tame/core/vector/cmatch.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<package xmlns="http://www.lovullo.com/rater"
  xmlns:c="http://www.lovullo.com/calc"
  core="true"
  desc="Vector operations on classification matches">

  <import package="../base" />
  <import package="arithmetic" export="true" />


  <!--
    This wonderful little gem takes a classification match and stores it in a
    vector, allowing for hassle-free use in calculations without awkward
    hasany() calls on classification matrices (where a classification yields a
    matrix, that is). This is useless for classifications that yield vectors,
    since the result will be the same.

    This template is also useful for combining various classification vectors
    and matrices, whoose reduction would otherwise be a bit complicated. Of
    course, the alternative there is also to create a classification that
    relies on other classifications; use your best judgement.

    This exploits the fact that _CMATCH_'s are always vectors, even if we are
    matching on a matrix.  As such, the system has already gone through the
    trouble of reducing the matrix into a vector for us, so all we need to do
    is store each value into a vector, which can be easily accomplished using a
    generator.

    This is an excellent example of building a feature atop of the DSL without
    having to add a new language feature.
  -->
  <template name="_cmatch-to-vector_" desc="Vectorizes a classification match">
    <param name="@class@" desc="Classification match string" />
    <param name="@generates@" desc="Variable to yield generates (will yield a vector)" />
    <param name="@keep@" desc="Rate block @keep">
      <text></text>
    </param>

    <param name="@yields@" desc="Dummy variable to yield generates (useless, but required)">
      <text>__</text>
      <param-value name="@generates@" />
    </param>

    <param name="@gendesc@" desc="Generator description">
      <text>Vector containing boolean </text>
      <param-value name="@class@" />
      <text> classification matches</text>
    </param>

    <param name="@sym@" desc="Generator symbol (corresponds to @generates@)">
      <!-- defaults to nothing -->
      <text></text>
    </param>

    <!-- this conversion is as simple as using a generator to yield the value
         of _CMATCH_ for each index -->
    <rate class="@class@" accumulate="none" yields="@yields@" always="true" keep="@keep@">
      <c:sum of="_CMATCH_" index="k" generates="@generates@" desc="@gendesc@" sym="@sym@">
        <c:value-of name="_CMATCH_" index="k" />
      </c:sum>
    </rate>
  </template>


  <template name="_cmatch-to-scalar_" desc="Reduces a classification match into a scalar">
    <param name="@class@" desc="Classification match string" />
    <param name="@yields@" desc="Variable to yield into" />
    <param name="@sym@" desc="Yield symbol (defaults to nothing)">
      <!-- defaults to nothing -->
      <text></text>
    </param>

    <param name="@keep@" desc="Rate block @keep">
      <text></text>
    </param>


    <rate class="@class@" accumulate="none" yields="@yields@" sym="@sym@" keep="@keep@">
      <!-- if any single one matches, then we want to yield a 1 -->
      <c:apply name="maxreduce" maxreduce_set="_CMATCH_" />
    </rate>
  </template>



  <!--
    Counts one for each classification vector match
  -->
  <template name="_cmatch-count_" desc="Counts the number of classification matches of a vector">
    <param name="@class@" desc="Classification match" />
    <param name="@yields@" desc="Value to yield" />

    <!-- nothing by default -->
    <param name="@no@" desc="Non-match">
      <text></text>
    </param>


    <rate class="@class@" no="@no@" yields="@yields@">
      <c:sum of="_CMATCH_" />
    </rate>
  </template>


  <!-- because verbose repition is an evil -->
  <inline-template>
    <for-each>
      <set cmp="eq" />
      <set cmp="ne" />
      <set cmp="gt" />
      <set cmp="gte" />
      <set cmp="lt" />
      <set cmp="lte" />
    </for-each>


    <template name="_match-{@cmp@}_" desc="Match value {@cmp@}">
      <param name="@on@" desc="Value to assert" />

      <!-- pick one -->
      <param name="@const@" desc="Match against constant value" />
      <param name="@value@" desc="Match against variable" />

      <match on="@on@">
        <dyn-node name="c:{@cmp@}">
          <if name="@const@">
            <c:const value="@const@" type="float" desc="Comparison" />
          </if>

          <unless name="@const@">
            <c:value-of name="@value@" />
          </unless>
        </dyn-node>
      </match>
    </template>
  </inline-template>


  <template name="_match-class_"
               desc="Match on a class name (rather than @yields)">
    <param name="@name@" desc="Classification name" />

    <param name="@__yields@" desc="Classification yield to match on">
      <param-class-to-yields name="@name@" />
    </param>

    <param name="@value@" desc="Value to match on">
      <text></text>
    </param>

    <match on="@__yields@" value="@value@" />
  </template>
</package>