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
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
package dotty.tools.dotc.util
import scala.annotation.tailrec
import scala.collection.mutable
object DiffUtil {
private final val ANSI_DEFAULT = "\u001B[0m"
private final val ANSI_RED = "\u001B[31m"
private final val ANSI_GREEN = "\u001B[32m"
private final val DELETION_COLOR = ANSI_RED
private final val ADDITION_COLOR = ANSI_GREEN
def mkColoredCodeDiff(code: String, lastCode: String, printDiffDel: Boolean): String = {
@tailrec def splitTokens(str: String, acc: List[String] = Nil): List[String] = {
if (str == "") {
acc.reverse
} else {
val head = str.charAt(0)
val (token, rest) = if (Character.isAlphabetic(head) || Character.isDigit(head)) {
str.span(c => Character.isAlphabetic(c) || Character.isDigit(c))
} else if (Character.isMirrored(head) || Character.isWhitespace(head)) {
str.splitAt(1)
} else {
str.span { c =>
!Character.isAlphabetic(c) && !Character.isDigit(c) &&
!Character.isMirrored(c) && !Character.isWhitespace(c)
}
}
splitTokens(rest, token :: acc)
}
}
val tokens = splitTokens(code, Nil).toArray
val lastTokens = splitTokens(lastCode, Nil).toArray
val diff = hirschberg(lastTokens, tokens)
diff.collect {
case Unmodified(str) => str
case Inserted(str) => ADDITION_COLOR + str + ANSI_DEFAULT
case Modified(old, str) if printDiffDel => DELETION_COLOR + old + ADDITION_COLOR + str + ANSI_DEFAULT
case Modified(_, str) => ADDITION_COLOR + str + ANSI_DEFAULT
case Deleted(str) if printDiffDel => DELETION_COLOR + str + ANSI_DEFAULT
}.mkString
}
private sealed trait Patch
private final case class Unmodified(str: String) extends Patch
private final case class Modified(original: String, str: String) extends Patch
private final case class Deleted(str: String) extends Patch
private final case class Inserted(str: String) extends Patch
private def hirschberg(a: Array[String], b: Array[String]): Array[Patch] = {
def build(x: Array[String], y: Array[String], builder: mutable.ArrayBuilder[Patch]): Unit = {
if (x.isEmpty) {
builder += Inserted(y.mkString)
} else if (y.isEmpty) {
builder += Deleted(x.mkString)
} else if (x.length == 1 || y.length == 1) {
needlemanWunsch(x, y, builder)
} else {
val xlen = x.length
val xmid = xlen / 2
val ylen = y.length
val (x1, x2) = x.splitAt(xmid)
val leftScore = nwScore(x1, y)
val rightScore = nwScore(x2.reverse, y.reverse)
val scoreSum = (leftScore zip rightScore.reverse).map {
case (left, right) => left + right
}
val max = scoreSum.max
val ymid = scoreSum.indexOf(max)
val (y1, y2) = y.splitAt(ymid)
build(x1, y1, builder)
build(x2, y2, builder)
}
}
val builder = Array.newBuilder[Patch]
build(a, b, builder)
builder.result()
}
private def nwScore(x: Array[String], y: Array[String]): Array[Int] = {
def ins(s: String) = -2
def del(s: String) = -2
def sub(s1: String, s2: String) = if (s1 == s2) 2 else -1
val score = Array.fill(x.length + 1, y.length + 1)(0)
for (j <- 1 to y.length)
score(0)(j) = score(0)(j - 1) + ins(y(j - 1))
for (i <- 1 to x.length) {
score(i)(0) = score(i - 1)(0) + del(x(i - 1))
for (j <- 1 to y.length) {
val scoreSub = score(i - 1)(j - 1) + sub(x(i - 1), y(j - 1))
val scoreDel = score(i - 1)(j) + del(x(i - 1))
val scoreIns = score(i)(j - 1) + ins(y(j - 1))
score(i)(j) = scoreSub max scoreDel max scoreIns
}
}
Array.tabulate(y.length + 1)(j => score(x.length)(j))
}
private def needlemanWunsch(x: Array[String], y: Array[String], builder: mutable.ArrayBuilder[Patch]): Unit = {
def similarity(a: String, b: String) = if (a == b) 2 else -1
val d = 1
val score = Array.tabulate(x.length + 1, y.length + 1) { (i, j) =>
if (i == 0) d * j
else if (j == 0) d * i
else 0
}
for (i <- 1 to x.length) {
for (j <- 1 to y.length) {
val mtch = score(i - 1)(j - 1) + similarity(x(i - 1), y(j - 1))
val delete = score(i - 1)(j) + d
val insert = score(i)(j - 1) + d
score(i)(j) = mtch max insert max delete
}
}
var alignment = List.empty[Patch]
var i = x.length
var j = y.length
while (i > 0 || j > 0) {
if (i > 0 && j > 0 && score(i)(j) == score(i - 1)(j - 1) + similarity(x(i - 1), y(j - 1))) {
val newHead =
if (x(i - 1) == y(j - 1)) Unmodified(x(i - 1))
else Modified(x(i - 1), y(j - 1))
alignment = newHead :: alignment
i = i - 1
j = j - 1
} else if (i > 0 && score(i)(j) == score(i - 1)(j) + d) {
alignment = Deleted(x(i - 1)) :: alignment
i = i - 1
} else {
alignment = Inserted(y(j - 1)) :: alignment
j = j - 1
}
}
builder ++= alignment
}
}
|
