From f50c2299fa376345cc163cf73175132fabb5d82c Mon Sep 17 00:00:00 2001
From: Mike Gerwitz <gerwitzm@lovullo.com>
Date: Fri, 21 Nov 2014 09:15:24 -0500
Subject: [PATCH] f:apply implemented

Although the general concept was independently discovered, the finer details
of this implementation are motivated by the excellent, comprehensive work of
Dimitre Novatchev[0].

For those of us who either can't, or don't wish to, abaondon XSLT.

[0]: http://conferences.idealliance.org/extreme/html/2006/Novatchev01/EML2006Novatchev01.html
---
 src/apply.xsl       | 196 ++++++++++++++++++++++++++++++++++++++++++++
 test/apply-test.xsl | 123 +++++++++++++++++++++++++++
 test/apply.xspec    | 175 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 494 insertions(+)
 create mode 100644 src/apply.xsl
 create mode 100644 test/apply-test.xsl
 create mode 100644 test/apply.xspec

diff --git a/src/apply.xsl b/src/apply.xsl
new file mode 100644
index 0000000..d4fda90
--- /dev/null
+++ b/src/apply.xsl
@@ -0,0 +1,196 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!--
+  Dynamic function application
+
+  Copyright (C) 2014 LoVullo Associates, Inc.
+
+    This file is part of hoxsl.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+  This can be used to create higher-order functions.
+
+  If you need more arguments than this, then you may want to consider
+  another approach.
+-->
+
+<stylesheet version="2.0"
+  xmlns="http://www.w3.org/1999/XSL/Transform"
+  xmlns:xs="http://www.w3.org/2001/XMLSchema"
+  xmlns:f="http://www.lovullo.com/xslink/apply">
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+
+  <apply-templates select="$fnref" mode="f:apply" />
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+  <param name="arg4" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+    <with-param name="arg4" select="$arg4" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+  <param name="arg4" />
+  <param name="arg5" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+    <with-param name="arg4" select="$arg4" />
+    <with-param name="arg5" select="$arg5" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+  <param name="arg4" />
+  <param name="arg5" />
+  <param name="arg6" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+    <with-param name="arg4" select="$arg4" />
+    <with-param name="arg5" select="$arg5" />
+    <with-param name="arg6" select="$arg6" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+  <param name="arg4" />
+  <param name="arg5" />
+  <param name="arg6" />
+  <param name="arg7" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+    <with-param name="arg4" select="$arg4" />
+    <with-param name="arg5" select="$arg5" />
+    <with-param name="arg6" select="$arg6" />
+    <with-param name="arg7" select="$arg7" />
+  </apply-templates>
+</function>
+
+
+<function name="f:apply">
+  <param name="fnref" as="element()" />
+  <param name="arg1" />
+  <param name="arg2" />
+  <param name="arg3" />
+  <param name="arg4" />
+  <param name="arg5" />
+  <param name="arg6" />
+  <param name="arg7" />
+  <param name="arg8" />
+
+  <apply-templates select="$fnref" mode="f:apply">
+    <with-param name="arg1" select="$arg1" />
+    <with-param name="arg2" select="$arg2" />
+    <with-param name="arg3" select="$arg3" />
+    <with-param name="arg4" select="$arg4" />
+    <with-param name="arg5" select="$arg5" />
+    <with-param name="arg6" select="$arg6" />
+    <with-param name="arg7" select="$arg7" />
+    <with-param name="arg8" select="$arg8" />
+  </apply-templates>
+</function>
+
+
+<!--
+  Abort processing on unknown function reference
+
+  This will occur if no application template is defined for the
+  given function reference.  Override it if you wish to perform
+  autoloading or what have you.
+
+  If you generate the nullary and application template using
+  apply-gen, then you won't have to worry about this.
+-->
+<template mode="f:apply"
+          match="*"
+          priority="1">
+  <message terminate="yes">
+    <text>error: cannot apply unknown function reference: </text>
+    <copy-of select="." />
+  </message>
+</template>
+
+</stylesheet>
diff --git a/test/apply-test.xsl b/test/apply-test.xsl
new file mode 100644
index 0000000..939675b
--- /dev/null
+++ b/test/apply-test.xsl
@@ -0,0 +1,123 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Tests dynamic function application
+
+  Copyright (C) 2014 LoVullo Associates, Inc.
+
+    This file is part of hoxsl.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<stylesheet version="2.0"
+            xmlns="http://www.w3.org/1999/XSL/Transform"
+            xmlns:f="http://www.lovullo.com/xslink/apply"
+            xmlns:foo="http://www.lovullo.com/_junk">
+
+  <import href="../src/apply.xsl" />
+
+
+  <template mode="f:apply" match="foo:fn0">
+    <!-- return something to show that we were called properly -->
+    <sequence select="0" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn1">
+    <param name="arg1" />
+
+    <sequence select="string($arg1)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn2">
+    <param name="arg1" />
+    <param name="arg2" />
+
+    <sequence select="concat($arg1, $arg2)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn3">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+
+    <sequence select="concat($arg1, $arg2, $arg3)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn4">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+    <param name="arg4" />
+
+    <sequence select="concat($arg1, $arg2, $arg3, $arg4)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn5">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+    <param name="arg4" />
+    <param name="arg5" />
+
+    <sequence select="concat($arg1, $arg2, $arg3, $arg4,
+                        $arg5)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn6">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+    <param name="arg4" />
+    <param name="arg5" />
+    <param name="arg6" />
+
+    <sequence select="concat($arg1, $arg2, $arg3, $arg4,
+                        $arg5, $arg6)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn7">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+    <param name="arg4" />
+    <param name="arg5" />
+    <param name="arg6" />
+    <param name="arg7" />
+
+    <sequence select="concat($arg1, $arg2, $arg3, $arg4,
+                        $arg5, $arg6, $arg7)" />
+  </template>
+
+
+  <template mode="f:apply" match="foo:fn8">
+    <param name="arg1" />
+    <param name="arg2" />
+    <param name="arg3" />
+    <param name="arg4" />
+    <param name="arg5" />
+    <param name="arg6" />
+    <param name="arg7" />
+    <param name="arg8" />
+
+    <sequence select="concat($arg1, $arg2, $arg3, $arg4,
+                        $arg5, $arg6, $arg7, $arg8)" />
+  </template>
+</stylesheet>
diff --git a/test/apply.xspec b/test/apply.xspec
new file mode 100644
index 0000000..0cc9b35
--- /dev/null
+++ b/test/apply.xspec
@@ -0,0 +1,175 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Tests dynamic function application
+
+  Copyright (C) 2014 LoVullo Associates, Inc.
+
+    This file is part of hoxsl.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<description xmlns="http://www.jenitennison.com/xslt/xspec"
+             xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+             xmlns:f="http://www.lovullo.com/xslink/apply"
+             xmlns:foo="http://www.lovullo.com/_junk"
+             stylesheet="apply-test.xsl">
+
+  <scenario label="f:apply">
+    <scenario label="applied to a function reference element">
+      <variable name="arg"
+                select="'foo'" />
+
+      <call function="f:apply">
+        <param name="fnref">
+          <foo:fn1 />
+        </param>
+        <param name="arg1" select="$arg" />
+      </call>
+
+      <!-- our test appliaction template simply echoes back its only
+           argument -->
+      <expect label="applies application template with mode f:apply"
+              test="$x:result = ($arg)" />
+    </scenario>
+
+
+    <scenario label="applying">
+      <scenario label="nullary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn0 /></param>
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = 0" />
+      </scenario>
+
+
+      <scenario label="unary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn1 /></param>
+          <param name="arg1" select="1" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '1'" />
+      </scenario>
+
+
+      <scenario label="binary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn2 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '12'" />
+      </scenario>
+
+
+      <scenario label="ternary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn3 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '123'" />
+      </scenario>
+
+
+      <scenario label="4-ary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn4 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+          <param name="arg4" select="4" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '1234'" />
+      </scenario>
+
+
+      <scenario label="5-ary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn5 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+          <param name="arg4" select="4" />
+          <param name="arg5" select="5" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '12345'" />
+      </scenario>
+
+
+      <scenario label="6-ary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn6 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+          <param name="arg4" select="4" />
+          <param name="arg5" select="5" />
+          <param name="arg6" select="6" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '123456'" />
+      </scenario>
+
+
+      <scenario label="7-ary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn7 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+          <param name="arg4" select="4" />
+          <param name="arg5" select="5" />
+          <param name="arg6" select="6" />
+          <param name="arg7" select="7" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '1234567'" />
+      </scenario>
+
+
+      <scenario label="8-ary function">
+        <call function="f:apply">
+          <param name="fnref"><foo:fn8 /></param>
+          <param name="arg1" select="1" />
+          <param name="arg2" select="2" />
+          <param name="arg3" select="3" />
+          <param name="arg4" select="4" />
+          <param name="arg5" select="5" />
+          <param name="arg6" select="6" />
+          <param name="arg7" select="7" />
+          <param name="arg8" select="8" />
+        </call>
+
+        <expect label="passes each argument"
+                test="$x:result = '12345678'" />
+      </scenario>
+    </scenario>
+  </scenario>
+</description>