Add repeat parser

1 files changed, 17 insertions, 6 deletions

diff --git a/parser.lisp b/parser.lisp
index 5470523..82f619e 100644
--- a/parser.lisp
+++ b/parser.lisp
@@ -26,8 +26,8 @@
     (make-parsing :tree tree :left input)))
 
 (defun bind-with-input (p f)
-  (declare (optimize (speed 3)))
-  (declare (type function p f))
+  (declare (optimize (speed 3))
+           (function p f))
   (lambda (input)
     (let ((r (funcall p input)))
       (if (parsing-p r)
@@ -36,8 +36,8 @@
         r))))
 
 (defun bind (p f)
-  (declare (optimize (speed 3)))
-  (declare (type function p f))
+  (declare (optimize (speed 3))
+           (function p f))
   (lambda (input)
     (let ((r (funcall p input)))
       (if (parsing-p r)
@@ -46,8 +46,8 @@
         r))))
 
 (defun discarding-bind (p f)
-  (declare (optimize (speed 3)))
-  (declare (type function p f))
+  (declare (optimize (speed 3))
+           (function p f))
   (lambda (input)
     (let ((r (funcall p input)))
       (if (parsing-p r)
@@ -130,6 +130,17 @@
          (xs (optional (many p))))
     (cons x xs)))
 
+(defun repeat (p min &optional (max 0))
+  (if (> min 0)
+    (comp ((x p)
+           (xs (repeat p (1- min) (1- max))))
+      (cons x xs))
+    (if (> max 0)
+      (comp ((x (optional p))
+             (xs (repeat p 0 (if x (1- max) 0))))
+        (if x (cons x xs) x))
+      nothing)))
+
 (defparameter whitespace
   (comp ((_ (optional (many (unit char:whitespace?)))))
     nil))