pnsingletdown

Purpose

Fetch the child of a parse tree node, obeying rules about going down a "singlet chain." That is, get child only if no branching and if not going down past node with BASE flag set.

Syntax

returnedPnode = pnsingletdown(aPnode)

returnedPnode - type: pnode
aPnode - type: pnode

Returns

Remarks

Example

# Example shows a way to "layer" semantics in parse tree.
@POST
G("last") = lasteltnode(4);               # Get last noun node.
G("noun sem") = pnsingletdown(G("last")); # Get semantic node under _noun.
if (G("noun sem")                         # If got a semantic guy, eg "_house",
     && (G("name") = pnname(G("noun sem")))# (and get the name of the node)
     && strchr(G("noun sem"),"_") )        # and it's nonliteral.
    {
    group(1,4,G("name"));                  # "Promote" the sem, eg, "_house".
    group(1,1,"_np"); # Now layer on the np. Note numbering has changed.
    }
else
    group(1,4,"_np");        # No semantic guy, just build noun phrase.
@RULES
_xNIL <- _det [s] _quan [s] _adj [s plus] _noun [s plus] @@