Make many into an iterative parser

1 files changed, 21 insertions, 30 deletions

diff --git a/core.lisp b/core.lisp
index 6e4bf6e..ac06a1f 100644
--- a/core.lisp
+++ b/core.lisp
@@ -30,37 +30,28 @@
        (make-failure :place input
                      :message (format nil "Reached end of input. Expected: ~a." ',predicate)))))
 
-(defparameter end
+(defun one-of (first-parser second-parser &rest other-parsers)
   (lambda (input)
-    (if (has-data? input)
-      (make-failure :place input :message "Didn't reach end of input.")
-      (make-parsing :tree nil :left input))))
-
-(defun select-parser (input parsers)
-  (let ((result (make-failure :place input)))
-    (dolist (p parsers)
-      (let ((r (funcall p input)))
-        (cond ((parsing-p r)
-               (when (or (not (parsing-p result))
-                         (> (input-cursor (parsing-left r))
-                            (input-cursor (parsing-left result))))
-                 (setf result r)))
-              ((failure-p r)
-               (when (failure-p result)
-                 (let ((priority-cmp (- (failure-priority r)
-                                        (failure-priority result))))
-                   (when (or (> priority-cmp 0)
-                             (and (= priority-cmp 0)
-                                  (>= (input-cursor (failure-place r))
-                                      (input-cursor (failure-place result)))))
-                     (setf result r)))))
-              (t (error (format nil "Invalid return value: ~a." r))))))
-    result))
-
-(defmacro one-of (first-parser second-parser &rest other-parsers)
-  `(lambda (input)
-     (select-parser input
-                    (list ,first-parser ,second-parser ,@other-parsers))))
+    (let ((parsers `(,first-parser ,second-parser ,@other-parsers))
+          (result (make-failure :place input)))
+      (dolist (p parsers)
+        (let ((r (funcall p input)))
+          (cond ((parsing-p r)
+                 (when (or (not (parsing-p result))
+                           (> (input-cursor (parsing-left r))
+                              (input-cursor (parsing-left result))))
+                   (setf result r)))
+                ((failure-p r)
+                 (when (failure-p result)
+                   (let ((priority-cmp (- (failure-priority r)
+                                          (failure-priority result))))
+                     (when (or (> priority-cmp 0)
+                               (and (= priority-cmp 0)
+                                    (>= (input-cursor (failure-place r))
+                                        (input-cursor (failure-place result)))))
+                       (setf result r)))))
+                (t (error (format nil "Invalid return value: ~a." r))))))
+      result)))
 
 ;;; TODO: Find a way to be able to use the input without needing to define a name for it.
 (defmacro comp (bindings &body body)