From 8a5814464682be4b5a2ea977a1c356039f8bc238 Mon Sep 17 00:00:00 2001
From: Eric Wolf <robo-eric@gmx.de>
Date: Tue, 9 Apr 2024 22:25:32 +0200
Subject: [PATCH] add predefined variables

Inspired by `sympy.abc`
---
 docs/api/terms.rst                    |  1 +
 docs/api/terms/abc.rst                |  8 ++++++++
 src/lambda_calculus/terms/__init__.py |  1 +
 src/lambda_calculus/terms/abc.py      | 17 +++++++++++++++++
 tests/terms/test_abc.py               | 24 ++++++++++++++++++++++++
 5 files changed, 51 insertions(+)
 create mode 100644 docs/api/terms/abc.rst
 create mode 100644 src/lambda_calculus/terms/abc.py
 create mode 100644 tests/terms/test_abc.py

diff --git a/docs/api/terms.rst b/docs/api/terms.rst
index 12e1c6a..b05ed74 100644
--- a/docs/api/terms.rst
+++ b/docs/api/terms.rst
@@ -4,6 +4,7 @@ Package terms
 .. toctree::
    :maxdepth: 2
 
+   terms/abc
    terms/logic
    terms/arithmetic
    terms/pairs
diff --git a/docs/api/terms/abc.rst b/docs/api/terms/abc.rst
new file mode 100644
index 0000000..d53c64a
--- /dev/null
+++ b/docs/api/terms/abc.rst
@@ -0,0 +1,8 @@
+Module abc
+==========
+
+.. toctree::
+   :maxdepth: 2
+
+.. automodule:: lambda_calculus.terms.abc
+    :members:
\ No newline at end of file
diff --git a/src/lambda_calculus/terms/__init__.py b/src/lambda_calculus/terms/__init__.py
index 0b56ce3..6d18ce2 100644
--- a/src/lambda_calculus/terms/__init__.py
+++ b/src/lambda_calculus/terms/__init__.py
@@ -17,6 +17,7 @@
     "Variable",
     "Abstraction",
     "Application",
+    "abc",
     "arithmetic",
     "logic",
     "pairs",
diff --git a/src/lambda_calculus/terms/abc.py b/src/lambda_calculus/terms/abc.py
new file mode 100644
index 0000000..37c7711
--- /dev/null
+++ b/src/lambda_calculus/terms/abc.py
@@ -0,0 +1,17 @@
+#!/usr/bin/python3
+
+"""Predefined Variables for all ASCII letters"""
+
+from string import ascii_letters
+from . import Variable
+
+__all__ = tuple(ascii_letters)
+
+# better IDE autocompletion
+a, b, c, d, e, f, g, h, i, j = map(Variable, "abcdefghij")
+k, l, m, n, o, p, q, r, s, t = map(Variable, "klmnopqrst")
+u, v, w, x, y, z = map(Variable, "uvwxyz")
+
+A, B, C, D, E, F, G, H, I, J = map(Variable, "ABCDEFGHIJ")
+K, L, M, N, O, P, Q, R, S, T = map(Variable, "KLMNOPQRST")
+U, V, W, X, Y, Z = map(Variable, "UVWXYZ")
diff --git a/tests/terms/test_abc.py b/tests/terms/test_abc.py
new file mode 100644
index 0000000..2ed874b
--- /dev/null
+++ b/tests/terms/test_abc.py
@@ -0,0 +1,24 @@
+#!/usr/bin/python3
+
+"""Tests for the predefined variables"""
+
+from unittest import TestCase
+from string import ascii_letters
+from lambda_calculus.terms import Variable, abc
+
+
+class PredefinedVariablesTest(TestCase):
+    """Tests for the predefined variables"""
+
+    def test_complete(self) -> None:
+        """Check whether all letters exist"""
+        self.assertEqual(tuple(ascii_letters), abc.__all__)
+        for letter in ascii_letters:
+            self.assertTrue(hasattr(abc, letter))
+
+    def test_variables(self) -> None:
+        """Test the predefined variables"""
+        for letter in ascii_letters:
+            variable = getattr(abc, letter)
+            self.assertIsInstance(variable, Variable)
+            self.assertEqual(variable.name, letter)