We use different classes to parce EL:
org.jboss.tools.common.model.util.ELParser (Used by JSF Conten Assist and VPE bundle resolver)
org.jboss.tools.seam.internal.core.el.SeamELTokenizer (Used by Seam Content Assist and Validator)
org.jboss.tools.jsf.text.ext.hyperlink.JSPExprHyperlinkPartitioner (Used by JSF Hiperlinks)

We have to refactor it to use one Basic Parcer for EL and maybe have some implementation for special cases if we need it.