shell: more foundations from Lisp

shell/data.limg

@@ -9,6 +9,11 @@
   `((fn (,var) ,@body) ,val))])
     (when . [(mac (when cond . body)
   `(if ,cond (do ,@body) ()))])
+    (iflet . [(mac (iflet var expr then else)
+  `(let ,var ,expr
+     (if ,var ,then ,else)))])
+    (aif . [(mac (aif expr then else)
+  `(iflet it ,expr ,then ,else))])
     (list . [(def (list . args)
   # we should probably make a copy here
   args)])
@@ -21,6 +26,45 @@
     ()
     (cons (f (car xs))
           (map1 f (cdr xs)))))])
+    (compose . [(def (compose f g)
+  (fn args
+    (f (g args))))])
+    (some . [(def (some f xs)
+  (if (no xs)
+    ()
+    (if (f (car xs))
+      xs
+      (some f (cdr xs)))))])
+    (any . some)
+    (all . [(def (all f xs)
+  (if (no xs)
+    1
+    (if (f (car xs))
+      (all f (cdr xs))
+      ())))])
+    (find . [(def (find x xs)
+  (if (no xs)
+    ()
+    (if (= x (car xs))
+      1
+      (find x (cdr xs)))))])
+    (afn . [(mac (afn params . body)
+  `(let self ()
+     (set self (fn ,params ,@body))))])
+    (rem . [(def (rem f xs)
+  (if (no xs)
+    ()
+    (let rest (rem f (cdr xs))
+      (if (f (car xs))
+        rest
+        (cons (car xs) rest)))))])
+    (keep . [(def (keep f xs)
+  (if (no xs)
+    ()
+    (let rest (keep f (cdr xs))
+      (if (f (car xs))
+        (cons (car xs) rest)
+        rest))))])
     (++ . [(mac (++ var) `(set ,var (+ ,var 1)))])
     (+= . [(mac (+= var inc)
   `(set ,var (+ ,var ,inc)))])