xref: /external/antlr/antlr-3.4/runtime/JavaScript/src/org/antlr/runtime/tree/CommonTreeAdaptor.js

/** A TreeAdaptor that works with any Tree implementation.  It provides
 *  really just factory methods; all the work is done by BaseTreeAdaptor.
 *  If you would like to have different tokens created than ClassicToken
 *  objects, you need to override this and then set the parser tree adaptor to
 *  use your subclass.
 *
 *  To get your parser to build nodes of a different type, override
 *  create(Token).
 */
org.antlr.runtime.tree.CommonTreeAdaptor = function() {};

org.antlr.lang.extend(org.antlr.runtime.tree.CommonTreeAdaptor,
                  org.antlr.runtime.tree.BaseTreeAdaptor, {
    /** Duplicate a node.  This is part of the factory;
     *    override if you want another kind of node to be built.
     *
     *  I could use reflection to prevent having to override this
     *  but reflection is slow.
     */
    dupNode: function(t) {
        if ( !org.antlr.lang.isValue(t) ) {
            return null;
        }
        return t.dupNode();
    },

    create: function(payload) {
        if (arguments.length>1) {
            return org.antlr.runtime.tree.CommonTreeAdaptor.superclass.create.apply(this, arguments);
        }
        return new org.antlr.runtime.tree.CommonTree(payload);
    },

    /** Tell me how to create a token for use with imaginary token nodes.
     *  For example, there is probably no input symbol associated with imaginary
     *  token DECL, but you need to create it as a payload or whatever for
     *  the DECL node as in ^(DECL type ID).
     *
     *  If you care what the token payload objects' type is, you should
     *  override this method and any other createToken variant.
     *
     * Tell me how to create a token for use with imaginary token nodes.
     *  For example, there is probably no input symbol associated with imaginary
     *  token DECL, but you need to create it as a payload or whatever for
     *  the DECL node as in ^(DECL type ID).
     *
     *  This is a variant of createToken where the new token is derived from
     *  an actual real input token.  Typically this is for converting '{'
     *  tokens to BLOCK etc...  You'll see
     *
     *    r : lc='{' ID+ '}' -> ^(BLOCK[$lc] ID+) ;
     *
     *  If you care what the token payload objects' type is, you should
     *  override this method and any other createToken variant.
     */
    createToken: function(fromToken) {
        if (arguments.length===2) {
            return new org.antlr.runtime.CommonToken(arguments[0], arguments[1]);
        } else {
            return new org.antlr.runtime.CommonToken(arguments[0]);
        }
    },

    /** Track start/stop token for subtree root created for a rule.
     *  Only works with Tree nodes.  For rules that match nothing,
     *  seems like this will yield start=i and stop=i-1 in a nil node.
     *  Might be useful info so I'll not force to be i..i.
     */
    setTokenBoundaries: function(t, startToken, stopToken) {
        if ( !org.antlr.lang.isValue(t) ) {
            return;
        }
        var start = 0,
            stop = 0;
        if ( org.antlr.lang.isValue(startToken) ) {
            if (startToken.getTokenIndex) {
                start = startToken.getTokenIndex();
            } else if (startToken.getStartIndex) {
                start = startToken.getStartIndex();
            } else {
                start = startToken.getTokenStartIndex();
            }
        }
        if ( org.antlr.lang.isValue(stopToken) ) {
            if (stop.getTokenIndex) {
                stop = stopToken.getTokenIndex();
            } else if (stopToken.getStopIndex) {
                stop = stopToken.getStopIndex();
            } else {
                stop = stopToken.getTokenStopIndex();
            }
        }
        t.setTokenStartIndex(start);
        t.setTokenStopIndex(stop);
    },

    getTokenStartIndex: function(t) {
        if (!t) {
            return -1;
        }
        return t.getTokenStartIndex();
    },

    getTokenStopIndex: function(t) {
        if (!t) {
            return -1;
        }
        return t.getTokenStopIndex();
    },

    getText: function(t) {
        if (!t) {
            return null;
        }
        return t.getText();
    },

    getType: function(t) {
        if (!t) {
            return org.antlr.runtime.Token.INVALID_TOKEN_TYPE;
        }
        return t.getType();
    },

    /** What is the Token associated with this node?  If
     *  you are not using CommonTree, then you must
     *  override this in your own adaptor.
     */
    getToken: function(t) {
        if ( t instanceof org.antlr.runtime.tree.CommonTree ) {
            return t.getToken();
        }
        return null; // no idea what to do
    },

    getChild: function(t, i) {
        if (!t) {
            return null;
        }
        return t.getChild(i);
    },

    getChildCount: function(t) {
        if (!t) {
            return 0;
        }
        return t.getChildCount();
    },

    getParent: function(t) {
        return t.getParent();
    },

    setParent: function(t, parent) {
        t.setParent(parent);
    },

    getChildIndex: function(t) {
        return t.getChildIndex();
    },

    setChildIndex: function(t, index) {
        t.setChildIndex(index);
    },

    replaceChildren: function(parent, startChildIndex, stopChildIndex, t) {
        if ( parent ) {
            parent.replaceChildren(startChildIndex, stopChildIndex, t);
        }
    }
});