JPH0155491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a character type determination method, and particularly to a determination method suitable for determining the type of characters input to a computer.

There are various types of characters that computers handle, such as numbers, alphabetic characters, and special characters. For this reason, it is necessary to recognize what type of character the character to be input now is. Conversely, for example, in the Fortran language, characters such as A001 may be input, but A
Assuming that there is no possibility that a character including a special character such as %01 is input, it can be immediately determined at the input stage that this is an incorrect character input.

In any case, it is important to determine the type of character input to the computer. However, it is not necessary to specifically determine the content of each type of character.

There are roughly two conventional determination methods. The first method uses, for example, the 256 numerical values from 0 to 259 assigned to all types of characters in the EBCDIC writing system, and narrows down the range of applicable character types by comparing the numerical values. be. The second method is to prepare in advance a numerical value table of character types, such as 1 for alphabetic characters and 2 for numbers, and determine the range of character types while corresponding to this numerical value table. All of the above methods have almost no problem in normal determination, but become extremely inefficient when it comes to determining multiple types of compound characters. For example, the first method described above has the disadvantage that the number of determinations increases and it takes a lot of time;
The method described above has the disadvantage that the numerical table alone is insufficient and another table must be introduced.

It is therefore an object of the present invention to eliminate the above-mentioned disadvantages and to
It is an object of the present invention to propose a character type determination method that can complete the determination with approximately one determination operation and a single table.

In accordance with the above object, the present invention provides a character type determination method for determining the character type of an input character, which is an identification mark that displays all the characters classified into each character type, and has a fixed bit length. and has a different bit pattern for each character type.
When one character input is given, the logical product of the binary identification indicator indicating the character type to which the character should belong and the binary identification indicator indicating the character type of the character input that was actually input. This method is characterized in that calculations are performed with mutual bit positions aligned, and a judgment result is obtained from the calculation results.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a diagram showing a code system for character types for character input, and shows a so-called EBCDIC code. Overall, functional characters, special characters, alphanumeric characters (letters,
The characters are divided into a hierarchy of numbers), lowercase English letters, and uppercase English letters, and each character is assigned a series of numerical values (codes) 0 to 63, 64 to 127, and so on. Both the conventional method and the method of the present invention make determinations using these series of numerical values, but the specific methods are different.

According to the first conventional method, the determination is made in the following procedure. This will be explained using a diagram.

FIG. 2A is a flowchart showing the steps of the first conventional method for determining whether input characters belong to the numeric type, and FIG. 2B shows steps for determining whether input characters belong to the alphabet type. 2 is a flowchart showing steps according to a first conventional method for determining . The numerical values indicated by n≧240 and n≦249 in Figure 2A represent the hierarchy of numbers (0 to 9) in Figure 1, and if the character input corresponds to a value between 240 and 249 (0 -9). However, when it comes to determining alphabetic characters, the process becomes even more complicated, as shown in FIG. 2B. This is because there are uppercase letters and lowercase letters, and each letter is further divided into three groups. Therefore, the flowchart of the steps to be taken when a mixed alphanumeric character input is given becomes even more complex. In addition, since the hardware for size comparison is usually not simple,
It is disadvantageous in terms of determination time and hardware scale.

FIG. 3A is a flowchart showing the steps of a second conventional method for determining whether input characters belong to the type of alphanumeric characters, and FIG. It is a flowchart showing the steps of a second conventional method for making such a determination. In this second conventional method, the groups (0 to 63), (64 to 127), (129 to
137), (145-153)...for example, the numbers 1, 2, 3,
4. Use a table that allocates... If the number 1 is assigned to a group of alphabetic characters, whether or not T _o is a number will be determined based on whether T o is 1 (YES) or not (NO).
T _o indicates the numerical value assigned in the table above for the character input. However, this second conventional method also has disadvantages when detailed judgments such as whether or not a letter is an uppercase alphabetic character are made. FIG. 3C is a flowchart used to explain the disadvantages of the second conventional method. In this figure, U _o is
The allocated numerical values in the newly introduced table (U) are shown for more detailed judgment.

Therefore, the present invention eliminates the drawbacks of the first and second conventional methods described above, and can handle character input of any combination of character types with one judgment operation, one table, and simple hardware. We will propose a possible determination method. Here, the meaning of "any combination of character types" will be briefly explained.

FIG. 4 is a diagram schematically showing combinations of character types to be determined. In this diagram, when the character input consists of only numbers, only uppercase alphabetic characters, and only lowercase alphabetic characters, it falls within circle 1, circle 2, and circle 3, respectively, and when it consists of only alphanumeric characters, it falls within circle 4. If there are only alphabetic characters, it is 5 yen.
It is well within the range of Although there are other combinations, five cases are illustrated. A new table is prepared so that determination can be made easily in any of these cases. FIG. 5 is a diagram showing a table used to implement the method of the invention. In the table 50 shown in this figure, unlike the second conventional method described above, each character type is represented by a binary number (in that conventional method, decimal values of 1, 2, 3, 4, etc. are assigned). Ta). That is, (00000001),
They are waving identification signs such as (00000010)... In addition,
The representations of the individual characters within each character type are conventionally stored in separate memories along the codes of FIG.

The use of such binary identification marks simply eliminates the above-mentioned drawbacks of the prior art methods. FIG. 6 is a diagram schematically showing an embodiment of the determination method according to the present invention. F in this figure is an identification mark (00000010,
0000100...etc.), F _r is, for example, a reference identification mark for judgment (00000010, etc.) supplied from the computer side.
0000100…etc.). Which mark (F, F _r )
is also defined by table 50.

If the currently given character input should be a number, (00000001) is set as F _r . If the actual character input is a number (00000001), if we calculate the logical product () of these, we get 00000001 (←F) )00000001 (←F _r ) 1 (←R), so (R=1) , the currently given character input is determined to be a number. If a capital letter (00000010) is set as F _r , then 00000001 (←F) ) 00000010 (←F _r ) 0 (←R) (R = 0), so the input character is not a capital letter. is determined. Note that the logical product is the sixth
In the AND gate shown in the figure, R is the result of the logical product operation, that is, the judgment result.

Furthermore, if the currently given character input should be a mixture of alphabetic characters (including uppercase and lowercase letters) and numbers, then F _r =00000111 may be set as F _r . Of these 111, the first 1 (on the left) corresponds to a lowercase alphabetic letter, and the following 11 correspond to uppercase English letters and numerical identification marks, respectively. In any case, among the bits of F _r , set 1 to the bit you want to judge.
If you set , the determination can be completed with a simple logical AND operation.

As explained above, according to the present invention, with only one operation and simple hardware (AND),
It is possible to judge all combinations of complex character inputs.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the code system of the character type of character input, and FIG. Figure 2B is a flowchart showing the steps of the first conventional method for determining whether input characters belong to the type of alphabetic characters, and Figure 3A shows steps for determining whether inputted characters belong to the type of alphabetic characters. FIG. 3B is a flowchart showing steps according to a second conventional method for determining whether character input belongs to the alphanumeric type;
FIG. 3C is a flowchart used to explain the disadvantages of the second conventional method, FIG. 4 is a diagram schematically showing combinations of character types to be determined, and FIG.
This figure shows a table used to implement the method of the present invention, and FIG. 6 is a diagram schematically showing an embodiment of the determination method according to the present invention. 1, 2, 3, 4, 5... Range of character types, 5
0...Table, F...Identification indicator for input characters, F _r ...Reference identification indicator for judgment, R...Computation result, AND...
AND gate.

Claims (1)

[Scope of Claims] 1. In a character type determination method for determining the character type of input characters, an identification mark for displaying all of the characters classified according to the character type, from a certain bit length. and having a bit pattern that is different for each character type is assigned in advance, and when a certain character input is given, the binary identification mark indicates the character type to which the character belongs; A logical product operation with the binary identification indicator indicating the character type of the character actually inputted is performed with mutual bit positions aligned, and a determination result is obtained from the result of the operation. How to determine the character type.