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
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.hosted.node.admin.task.util.template;
import com.yahoo.vespa.hosted.node.admin.task.util.text.Cursor;
import com.yahoo.vespa.hosted.node.admin.task.util.text.CursorRange;
import java.util.Optional;
/**
* Parses a template String, see {@link Template} for details.
*
* @author hakonhall
*/
public class TemplateParser {
private final TemplateDescriptor descriptor;
private final Cursor start;
private final Cursor current;
private final Template template;
private final FormEndsIn formEndsIn;
public static Template parse(TemplateDescriptor descriptor, String text) {
return parse(descriptor, new Cursor(text), FormEndsIn.EOT).template();
}
private static TemplateParser parse(TemplateDescriptor descriptor, Cursor start, FormEndsIn formEndsIn) {
var parser = new TemplateParser(descriptor, start, formEndsIn);
parser.parse();
return parser;
}
enum FormEndsIn { EOT, END }
TemplateParser(TemplateDescriptor descriptor, Cursor start, FormEndsIn formEndsIn) {
this.descriptor = descriptor;
this.start = new Cursor(start);
this.current = new Cursor(start);
this.template = new Template(start);
this.formEndsIn = formEndsIn;
}
CursorRange range() { return new CursorRange(start, current); }
Template template() { return template; }
private void parse() {
do {
current.advanceTo(descriptor.startDelimiter());
if (!current.equals(start)) {
template.appendLiteralSection(current);
}
if (current.eot()) return;
if (!parseSection()) return;
} while (true);
}
/** Returns true if end was reached (according to formEndsIn). */
private boolean parseSection() {
current.skip(descriptor.startDelimiter());
if (current.skip('=')) {
parseExpression();
} else {
var startOfType = new Cursor(current);
String type = skipId().orElseThrow(() -> new BadTemplateException(current, "Missing section name"));
switch (type) {
case "end":
if (formEndsIn == FormEndsIn.EOT)
throw new BadTemplateException(startOfType, "Extraneous 'end'");
parseEndAttribute();
return false;
case "list":
parseListSection();
break;
default:
throw new BadTemplateException(startOfType, "Unknown section '" + type + "'");
}
}
return !current.eot();
}
private void parseExpression() {
var nameStart = new Cursor(current);
String name = parseId();
parseEndDelimiter(false);
template.appendVariableSection(name, nameStart, current);
}
private void parseEndAttribute() {
parseEndDelimiter(true);
}
private void parseListSection() {
skipWhitespace();
var startOfName = new Cursor(current);
String name = parseId();
parseEndDelimiter(true);
TemplateParser bodyParser = parse(descriptor, current, FormEndsIn.END);
current.set(bodyParser.current);
template.appendListSection(name, startOfName, current, bodyParser.template());
}
private void skipWhitespace() {
if (!current.skipWhitespace()) {
throw new BadTemplateException(current, "Expected whitespace");
}
}
private String parseId() {
return skipId().orElseThrow(() -> new BadTemplateException(current, "Expected identifier"));
}
private Optional<String> skipId() { return Token.skipId(current); }
private void parseEndDelimiter(boolean removeFollowingNewline) {
if (!current.skip(descriptor.endDelimiter())) {
throw new BadTemplateException(current, "Expected section end (" + descriptor.endDelimiter() + ")");
}
if (removeFollowingNewline) current.skip('\n');
}
}
|
