/
mclass.js
168 lines (152 loc) · 5.18 KB
/
mclass.js
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
// @flow
import defineFunction, {ordargument} from "../defineFunction";
import buildCommon from "../buildCommon";
import mathMLTree from "../mathMLTree";
import utils from "../utils";
import type {AnyParseNode} from "../parseNode";
import * as html from "../buildHTML";
import * as mml from "../buildMathML";
import type {ParseNode} from "../parseNode";
const makeSpan = buildCommon.makeSpan;
function htmlBuilder(group: ParseNode<"mclass">, options) {
const elements = html.buildExpression(group.body, options, true);
return makeSpan([group.mclass], elements, options);
}
function mathmlBuilder(group: ParseNode<"mclass">, options) {
let node: mathMLTree.MathNode;
const inner = mml.buildExpression(group.body, options);
if (group.mclass === "minner") {
node = new mathMLTree.MathNode("mpadded", inner);
} else if (group.mclass === "mord") {
if (group.isCharacterBox) {
node = inner[0];
node.type = "mi";
} else {
node = new mathMLTree.MathNode("mi", inner);
}
} else {
if (group.isCharacterBox) {
node = inner[0];
node.type = "mo";
} else {
node = new mathMLTree.MathNode("mo", inner);
}
// Set spacing based on what is the most likely adjacent atom type.
// See TeXbook p170.
if (group.mclass === "mbin") {
node.attributes.lspace = "0.22em"; // medium space
node.attributes.rspace = "0.22em";
} else if (group.mclass === "mpunct") {
node.attributes.lspace = "0em";
node.attributes.rspace = "0.17em"; // thinspace
} else if (group.mclass === "mopen" || group.mclass === "mclose") {
node.attributes.lspace = "0em";
node.attributes.rspace = "0em";
} else if (group.mclass === "minner") {
node.attributes.lspace = "0.0556em"; // 1 mu is the most likely option
node.attributes.width = "+0.1111em";
}
// MathML <mo> default space is 5/18 em, so <mrel> needs no action.
// Ref: https://developer.mozilla.org/en-US/docs/Web/MathML/Element/mo
}
return node;
}
// Math class commands except \mathop
defineFunction({
type: "mclass",
names: [
"\\mathord", "\\mathbin", "\\mathrel", "\\mathopen",
"\\mathclose", "\\mathpunct", "\\mathinner",
],
props: {
numArgs: 1,
primitive: true,
},
handler({parser, funcName}, args) {
const body = args[0];
return {
type: "mclass",
mode: parser.mode,
mclass: "m" + funcName.slice(5), // TODO(kevinb): don't prefix with 'm'
body: ordargument(body),
isCharacterBox: utils.isCharacterBox(body),
};
},
htmlBuilder,
mathmlBuilder,
});
export const binrelClass = (arg: AnyParseNode): string => {
// \binrel@ spacing varies with (bin|rel|ord) of the atom in the argument.
// (by rendering separately and with {}s before and after, and measuring
// the change in spacing). We'll do roughly the same by detecting the
// atom type directly.
const atom = (arg.type === "ordgroup" && arg.body.length ? arg.body[0] : arg);
if (atom.type === "atom" && (atom.family === "bin" || atom.family === "rel")) {
return "m" + atom.family;
} else {
return "mord";
}
};
// \@binrel{x}{y} renders like y but as mbin/mrel/mord if x is mbin/mrel/mord.
// This is equivalent to \binrel@{x}\binrel@@{y} in AMSTeX.
defineFunction({
type: "mclass",
names: ["\\@binrel"],
props: {
numArgs: 2,
},
handler({parser}, args) {
return {
type: "mclass",
mode: parser.mode,
mclass: binrelClass(args[0]),
body: ordargument(args[1]),
isCharacterBox: utils.isCharacterBox(args[1]),
};
},
});
// Build a relation or stacked op by placing one symbol on top of another
defineFunction({
type: "mclass",
names: ["\\stackrel", "\\overset", "\\underset"],
props: {
numArgs: 2,
},
handler({parser, funcName}, args) {
const baseArg = args[1];
const shiftedArg = args[0];
let mclass;
if (funcName !== "\\stackrel") {
// LaTeX applies \binrel spacing to \overset and \underset.
mclass = binrelClass(baseArg);
} else {
mclass = "mrel"; // for \stackrel
}
const baseOp = {
type: "op",
mode: baseArg.mode,
limits: true,
alwaysHandleSupSub: true,
parentIsSupSub: false,
symbol: false,
suppressBaseShift: funcName !== "\\stackrel",
body: ordargument(baseArg),
};
const supsub = {
type: "supsub",
mode: shiftedArg.mode,
base: baseOp,
sup: funcName === "\\underset" ? null : shiftedArg,
sub: funcName === "\\underset" ? shiftedArg : null,
};
return {
type: "mclass",
mode: parser.mode,
mclass,
body: [supsub],
isCharacterBox: utils.isCharacterBox(supsub),
};
},
htmlBuilder,
mathmlBuilder,
});