equal
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inserted
replaced
10 case class CHAR(c: Char) extends Rexp |
10 case class CHAR(c: Char) extends Rexp |
11 case class ALTs(rs: List[Rexp]) extends Rexp // alternatives |
11 case class ALTs(rs: List[Rexp]) extends Rexp // alternatives |
12 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp // sequence |
12 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp // sequence |
13 case class STAR(r: Rexp) extends Rexp // star |
13 case class STAR(r: Rexp) extends Rexp // star |
14 |
14 |
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15 import scala.language.implicitConversions |
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16 import scala.language.reflectiveCalls |
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17 |
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18 def charlist2rexp(s: List[Char]): Rexp = s match { |
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19 case Nil => ONE |
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20 case c::Nil => CHAR(c) |
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21 case c::s => SEQ(CHAR(c), charlist2rexp(s)) |
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22 } |
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23 implicit def string2rexp(s: String): Rexp = charlist2rexp(s.toList) |
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24 |
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25 |
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26 // "a|b" |
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27 ALT(CHAR('a'), CHAR('b')) |
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28 |
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29 val reg : Rexp = "a" | "b" // CHAR('a') |
15 |
30 |
16 // some convenience for typing regular expressions |
31 // some convenience for typing regular expressions |
17 |
32 |
18 //the usual binary choice can be defined in terms of ALTs |
33 //the usual binary choice can be defined in terms of ALTs |
19 def ALT(r1: Rexp, r2: Rexp) = ALTs(List(r1, r2)) |
34 def ALT(r1: Rexp, r2: Rexp) = ALTs(List(r1, r2)) |
26 case Nil => ONE |
41 case Nil => ONE |
27 case c::Nil => CHAR(c) |
42 case c::Nil => CHAR(c) |
28 case c::s => SEQ(CHAR(c), charlist2rexp(s)) |
43 case c::s => SEQ(CHAR(c), charlist2rexp(s)) |
29 } |
44 } |
30 implicit def string2rexp(s: String): Rexp = charlist2rexp(s.toList) |
45 implicit def string2rexp(s: String): Rexp = charlist2rexp(s.toList) |
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46 |
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47 |
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48 |
31 |
49 |
32 implicit def RexpOps (r: Rexp) = new { |
50 implicit def RexpOps (r: Rexp) = new { |
33 def | (s: Rexp) = ALT(r, s) |
51 def | (s: Rexp) = ALT(r, s) |
34 def % = STAR(r) |
52 def % = STAR(r) |
35 def ~ (s: Rexp) = SEQ(r, s) |
53 def ~ (s: Rexp) = SEQ(r, s) |