refactor tests, add working code for list

6 files changed, 205 insertions, 36 deletions

diff --git a/mcgoron.iterator.exceptions.sld b/mcgoron.iterator.exceptions.sld
index b989a6c..ce1b8db 100644
--- a/mcgoron.iterator.exceptions.sld
+++ b/mcgoron.iterator.exceptions.sld
@@ -21,7 +21,10 @@
           non-integer-movement-exception non-integer-movement-exception?
           non-integer-movement-exception:spaces
           negative-movement-exception negative-movement-exception?
-          negative-movement-exception:spaces)
+          negative-movement-exception:spaces
+          improper-list-exception improper-list-exception?
+          improper-list-exception:idx
+          improper-list-exception:cdr)
   (begin
     (define-record-type <field-not-found-exception>
       (field-not-found-exception field iterator)
@@ -35,5 +38,10 @@
     (define-record-type <negative-movement-exception>
       (negative-movement-exception spaces)
       negative-movement-exception?
-      (spaces negative-movement-exception:spaces))))
+      (spaces negative-movement-exception:spaces))
+    (define-record-type <improper-list-exception>
+      (improper-list-exception idx cdr)
+      improper-list-exception?
+      (idx improper-list-exception:idx)
+      (cdr improper-list-exception:cdr))))
 
diff --git a/mcgoron.iterator.list.scm b/mcgoron.iterator.list.scm
new file mode 100644
index 0000000..3638614
--- /dev/null
+++ b/mcgoron.iterator.list.scm
@@ -0,0 +1,87 @@
+#| Copyright 2024 Peter McGoron
+ |
+ | 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.
+ |-------------------------------------------------------------------------
+ | This is a list iterator that allows for mutation of the list.
+ |
+ | The list iterator is made up of
+ | * the `signifier`: the head of the list.
+ | * the `previous` values, which is a list of all cons cells prior to the
+ |   current cons cell, in reverse.
+ | * the index, which is the index of the current element in the list. This
+ |   is updated internally but not used internally, so the root index does
+ |   not have to be 0.
+ | * the `next` list, which is either empty or has as it's car the current
+ |   item.
+ |#
+
+(define (make-list-iterator signifier previous idx rest)
+  (when (not (or (pair? rest) (null? rest)))
+    (raise (improper-list-exception idx rest)))
+  (make-iterator
+   (lambda () (null? previous))
+   (lambda () (null? rest))
+   (lambda (num)
+     (cond
+       ((not (integer?))
+        (raise (non-integer-movement-exception spaces)))
+       ((negative? num)
+        (let loop ((cntr (- num))
+                   (previous previous)
+                   (rest rest))
+          (cond
+            ((= num 0) (make-list-iterator signifier
+                                           previous
+                                           (+ total num)
+                                           rest))
+            ((null? previous) #f)
+            (else (loop (- cntr 1)
+                        (cdr previous)
+                        (car previous))))))
+       (else
+        (let loop ((cntr num)
+                   (previous previous)
+                   (rest rest))
+          (cond
+            ((= num 0) (make-list-iterator signifier
+                                           previous
+                                           (+ total num)
+                                           rest))
+            ((null? rest) #f)
+            (else (loop (- 1 num)
+                        (cons rest previous)
+                        (cdr rest))))))))
+   (lambda ()
+     (if (null? rest)
+         (error "cannot ref end of list" previous rest)
+         (car rest)))
+   (lambda (predicate? other-iterators)
+     (let ((cmp (make-default-comparator)))
+       (iteratively-apply-predicate
+        (lambda (x y)
+          (predicate? cmp (get-private x) (get-private y)))
+        idx
+        other-iterators)))
+   idx))
+
+(define (list-iterator-start rest)
+  (make-list-iterator rest '() 0 rest))
+
+(define (list-iterator-to-end itr)
+  (if (iterator-end? itr)
+      itr
+      (list-iterator-to-end (iterator-advance itr 1))))
+
+(define (list-iterator-end lst)
+  (list-iterator-to-end (list-iterator-start lst)))
+
diff --git a/mcgoron.iterator.list.sld b/mcgoron.iterator.list.sld
new file mode 100644
index 0000000..e3e5da8
--- /dev/null
+++ b/mcgoron.iterator.list.sld
@@ -0,0 +1,22 @@
+#| Copyright 2024 Peter McGoron
+ |
+ | 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 (mcgoron iterator list)
+  (import (scheme base) (srfi 128)
+          (mcgoron iterator base) (mcgoron iterator exceptions))
+  (export list-iterator-start list-iterator-end
+          make-list-iterator)
+  (include "mcgoron.iterator.list.scm"))
+
diff --git a/tests/list.scm b/tests/list.scm
new file mode 100644
index 0000000..02a0c52
--- /dev/null
+++ b/tests/list.scm
@@ -0,0 +1,32 @@
+#| Copyright 2024 Peter McGoron
+ |
+ | 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.
+ |#
+(import (mcgoron iterator list))
+
+(let ((itr (list-iterator-start '())))
+  (test-begin "empty list")
+  (test-assert "iterator-at-start?" (iterator-at-start? itr))
+  (test-assert "iterator-at-end?" (iterator-at-end? itr))
+  (test-assert "iterator-advance 1" (not (iterator-advance itr 1)))
+  (test-assert "iterator-advance -1" (not (iterator-advance itr -1)))
+  (test "iterator->index" 0 (iterator->index itr))
+  (test-assert "iterator=?" (iterator=? itr (list-iterator-end '())))
+  (test-error "iterator-ref" (iterator-ref itr))
+  (test-end "empty list"))
+
+(let* ((lst '(1 2))
+       (itr (list-iterator-start lst)))
+  ()
+  )
+
diff --git a/tests/run.scm b/tests/run.scm
index 6d7abfe..f62c232 100644
--- a/tests/run.scm
+++ b/tests/run.scm
@@ -19,40 +19,9 @@
 
 ;;; TODO: Make a custom SRFI-64 test runner that emulates CHICKEN test.
 
-(import (mcgoron iterator string) (mcgoron iterator base))
+(import (mcgoron iterator base))
 
-(let* ((str "")
-       (itr (string-iterator-start str)))
-  (test-group "empty-string"
-    (test-assert "iterator-at-start?" (iterator-at-start? itr))
-    (test-assert "iterator-at-end?" (iterator-at-end? itr))
-    (test-assert "iterator-advance 1" (not (iterator-advance itr 1)))
-    (test-assert "iterator-advance -1" (not (iterator-advance itr -1)))
-    (test "iterator->index" 0 (iterator->index itr))
-    (test-assert "iterator=?" (iterator=? itr (string-iterator-end str)))
-    (test-error "iterator-ref" (iterator-ref itr))))
+(include "string.scm")
+#;(include "list.scm")
 
-(let* ((str "a")
-       (itr (string-iterator-start str))
-       (itr-from-itr (string-iterator-start itr)))
-  (test-group "non empty string"
-    (test-assert "iterator-at-start?" (iterator-at-start? itr))
-    (test-assert "iterator-at-end?" (not (iterator-at-end? itr)))
-    (test-assert (iterator=? itr itr-from-itr))
-    (test "iterator-ref 0" #\a (iterator-ref itr))
-    (test-assert "iterator-advance start -1" (not (iterator-advance itr -1)))
-    (let ((next-itr (iterator-advance itr 1)))
-      (test-assert "iterator? advanced" (iterator? next-itr))
-      (test-assert "iterator-at-end? advanced" (iterator-at-end? next-itr))
-      (test-assert "iterator=? end advanced"
-                   (iterator=? next-itr (string-iterator-end str)))
-      (test-assert "iterator=? itr next-itr"
-                   (not (iterator=? itr next-itr)))
-      (test-assert "iterator<? itr next-itr"
-                   (iterator<? itr next-itr))
-      (test-assert "iterator=? itr previous"
-                   (iterator=? itr (iterator-advance next-itr -1)))
-      (test "iterator->index next-itr" 1
-            (iterator->index next-itr))
-      (test-error "iterator-ref next-itr" (iterator-ref next-itr)))))
 (test-exit)
diff --git a/tests/string.scm b/tests/string.scm
new file mode 100644
index 0000000..bf89662
--- /dev/null
+++ b/tests/string.scm
@@ -0,0 +1,51 @@
+#| Copyright 2024 Peter McGoron
+ |
+ | 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.
+ |#
+(import (mcgoron iterator string))
+
+(let* ((str "")
+       (itr (string-iterator-start str)))
+  (test-group "empty-string"
+    (test-assert "iterator-at-start?" (iterator-at-start? itr))
+    (test-assert "iterator-at-end?" (iterator-at-end? itr))
+    (test-assert "iterator-advance 1" (not (iterator-advance itr 1)))
+    (test-assert "iterator-advance -1" (not (iterator-advance itr -1)))
+    (test "iterator->index" 0 (iterator->index itr))
+    (test-assert "iterator=?" (iterator=? itr (string-iterator-end str)))
+    (test-error "iterator-ref" (iterator-ref itr))))
+
+(let* ((str "a")
+       (itr (string-iterator-start str))
+       (itr-from-itr (string-iterator-start itr)))
+  (test-group "non empty string"
+    (test-assert "iterator-at-start?" (iterator-at-start? itr))
+    (test-assert "iterator-at-end?" (not (iterator-at-end? itr)))
+    (test-assert (iterator=? itr itr-from-itr))
+    (test "iterator-ref 0" #\a (iterator-ref itr))
+    (test-assert "iterator-advance start -1" (not (iterator-advance itr -1)))
+    (let ((next-itr (iterator-advance itr 1)))
+      (test-assert "iterator? advanced" (iterator? next-itr))
+      (test-assert "iterator-at-end? advanced" (iterator-at-end? next-itr))
+      (test-assert "iterator=? end advanced"
+                   (iterator=? next-itr (string-iterator-end str)))
+      (test-assert "iterator=? itr next-itr"
+                   (not (iterator=? itr next-itr)))
+      (test-assert "iterator<? itr next-itr"
+                   (iterator<? itr next-itr))
+      (test-assert "iterator=? itr previous"
+                   (iterator=? itr (iterator-advance next-itr -1)))
+      (test "iterator->index next-itr" 1
+            (iterator->index next-itr))
+      (test-error "iterator-ref next-itr" (iterator-ref next-itr)))))
+