1 files changed, 81 insertions, 0 deletions
diff --git a/stdlib/param.tl b/stdlib/param.tl
new file mode 100644
index 00000000..0551e9ce
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+++ b/stdlib/param.tl
@@ -0,0 +1,81 @@
+;; Copyright 2019-2021
+;; Kaz Kylheku <kaz@kylheku.com>
+;; Vancouver, Canada
+;; All rights reserved.
+;;
+;; Redistribution and use in source and binary forms, with or without
+;; modification, are permitted provided that the following conditions are met:
+;;
+;; 1. Redistributions of source code must retain the above copyright notice, this
+;;    list of conditions and the following disclaimer.
+;;
+;; 2. Redistributions in binary form must reproduce the above copyright notice,
+;;    this list of conditions and the following disclaimer in the documentation
+;;    and/or other materials provided with the distribution.
+;;
+;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+;; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+;; DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+;; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+;; SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+;; CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+;; OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+(compile-only
+  (defstruct param-parser-base nil
+    syntax form
+    rest req opt key
+    nreq nopt nfix
+
+    (:postinit (me)
+      (let* ((rest (nthlast 0 me.syntax))
+             (fixed (ldiff me.syntax rest))
+             nonkey key)
+        (cond
+          (me.mac-param-p
+            (while fixed
+              (let ((pp (pop fixed)))
+                (caseq pp
+                  ((:env :whole :form)
+                   (unless fixed
+                     (compile-error me.form "~s requires argument" pp))
+                   (push (cons pp (pop fixed)) key))
+                  (t (push pp nonkey)))))
+            (set nonkey (nreverse nonkey)
+                 key (nreverse key)))
+          (t (set nonkey fixed)))
+        (tree-bind (: rp opt) (split* nonkey (op where (op eq :)))
+          (set me.rest rest
+               me.req rp
+               me.opt (mapcar [iffi atom list] opt)
+               me.key key
+               me.nreq (len rp)
+               me.nopt (len opt)
+               me.nfix (+ me.nreq me.nopt)))))
+
+    (:method opt-syms (me)
+      (build
+        (each ((o me.opt))
+          (caseql (len o)
+            ((1 2) (add (car o)))
+            (3 (add (car o) (caddr o))))))))
+
+  (defstruct (fun-param-parser syntax form) param-parser-base
+    (mac-param-p nil))
+
+  (defstruct (mac-param-parser syntax form) param-parser-base
+    (mac-param-p t))
+
+  (defstruct (param-info fun) nil
+    fun
+    nreq nopt nfix rest
+    (:postinit (me)
+      (let* ((fix (fun-fixparam-count me.fun))
+             (opt (fun-optparam-count me.fun)))
+        (set me.nreq (- fix opt)
+             me.nopt opt
+             me.nfix fix
+             me.rest (fun-variadic me.fun))))))