JPS62154024A - Tree structure data processing system - Google Patents

Abstract

PURPOSE:To efficiently express even a specific binary tree (list structure) in terms of memory by setting to each cell a bit field giving meanings equivalent to denoting the function element of list structure. CONSTITUTION:The titled system relates to a data expression system when a tree structure storage program 414 stores data of tree structure in a data part 420. Memory composed of 32 bits, called a 'cell', comprises the data part, and the target tree structure is expressed by said cell group. If a name identifier field 35 expresses a function name identifier, that is, when a name identification field 34 is '01', a cell following the cell concerned denotes the argument of the function. In the cell expressing the argument, a list bit field 32 is used for showing whether continuously an argument cell exists or not. '1' and '0' show that the following cell is an argument cell and that it is not an argument cell, respectively. The former means that the cell concerned is a finals argument cell.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a processing method for tree-structured data, and in particular, it is capable of expressing an n-ary tree structure and expresses a specific binary tree structure with memory efficiency. This invention relates to a tree structure data processing method suitable for processing data.

[Background of the invention]

In the conventional n-linked tree structure data representation method, for example, two types of cells (Funetor cell and Reference cell) are provided, and n-launched m-argument nodes are represented by m+1 consecutive cells, and the relationship between the nodes is defined as Reference. It was a system that used cells to represent it. n-ary tree structure data f
The first example of expressing (a, g (b), c) using this method is
Shown in Figure (a).

Among the n-ary tree structure data, a specific binary tree structure (list structure) used to represent an arrangement of data is frequently used. However, the conventional method does not take this point into account, and when expressing a sequence of Q pieces of data, 3
Twelve cells were required. Three pieces of data a, b,
Figure 1 (b
).

Here, "・" is the function name of the list structure, rN I LJ
is data unique to the list structure that indicates the end of the sequence.

cdrcodiB as an efficient representation method for list structures
The 0-hydro type, which is a known method, has 2 bits of additional information in each cell, and has 4 bits of information: CAR, CDR, NEXT, and NIL.
By providing different cell types, Q data arrays are expressed by Q cells.

The list structure of FIG. 1(b) can be expressed as shown in FIG.

However, if this method is used to express the list structure as an n-ary tree structure, cdrcoding can efficiently express the list structure.
The characteristics of the method are lost. For example, when expressing n launches as shown in Figure 1(a), 2 launches as shown in Figure 3(a).
It has to be converted to Shinki, that is, cdrcodin
The meaning expressed by the g method must be changed. In this case, the structure in FIG. 2 is a(b).

Therefore, to represent the sequence of three data a, b, and c, nine cells must be used as shown in FIG. 3(b).

Regarding cdrcoding, for example, see Greenblatt et al., "The Lisp Machine," MIT Artificial Intelligence Research Institute, 1979 (Green blatt, R.
ichartetal, “The Li5p
Machine” IT ArtificialI
intelligence Laboratory 19
79), etc.

[Purpose of the invention]

An object of the present invention is to be able to express an n-chained data structure,
Another object of the present invention is to provide a tree-structured data processing method that enables n-ary tree-structured data that can express specific binary data (list structure) with high memory efficiency.

[Summary of the invention]

To achieve the above object, the present invention sets a bit field in each cell to have a meaning equivalent to representing a function of a list structure.

This differs from the cdrcoding method in that it does not have a bit field to represent the end of the list, unlike the cdrcoding method. It also differs from the conventional n-ary tree structure representation method in that a "list bit field" is set within the cell.

As a result, this method can achieve memory efficiency characteristics intermediate between the cdrcoding method and the conventional n-launch representation method. As far as n-ary launches other than list structures are concerned, memory efficiency is lower than conventional n-ary tree structures due to the "list bit field," but list structures can be expressed with memory efficiency.

When expressing only a list structure, "The memory efficiency is lower than the cdrcoding method because it requires a cell to represent the end of the list, but the 1-hydro method can also represent n launches. Therefore, the n-ary tree structure and the list When structures coexist, it can be said that this method can express these structures with more memory efficiency than either of the two conventional methods.

Furthermore, when representing an n-ary node, the "list bit field" can also be used to indicate the end of the argument for that node, so the memory efficiency deterioration in the n-ary tree structure representation is substantially reduced by each Less than 1 bit per cell.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The present invention shows a simple tree structure operation display system as an embodiment. FIG. 4(a) shows the hardware configuration of this system, in which a central processing unit 41, a storage device @42, an input/output management device 43 are connected by a data bus 44, and a CRT
A display device 45 and a key input device 46 are connected to the X output management device 43 by another data bus 47. FIG. 4(b) shows the software configuration of this system, including a monitor program 411, an input prompt A program section 410 consisting of a display program 412, an input tree structure analysis program 413, a tree structure storage program 414, a tree structure search program 415, and a tree structure display program 416, and a data section 42 that stores tree structure data.
Consists of 0.

Figure 5 shows the flow of processing in this system.

This part corresponds to the operation content of the monitor program 411. When the system is started, the input prompting display program 412 is started (51), and the CRT display device 4
Display an input prompt symbol above 5, then start the input tree structure analysis program 413 that reads and analyzes input data (tree structure) from the operator (52), and determines the value of the input data (53). ), tree structure storage program 4
14 or start the tree structure search program 415.
4.55) Store the tree structure data in the data section 420, or start the zero-order tree structure display program 416 that searches the stored tree structure data.56) Store the stored tree structure data or search the tree structure data. Display the data on a CR7 display.

In the present invention, the tree structure storage program 414
This relates to a data representation method when storing tree-structured data in 0. The data section consists of a memory unit consisting of 32 bits called 1' cell, and the target tree structure is expressed by a collection of these "cells".The structure of the cell will be explained in detail below.

As shown in Figure 6(a), 32 bits are stored in one cell (3
0), and the lower two bits are respectively a pointer bit field (31) and a list bit field (32).
shall be. The remaining 30 bits are called the content field (33).

List bit field (32) is used when the cell belongs to a list structure, its first argument is represented by a content field and a pointer bit field, and the following cell is the second argument of the list structure. (I I+
, otherwise it is set as “OI+”.

The pointer bit field (31) is set to ``1'' when the content field of the cell in question represents a pointer pointing to another cell, otherwise it is set to ``0''.

When the pointer bit field (31) is "0", that is, when the content field (33) is not a pointer pointing to another cell, the content field (33) further contains:
As shown in Figure 6(b), the name identifier field (35
) and a name type field (34).

The name type field (34) is "o o' when the name identifier field (35) represents a constant name identifier.
'', when representing a function name identifier, use Lg O11+.

When the name identifier field (35) represents a function name identifier, that is, the name type field (34) is “01”.
'', the cell following the cell represents the argument of the function. In the cell representing the argument, the list bit field (32) is used to indicate whether the argument cell is present or not; '1 ” indicates that the following cell is also an argument cell, and par 0' indicates that it is not, that is, the cell in question is the last argument cell. Note that the list pici field is "1" and the pointer bit field is "
The combination of expressions "0" and "01" in the name type field is not allowed.

In this embodiment, the n water flow structure data f (a, g (b), c) shown in FIG. 1(a) can be expressed by six cells as shown in FIG. 3(c). Further, the list structure representing the arrangement of three data items a, b, and c shown in FIG. 1(b) can be expressed by four cells as shown in FIG. 6(d).

〔Effect of the invention〕

According to the present invention, an n-tree structure can be expressed with the same number of cells as a conventional n-tree structure, and a specific binary tree structure (list structure) can be expressed by the number of data items expressed by that structure. Q
, then R+1 cells can be represented.

The conventional n-ary tree structure representation method (n method) and cdrcod
ing method (cdr method) and cdr expressing n launch
In each of the coding method (yl-cdr method) and the method of the present invention, an n-ary tree structure has n nodes and the number of arguments for each node is nl, and an arrangement of a pieces of data. When expressing a list structure representing

[Brief explanation of drawings]

FIGS. 1(a) and 3(b) are explanatory diagrams showing an example of a conventional n-tree data representation method, and FIGS. 2 and 3(a). (b) is the conventional binary water data representation method (cdrcodi).
ng method), FIG. 4(a) is a block diagram showing the hardware configuration of the present invention, FIG. 4(b) is a block diagram showing the software I/ware configuration of the present invention, and FIG. 6 is a flowchart showing the flow of the present invention, and FIGS. 6(a) to 6(d) are explanatory diagrams showing examples of n-launch data expression and list structure data expression according to the present invention. 30... Cell, 31... Pointer bit field, 32... List bit field, 33... Content field, 34... Name identifier field, 35...
... Famous confectionery 1 Figure (Doshiri (b) ¥J Z Figure 13 Figure (phantom (shi) inferior 〆 Figure (b) <C) Cd)

Claims (1)

[Scope of Claims] 1. A storage element group (cell) consisting of a predetermined number of words serving as a basic unit for representing tree-structured data, including a content field, a list bit field, and a pointer bit field; indicates that the cell represents the first argument of a specific binary tree structure (list structure), and that the cell that can be considered to occupy a continuous portion on the storage device represents the second argument of the list structure. The tree-structured data is a field that indicates whether or not the cell is a pointer, and the "pointer bit field" is a field that indicates whether or not the content field of the cell represents a pointer to another cell. Processing method. 2. When the pointer bit field indicates that the content field does not represent a pointer to another cell, the content field is further composed of a name identifier field and a name type field, and the name type is The child field indicates whether the name identifier field of the cell represents a constant name or a function name, and further, the name type field indicates that the name identifier field represents a function name. 1, the arguments of the function can be considered to occupy a contiguous portion of the storage device.
A tree-structured data processing method characterized by representing data using two or more cells.