tame/core/vector/define.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
  Copyright (C) 2014-2020 Ryan Specialty Group, LLC.

  This file is part of tame-core.

  tame-core 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/>.
-->
<package xmlns="http://www.lovullo.com/rater"
  xmlns:c="http://www.lovullo.com/calc"
  xmlns:t="http://www.lovullo.com/rater/apply-template"
  core="true"
  desc="Vector definition">

  This package provides a type of global~\tt{let}.
  The term ``define'' is consistent with the influence of the language
    Scheme on this system.
  One a primitive is provided,
    this abstraction can be modified to make use of it.

  This addresses the challenge with defining arbitrary values.
  TAME was designed for a map-reduce style of computation that
    maintains index assocaitions.
  This makes it easy to reason about data flow.

  Consequently,
    arbitrary definitions should be used sparingly until they become a core
      feature of TAME.


  <template name="_define-vector_"
            desc="Define a vector with an arbitrary value">
    <param name="@values@"    desc="Definition" />
    <param name="@generates@" desc="Vector name" />
    <param name="@desc@"      desc="Vector description" />


    <rate yields="_{@generates@}">
      <c:let>
        <c:values>
          <c:value name="value" type="float" set="vector"
                   desc="{@desc@} (intermediate value)">
            <param-copy name="@values@" />
          </c:value>
        </c:values>

        <!-- effectively means @generates@ = value -->
        <c:sum of="value" generates="@generates@" index="k"
               desc="@desc@">
          <c:value-of name="value" index="k" />
        </c:sum>
      </c:let>
    </rate>
  </template>
</package>