Tutorial03 introduces custom types.
Custom types are specified similar to sentences, but
In this particular example, using a custom type for the filter size doesn't provide any advantage. In general, one would use custom types to
This will be demonstrated in subsequent tutorials.
For details, see also
<!doctype html>
<html>
<body>
<!-- The HTML element that will hold the editor -->
<div id="nls-container"></div>
<!-- The only javascript file needed for nlScript -->
<script src="https://cdn.jsdelivr.net/npm/@nlscript/nlscript@0.3.0/dist/umd/nlScript.js"></script>
<!-- Load the library for the actual processing -->
<script src="preprocessing.js"></script>
<script>
let preprocessing = new Preprocessing("output");
let parser = new nlScript.Parser();
// Create a custom type 'filter-size'
parser.defineType(
// The name of the type:
"filter-size",
// The pattern to parse (i.e. a floating point number, followed by the literal " pixel(s)".
"{stddev:float} pixel(s)",
// An Evaluator, which in this case just returns the parsed standard deviation as a Double.
// In principle, a custom type can evaluate to any object
pn => pn.evaluate("stddev"));
// Custom types can then be used to define other custom types, or to define sentences
parser.defineSentence(
"Apply Gaussian blurring with a standard deviation of {stddev:filter-size}.",
pn => {
let stdDev = pn.evaluate("stddev");
preprocessing.gaussianBlur(stdDev);
preprocessing.show("output");
return undefined;
});
new nlScript.ACEditor(parser, document.getElementById("nls-container"));
</script>
</body>
</html>
