When the scanner sees “< <%" it interprets this as a LEFT_SHIFT ("<<") plus trailing garbage.

If you really want to re-interpret this you'd just have to add a few lines to the ScannerAdaptor (let's see if the code get's through):

} else if (token == TerminalTokens.TokenNameLEFT_SHIFT) {
    char[] source = getSource();
    int pos = getCurrentPosition();
    if (source[pos] == ‘%’) { // detecting the opening “< <%" ?
        setCurrentPosition(pos-1); // put back the second '<'
	return TerminalTokens.TokenNameLESS; // return the first '<'
    }

So it is possible, though I think it would actually be confusing if “<<” is broken into two parts.

best
Stephan

Hi Stephan,

Thanks for answer and sorry for the delay of my new comments.

The first part of your explanation is very clear. I will now try to clarify my question on the ‘<<’ token.

First I write to write a conditional expression.
‘if ( 1 <=<%one%>) {}’
The compiler does not complain. Then I modify my code:
‘if ( 1 <<%one%>) {}’
And the compiler complains. I do not understand why. I only replace a binary operator ‘<=’ by a new one ‘<’. Now if I add some layouts after the first ‘<’, it works…
‘if ( 1 < <%one%>) {}’

PS. I read again my first post and my <%one%> disappeared. This perhaps explains why my question was difficult to understand

Thanks for answer and sorry for the delay of my new comments.

The first part of your explanation is very clear. I will now try to clarify my question on the ‘<<’ token.

First I write to write a conditional expression. Of course, It uses a expression:
‘if ( 1 <=) {}’
The compiler does not complain. Then I modify my code:
‘if ( 1 <) {}’
And the compiler complains. I do not understand why. I only replace a binary operator ‘<=’ by a new one ‘<’. Now if I add some layouts after the first ‘<’, it works…
‘if ( 1 < ) {}’

PS. I read again my first post and my (whitout spaces) disappeared. This perhaps explains why my question was difficult to understand

I’m not sure I understand your syntax examples but yes, < < and < are different tokens which could create a conflict (try asking for TokenNameLEFT_SHIFT etc.).

Is it any clearer now?
Stephan

[1] full sources are at http://www.objectteams.org/examples/embedded-expression-language-v2.zip