Idiomatically determine all the characters that can be used for symbols: Difference between revisions
Idiomatically determine all the characters that can be used for symbols (view source)
Revision as of 18:26, 18 September 2017
, 6 years agoAdded Kotlin
(→{{header|Tcl}}: Output limited to first 256 characters as previous output size was preventing this page from displaying properly) |
(Added Kotlin) |
||
Line 198:
<lang jq>count("S"; 0; 1114112)</lang>
The result is 3958.
=={{header|Kotlin}}==
{{trans|Java}}
According to the Kotlin grammar, the rules regarding which characters can appear in symbols (or identifiers as we usually call them) are the same as in Java, namely:
1. An identifier is a sequence of any number of unicode letters or digits, other than a reserved word.
2. Identifiers are case sensitive.
3. The first character must be a letter, an underscore or a $ sign. Subsequent characters can include digits and certain control characters as well though the latter are ignored for identifier matching purposes.
However, in practice, identifiers which include a $ symbol or control characters don't compile unless (in the case of $) the entire identifier is enclosed in back-ticks. The use of this device also allows one to use a reserved word or many otherwise prohibited unicode characters in an identifier including spaces and dashes.
A Kotlin label name is a valid identifier followed by an @ symbol and an annotation name is an identifier preceded by an @ symbol.
<lang scala>// version 1.1.4-3
typealias CharPredicate = (Char) -> Boolean
fun printChars(msg: String, start: Int, end: Int, limit: Int, p: CharPredicate, asInt: Boolean) {
print(msg)
(start until end).map { it.toChar() }
.filter { p(it) }
.take(limit)
.forEach { print(if (asInt) "[${it.toInt()}]" else it) }
println("...")
}
fun main(args: Array<String>) {
printChars("Kotlin Identifier start: ", 0, 0x10FFFF, 72,
Char::isJavaIdentifierStart, false)
printChars("Kotlin Identifier part: ", 0, 0x10FFFF, 25,
Character::isJavaIdentifierPart, true)
printChars("Kotlin Identifier ignorable: ", 0, 0x10FFFF, 25,
Character::isIdentifierIgnorable, true)
}</lang>
{{out}}
<pre>
Kotlin Identifier start: $ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz¢£¤¥ªµºÀÁÂÃÄÅÆÇÈÉÊ...
Kotlin Identifier part: [0][1][2][3][4][5][6][7][8][14][15][16][17][18][19][20][21][22][23][24][25][26][27][36][48]...
Kotlin Identifier ignorable: [0][1][2][3][4][5][6][7][8][14][15][16][17][18][19][20][21][22][23][24][25][26][27][127][128]...
</pre>
=={{header|ooRexx}}==
| |||