Xtext, transform ascii character to math symboles - eclipse

Question

How can a xtext editor translate (for example) -> to the latex symbol \rightarrow?

Answer 1

Have a look at the nice feature of autoedit
public class MyDslDefaultAutoEditStrategyProvider extends DefaultAutoEditStrategyProvider {
#Inject
protected Provider<ShortCutEditStrategy> shortCut;
#Override
protected void configureStringLiteral(IEditStrategyAcceptor acceptor) {
acceptor.accept(shortCut.get().configure("->", "\\rightarrow"), IDocument.DEFAULT_CONTENT_TYPE);
}
}
and dont forget the binding
override Class<? extends AbstractEditStrategyProvider> bindAbstractEditStrategyProvider() {
MyDslDefaultAutoEditStrategyProvider
}

Answer 2

It's quite easy using JavaScript. This simple script should help:
replaceText('->', '\rightarrow');
var replaceText = function (search, replaceWith) {
var area = document.getElementById("area");
var getCount = function (str, search) {
return str.split(search).length - 1;
};
if (area.value.indexOf(search) >= 0) {
var start = area.selectionStart;
var end = area.selectionEnd;
var textBefore = area.value.substr(0, end);
var lengthDiff = (replaceWith.length - search.length) * getCount(textBefore, search);
area.value = area.value.replace(search, replaceWith);
area.selectionStart = start + lengthDiff;
area.selectionEnd = end + lengthDiff;
}
};
This full text can be easily adapted for your use- here's a full example.
<textarea id="area"></textarea>
<script>
function keyDownTextField() {
replaceText('->', '\u2192');
}
var replaceText = function (search, replaceWith) {
var area = document.getElementById("area");
var getCount = function (str, search) {
return str.split(search).length - 1;
};
if (area.value.indexOf(search) >= 0) {
var start = area.selectionStart;
var end = area.selectionEnd;
var textBefore = area.value.substr(0, end);
var lengthDiff = (replaceWith.length - search.length) * getCount(textBefore, search);
area.value = area.value.replace(search, replaceWith);
area.selectionStart = start + lengthDiff;
area.selectionEnd = end + lengthDiff;
}
};
document.addEventListener("keydown", keyDownTextField, false);
</script>