Class: Trees

Inherits:
Object show all
Defined in:
lib/antlr4/tree/Trees.rb

Overview

A set of utility routines useful for all kinds of ANTLR trees.# from io import StringIO from antlr4.Token import Token from antlr4.Utils import escapeWhitespace from antlr4.tree.Tree import RuleNode, ErrorNode, TerminalNode, Tree, ParseTree

Class Method Summary collapse

Class Method Details

._findAllNodes(t, index, findTokens, nodes) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 89

def self._findAllNodes(t, index, findTokens, nodes)
    #from antlr4.ParserRuleContext import ParserRuleContext
    # check this node (the root) first
    if findTokens and t.kind_of? TerminalNode then
        nodes.push(t) if t.symbol.type==index
    elsif not findTokens and t.kind_of? ParserRuleContext then
        nodes.push(t) if t.ruleIndex == index
    end
    # check children
    for i in 0 .. t.getChildCount()-1
        self._findAllNodes(t.getChild(i), index, findTokens, nodes)
    end
end

.descendants(t) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 103

def self.descendants(t)
    nodes = Array.new
    nodes.push(t)
    for i in 0..t.getChildCount()-1 
        nodes.concat(self.descendants(t.getChild(i)))
    end
    return nodes
end

.findAllNodes(cls, t, index, findTokens) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 83

def self.findAllNodes(cls, t, index, findTokens)
    nodes = Array.new
    _findAllNodes(t, index, findTokens, nodes)
    return nodes
end

.findAllRuleNodes(t, ruleIndex) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 79

def self.findAllRuleNodes(t, ruleIndex)
    return findAllNodes(t, ruleIndex, false)
end

.findAllTokenNodes(t, ttype) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 75

def self.findAllTokenNodes(t, ttype)
    return findAllNodes(t, ttype, true)
end

.getAncestors(t) ⇒ Object

Return a list of all ancestors of this node. The first node of

list is the root and the last is the parent of this node.



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# File 'lib/antlr4/tree/Trees.rb', line 65

def self.getAncestors(t)
    ancestors = []
    t = t.getParent()
    while not t.nil? do
        ancestors.unshift(t) # insert at start
        t = t.getParent()
    end
    return ancestors
end

.getChildren(t) ⇒ Object

Return ordered list of all children of this node



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# File 'lib/antlr4/tree/Trees.rb', line 58

def self.getChildren(t)
    return (0 .. t.getChildCount()-1).map{|i| t.getChild(i) }
end

.getNodeText(t, ruleNames = nil, recog = nil) ⇒ Object 



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# File 'lib/antlr4/tree/Trees.rb', line 34

def self.getNodeText(t, ruleNames=nil, recog=nil) 
    if not recog.nil? then 
        ruleNames = recog.ruleNames
    end
    if not ruleNames.nil? then 
        if t.kind_of? RuleNode then
            return ruleNames[t.getRuleContext().getRuleIndex()]
        elsif t.kind_of? ErrorNode then
            return t.to_s
        elsif t.kind_of? TerminalNode then
            if not t.symbol.nil? then 
                return t.symbol.text
            end
        end
    end
    # no recog for rule names
    payload = t.getPayload()
    if payload.kind_of? Token then
        return payload.text
    end
    return t.getPayload().to_s
end

.toStringTree(t, ruleNames = nil, recog = nil) ⇒ Object

node payloads to get the text for the nodes. Detect

parse trees and extract data appropriately.



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# File 'lib/antlr4/tree/Trees.rb', line 12

def self.toStringTree(t, ruleNames=nil, recog=nil)
    if not recog.nil? then 
        ruleNames = recog.ruleNames
    end
    s = getNodeText(t, ruleNames).escapeWhitespace(false)
    if t.getChildCount()==0 then
        return s
    end
    StringIO.open  do |buf|
        buf.write("(")
        buf.write(s)
        buf.write(' ')
        for i in 0..t.getChildCount()-1 do
            if i > 0 then
                buf.write(' ')
            end
            buf.write(toStringTree(t.getChild(i), ruleNames))
        end
        buf.write(")")
        return buf.string()
    end
end