com.github.treepat.target_tree.default_tree.DefaultTargetTree.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of Treepat Show documentation

Treepat is a language to recognise patterns in trees in a similar way as regular expressions recognize patterns in strings. Treepat includes analogous operators to regex union, concatenation, and closure, which are extended to the notion of trees.

There is a newer version: 2.0.0

Show newest version

package com.github.treepat.target_tree.default_tree

import antlr.tree_format.TreeFormatLexer
import antlr.tree_format.TreeFormatParser
import com.github.treepat.grammars.antlr.tree_format.TreeFormatVisitorImplementation
import com.github.treepat.target_tree.TargetTree
import com.github.treepat.target_tree.TargetTreeNode
import java.nio.file.Path
import org.antlr.v4.runtime.CharStreams
import org.antlr.v4.runtime.CommonTokenStream
import org.antlr.v4.runtime.tree.ParseTree

class DefaultTargetTree(override var root: T? = null) :
    TargetTree {

    /**
     * Read tree from grammar.antlr.
     */
    constructor(tree_file: Path) : this() {
        val lexer = TreeFormatLexer(CharStreams.fromPath(tree_file))
        val tokenStream = CommonTokenStream(lexer)
        val fileParser = TreeFormatParser(tokenStream)
        val tree: ParseTree = fileParser.subtree()
        val treeVisitor = TreeFormatVisitorImplementation()
        @Suppress("UNCHECKED_CAST")
        root = treeVisitor.visit(tree) as? T
    }
}