* eval.c (eval_init): Register new functions posqual, posql,

posq, pos, and pos_if as intrinsics.

* lib.c (posqual, posql, posq, pos, pos_if): New functions.

* lib.h (posqual, posql, posq, pos, pos_if): Declared.

* txr.1: Documented

5 files changed, 149 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index cdc54316..ce8a80ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2014-02-11  Kaz Kylheku  <kaz@kylheku.com>
 
+	* eval.c (eval_init): Register new functions posqual, posql,
+	posq, pos, and pos_if as intrinsics.
+
+	* lib.c (posqual, posql, posq, pos, pos_if): New functions.
+
+	* lib.h (posqual, posql, posq, pos, pos_if): Declared.
+
+	* txr.1: Documented
+
+2014-02-11  Kaz Kylheku  <kaz@kylheku.com>
+
 	* eval.c (eval_init): Turn a require argument into an optional
 	one for the functions some, all and none.
 
diff --git a/eval.c b/eval.c
index 82aa8ea0..92c4afe1 100644
--- a/eval.c
+++ b/eval.c
@@ -2412,6 +2412,11 @@ void eval_init(void)
   reg_fun(intern(lit("countql"), user_package), func_n2(countql));
   reg_fun(intern(lit("countq"), user_package), func_n2(countq));
   reg_fun(intern(lit("count-if"), user_package), func_n3o(count_if, 2));
+  reg_fun(intern(lit("posqual"), user_package), func_n2(posqual));
+  reg_fun(intern(lit("posql"), user_package), func_n2(posql));
+  reg_fun(intern(lit("posq"), user_package), func_n2(posq));
+  reg_fun(intern(lit("pos"), user_package), func_n4o(pos, 2));
+  reg_fun(intern(lit("pos-if"), user_package), func_n3o(pos_if, 2));
   reg_fun(intern(lit("some"), user_package), func_n3o(some_satisfy, 1));
   reg_fun(intern(lit("all"), user_package), func_n3o(all_satisfy, 1));
   reg_fun(intern(lit("none"), user_package), func_n3o(none_satisfy, 1));
diff --git a/lib.c b/lib.c
index 1b0199c2..8787cb8f 100644
--- a/lib.c
+++ b/lib.c
@@ -4793,6 +4793,72 @@ val find_if(val pred, val list, val key)
   return nil;
 }
 
+val posqual(val obj, val list)
+{
+  val pos = zero;
+
+  for (; list; list = cdr(list), pos = plus(pos, one))
+    if (equal(car(list), obj))
+      return pos;
+
+  return nil;
+}
+
+val posql(val obj, val list)
+{
+  val pos = zero;
+
+  for (; list; list = cdr(list), pos = plus(pos, one))
+    if (eql(car(list), obj))
+      return pos;
+
+  return nil;
+}
+
+val posq(val obj, val list)
+{
+  val pos = zero;
+
+  for (; list; list = cdr(list), pos = plus(pos, one))
+    if (eq(car(list), obj))
+      return pos;
+
+  return nil;
+}
+
+val pos(val item, val list, val testfun, val keyfun)
+{
+  val pos = zero;
+  testfun = default_arg(testfun, equal_f);
+  keyfun = default_arg(keyfun, identity_f);
+
+  for (; list; list = cdr(list), pos = plus(pos, one)) {
+    val elem = car(list);
+    val key = funcall1(keyfun, elem);
+
+    if (funcall2(testfun, item, key))
+      return pos;
+  }
+
+  return nil;
+}
+
+
+val pos_if(val pred, val list, val key)
+{
+  val pos = zero;
+  key = default_arg(key, identity_f);
+
+  for (; list; list = cdr(list), pos = plus(pos, one)) {
+    val item = car(list);
+    val subj = funcall1(key, item);
+
+    if (funcall1(pred, subj))
+      return pos;
+  }
+
+  return nil;
+}
 
 val set_diff(val list1, val list2, val testfun, val keyfun)
 {
diff --git a/lib.h b/lib.h
index 869d3c31..77ca800d 100644
--- a/lib.h
+++ b/lib.h
@@ -679,6 +679,11 @@ val sort(val seq, val lessfun, val keyfun);
 val multi_sort(val lists, val funcs, val key_funcs);
 val find(val list, val key, val testfun, val keyfun);
 val find_if(val pred, val list, val key);
+val posqual(val obj, val list);
+val posql(val obj, val list);
+val posq(val obj, val list);
+val pos(val list, val key, val testfun, val keyfun);
+val pos_if(val pred, val list, val key);
 val set_diff(val list1, val list2, val testfun, val keyfun);
 val length(val seq);
 val sub(val seq, val from, val to);
diff --git a/txr.1 b/txr.1
index 93aca12d..976b4c34 100644
--- a/txr.1
+++ b/txr.1
@@ -7025,6 +7025,68 @@ transformed to an argument to <predicate-function>. If this argument is omitted
 then the predicate function is applied to the elements directly, a behavior
 which is identical to <key-function> being (fun identity).
 
+.SS Functions posqual, posql and posq
+
+.TP
+Syntax:
+
+  (posq <object> <list>)
+  (posql <object> <list>)
+  (posqual <object> <list>)
+
+.TP
+Description
+
+The posq, posql and posqual functions return the zero-based position of the
+first item in <list> which is, respectively, eq, eql or equal to <object>.
+
+.SS Functions posqual, posql and posq
+
+.TP
+Syntax:
+
+  (posq <object> <list>)
+  (posql <object> <list>)
+  (posqual <object> <list>)
+
+.TP
+Description
+
+The posq, posql and posqual functions return the zero-based position of the
+first item in <list> which is, respectively, eq, eql or equal to <object>.
+
+.SS Functions pos and pos-if
+
+.TP
+Syntax:
+
+  (pos <key> <list> [<testfun> [<keyfun>]])
+  (pos-if <predfun> <list> [<keyfun>])
+
+.TP
+Description:
+
+The pos and pos-if functions search through a list for an item which
+matches a key, or satisfies a predicate function, respectively.
+They return the zero based position of the matching item.
+
+The keyfun argument specifies a function which is applied to the elements
+of the list to produce the comparison key. If this argument is omitted,
+then the untransformed elements of the list themselves are searched.
+
+The pos function's testfun argument specifies the test function which
+is used to compare the comparison keys from the list to the search key.
+If this argument is omitted, then the equal function is used.
+The position of the first element from the list whose comparison key (as
+retrieved by the key function) matches the search (under the test function) is
+returned. If no such element is found, nil is returned.
+
+The pos-if function's predfun argument specifies a predicate function
+which is applied to the successive comparison keys pulled from the list
+by applying the key function to successive elements. The position of
+the first element for which the predicate function yields true is returned. If
+no such element is found, nil is returned.
+
 .SS Function tree-find
 
 .TP