |> Enum.sort()}
if cached = Core.get_op_cache(cache_key) do
cached
else
res =
case Core.get_node(id) do
true -> type_any()
false -> type_none()
# Applicators and terminals are already simple
{{:all_elements}, _} -> id
# Now, it must be a test node
{var, y, n, d} ->
case PredicateLogic.check_implication(var, constraints) do
true -> simplify(y, constraints)
false -> simplify(n, constraints)
:unknown ->
res_y = simplify(y, Map.put(constraints, var, true))
res_n = simplify(n, Map.put(constraints, var, false))
res_d = simplify(d, Map.put(constraints, var, :dc))
Core.make_node(var, res_y, res_n, res_d)
end
end
Core.put_op_cache(cache_key, res)
res
end
end
defp prefix_tdd_vars(tdd_id, prefix_fun) do
cache_key = {:prefix, tdd_id, inspect(prefix_fun)}
if cached = Core.get_op_cache(cache_key) do
cached
else
res =
case Core.get_node(tdd_id) do
true ->
type_any()
false ->
type_none()
{{:all_elements}, _} ->
raise "Cannot prefix a TDD containing an applicator node"
{var, y, n, d} ->
new_var = prefix_fun.(var)
res_y = prefix_tdd_vars(y, prefix_fun)
res_n = prefix_tdd_vars(n, prefix_fun)
res_d = prefix_tdd_vars(d, prefix_fun)
Core.make_node(new_var, res_y, res_n, res_d)
end
Core.put_op_cache(cache_key, res)
res
end
end
def print_tdd(id, indent \\ 0) do
prefix = String.duplicate(" ", indent)
details = Core.get_node(id)
IO.puts("#{prefix}ID #{id}: #{inspect(details)}")
case details do
{_var, y, n, d} ->
IO.puts("#{prefix} Yes ->"); print_tdd(y, indent + 1)
IO.puts("#{prefix} No ->"); print_tdd(n, indent + 1)
IO.puts("#{prefix} DC ->"); print_tdd(d, indent + 1)
{{:all_elements}, elem_id} ->
IO.puts("#{prefix} Element Type ->"); print_tdd(elem_id, indent + 1)
_ -> :ok
end
end
end
# --- Example Usage ---
Tdd.init_tdd_system()
# Basic Types
tdd_foo = Tdd.type_atom_literal(:foo)
tdd_bar = Tdd.type_atom_literal(:bar)
tdd_atom = Tdd.type_atom()
tdd_empty_tuple = Tdd.type_empty_tuple()
tdd_any = Tdd.type_any()
tdd_none = Tdd.type_none()
test = fn name, expected, result ->
current_failures = Process.get(:test_failures, [])
if expected != result do
Process.put(:test_failures, [name | current_failures])
end
status = if expected == result, do: "PASSED", else: "FAILED"
IO.puts("#{name} (Expected: #{expected}) -> Result: #{result} - #{status}")
end
# Basic Types
tdd_foo = Tdd.type_atom_literal(:foo)
tdd_bar = Tdd.type_atom_literal(:bar)
tdd_baz = Tdd.type_atom_literal(:baz)
tdd_atom = Tdd.type_atom()
tdd_empty_tuple = Tdd.type_empty_tuple()
tdd_tuple = Tdd.type_tuple()
# Tuple of size 2, e.g. {any, any}
tdd_tuple_s2 = Tdd.type_tuple_sized_any(2)
tdd_any = Tdd.type_any()
tdd_none = Tdd.type_none()
test_all = fn ->
IO.puts("\n--- TDD for :foo ---")
Tdd.print_tdd(tdd_foo)
IO.puts("\n--- TDD for not :foo ---")
Tdd.print_tdd(Tdd.negate(tdd_foo))
IO.puts("\n--- TDD for atom ---")
Tdd.print_tdd(tdd_atom)
IO.puts("\n--- TDD for not atom ---")
# Expected: make_node(@v_is_atom, @false_node_id, @true_node_id, @true_node_id)
# This represents "anything that is not an atom". The DC branch becomes true because if
# "is_atom" test is irrelevant for "not atom", it means it's part of "not atom".
Tdd.print_tdd(Tdd.negate(tdd_atom))
IO.puts("\n--- TDD for :foo and :bar (should be none) ---")
tdd_foo_and_bar = Tdd.intersect(tdd_foo, tdd_bar)
# Expected ID 0: :false_terminal
Tdd.print_tdd(tdd_foo_and_bar)
IO.puts("\n--- TDD for :foo and atom (should be :foo) ---")
tdd_foo_and_atom = Tdd.intersect(tdd_foo, tdd_atom)
# Expected to be structurally identical to tdd_foo
Tdd.print_tdd(tdd_foo_and_atom)
IO.puts("\n--- Basic Subtyping Tests ---")
test.(":foo <: atom", true, Tdd.is_subtype(tdd_foo, tdd_atom))
test.("atom <: :foo", false, Tdd.is_subtype(tdd_atom, tdd_foo))
test.(":foo <: :bar", false, Tdd.is_subtype(tdd_foo, tdd_bar))
test.(":foo <: :foo", true, Tdd.is_subtype(tdd_foo, tdd_foo))
test.("{} <: tuple", true, Tdd.is_subtype(tdd_empty_tuple, tdd_tuple))
test.("tuple <: {}", false, Tdd.is_subtype(tdd_tuple, tdd_empty_tuple))
test.(":foo <: {}", false, Tdd.is_subtype(tdd_foo, tdd_empty_tuple))
test.("tuple_size_2 <: tuple", true, Tdd.is_subtype(tdd_tuple_s2, tdd_tuple))
test.("tuple <: tuple_size_2", false, Tdd.is_subtype(tdd_tuple, tdd_tuple_s2))
test.("tuple_size_2 <: {}", false, Tdd.is_subtype(tdd_tuple_s2, tdd_empty_tuple))
IO.puts("\n--- Any/None Subtyping Tests ---")
test.("any <: :foo", false, Tdd.is_subtype(tdd_any, tdd_foo))
test.(":foo <: any", true, Tdd.is_subtype(tdd_foo, tdd_any))
test.("none <: :foo", true, Tdd.is_subtype(tdd_none, tdd_foo))
test.(":foo <: none", false, Tdd.is_subtype(tdd_foo, tdd_none))
test.("none <: any", true, Tdd.is_subtype(tdd_none, tdd_any))
test.("any <: none", false, Tdd.is_subtype(tdd_any, tdd_none))
test.("any <: any", true, Tdd.is_subtype(tdd_any, tdd_any))
test.("none <: none", true, Tdd.is_subtype(tdd_none, tdd_none))
IO.puts("\n--- Union related Subtyping ---")
tdd_foo_or_bar = Tdd.sum(tdd_foo, tdd_bar)
tdd_foo_or_bar_or_baz = Tdd.sum(tdd_foo_or_bar, tdd_baz)
test.(":foo <: (:foo | :bar)", true, Tdd.is_subtype(tdd_foo, tdd_foo_or_bar))
test.(":baz <: (:foo | :bar)", false, Tdd.is_subtype(tdd_baz, tdd_foo_or_bar))
test.("(:foo | :bar) <: atom", true, Tdd.is_subtype(tdd_foo_or_bar, tdd_atom))
test.("atom <: (:foo | :bar)", false, Tdd.is_subtype(tdd_atom, tdd_foo_or_bar))
test.(
"(:foo | :bar) <: (:foo | :bar | :baz)",
true,
Tdd.is_subtype(tdd_foo_or_bar, tdd_foo_or_bar_or_baz)
)
test.(
"(:foo | :bar | :baz) <: (:foo | :bar)",
false,
Tdd.is_subtype(tdd_foo_or_bar_or_baz, tdd_foo_or_bar)
)
# Test against a non-member of the union
test.("(:foo | :bar) <: :baz", false, Tdd.is_subtype(tdd_foo_or_bar, tdd_baz))
IO.puts("\n--- Intersection related Subtyping ---")
# Should be equivalent to tdd_foo
tdd_atom_and_foo = Tdd.intersect(tdd_atom, tdd_foo)
# Should be tdd_none
tdd_atom_and_tuple = Tdd.intersect(tdd_atom, tdd_tuple)
test.("(atom & :foo) <: :foo", true, Tdd.is_subtype(tdd_atom_and_foo, tdd_foo))
test.(":foo <: (atom & :foo)", true, Tdd.is_subtype(tdd_foo, tdd_atom_and_foo))
test.("(atom & tuple) <: none", true, Tdd.is_subtype(tdd_atom_and_tuple, tdd_none))
test.("none <: (atom & tuple)", true, Tdd.is_subtype(tdd_none, tdd_atom_and_tuple))
test.("(atom & :foo) <: :bar", false, Tdd.is_subtype(tdd_atom_and_foo, tdd_bar))
# An intersection is a subtype of its components
test.("(atom & :foo) <: atom", true, Tdd.is_subtype(tdd_atom_and_foo, tdd_atom))
# (none <: atom)
test.("(atom & tuple) <: atom", true, Tdd.is_subtype(tdd_atom_and_tuple, tdd_atom))
# (none <: tuple)
test.("(atom & tuple) <: tuple", true, Tdd.is_subtype(tdd_atom_and_tuple, tdd_tuple))
IO.puts("\n--- Negation related Subtyping (Contrapositives) ---")
# Reminder: ¬A <: ¬B is equivalent to B <: A (contrapositive)
# Test 1: ¬atom <: ¬:foo (Equivalent to :foo <: atom, which is true)
test.("¬atom <: ¬:foo", true, Tdd.is_subtype(Tdd.negate(tdd_atom), Tdd.negate(tdd_foo)))
# Test 2: ¬:foo <: ¬atom (Equivalent to atom <: :foo, which is false)
test.("¬:foo <: ¬atom", false, Tdd.is_subtype(Tdd.negate(tdd_foo), Tdd.negate(tdd_atom)))
# Double negation
test.("¬(¬:foo) <: :foo", true, Tdd.is_subtype(Tdd.negate(Tdd.negate(tdd_foo)), tdd_foo))
test.(":foo <: ¬(¬:foo)", true, Tdd.is_subtype(tdd_foo, Tdd.negate(Tdd.negate(tdd_foo))))
# Disjoint types
test.("atom <: ¬tuple", true, Tdd.is_subtype(tdd_atom, Tdd.negate(tdd_tuple)))
test.("tuple <: ¬atom", true, Tdd.is_subtype(tdd_tuple, Tdd.negate(tdd_atom)))
test.(":foo <: ¬{}", true, Tdd.is_subtype(tdd_foo, Tdd.negate(tdd_empty_tuple)))
IO.puts("\n--- Mixed Types & Complex Subtyping ---")
tdd_atom_or_tuple = Tdd.sum(tdd_atom, tdd_tuple)
tdd_foo_or_empty_tuple = Tdd.sum(tdd_foo, tdd_empty_tuple)
test.(
"(:foo | {}) <: (atom | tuple)",
true,
Tdd.is_subtype(tdd_foo_or_empty_tuple, tdd_atom_or_tuple)
)
test.(
"(atom | tuple) <: (:foo | {})",
false,
Tdd.is_subtype(tdd_atom_or_tuple, tdd_foo_or_empty_tuple)
)
test.(":foo <: (atom | tuple)", true, Tdd.is_subtype(tdd_foo, tdd_atom_or_tuple))
test.("{} <: (atom | tuple)", true, Tdd.is_subtype(tdd_empty_tuple, tdd_atom_or_tuple))
# De Morgan's Law illustration (A | B = ¬(¬A & ¬B))
# (:foo | :bar) <: ¬(¬:foo & ¬:bar)
tdd_not_foo_and_not_bar = Tdd.intersect(Tdd.negate(tdd_foo), Tdd.negate(tdd_bar))
test.(
"(:foo | :bar) <: ¬(¬:foo & ¬:bar)",
true,
Tdd.is_subtype(tdd_foo_or_bar, Tdd.negate(tdd_not_foo_and_not_bar))
)
test.(
"¬(¬:foo & ¬:bar) <: (:foo | :bar)",
true,
Tdd.is_subtype(Tdd.negate(tdd_not_foo_and_not_bar), tdd_foo_or_bar)
)
# Type difference: atom - :foo (represented as atom & ¬:foo)
tdd_atom_minus_foo = Tdd.intersect(tdd_atom, Tdd.negate(tdd_foo))
test.("(atom - :foo) <: atom", true, Tdd.is_subtype(tdd_atom_minus_foo, tdd_atom))
test.("(atom - :foo) <: :foo", false, Tdd.is_subtype(tdd_atom_minus_foo, tdd_foo))
# True if :bar is in (atom - :foo)
test.("(atom - :foo) <: :bar", false, Tdd.is_subtype(tdd_atom_minus_foo, tdd_bar))
test.(":bar <: (atom - :foo)", true, Tdd.is_subtype(tdd_bar, tdd_atom_minus_foo))
# (atom - :foo) | :foo should be atom
tdd_recombined_atom = Tdd.sum(tdd_atom_minus_foo, tdd_foo)
test.("((atom - :foo) | :foo) <: atom", true, Tdd.is_subtype(tdd_recombined_atom, tdd_atom))
test.("atom <: ((atom - :foo) | :foo)", true, Tdd.is_subtype(tdd_atom, tdd_recombined_atom))
# (atom | {}) & (tuple | :foo) must be (:foo | {})
# Represents `atom() | {}`
tdd_atom_or_empty = Tdd.sum(tdd_atom, tdd_empty_tuple)
# Represents `tuple() | :foo`
tdd_tuple_or_foo = Tdd.sum(tdd_tuple, tdd_foo)
intersected_complex = Tdd.intersect(tdd_atom_or_empty, tdd_tuple_or_foo)
# Expected result for intersected_complex is tdd_foo_or_empty_tuple
test.(
"(atom | {}) & (tuple | :foo) <: (:foo | {})",
true,
Tdd.is_subtype(intersected_complex, tdd_foo_or_empty_tuple)
)
test.(
"(:foo | {}) <: (atom | {}) & (tuple | :foo)",
true,
Tdd.is_subtype(tdd_foo_or_empty_tuple, intersected_complex)
)
# {} | tuple_size_2 should be a subtype of tuple
tdd_empty_or_s2 = Tdd.sum(tdd_empty_tuple, tdd_tuple_s2)
test.("({} | tuple_size_2) <: tuple", true, Tdd.is_subtype(tdd_empty_or_s2, tdd_tuple))
test.(
"({} | tuple_size_2) <: ({} | tuple_size_2)",
true,
Tdd.is_subtype(tdd_empty_or_s2, tdd_empty_or_s2)
)
test.(
"({} | tuple_size_2) <: tuple_size_2",
false,
Tdd.is_subtype(tdd_empty_or_s2, tdd_tuple_s2)
)
# IO.puts("\n--- TDD structure for (atom - :foo) ---")
# Tdd.print_tdd(tdd_atom_minus_foo)
# IO.puts("\n--- TDD structure for ((atom - :foo) | :foo) which should be 'atom' ---")
# Tdd.print_tdd(tdd_recombined_atom)
# IO.puts("\n--- TDD structure for 'atom' for comparison ---")
# Tdd.print_tdd(tdd_atom)
IO.inspect(Process.get(:test_failures, []))
end
defmodule IntegerTests do
def run(test_fn) do
Process.put(:test_failures, [])
# Reset for each test group if needed, or once globally
Tdd.init_tdd_system()
# Integer types
tdd_int = Tdd.type_integer()
tdd_int_5 = Tdd.type_int_eq(5)
tdd_int_7 = Tdd.type_int_eq(7)
# x < 10
tdd_int_lt_10 = Tdd.type_int_lt(10)
# x > 3
tdd_int_gt_3 = Tdd.type_int_gt(3)
# x < 3
tdd_int_lt_3 = Tdd.type_int_lt(3)
# x > 10
tdd_int_gt_10 = Tdd.type_int_gt(10)
tdd_atom_foo = Tdd.type_atom_literal(:foo)
#
# IO.puts("\n--- Integer Type Structures ---")
# IO.puts("Integer:")
# Tdd.print_tdd(tdd_int)
# IO.puts("Int == 5:")
# Tdd.print_tdd(tdd_int_5)
# IO.puts("Int < 10:")
# Tdd.print_tdd(tdd_int_lt_10)
IO.puts("\n--- Integer Subtyping Tests ---")
test_fn.("int_5 <: integer", true, Tdd.is_subtype(tdd_int_5, tdd_int))
test_fn.("integer <: int_5", false, Tdd.is_subtype(tdd_int, tdd_int_5))
test_fn.("int_5 <: int_7", false, Tdd.is_subtype(tdd_int_5, tdd_int_7))
test_fn.("int_5 <: int_5", true, Tdd.is_subtype(tdd_int_5, tdd_int_5))
test_fn.("int_5 <: atom_foo", false, Tdd.is_subtype(tdd_int_5, tdd_atom_foo))
test_fn.("int_lt_10 <: integer", true, Tdd.is_subtype(tdd_int_lt_10, tdd_int))
test_fn.("integer <: int_lt_10", false, Tdd.is_subtype(tdd_int, tdd_int_lt_10))
# 5 < 10
test_fn.("int_5 <: int_lt_10", true, Tdd.is_subtype(tdd_int_5, tdd_int_lt_10))
test_fn.("int_lt_10 <: int_5", false, Tdd.is_subtype(tdd_int_lt_10, tdd_int_5))
test_fn.("int_gt_3 <: integer", true, Tdd.is_subtype(tdd_int_gt_3, tdd_int))
# 5 > 3
test_fn.("int_5 <: int_gt_3", true, Tdd.is_subtype(tdd_int_5, tdd_int_gt_3))
test_fn.("int_gt_3 <: int_5", false, Tdd.is_subtype(tdd_int_gt_3, tdd_int_5))
# x < 3 implies x < 10
test_fn.("int_lt_3 <: int_lt_10", true, Tdd.is_subtype(tdd_int_lt_3, tdd_int_lt_10))
# x > 10 implies x > 3
test_fn.("int_gt_10 <: int_gt_3", true, Tdd.is_subtype(tdd_int_gt_10, tdd_int_gt_3))
test_fn.("int_lt_10 <: int_lt_3", false, Tdd.is_subtype(tdd_int_lt_10, tdd_int_lt_3))
test_fn.("int_gt_3 <: int_gt_10", false, Tdd.is_subtype(tdd_int_gt_3, tdd_int_gt_10))
IO.puts("\n--- Integer Intersection Tests (should resolve to none for contradictions) ---")
intersect_5_7 = Tdd.intersect(tdd_int_5, tdd_int_7)
test_fn.("int_5 & int_7 == none", true, intersect_5_7 == Tdd.type_none())
# IO.puts("Structure of int_5 & int_7 (should be ID 0):")
# Tdd.print_tdd(intersect_5_7)
# x < 3 AND x > 10
intersect_lt3_gt10 = Tdd.intersect(tdd_int_lt_3, tdd_int_gt_10)
test_fn.("int_lt_3 & int_gt_10 == none", true, intersect_lt3_gt10 == Tdd.type_none())
# IO.puts("Structure of int_lt_3 & int_gt_10 (should be ID 0):")
# Tdd.print_tdd(intersect_lt3_gt10)
# x < 10 AND x > 3 (e.g. 4,5..9)
intersect_lt10_gt3 = Tdd.intersect(tdd_int_lt_10, tdd_int_gt_3)
test_fn.("int_lt_10 & int_gt_3 != none", true, intersect_lt10_gt3 != Tdd.type_none())
# IO.puts("Structure of int_lt_10 & int_gt_3 (should be non-empty):")
# Tdd.print_tdd(intersect_lt10_gt3)
# Test a value within this intersection
test_fn.(
"int_5 <: (int_lt_10 & int_gt_3)",
true,
Tdd.is_subtype(tdd_int_5, intersect_lt10_gt3)
)
# x == 5 AND x < 3
intersect_5_lt3 = Tdd.intersect(tdd_int_5, tdd_int_lt_3)
test_fn.("int_5 & int_lt_3 == none", true, intersect_5_lt3 == Tdd.type_none())
IO.puts("\n--- Integer Union Tests ---")
union_5_7 = Tdd.sum(tdd_int_5, tdd_int_7)
test_fn.("int_5 <: (int_5 | int_7)", true, Tdd.is_subtype(tdd_int_5, union_5_7))
test_fn.("int_7 <: (int_5 | int_7)", true, Tdd.is_subtype(tdd_int_7, union_5_7))
test_fn.("int_lt_3 <: (int_5 | int_7)", false, Tdd.is_subtype(tdd_int_lt_3, union_5_7))
# IO.puts("Structure of int_5 | int_7:")
# Tdd.print_tdd(union_5_7)
# (int < 3) | (int > 10)
union_disjoint_ranges = Tdd.sum(tdd_int_lt_3, tdd_int_gt_10)
test_fn.(
"int_eq(0) <: (int < 3 | int > 10)",
true,
Tdd.is_subtype(Tdd.type_int_eq(0), union_disjoint_ranges)
)
test_fn.(
"int_eq(5) <: (int < 3 | int > 10)",
false,
Tdd.is_subtype(Tdd.type_int_eq(5), union_disjoint_ranges)
)
test_fn.(
"int_eq(12) <: (int < 3 | int > 10)",
true,
Tdd.is_subtype(Tdd.type_int_eq(12), union_disjoint_ranges)
)
IO.inspect(Process.get(:test_failures, []))
end
end
defmodule TupleTests do
import Tdd
def run(test_fn) do
Process.put(:test_failures, [])
# Re-init the system for a clean slate for these tests
Tdd.init_tdd_system()
IO.puts("\n--- Running TupleTests ---")
# --- Basic Types for convenience ---
t_atom = type_atom()
t_int = type_integer()
t_foo = type_atom_literal(:foo)
t_bar = type_atom_literal(:bar)
t_int_5 = type_int_eq(5)
t_int_6 = type_int_eq(6)
t_int_pos = type_int_gt(0)
t_any = type_any()
t_none = type_none()
# any tuple
t_tuple = type_tuple()
t_empty_tuple = type_empty_tuple()
# --- Specific Tuple Types ---
# {atom(), integer()}
tup_atom_int = type_tuple([t_atom, t_int])
# {:foo, 5}
tup_foo_5 = type_tuple([t_foo, t_int_5])
# {pos_integer(), atom()}
tup_pos_atom = type_tuple([t_int_pos, t_atom])
# {atom(), any}
tup_atom_any = type_tuple([t_atom, t_any])
# {any, integer()}
tup_any_int = type_tuple([t_any, t_int])
# a tuple of size 2, {any, any}
tup_s2_any = type_tuple_sized_any(2)
# a tuple of size 3, {any, any, any}
tup_s3_any = type_tuple_sized_any(3)
# {integer(), atom()}
tup_int_atom = type_tuple([t_int, t_atom])
# {{:foo}}
tup_nested_foo = type_tuple([type_tuple([t_foo])])
# {{atom()}}
tup_nested_atom = type_tuple([type_tuple([t_atom])])
# {any, none} -> this should resolve to none
tup_with_none = type_tuple([t_any, t_none])
IO.puts("\n--- Section: Basic Subtyping ---")
test_fn.("{:foo, 5} <: {atom, int}", true, is_subtype(tup_foo_5, tup_atom_int))
test_fn.("{atom, int} <: {:foo, 5}", false, is_subtype(tup_atom_int, tup_foo_5))
test_fn.("{:foo, 5} <: {pos_int, atom}", false, is_subtype(tup_foo_5, tup_pos_atom))
test_fn.("{pos_int, atom} <: {atom, int}", false, is_subtype(tup_pos_atom, tup_atom_int))
test_fn.("{atom, int} <: tuple()", true, is_subtype(tup_atom_int, t_tuple))
test_fn.("tuple() <: {atom, int}", false, is_subtype(t_tuple, tup_atom_int))
IO.puts("\n--- Section: Size-related Subtyping ---")
test_fn.("{atom, int} <: tuple_size_2_any", true, is_subtype(tup_atom_int, tup_s2_any))
test_fn.("tuple_size_2_any <: {atom, int}", false, is_subtype(tup_s2_any, tup_atom_int))
test_fn.("{atom, int} <: tuple_size_3_any", false, is_subtype(tup_atom_int, tup_s3_any))
test_fn.("tuple_size_2_any <: tuple_size_3_any", false, is_subtype(tup_s2_any, tup_s3_any))
test_fn.("{} <: tuple()", true, is_subtype(t_empty_tuple, t_tuple))
test_fn.("{} <: tuple_size_2_any", false, is_subtype(t_empty_tuple, tup_s2_any))
IO.puts("\n--- Section: Intersection ---")
# {atom, any} & {any, int} -> {atom, int}
intersect1 = intersect(tup_atom_any, tup_any_int)
test_fn.("({atom,any} & {any,int}) == {atom,int}", true, intersect1 == tup_atom_int)
# {atom, int} & {int, atom} -> none
intersect2 = intersect(tup_atom_int, tup_int_atom)
test_fn.("({atom,int} & {int,atom}) == none", true, intersect2 == t_none)
# tuple_size_2 & tuple_size_3 -> none
intersect3 = intersect(tup_s2_any, tup_s3_any)
test_fn.("(tuple_size_2 & tuple_size_3) == none", true, intersect3 == t_none)
# tuple() & {atom, int} -> {atom, int}
intersect4 = intersect(t_tuple, tup_atom_int)
test_fn.("(tuple() & {atom,int}) == {atom,int}", true, intersect4 == tup_atom_int)
IO.puts("\n--- Section: Union ---")
# {:foo, 5} | {pos_int, atom}
union1 = sum(tup_foo_5, tup_pos_atom)
test_fn.("{:foo, 5} <: ({:foo, 5} | {pos_int, atom})", true, is_subtype(tup_foo_5, union1))
test_fn.(
"{pos_int, atom} <: ({:foo, 5} | {pos_int, atom})",
true,
is_subtype(tup_pos_atom, union1)
)
test_fn.(
"{atom, int} <: ({:foo, 5} | {pos_int, atom})",
false,
is_subtype(tup_atom_int, union1)
)
# {atom, any} | {any, int} -> a complex type, let's check subtyping against it
union2 = sum(tup_atom_any, tup_any_int)
# {atom, int} is in both parts of the union.
test_fn.("{atom, int} <: ({atom,any} | {any,int})", true, is_subtype(tup_atom_int, union2))
# {:foo, :bar} is only in {atom, any}.
test_fn.(
"{:foo, :bar} <: ({atom,any} | {any,int})",
true,
is_subtype(type_tuple([t_foo, t_bar]), union2)
)
# {5, 6} is only in {any, int}.
test_fn.(
"{5, 6} <: ({atom,any} | {any,int})",
true,
is_subtype(type_tuple([t_int_5, t_int_6]), union2)
)
# {5, :foo} is in neither part of the union.
test_fn.(
"{5, :foo} <: ({atom,any} | {any,int})",
false,
is_subtype(type_tuple([t_int_5, t_foo]), union2)
)
IO.puts("\n--- Section: Negation and Type Difference ---")
# atom is disjoint from tuple, so atom <: ¬tuple
test_fn.("atom <: ¬tuple", true, is_subtype(t_atom, negate(t_tuple)))
# A specific tuple should not be a subtype of the negation of a more general tuple type it belongs to
test_fn.("{atom, int} <: ¬tuple()", false, is_subtype(tup_atom_int, negate(t_tuple)))
# {int, atom} is a subtype of ¬{atom, int} because their elements differ
test_fn.("{int, atom} <: ¬{atom, int}", true, is_subtype(tup_int_atom, negate(tup_atom_int)))
# tuple_size_3 is a subtype of ¬tuple_size_2 because their sizes differ
test_fn.("tuple_size_3 <: ¬tuple_size_2", true, is_subtype(tup_s3_any, negate(tup_s2_any)))
# Type difference: tuple_size_2 - {atom, any} -> should be {¬atom, any} for size 2 tuples.
diff1 = intersect(tup_s2_any, negate(tup_atom_any))
# {integer, integer} has a first element that is not an atom, so it should be in the difference.
tup_int_int = type_tuple([t_int, t_int])
test_fn.("{int, int} <: (tuple_size_2 - {atom, any})", true, is_subtype(tup_int_int, diff1))
test_fn.(
"{atom, int} <: (tuple_size_2 - {atom, any})",
false,
is_subtype(tup_atom_int, diff1)
)
IO.puts("\n--- Section: Nested Tuples ---")
test_fn.("{{:foo}} <: {{atom}}", true, is_subtype(tup_nested_foo, tup_nested_atom))
test_fn.("{{atom}} <: {{:foo}}", false, is_subtype(tup_nested_atom, tup_nested_foo))
# Intersection of disjoint nested types: {{:foo}} & {{:bar}}
intersect_nested = intersect(tup_nested_foo, type_tuple([type_tuple([t_bar])]))
test_fn.("{{:foo}} & {{:bar}} == none", true, intersect_nested == t_none)
# Union of nested types
union_nested = sum(tup_nested_foo, type_tuple([type_tuple([t_bar])]))
test_fn.("{{:foo}} <: ({{:foo}} | {{:bar}})", true, is_subtype(tup_nested_foo, union_nested))
test_fn.(
"{{:bar}} <: ({{:foo}} | {{:bar}})",
true,
is_subtype(type_tuple([type_tuple([t_bar])]), union_nested)
)
test_fn.(
"{{atom}} <: ({{:foo}} | {{:bar}})",
false,
is_subtype(tup_nested_atom, union_nested)
)
IO.puts("\n--- Section: Edge Cases (any, none) ---")
# A type `{any, none}` should not be possible. The value `none` cannot exist.
# The simplification logic should reduce this to `type_none`.
test_fn.("{any, none} == none", true, tup_with_none == t_none)
# Intersection with a tuple containing none should result in none
intersect_with_none_tuple = intersect(tup_atom_int, tup_with_none)
test_fn.("{atom,int} & {any,none} == none", true, intersect_with_none_tuple == t_none)
# Union with a tuple containing none should be a no-op
union_with_none_tuple = sum(tup_atom_int, tup_with_none)
test_fn.("{atom,int} | {any,none} == {atom,int}", true, union_with_none_tuple == tup_atom_int)
# --- Original tests from problem description for regression ---
IO.puts("\n--- Specific Tuple Subtyping Test (Original) ---")
test_fn.(
"{1, :foo} <: {int_gt_0, :foo | :bar}",
true,
is_subtype(
type_tuple([type_int_eq(1), type_atom_literal(:foo)]),
type_tuple([type_int_gt(0), sum(type_atom_literal(:foo), type_atom_literal(:bar))])
)
)
test_fn.(
"{0, :foo} <: {int_gt_0, :foo | :bar}",
false,
is_subtype(
type_tuple([type_int_eq(0), type_atom_literal(:foo)]),
type_tuple([type_int_gt(0), sum(type_atom_literal(:foo), type_atom_literal(:bar))])
)
)
test_fn.(
"{1, :kek} <: {int_gt_0, :foo | :bar}",
false,
is_subtype(
type_tuple([
type_int_eq(1),
type_atom_literal(:kek)
]),
type_tuple([type_int_gt(0), sum(type_atom_literal(:foo), type_atom_literal(:bar))])
)
)
IO.inspect(Process.get(:test_failures, []), label: "TupleTests failures")
end
end
defmodule ListTests do
import Tdd
def run(test_fn) do
Process.put(:test_failures, [])
Tdd.init_tdd_system()
IO.puts("\n--- Running ListTests ---")
# --- Basic Types ---
t_atom = type_atom()
t_int = type_integer()
t_foo = type_atom_literal(:foo)
t_bar = type_atom_literal(:bar)
t_any = type_any()
t_none = type_none()
# --- List Types ---
t_list = type_list()
t_empty_list = type_empty_list()
# [atom | list]
t_cons_atom_list = type_cons(t_atom, t_list)
# [:foo | []]
t_cons_foo_empty = type_cons(t_foo, t_empty_list)
# [atom | []]
t_cons_atom_empty = type_cons(t_atom, t_empty_list)
# [any | []]
t_cons_any_empty = type_cons(t_any, t_empty_list)
# [integer | list]
t_cons_int_list = type_cons(t_int, t_list)
IO.puts("\n--- Section: Basic List Subtyping ---")
test_fn.("[] <: list", true, is_subtype(t_empty_list, t_list))
test_fn.("list <: []", false, is_subtype(t_list, t_empty_list))
test_fn.("[atom|list] <: list", true, is_subtype(t_cons_atom_list, t_list))
test_fn.("list <: [atom|list]", false, is_subtype(t_list, t_cons_atom_list))
test_fn.("[] <: [atom|list]", false, is_subtype(t_empty_list, t_cons_atom_list))
test_fn.("[atom|list] <: []", false, is_subtype(t_cons_atom_list, t_empty_list))
test_fn.("list <: atom", false, is_subtype(t_list, t_atom))
test_fn.("atom <: list", false, is_subtype(t_atom, t_list))
IO.puts("\n--- Section: Cons Subtyping (Covariance) ---")
# Head is a subtype
test_fn.("[:foo|[]] <: [atom|[]]", true, is_subtype(t_cons_foo_empty, t_cons_atom_empty))
test_fn.("[atom|[]] <: [:foo|[]]", false, is_subtype(t_cons_atom_empty, t_cons_foo_empty))
# Tail is a subtype
test_fn.("[atom|[]] <: [atom|list]", true, is_subtype(t_cons_atom_empty, t_cons_atom_list))
test_fn.("[atom|list] <: [atom|[]]", false, is_subtype(t_cons_atom_list, t_cons_atom_empty))
# Both are subtypes
test_fn.("[:foo|[]] <: [atom|list]", true, is_subtype(t_cons_foo_empty, t_cons_atom_list))
# Neither is a subtype
test_fn.("[atom|list] <: [:foo|[]]", false, is_subtype(t_cons_atom_list, t_cons_foo_empty))
# A list of length 1 is a subtype of a list of any element of length 1
test_fn.("[atom|[]] <: [any|[]]", true, is_subtype(t_cons_atom_empty, t_cons_any_empty))
IO.puts("\n--- Section: List Intersection ---")
# [atom|list] & [integer|list] -> should be none due to head conflict
intersect1 = intersect(t_cons_atom_list, t_cons_int_list)
test_fn.("[atom|list] & [integer|list] == none", true, intersect1 == t_none)
# [any|[]] & [atom|list] -> should be [atom|[]]
intersect2 = intersect(t_cons_any_empty, t_cons_atom_list)
test_fn.("([any|[]] & [atom|list]) == [atom|[]]", true, intersect2 == t_cons_atom_empty)
# [] & [atom|list] -> should be none because one is empty and one is not
intersect3 = intersect(t_empty_list, t_cons_atom_list)
test_fn.("[] & [atom|list] == none", true, intersect3 == t_none)
IO.puts("\n--- Section: List Union ---")
# [] | [atom|[]]
union1 = sum(t_empty_list, t_cons_atom_empty)
test_fn.("[] <: ([] | [atom|[]])", true, is_subtype(t_empty_list, union1))
test_fn.("[atom|[]] <: ([] | [atom|[]])", true, is_subtype(t_cons_atom_empty, union1))
test_fn.(
"[integer|[]] <: ([] | [atom|[]])",
false,
is_subtype(type_cons(t_int, t_empty_list), union1)
)
# [:foo|[]] | [:bar|[]]
union2 = sum(t_cons_foo_empty, type_cons(t_bar, t_empty_list))
# This union is a subtype of [atom|[]]
test_fn.("([:foo|[]] | [:bar|[]]) <: [atom|[]]", true, is_subtype(union2, t_cons_atom_empty))
test_fn.("[atom|[]] <: ([:foo|[]] | [:bar|[]])", false, is_subtype(t_cons_atom_empty, union2))
IO.puts("\n--- Section: List Negation ---")
# list is a subtype of not(atom)
test_fn.("list <: ¬atom", true, is_subtype(t_list, negate(t_atom)))
# A non-empty list is a subtype of not an empty list
test_fn.("[atom|list] <: ¬[]", true, is_subtype(t_cons_atom_list, negate(t_empty_list)))
# [integer|list] is a subtype of not [atom|list]
test_fn.(
"[integer|list] <: ¬[atom|list]",
true,
is_subtype(t_cons_int_list, negate(t_cons_atom_list))
)
IO.inspect(Process.get(:test_failures, []), label: "ListTests failures")
end
end
defmodule ListOfTests do
import Tdd
def run(test_fn) do
Process.put(:test_failures, [])
Tdd.init_tdd_system()
IO.puts("\n--- Running ListOfTests ---")
# --- Basic Types ---
t_atom = type_atom()
t_int = type_integer()
t_pos_int = type_int_gt(0)
t_int_5 = type_int_eq(5)
# --- list(X) Types ---
t_list_of_int = type_list_of(t_int)
t_list_of_pos_int = type_list_of(t_pos_int)
t_list_of_atom = type_list_of(t_atom)
# --- Specific List Types ---
t_list = type_list()
t_empty_list = type_empty_list()
# [5]
t_list_one_int = type_cons(t_int_5, t_empty_list)
# [:foo]
t_list_one_atom = type_cons(type_atom_literal(:foo), t_empty_list)
# [5, :foo]
t_list_int_and_atom = type_cons(t_int_5, type_cons(type_atom_literal(:foo), t_empty_list))
IO.puts("\n--- Section: Basic list(X) Subtyping ---")
test_fn.("list(integer) <: list()", true, is_subtype(t_list_of_int, t_list))
test_fn.("list() <: list(integer)", false, is_subtype(t_list, t_list_of_int))
test_fn.("[] <: list(integer)", true, is_subtype(t_empty_list, t_list_of_int))
test_fn.("[5] <: list(integer)", true, is_subtype(t_list_one_int, t_list_of_int))
test_fn.("[:foo] <: list(integer)", false, is_subtype(t_list_one_atom, t_list_of_int))
test_fn.("[5, :foo] <: list(integer)", false, is_subtype(t_list_int_and_atom, t_list_of_int))
test_fn.(
"[5, :foo] <: list(any)",
true,
is_subtype(t_list_int_and_atom, type_list_of(type_any()))
)
IO.puts("\n--- Section: Covariance of list(X) ---")
test_fn.(
"list(pos_integer) <: list(integer)",
true,
is_subtype(t_list_of_pos_int, t_list_of_int)
)
test_fn.(
"list(integer) <: list(pos_integer)",
false,
is_subtype(t_list_of_int, t_list_of_pos_int)
)
IO.puts("\n--- Section: Intersection of list(X) ---")
# list(integer) & list(pos_integer) should be list(pos_integer)
intersect1 = intersect(t_list_of_int, t_list_of_pos_int)
test_fn.(
"(list(int) & list(pos_int)) == list(pos_int)",
true,
intersect1 == t_list_of_pos_int
)
# list(integer) & list(atom) should be just [] (empty list is the only common member)
# The system simplifies this intersection to a type that only accepts the empty list.
intersect2 = intersect(t_list_of_int, t_list_of_atom)
test_fn.("[] <: (list(int) & list(atom))", true, is_subtype(t_empty_list, intersect2))
test_fn.("[5] <: (list(int) & list(atom))", false, is_subtype(t_list_one_int, intersect2))
test_fn.("[:foo] <: (list(int) & list(atom))", false, is_subtype(t_list_one_atom, intersect2))
# It should be equivalent to `type_empty_list`
test_fn.("(list(int) & list(atom)) == []", true, intersect2 == t_empty_list)
IO.puts("\n--- Section: Intersection of list(X) with cons ---")
# list(integer) & [:foo | []] -> should be none
intersect3 = intersect(t_list_of_int, t_list_one_atom)
test_fn.("list(integer) & [:foo] == none", true, intersect3 == type_none())
# list(integer) & [5 | []] -> should be [5 | []]
intersect4 = intersect(t_list_of_int, t_list_one_int)
test_fn.("list(integer) & [5] == [5]", true, intersect4 == t_list_one_int)
# list(integer) & [5, :foo] -> should be none
intersect5 = intersect(t_list_of_int, t_list_int_and_atom)
test_fn.("list(integer) & [5, :foo] == none", true, intersect5 == type_none())
IO.inspect(Process.get(:test_failures, []), label: "ListOfTests failures")
end
end
defmodule AdhocTest do
import Tdd
def run(test_fn) do
# --- Basic Types ---
t_int = type_integer()
t_pos_int = type_int_gt(0)
# --- list(X) Types ---
t_list_of_int = type_list_of(t_int)
t_list_of_pos_int = type_list_of(t_pos_int)
print_tdd(t_list_of_int)
print_tdd(t_list_of_pos_int)
# --- Specific List Types ---
intersect1 = intersect(t_list_of_int, t_list_of_pos_int)
print_tdd(intersect1)
print_tdd(14)
print_tdd(16)
test_fn.(
"(list(int) & list(pos_int)) == list(pos_int)",
true,
intersect1 == t_list_of_pos_int
)
end
end
test_all.()
# IntegerTests.run(test)
# TupleTests.run(test)
# ListTests.run(test)
# ListOfTests.run(test)
# AdhocTest.run(test)