rbbinode.cpp | Explore in Territory

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
***************************************************************************
*   Copyright (C) 2002-2016 International Business Machines Corporation   *
*   and others. All rights reserved.                                      *
***************************************************************************
*/

//
//  File:  rbbinode.cpp
//
//         Implementation of class RBBINode, which represents a node in the
//         tree generated when parsing the Rules Based Break Iterator rules.
//
//         This "Class" is actually closer to a struct.
//         Code using it is expected to directly access fields much of the time.
//

#include "unicode/utypes.h"

#if !UCONFIG_NO_BREAK_ITERATION

#include "unicode/unistr.h"
#include "unicode/uniset.h"
#include "unicode/uchar.h"
#include "unicode/parsepos.h"

#include "cstr.h"
#include "uvector.h"

#include "rbbirb.h"
#include "rbbinode.h"

#include "uassert.h"


U_NAMESPACE_BEGIN

#ifdef RBBI_DEBUG
static int  gLastSerial = 0;
#endif


//-------------------------------------------------------------------------
//
//    Constructor.   Just set the fields to reasonable default values.
//
//-------------------------------------------------------------------------
RBBINode::RBBINode(NodeType t) : … { … }


RBBINode::RBBINode(const RBBINode &other) : … { … }


//-------------------------------------------------------------------------
//
//    Destructor.   Deletes both this node AND any child nodes,
//                  except in the case of variable reference nodes.  For
//                  these, the l. child points back to the definition, which
//                  is common for all references to the variable, meaning
//                  it can't be deleted here.
//
//-------------------------------------------------------------------------
RBBINode::~RBBINode() { … }

/**
 * Non-recursive delete of a node + its children. Used from the node destructor
 * instead of the more obvious recursive implementation to avoid problems with
 * stack overflow with some perverse test rule data (from fuzzing).
 */
void RBBINode::NRDeleteNode(RBBINode *node) { … }

//-------------------------------------------------------------------------
//
//    cloneTree     Make a copy of the subtree rooted at this node.
//                  Discard any variable references encountered along the way,
//                  and replace with copies of the variable's definitions.
//                  Used to replicate the expression underneath variable
//                  references in preparation for generating the DFA tables.
//
//-------------------------------------------------------------------------
RBBINode *RBBINode::cloneTree() { … }



//-------------------------------------------------------------------------
//
//   flattenVariables   Walk a parse tree, replacing any variable
//                      references with a copy of the variable's definition.
//                      Aside from variables, the tree is not changed.
//
//                      Return the root of the tree.  If the root was not a variable
//                      reference, it remains unchanged - the root we started with
//                      is the root we return.  If, however, the root was a variable
//                      reference, the root of the newly cloned replacement tree will
//                      be returned, and the original tree deleted.
//
//                      This function works by recursively walking the tree
//                      without doing anything until a variable reference is
//                      found, then calling cloneTree() at that point.  Any
//                      nested references are handled by cloneTree(), not here.
//
//-------------------------------------------------------------------------
constexpr int kRecursiveDepthLimit = …;
RBBINode *RBBINode::flattenVariables(UErrorCode& status, int depth) { … }


//-------------------------------------------------------------------------
//
//  flattenSets    Walk the parse tree, replacing any nodes of type setRef
//                 with a copy of the expression tree for the set.  A set's
//                 equivalent expression tree is precomputed and saved as
//                 the left child of the uset node.
//
//-------------------------------------------------------------------------
void RBBINode::flattenSets() { … }



//-------------------------------------------------------------------------
//
//   findNodes()     Locate all the nodes of the specified type, starting
//                   at the specified root.
//
//-------------------------------------------------------------------------
void   RBBINode::findNodes(UVector *dest, RBBINode::NodeType kind, UErrorCode &status) { … }


//-------------------------------------------------------------------------
//
//    print.         Print out a single node, for debugging.
//
//-------------------------------------------------------------------------
#ifdef RBBI_DEBUG

static int32_t serial(const RBBINode *node) {
    return (node == nullptr? -1 : node->fSerialNum);
}


void RBBINode::printNode(const RBBINode *node) {
    static const char * const nodeTypeNames[] = {
                "setRef",
                "uset",
                "varRef",
                "leafChar",
                "lookAhead",
                "tag",
                "endMark",
                "opStart",
                "opCat",
                "opOr",
                "opStar",
                "opPlus",
                "opQuestion",
                "opBreak",
                "opReverse",
                "opLParen"
    };

    if (node==nullptr) {
        RBBIDebugPrintf("%10p", (void *)node);
    } else {
        RBBIDebugPrintf("%10p %5d %12s %c%c  %5d       %5d     %5d       %6d     %d ",
            (void *)node, node->fSerialNum, nodeTypeNames[node->fType],
            node->fRuleRoot?'R':' ', node->fChainIn?'C':' ',
            serial(node->fLeftChild), serial(node->fRightChild), serial(node->fParent),
            node->fFirstPos, node->fVal);
        if (node->fType == varRef) {
            RBBI_DEBUG_printUnicodeString(node->fText);
        }
    }
    RBBIDebugPrintf("\n");
}
#endif


#ifdef RBBI_DEBUG
U_CFUNC void RBBI_DEBUG_printUnicodeString(const UnicodeString &s, int minWidth) {
    RBBIDebugPrintf("%*s", minWidth, CStr(s)());
}
#endif


//-------------------------------------------------------------------------
//
//    print.         Print out the tree of nodes rooted at "this"
//
//-------------------------------------------------------------------------
#ifdef RBBI_DEBUG
void RBBINode::printNodeHeader() {
    RBBIDebugPrintf(" Address   serial        type     LeftChild  RightChild   Parent   position value\n");
}
    
void RBBINode::printTree(const RBBINode *node, UBool printHeading) {
    if (printHeading) {
        printNodeHeader();
    }
    printNode(node);
    if (node != nullptr) {
        // Only dump the definition under a variable reference if asked to.
        // Unconditionally dump children of all other node types.
        if (node->fType != varRef) {
            if (node->fLeftChild != nullptr) {
                printTree(node->fLeftChild, false);
            }
            
            if (node->fRightChild != nullptr) {
                printTree(node->fRightChild, false);
            }
        }
    }
}
#endif



U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
godot/thirdparty/icu4c/common/rbbinode.cpp
