move tests to their own file; use debruijn form to test alpha equivalence

2 files changed, 94 insertions, 0 deletions

diff --git a/test/examples/untyped-lambda-calculus.scm b/test/examples/untyped-lambda-calculus.scm
new file mode 100644
index 0000000..46f3f60
--- /dev/null
+++ b/test/examples/untyped-lambda-calculus.scm
@@ -0,0 +1,71 @@
+#| Copyright (c) Peter McGoron 2025
+ |
+ | Licensed under the Apache License, Version 2.0 (the "License");
+ | you may not use this file except in compliance with the License.
+ | You may obtain a copy of the License at
+ |
+ |     http://www.apache.org/licenses/LICENSE-2.0
+ |
+ | Unless required by applicable law or agreed to in writing, software
+ | distributed under the License is distributed on an "AS IS" BASIS,
+ | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ | See the License for the specific language governing permissions and
+ | limitations under the License.
+ |#
+
+(define-syntax test-alpha
+  (syntax-rules ()
+    ((test-alpha name (inputs ...) output)
+
+     (let-values (((global-map expanded-list)
+                   (expand initial-environment
+                           (list (empty-wrap (quote inputs)) ...))))
+       (test-equal name
+                   (map (lambda (term)
+                          (debruijnize global-map term '()))
+                        expanded-list)
+                   (quote output))))))
+
+(define (test-expander)
+  (test-alpha "identity"
+              ((lambda x x))
+              ((lambda 0)))
+  (test-alpha "let-syntax of identifier"
+              ((let-syntax ((λ lambda))
+                 (λ x x)))
+              ((lambda 0)))
+  (test-alpha "lexical renaming of keywords"
+              ((lambda lambda (lambda lambda)))
+              ((lambda (0 0))))
+  (test-alpha "simple define-syntax"
+              ((define-syntax let
+                 (syntax-rules ()
+                   ((let ((name value)) body)
+                    ((lambda name body) value))))
+               (let ((x (f y))) (f x)))
+              (((lambda (f 0)) (f y))))
+  (test-alpha "define-syntax with ellipsis"
+              ((define-syntax let
+                 (syntax-rules ()
+                   ((let ((name value)) body)
+                    ((lambda name body) value))))
+               (define-syntax or
+                 (syntax-rules ()
+                   ((or) false)
+                   ((or x y ...)
+                    (let ((tmp x))
+                      (if tmp tmp (or y ...))))))
+               (or a tmp b))
+              (((lambda (if 0
+                            0
+                            ((lambda (if 0
+                                         0
+                                         ((lambda (if 0
+                                                     0
+                                                     false))
+                                          b))) tmp))) a))))
+
+(define (test-untyped-lambda-calculus)
+  (test-group "untyped lambda calculus"
+    (test-expander)))
+
diff --git a/test/examples/untyped-lambda-calculus.sld b/test/examples/untyped-lambda-calculus.sld
new file mode 100644
index 0000000..6d85eed
--- /dev/null
+++ b/test/examples/untyped-lambda-calculus.sld
@@ -0,0 +1,23 @@
+#| Copyright (c) Peter McGoron 2025
+ |
+ | Licensed under the Apache License, Version 2.0 (the "License");
+ | you may not use this file except in compliance with the License.
+ | You may obtain a copy of the License at
+ |
+ |     http://www.apache.org/licenses/LICENSE-2.0
+ |
+ | Unless required by applicable law or agreed to in writing, software
+ | distributed under the License is distributed on an "AS IS" BASIS,
+ | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ | See the License for the specific language governing permissions and
+ | limitations under the License.
+ |#
+
+(define-library (multisyntax examples untyped-lambda-calculus test)
+  (import (scheme base) (srfi 64)
+          (multisyntax syntax-object) (multisyntax examples untyped-lambda-calculus))
+  (cond-expand
+    (chicken (import (chicken condition)))
+    (else))
+  (export test-untyped-lambda-calculus)
+  (include "untyped-lambda-calculus.scm"))
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