@mmnaii/jisx0208

jisx0208

Description

jisx0208 provides methods about the row-cell defined by the JIS X 0208.

Requirements

• node.js -- v8 or newer

Install

npm install @mmnaii/jisx0208

Examples

• To convert a row-cell to the corresponding code of Shift_JIS:

const jisx0208 = require('@mmnaii/jisx0208');

// {16, 1}, [0x88, 0x9F](Shift_JIS) : "亜"
jisx0208.rowCellToSjis(16, 1);// [136, 159] ([0x88, 0x9F])

• To convert a code of EUC-JP to the corresponding row-cell:

const jisx0208 = require('@mmnaii/jisx0208');

// {84, 6}, [0xF4, 0xA6](EUC-JP) : "熙"
jisx0208.eucjpToRowCell(0xF4, 0xA6);// [84, 6]

Encoding

To the row-cell of the JIS X 0208, the edition 1990 or later applies.

As the encoding scheme to and from which a row-cell is converted, EUC-JP and Shift_JIS are supported.

As far as a row-cell is in the range of {1, 1} to {94, 94}, the operation that is to convert a row-cell to a code of EUC-JP or Shift_JIS and to convert again the gotten code to a row-cell always results in the same original row-cell.

// Round-trip conversion

const jisx0208 = require('@mmnaii/jisx0208');

for (let row=1; row<=94; row++) {
	for (let cell=1; cell<=94; cell++) {
		assert.deepEqual([row, cell], jisx0208.sjisToRowCell(...jisx0208.rowCellToSjis(row, cell, true), true));
		assert.deepEqual([row, cell], jisx0208.eucjpToRowCell(...jisx0208.rowCellToEucjp(row, cell, true), true));
	}
}
// OK

API

jisx0208.isAssigned(row, cell)

• row {Integer}
• cell {Integer}
• Returns: {Boolean}

Returns true if a character is defined at the a row-cell {row, cell} by the JIS X 0208, false otherwise.

const jisx0208 = require('@mmnaii/jisx0208');

// {5, 2} : "ア"
jisx0208.isAssigned(5, 2);// true

// {13, 1} : "①", (CP932)
jisx0208.isAssigned(13, 1);// false

jisx0208.eucjpToRowCell(c1, c2, noAssert)

• c1 {Integer} The code of the first byte of the character represented by the EUC-JP two bytes sequence
• c2 {Integer} The code of the second byte of the character represented by the EUC-JP two bytes sequence
• noAssert {Boolean} Skip assignment validation? Default: false
• Returns: {Array|null}

Interpreting a two bytes sequence of codes [c1, c2] as a character represented by the EUC-JP, converts it to a row-cell of the JIS X 0208 and returns an array, of which length is 2, that contains the results in order of [row, cell]. Returns null if JIS X 0208 does not assigned a character at the converted row-cell.

A conversion from characters represented using single shifts to row-cells is not supported.

Setting noAssert to true omits the validation whether a character is assigned at the converted row-cell. But if [c1, c2] cannot be converted to the row-cell in the range of {1, 1} to {94, 94}, returns null regardless the setting of noAssert.

The arguments c1 and c2 are converted to eight bit unsigned integers before the operation.

const jisx0208 = require('@mmnaii/jisx0208');

// [0xA5, 0xA2](EUC-JP) : "ア"
jisx0208.eucjpToRowCell(0xA5, 0xA2);// [5, 2]

// [0x8E, 0xB1](EUC-JP) : "ｱ" (HALFWIDTH KATAKANA LETTER A)
jisx0208.eucjpToRowCell(0x8E, 0xB1);// null
jisx0208.eucjpToRowCell(0x8E, 0xB1, true);// null

// [0xAD, 0xA1](EUC-JP) : Not Assigned
jisx0208.eucjpToRowCell(0xAD, 0xA1);// null
jisx0208.eucjpToRowCell(0xAD, 0xA1, true);// [13, 1]

jisx0208.sjisToRowCell(c1, c2, noAssert)

• c1 {Integer} The code of the first byte of the character represented by the Shift_JIS two bytes sequence
• c2 {Integer} The code of the second byte of the character represented by the Shift_JIS two bytes sequence
• noAssert {Boolean} Skip assignment validation? Default: false
• Returns: {Array|null}

Interpreting a two bytes sequence of codes [c1, c2] as a character represented by the Shift_JIS, converts it to a row-cell of the JIS X 0208 and returns an array, of which length is 2, that contains the results in order of [row, cell]. Returns null if JIS X 0208 does not assigned a character at the converted row-cell.

A conversion from characters included in the character set defined by the JIS X 0201 to row-cells is not supported.

Setting noAssert to true omits the validation whether a character is assigned at the converted row-cell. But if [c1, c2] cannot be converted to the row-cell in the range of {1, 1} to {94, 94}, returns null regardless the setting of noAssert.

The arguments c1 and c2 are converted to eight bit unsigned integers before the operation.

const jisx0208 = require('@mmnaii/jisx0208');

// [0x83, 0x41](Shift_JIS) : "ア"
jisx0208.sjisToRowCell(0x83, 0x41);// [5, 2]

// [0xB1](EUC-JP) : "ｱ" (HALFWIDTH KATAKANA LETTER A)
jisx0208.sjisToRowCell(0xB1);// null

// [0x87, 0x40](CP932) : "①"
jisx0208.sjisToRowCell(0x87, 0x40);// null
jisx0208.sjisToRowCell(0x87, 0x40, true);// [13, 1]

jisx0208.rowCellToEucjp(row, cell, noAssert)

• row {Integer}
• cell {Integer}
• noAssert {Boolean} Skip assignment validation? Default: false
• Returns: {Array|null}

Encodes a character assigned at the row-cell {row, cell} in EUC-JP and returns the result, that is a two bytes sequence of codes [c1, c2], as an array, of which length is 2. Returns null if JIS X 0208 does not assigned a character at the converted row-cell.

Does not convert to characters represented using single shifts.

Setting noAssert to true omits the validation whether a character is assigned at the row-cell {row, cell}. But if {row, cell} is not in the range of {1, 1} to {94, 94}, returns null regardless the setting of noAssert.

const jisx0208 = require('@mmnaii/jisx0208');

// {5, 2} : "ア"
jisx0208.rowCellToEucjp(5, 2);// [165, 162] ([0xA5, 0xA2])

// {13, 1} : "①", (CP932)
jisx0208.rowCellToEucjp(13, 1);// null
jisx0208.rowCellToEucjp(13, 1, true);// [173, 161] (0xAD, 0xA1)

jisx0208.rowCellToSjis(row, cell, noAssert)

• row {Integer}
• cell {Integer}
• noAssert {Boolean} Skip assignment validation? Default: false
• Returns: {Array|null}

Encodes a character assigned at the row-cell {row, cell} in Shift_JIS and returns the result, that is a two bytes sequence of codes [c1, c2], as an array, of which length is 2. Returns null if JIS X 0208 does not assigned a character at the converted row-cell.

Does not convert to characters included in the character set defined by the JIS X 0201.

Setting noAssert to true omits the validation whether a character is assigned at the row-cell {row, cell}. But if {row, cell} is not in the range of {1, 1} to {94, 94}, returns null regardless the setting of noAssert.

const jisx0208 = require('@mmnaii/jisx0208');

// {5, 2} : "ア"
jisx0208.rowCellToSjis(5, 2);// [131, 65] ([0x83, 0x41])

// {13, 1} : "①", (CP932)
jisx0208.rowCellToSjis(13, 1);// null
jisx0208.rowCellToSjis(13, 1, true);// [135, 64] ([0x87, 0x40])

jisx0208.halfkanaToRowCell(code)

• code {Integer}
• Returns: {Array|null}

In the JIS X 0208 character set, finds a character corresponding to what the code represents by the eight bit code of the JIS X 0201, and returns the row-cell of the character as an array, of which length is 2, that contains the results in order of [row, cell].

But returns null if the code is not in the range where katakana graphic character set is assigned.

The argument code are converted to eight bit unsigned integers before the operation.

const jisx0208 = require('@mmnaii/jisx0208');

// [0xB1](JIS X 0201(8bit), Shift_JIS) : "ｱ" (HALFWIDTH KATAKANA LETTER A)
jisx0208.halfkanaToRowCell(0xB1);// [5, 2]
// {5, 2} : "ア" (KATAKANA LETTER A)

// [0x40](JIS X 0201(8bit), Shift_JIS) ; "A"
jisx0208.halfkanaToRowCell(0x40);// null