From 90bb65d4b4162df4099c811e802e452cd42d1c72 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Mon, 23 Mar 2020 19:11:17 -0700
Subject: New contains function: near alias of search.

Harmonizes with starts-with and ends-with.

* eval.c (eval_init): Register contains intrinsic.

* lib.c (contains): New function.

* lib.h (contains): Delared.

* txr.1: Documented.
---
 eval.c |  1 +
 lib.c  |  5 +++++
 lib.h  |  1 +
 txr.1  | 17 ++++++++++++++++-
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/eval.c b/eval.c
index dd2adcf4..805805b3 100644
--- a/eval.c
+++ b/eval.c
@@ -6892,6 +6892,7 @@ void eval_init(void)
   reg_fun(intern(lit("update"), user_package), func_n2(update));
   reg_fun(intern(lit("search"), user_package), func_n4o(search, 2));
   reg_fun(intern(lit("rsearch"), user_package), func_n4o(rsearch, 2));
+  reg_fun(intern(lit("contains"), user_package), func_n4o(contains, 2));
   reg_fun(intern(lit("where"), user_package), func_n2(where));
   reg_fun(intern(lit("select"), user_package), func_n2(sel));
   reg_fun(intern(lit("relate"), user_package), func_n3o(relate, 2));
diff --git a/lib.c b/lib.c
index 3dce3750..acf66f36 100644
--- a/lib.c
+++ b/lib.c
@@ -10786,6 +10786,11 @@ val search(val seq, val key, val testfun, val keyfun)
   }
 }
 
+val contains(val key, val seq, val testfun, val keyfun)
+{
+  return search(seq, key, testfun, keyfun);
+}
+
 static val rsearch_list(val seq, val key, val testfun, val keyfun)
 {
   val siter, kiter;
diff --git a/lib.h b/lib.h
index 6c5b17ef..115b11d2 100644
--- a/lib.h
+++ b/lib.h
@@ -1155,6 +1155,7 @@ val butlast(val seq, val idx);
 val replace(val seq, val items, val from, val to);
 val update(val seq, val fun);
 val search(val seq, val key, val from, val to);
+val contains(val key, val seq, val testfun, val keyfun);
 val rsearch(val seq, val key, val from, val to);
 val where(val func, val seq);
 val sel(val seq, val where);
diff --git a/txr.1 b/txr.1
index f0b1726d..0d087525 100644
--- a/txr.1
+++ b/txr.1
@@ -29680,7 +29680,7 @@ is returned.
 
 .coNP Function @ search
 .synb
-.mets (search < haystack < needle >> [ testfun <> [ keyfun ])
+.mets (search < haystack < needle >> [ testfun <> [ keyfun ]])
 .syne
 .desc
 The
@@ -29773,6 +29773,21 @@ with one argument. If it is not supplied, it defaults to
   [search "abcd" #(#\eC #\eD) : chr-toupper] -> 2
 .brev
 
+.coNP Function @ contains
+.synb
+.mets (contains < needle < haystack >> [ testfun <> [ keyfun ]])
+.syne
+.desc
+The syntax of the
+.code contains
+function differs from that of
+.codn search :
+that the
+.meta needle
+and
+.meta haystack
+arguments are reversed. The semantics is identical.
+
 .coNP Function @ rsearch
 .synb
 .mets (rsearch < haystack < needle >> [ testfun <> [ keyfun ])
-- 
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