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
|
// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.text;
/**
* Formats any parenthesis expression.
* In addition to the obvious this can also operate in "two column mode",
* wherein each chunk that will be formatted on a separate line may optionally
* contain a prefix marked by a start and end tab sign which will be printed in a left column of the given fixed size.
* The prefix itself is not formatted but will be cut if too long.
*
* @author bratseth
*/
public class ExpressionFormatter {
private static final int indentUnit = 2;
/** The size of the first column, or 0 if none */
private int firstColumnSize = 0;
private ExpressionFormatter(int firstColumnSize) {
this.firstColumnSize = firstColumnSize;
}
public String format(String parenthesisExpression) {
StringBuilder b = new StringBuilder();
format(parenthesisExpression, 0, b);
return b.toString();
}
private void format(String expression, int indent, StringBuilder b) {
if (expression.isEmpty()) return;
expression = appendFirstColumn(expression, b);
Markup next = Markup.next(expression);
appendIndent( ! next.isClose() || next.position() > 0 ? indent : indent - 2, b);
if (next.isEmpty()) {
b.append(expression);
}
else if (next.isComma()) {
b.append(expression, 0, next.position() + 1).append("\n");
format(expression.substring(next.position() + 1), indent, b);
}
else {
if ( next.isClose() && next.position() > 0) { // content before end parenthesis: content, newline, then end parenthesis
b.append(expression, 0, next.position()).append("\n");
appendFirstColumn(")", b);
appendIndent(indent - 2, b);
b.append(")\n");
}
else {
b.append(expression, 0, next.position() + 1).append("\n");
}
format(expression.substring(next.position() + 1), indent + (next.isOpen() ? indentUnit : -indentUnit), b);
}
}
private String appendFirstColumn(String expression, StringBuilder b) {
if (firstColumnSize == 0) return expression;
while (expression.charAt(0) == ' ')
expression = expression.substring(1);
if (expression.charAt(0) == '\t') {
int tab2 = expression.indexOf('\t', 1);
if (tab2 >= 0) {
String firstColumn = expression.substring(1, tab2);
b.append(asSize(firstColumnSize, firstColumn)).append(" ");
return expression.substring(tab2 + 1);
}
}
appendIndent(firstColumnSize + 1, b);
return expression;
}
private void appendIndent(int indent, StringBuilder b) {
b.append(" ".repeat(Math.max(0, indent)));
}
private String asSize(int size, String s) {
if (s.length() > size)
return s.substring(0, size);
else
return s + " ".repeat(size - s.length());
}
/** Convenience method creating a formatter and using it to format the given expression */
public static String on(String parenthesisExpression) {
return new ExpressionFormatter(0).format(parenthesisExpression);
}
public static ExpressionFormatter inTwoColumnMode(int firstColumnSize) {
return new ExpressionFormatter(firstColumnSize);
}
/** Contains the next position of each kind of markup, or Integer.MAX_VALUE if not present */
private static class Markup {
final int open, close, comma;
private Markup(int open, int close, int comma) {
this.open = open;
this.close = close;
this.comma = comma;
}
int position() {
return Math.min(Math.min(open, close), comma);
}
boolean isOpen() {
return open < close && open < comma;
}
boolean isClose() {
return close < open && close < comma;
}
boolean isComma() {
return comma < open && comma < close;
}
boolean isEmpty() {
return open == Integer.MAX_VALUE && close == Integer.MAX_VALUE && comma == Integer.MAX_VALUE;
}
static Markup next(String expression) {
int nextOpen = expression.indexOf('(');
int nextClose = expression.indexOf(')');
int nextComma = expression.indexOf(',');
if (nextOpen < 0)
nextOpen = Integer.MAX_VALUE;
if (nextClose < 0)
nextClose = Integer.MAX_VALUE;
if (nextComma < 0)
nextComma = Integer.MAX_VALUE;
return new Markup(nextOpen, nextClose, nextComma);
}
}
}
|
