blob: 562806b6eb2753762c974afcfd423cc76b3637b2 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/* NSC -- new Scala compiler
* Copyright 2006-2010 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package util
import annotation.{ tailrec, switch }
/** Contains constants and classifier methods for characters */
object Chars {
// Be very careful touching these.
// Apparently trivial changes to the way you write these constants
// will cause Scanners.scala to go from a nice efficient switch to
// a ghastly nested if statement which will bring the type checker
// to its knees. See ticket #1456
// Martin: (this should be verified now that the pattern rules have been redesigned).
final val LF = '\u000A'
final val FF = '\u000C'
final val CR = '\u000D'
final val SU = '\u001A'
/** Convert a character digit to an Int according to given base,
* -1 if no success */
def digit2int(ch: Char, base: Int): Int = {
if ('0' <= ch && ch <= '9' && ch < '0' + base)
ch - '0'
else if ('A' <= ch && ch < 'A' + base - 10)
ch - 'A' + 10
else if ('a' <= ch && ch < 'a' + base - 10)
ch - 'a' + 10
else
-1
}
/** Convert a character to a backslash-u escape */
def char2uescape(c: Char): String = {
var rest = c.toInt
val buf = new StringBuilder
for (i <- 1 to 4) {
buf ++= (rest % 16).toHexString
rest = rest / 16
}
"\\u" + buf.toString.reverse
}
/** Is character a line break? */
@inline def isLineBreakChar(c: Char) = (c: @switch) match {
case LF|FF|CR|SU => true
case _ => false
}
/** Is character a whitespace character (but not a new line)? */
def isWhitespace(c: Char) =
c == ' ' || c == '\t' || c == CR
/** Can character form part of a doc comment variable $xxx? */
def isVarPart(c: Char) =
'0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'
/** Can character start an alphanumeric Scala identifier? */
def isIdentifierStart(c: Char): Boolean =
(c == '_') || (c == '$') || Character.isUnicodeIdentifierStart(c)
/** Can character form part of an alphanumeric Scala identifier? */
def isIdentifierPart(c: Char) =
(c == '$') || Character.isUnicodeIdentifierPart(c)
/** Is character a math or other symbol in Unicode? */
def isSpecial(c: Char) = {
val chtp = Character.getType(c)
chtp == Character.MATH_SYMBOL.toInt || chtp == Character.OTHER_SYMBOL.toInt
}
/** Can character form part of a Scala operator name? */
def isOperatorPart(c : Char) : Boolean = (c: @switch) match {
case '~' | '!' | '@' | '#' | '%' |
'^' | '*' | '+' | '-' | '<' |
'>' | '?' | ':' | '=' | '&' |
'|' | '/' | '\\' => true
case c => isSpecial(c)
}
}
|