From 50807f3dd5241667dac0c0cc302042d648de4b42 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 28 Jul 2015 17:27:32 +0200
Subject: Add primop genList
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This can be used to implement functions like ‘imap’ (or for that
matter, ‘map’) without the quadratic complexity incurred by calling
‘++’ repeatedly.
---
 doc/manual/expressions/builtins.xml | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'doc/manual')

diff --git a/doc/manual/expressions/builtins.xml b/doc/manual/expressions/builtins.xml
index 099f90e786e5..4461570565e1 100644
--- a/doc/manual/expressions/builtins.xml
+++ b/doc/manual/expressions/builtins.xml
@@ -364,6 +364,24 @@ builtins.fromJSON ''{"x": [1, 2, 3], "y": null}''
   </varlistentry>
 
 
+  <varlistentry><term><function>builtins.genList</function>
+  <replaceable>generator</replaceable> <replaceable>length</replaceable></term>
+
+    <listitem><para>Generate list of size
+    <replaceable>length</replaceable>, with each element
+    <replaceable>i></replaceable> equal to the value returned by
+    <replaceable>generator</replaceable> <literal>i</literal>. For
+    example,
+
+<programlisting>
+builtins.genList (x: x * x) 5
+</programlisting>
+
+    returns the list <literal>[ 0 1 4 9 16 ]</literal>.</para></listitem>
+
+  </varlistentry>
+
+
   <varlistentry><term><function>builtins.getAttr</function>
   <replaceable>s</replaceable> <replaceable>set</replaceable></term>
 
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cgit 1.4.1