From dfef53750030612523a4edc1d63ce4f179745f7d Mon Sep 17 00:00:00 2001
From: Andrew Shitov <andy@shitov.ru>
Date: Wed, 9 Sep 2020 21:22:11 +0200
Subject: 77-2: a functional solution in XSLT

---
 challenge-077/ash/xslt/ch-2.xml  | 25 ++++++++++++++++++++++++
 challenge-077/ash/xslt/ch-2.xslt | 41 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 challenge-077/ash/xslt/ch-2.xml
 create mode 100644 challenge-077/ash/xslt/ch-2.xslt

diff --git a/challenge-077/ash/xslt/ch-2.xml b/challenge-077/ash/xslt/ch-2.xml
new file mode 100644
index 0000000000..ce27ac5cdb
--- /dev/null
+++ b/challenge-077/ash/xslt/ch-2.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0"?>
+
+<!--
+    Task 2 from
+    https://perlweeklychallenge.org/blog/perl-weekly-challenge-077/
+
+    To get a solution, run:
+    $ xsltproc ch-2.xslt ch-2.xml 
+
+    For the given example matrix, you get the following output (items count from 1):
+    1, 2
+    3, 1
+-->
+
+<matrix>
+    <row>
+        <item>O</item> <item>X</item> <item>O</item>
+    </row>
+    <row>
+        <item>O</item> <item>O</item> <item>O</item>
+    </row>
+    <row>
+        <item>X</item> <item>O</item> <item>O</item>
+    </row>
+</matrix>
diff --git a/challenge-077/ash/xslt/ch-2.xslt b/challenge-077/ash/xslt/ch-2.xslt
new file mode 100644
index 0000000000..3a1fb688da
--- /dev/null
+++ b/challenge-077/ash/xslt/ch-2.xslt
@@ -0,0 +1,41 @@
+<?xml version="1.0"?>
+
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+
+<xsl:output omit-xml-declaration="yes"/>
+
+<xsl:template match="/matrix">
+    <xsl:apply-templates select="row"/>
+</xsl:template>
+
+<xsl:template match="row">
+    <xsl:apply-templates select="item"/>
+</xsl:template>
+
+<!-- catch 'O's -->
+<xsl:template match="item"/>
+
+<xsl:template match="item[text() = 'X']">
+    <xsl:variable name="row" select="count(../preceding-sibling::*) + 1"/> <!-- position of parent -->
+    <xsl:variable name="col" select="position()"/>
+
+    <xsl:variable name="lonely" select="
+        (not(/matrix/row[$row    ]/item[$col - 1]) or /matrix/row[$row    ]/item[$col - 1] = 'O') and
+        (not(/matrix/row[$row    ]/item[$col + 1]) or /matrix/row[$row    ]/item[$col + 1] = 'O') and
+        (not(/matrix/row[$row + 1]/item[$col    ]) or /matrix/row[$row + 1]/item[$col    ] = 'O') and
+        (not(/matrix/row[$row - 1]/item[$col    ]) or /matrix/row[$row - 1]/item[$col    ] = 'O') and
+        (not(/matrix/row[$row + 1]/item[$col + 1]) or /matrix/row[$row + 1]/item[$col + 1] = 'O') and
+        (not(/matrix/row[$row - 1]/item[$col - 1]) or /matrix/row[$row - 1]/item[$col - 1] = 'O') and
+        (not(/matrix/row[$row + 1]/item[$col - 1]) or /matrix/row[$row + 1]/item[$col - 1] = 'O') and
+        (not(/matrix/row[$row - 1]/item[$col + 1]) or /matrix/row[$row - 1]/item[$col + 1] = 'O')
+    "/>
+
+    <xsl:if test="$lonely">
+        <xsl:value-of select="$row"/>
+        <xsl:text>, </xsl:text>
+        <xsl:value-of select="$col"/>
+        <xsl:text disable-output-escaping="yes">&#10;</xsl:text>
+    </xsl:if>
+</xsl:template>
+
+</xsl:stylesheet>
-- 
cgit