/*************************************************************
*
* Copyright (c) 2009-2022 The MathJax Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview A namespace for utility functions for the TeX Parser.
*
* @author v.sorge@mathjax.org (Volker Sorge)
*/
import {TEXCLASS, MmlNode} from '../../core/MmlTree/MmlNode.js';
import {EnvList} from './StackItem.js';
import {ArrayItem} from './base/BaseItems.js';
import ParseOptions from './ParseOptions.js';
import NodeUtil from './NodeUtil.js';
import TexParser from './TexParser.js';
import TexError from './TexError.js';
import {entities} from '../../util/Entities.js';
import {MmlMunderover} from '../../core/MmlTree/MmlNodes/munderover.js';
namespace ParseUtil {
// TODO (VS): Combine some of this with lengths in util.
const emPerInch = 7.2;
const pxPerInch = 72;
// Note, the following are TeX CM font values.
const UNIT_CASES: {[key: string]: ((m: number) => number)} = {
'em': m => m,
'ex': m => m * .43,
'pt': m => m / 10, // 10 pt to an em
'pc': m => m * 1.2, // 12 pt to a pc
'px': m => m * emPerInch / pxPerInch,
'in': m => m * emPerInch,
'cm': m => m * emPerInch / 2.54, // 2.54 cm to an inch
'mm': m => m * emPerInch / 25.4, // 10 mm to a cm
'mu': m => m / 18,
};
const num = '([-+]?([.,]\\d+|\\d+([.,]\\d*)?))';
const unit = '(pt|em|ex|mu|px|mm|cm|in|pc)';
const dimenEnd = RegExp('^\\s*' + num + '\\s*' + unit + '\\s*$');
const dimenRest = RegExp('^\\s*' + num + '\\s*' + unit + ' ?');
/**
* Matches for a dimension argument.
* @param {string} dim The argument.
* @param {boolean} rest Allow for trailing garbage in the dimension string.
* @return {[string, string, number]} The match result as (Anglosaxon) value,
* unit name, length of matched string. The latter is interesting in the
* case of trailing garbage.
*/
export function matchDimen(
dim: string, rest: boolean = false): [string, string, number] {
let match = dim.match(rest ? dimenRest : dimenEnd);
return match ?
muReplace([match[1].replace(/,/, '.'), match[4], match[0].length]) :
[null, null, 0];
}
/**
* Transforms mu dimension to em if necessary.
* @param {[string, string, number]} [value, unit, length] The dimension triple.
* @return {[string, string, number]} [value, unit, length] The transformed triple.
*/
function muReplace([value, unit, length]: [string, string, number]): [string, string, number] {
if (unit !== 'mu') {
return [value, unit, length];
}
let em = Em(UNIT_CASES[unit](parseFloat(value || '1')));
return [em.slice(0, -2), 'em', length];
}
/**
* Convert a dimension string into standard em dimension.
* @param {string} dim The attribute string.
* @return {number} The numerical value.
*/
export function dimen2em(dim: string): number {
let [value, unit] = matchDimen(dim);
let m = parseFloat(value || '1');
let func = UNIT_CASES[unit];
return func ? func(m) : 0;
}
/**
* Turns a number into an em value.
* @param {number} m The number.
* @return {string} The em dimension string.
*/
export function Em(m: number): string {
if (Math.abs(m) < .0006) {
return '0em';
}
return m.toFixed(3).replace(/\.?0+$/, '') + 'em';
}
/**
* Takes an array of numbers and returns a space-separated string of em values.
* @param {number[]} W The widths to be turned into em values
* @return {string} The numbers with em units, separated by spaces.
*/
export function cols(...W: number[]): string {
return W.map(n => Em(n)).join(' ');
}
/**
* Create an mrow that has stretchy delimiters at either end, as needed
* @param {ParseOptions} configuration Current parse options.
* @param {string} open The opening fence.
* @param {MmlNode} mml The enclosed node.
* @param {string} close The closing fence.
* @param {string=} big Bigg command.
*/
export function fenced(configuration: ParseOptions, open: string, mml: MmlNode,
close: string, big: string = '', color: string = '') {
// @test Fenced, Fenced3
let nf = configuration.nodeFactory;
let mrow = nf.create('node', 'mrow', [],
{open: open, close: close, texClass: TEXCLASS.INNER});
let mo;
if (big) {
mo = new TexParser('\\' + big + 'l' + open, configuration.parser.stack.env, configuration).mml();
} else {
let openNode = nf.create('text', open);
mo = nf.create('node', 'mo', [],
{fence: true, stretchy: true, symmetric: true, texClass: TEXCLASS.OPEN},
openNode);
}
NodeUtil.appendChildren(mrow, [mo, mml]);
if (big) {
mo = new TexParser('\\' + big + 'r' + close, configuration.parser.stack.env, configuration).mml();
} else {
let closeNode = nf.create('text', close);
mo = nf.create('node', 'mo', [],
{fence: true, stretchy: true, symmetric: true, texClass: TEXCLASS.CLOSE},
closeNode);
}
color && mo.attributes.set('mathcolor', color);
NodeUtil.appendChildren(mrow, [mo]);
return mrow;
}
/**
* Create an mrow that has \\mathchoice using \\bigg and \\big for the delimiters.
* @param {ParseOptions} configuration The current parse options.
* @param {string} open The opening fence.
* @param {MmlNode} mml The enclosed node.
* @param {string} close The closing fence.
* @return {MmlNode} The mrow node.
*/
export function fixedFence(configuration: ParseOptions, open: string,
mml: MmlNode, close: string): MmlNode {
// @test Choose, Over With Delims, Above with Delims
let mrow = configuration.nodeFactory.create('node',
'mrow', [], {open: open, close: close, texClass: TEXCLASS.ORD});
if (open) {
NodeUtil.appendChildren(mrow, [mathPalette(configuration, open, 'l')]);
}
if (NodeUtil.isType(mml, 'mrow')) {
NodeUtil.appendChildren(mrow, NodeUtil.getChildren(mml));
} else {
NodeUtil.appendChildren(mrow, [mml]);
}
if (close) {
NodeUtil.appendChildren(mrow, [mathPalette(configuration, close, 'r')]);
}
return mrow;
}
/**
* Generates a mathchoice element for fences. These will be resolved later,
* once the position, and therefore size, of the of the fenced expression is
* known.
* @param {ParseOptions} configuration The current parse otpions.
* @param {string} fence The fence.
* @param {string} side The side of the fence (l or r).
* @return {MmlNode} The mathchoice node.
*/
export function mathPalette(configuration: ParseOptions, fence: string,
side: string): MmlNode {
if (fence === '{' || fence === '}') {
fence = '\\' + fence;
}
let D = '{\\bigg' + side + ' ' + fence + '}';
let T = '{\\big' + side + ' ' + fence + '}';
return new TexParser('\\mathchoice' + D + T + T + T, {}, configuration).mml();
}
/**
* If the initial child, skipping any initial space or
* empty braces (TeXAtom with child being an empty inferred row),
* is an <mo>, precede it by an empty <mi> to force the <mo> to
* be infix.
* @param {ParseOptions} configuration The current parse options.
* @param {MmlNode[]} nodes The row of nodes to scan for an initial <mo>
*/
export function fixInitialMO(configuration: ParseOptions, nodes: MmlNode[]) {
for (let i = 0, m = nodes.length; i < m; i++) {
let child = nodes[i];
if (child && (!NodeUtil.isType(child, 'mspace') &&
(!NodeUtil.isType(child, 'TeXAtom') ||
(NodeUtil.getChildren(child)[0] &&
NodeUtil.getChildren(NodeUtil.getChildren(child)[0]).length)))) {
if (NodeUtil.isEmbellished(child) ||
(NodeUtil.isType(child, 'TeXAtom') && NodeUtil.getTexClass(child) === TEXCLASS.REL)) {
let mi = configuration.nodeFactory.create('node', 'mi');
nodes.unshift(mi);
}
break;
}
}
}
/**
* Break up a string into text and math blocks.
* @param {TexParser} parser The calling parser.
* @param {string} text The text in the math expression to parse.
* @param {number|string=} level The scriptlevel.
* @param {string} font The mathvariant to use
* @return {MmlNode[]} The nodes corresponding to the internal math expression.
*/
export function internalMath(parser: TexParser, text: string,
level?: number | string, font?: string): MmlNode[] {
if (parser.configuration.options.internalMath) {
return parser.configuration.options.internalMath(parser, text, level, font);
}
let mathvariant = font || parser.stack.env.font;
let def = (mathvariant ? {mathvariant} : {});
let mml: MmlNode[] = [], i = 0, k = 0, c, node, match = '', braces = 0;
if (text.match(/\\?[${}\\]|\\\(|\\(eq)?ref\s*\{/)) {
while (i < text.length) {
c = text.charAt(i++);
if (c === '$') {
if (match === '$' && braces === 0) {
// @test Interspersed Text
node = parser.create(
'node', 'TeXAtom',
[(new TexParser(text.slice(k, i - 1), {}, parser.configuration)).mml()]);
mml.push(node);
match = '';
k = i;
} else if (match === '') {
// @test Interspersed Text
if (k < i - 1) {
// @test Interspersed Text
mml.push(internalText(parser, text.slice(k, i - 1), def));
}
match = '$';
k = i;
}
} else if (c === '{' && match !== '') {
// @test Mbox Mbox, Mbox Math
braces++;
} else if (c === '}') {
// @test Mbox Mbox, Mbox Math
if (match === '}' && braces === 0) {
// @test Mbox Eqref, Mbox Math
let atom = (new TexParser(text.slice(k, i), {}, parser.configuration)).mml();
node = parser.create('node', 'TeXAtom', [atom], def);
mml.push(node);
match = '';
k = i;
} else if (match !== '') {
// @test Mbox Math, Mbox Mbox
if (braces) {
// @test Mbox Math, Mbox Mbox
braces--;
}
}
} else if (c === '\\') {
// @test Mbox Eqref, Mbox CR
if (match === '' && text.substr(i).match(/^(eq)?ref\s*\{/)) {
// @test Mbox Eqref
let len = ((RegExp as any)['$&'] as string).length;
if (k < i - 1) {
// @test Mbox Eqref
mml.push(internalText(parser, text.slice(k, i - 1), def));
}
match = '}';
k = i - 1;
i += len;
} else {
// @test Mbox CR, Mbox Mbox
c = text.charAt(i++);
if (c === '(' && match === '') {
// @test Mbox Internal Display
if (k < i - 2) {
// @test Mbox Internal Display
mml.push(internalText(parser, text.slice(k, i - 2), def));
}
match = ')'; k = i;
} else if (c === ')' && match === ')' && braces === 0) {
// @test Mbox Internal Display
node = parser.create(
'node', 'TeXAtom',
[(new TexParser(text.slice(k, i - 2), {}, parser.configuration)).mml()]);
mml.push(node);
match = '';
k = i;
} else if (c.match(/[${}\\]/) && match === '') {
// @test Mbox CR
i--;
text = text.substr(0, i - 1) + text.substr(i); // remove \ from \$, \{, \}, or \\
}
}
}
}
if (match !== '') {
// @test Internal Math Error
throw new TexError('MathNotTerminated', 'Math not terminated in text box');
}
}
if (k < text.length) {
// @test Interspersed Text, Mbox Mbox
mml.push(internalText(parser, text.slice(k), def));
}
if (level != null) {
// @test Label, Fbox, Hbox
mml = [parser.create('node', 'mstyle', mml, {displaystyle: false, scriptlevel: level})];
} else if (mml.length > 1) {
// @test Interspersed Text
mml = [parser.create('node', 'mrow', mml)];
}
return mml;
}
/**
* Parses text internal to boxes or labels.
* @param {TexParser} parser The current tex parser.
* @param {string} text The text to parse.
* @param {EnvList} def The attributes of the text node.
* @return {MmlNode} The text node.
*/
export function internalText(parser: TexParser, text: string, def: EnvList): MmlNode {
// @test Label, Fbox, Hbox
text = text.replace(/^\s+/, entities.nbsp).replace(/\s+$/, entities.nbsp);
let textNode = parser.create('text', text);
return parser.create('node', 'mtext', [], def, textNode);
}
/**
* Create an munderover node with the given script position.
* @param {TexParser} parser The current TeX parser.
* @param {MmlNode} base The base node.
* @param {MmlNode} script The under- or over-script.
* @param {string} pos Either 'over' or 'under'.
* @param {boolean} stack True if super- or sub-scripts should stack.
* @return {MmlNode} The generated node (MmlMunderover or TeXAtom)
*/
export function underOver(parser: TexParser, base: MmlNode, script: MmlNode, pos: string, stack: boolean): MmlNode {
// @test Overline
ParseUtil.checkMovableLimits(base);
if (NodeUtil.isType(base, 'munderover') && NodeUtil.isEmbellished(base)) {
// @test Overline Limits
NodeUtil.setProperties(NodeUtil.getCoreMO(base), {lspace: 0, rspace: 0});
const mo = parser.create('node', 'mo', [], {rspace: 0});
base = parser.create('node', 'mrow', [mo, base]);
// TODO? add an empty <mi> so it's not embellished any more
}
const mml = parser.create('node', 'munderover', [base]) as MmlMunderover;
NodeUtil.setChild(mml, pos === 'over' ? mml.over : mml.under, script);
let node: MmlNode = mml;
if (stack) {
// @test Overbrace 1 2 3, Underbrace, Overbrace Op 1 2
node = parser.create('node', 'TeXAtom', [mml], {texClass: TEXCLASS.OP, movesupsub: true});
}
NodeUtil.setProperty(node, 'subsupOK', true);
return node;
}
/**
* Set movablelimits to false if necessary.
* @param {MmlNode} base The base node being tested.
*/
export function checkMovableLimits(base: MmlNode) {
const symbol = (NodeUtil.isType(base, 'mo') ? NodeUtil.getForm(base) : null);
if (NodeUtil.getProperty(base, 'movablelimits') || (symbol && symbol[3] && symbol[3].movablelimits)) {
// @test Overline Sum
NodeUtil.setProperties(base, {movablelimits: false});
}
}
/**
* Trim spaces from a string.
* @param {string} text The string to clean.
* @return {string} The string with leading and trailing whitespace removed.
*/
export function trimSpaces(text: string): string {
if (typeof(text) !== 'string') {
return text;
}
let TEXT = text.trim();
if (TEXT.match(/\\$/) && text.match(/ $/)) {
TEXT += ' ';
}
return TEXT;
}
/**
* Sets alignment in array definitions.
* @param {ArrayItem} array The array item.
* @param {string} align The alignment string.
* @return {ArrayItem} The altered array item.
*/
export function setArrayAlign(array: ArrayItem, align: string): ArrayItem {
// @test Array1, Array2, Array Test
align = ParseUtil.trimSpaces(align || '');
if (align === 't') {
array.arraydef.align = 'baseline 1';
} else if (align === 'b') {
array.arraydef.align = 'baseline -1';
} else if (align === 'c') {
array.arraydef.align = 'axis';
} else if (align) {
array.arraydef.align = align;
} // FIXME: should be an error?
return array;
}
/**
* Replace macro parameters with their values.
* @param {TexParser} parser The current TeX parser.
* @param {string[]} args A list of arguments for macro parameters.
* @param {string} str The macro parameter string.
* @return {string} The string with all parameters replaced by arguments.
*/
export function substituteArgs(parser: TexParser, args: string[],
str: string): string {
let text = '';
let newstring = '';
let i = 0;
while (i < str.length) {
let c = str.charAt(i++);
if (c === '\\') {
text += c + str.charAt(i++);
}
else if (c === '#') {
c = str.charAt(i++);
if (c === '#') {
text += c;
} else {
if (!c.match(/[1-9]/) || parseInt(c, 10) > args.length) {
throw new TexError('IllegalMacroParam',
'Illegal macro parameter reference');
}
newstring = addArgs(parser, addArgs(parser, newstring, text),
args[parseInt(c, 10) - 1]);
text = '';
}
} else {
text += c;
}
}
return addArgs(parser, newstring, text);
}
/**
* Adds a new expanded argument to an already macro parameter string. Makes
* sure that macros are followed by a space if their names could accidentally
* be continued into the following text.
* @param {TexParser} parser The current TeX parser.
* @param {string} s1 The already expanded string.
* @param {string} s2 The string to add.
* @return {string} The combined string.
*/
export function addArgs(parser: TexParser, s1: string, s2: string): string {
if (s2.match(/^[a-z]/i) && s1.match(/(^|[^\\])(\\\\)*\\[a-z]+$/i)) {
s1 += ' ';
}
if (s1.length + s2.length > parser.configuration.options['maxBuffer']) {
throw new TexError('MaxBufferSize',
'MathJax internal buffer size exceeded; is there a' +
' recursive macro call?');
}
return s1 + s2;
}
/**
* Report an error if there are too many macro substitutions.
* @param {TexParser} parser The current TeX parser.
* @param {boolean} isMacro True if we are substituting a macro, false for environment.
*/
export function checkMaxMacros(parser: TexParser, isMacro: boolean = true) {
if (++parser.macroCount <= parser.configuration.options['maxMacros']) {
return;
}
if (isMacro) {
throw new TexError('MaxMacroSub1',
'MathJax maximum macro substitution count exceeded; ' +
'is here a recursive macro call?');
} else {
throw new TexError('MaxMacroSub2',
'MathJax maximum substitution count exceeded; ' +
'is there a recursive latex environment?');
}
}
/**
* Check for bad nesting of equation environments
*/
export function checkEqnEnv(parser: TexParser) {
if (parser.stack.global.eqnenv) {
// @test ErroneousNestingEq
throw new TexError('ErroneousNestingEq', 'Erroneous nesting of equation structures');
}
parser.stack.global.eqnenv = true;
}
/**
* Copy an MmlNode and add it (and its children) to the proper lists.
*
* @param {MmlNode} node The MmlNode to copy
* @param {TexParser} parser The active tex parser
* @return {MmlNode} The duplicate tree
*/
export function copyNode(node: MmlNode, parser: TexParser): MmlNode {
const tree = node.copy() as MmlNode;
const options = parser.configuration;
tree.walkTree((n: MmlNode) => {
options.addNode(n.kind, n);
const lists = (n.getProperty('in-lists') as string || '').split(/,/);
for (const list of lists) {
list && options.addNode(list, n);
}
});
return tree;
}
/**
* This is a placeholder for future security filtering of attributes.
* @param {TexParser} parser The current parser.
* @param {string} name The attribute name.
* @param {string} value The attribute value to filter.
* @return {string} The filtered value.
*/
export function MmlFilterAttribute(_parser: TexParser, _name: string, value: string): string {
// TODO: Implement in security package.
return value;
}
/**
* Initialises an stack environment with current font definition in the parser.
* @param {TexParser} parser The current tex parser.
* @return {EnvList} The initialised environment list.
*/
export function getFontDef(parser: TexParser): EnvList {
const font = parser.stack.env['font'];
return (font ? {mathvariant: font} : {});
}
/**
* Splits a package option list of the form [x=y,z=1] into an attribute list
* of the form {x: y, z: 1}.
* @param {string} attrib The attributes of the package.
* @param {{[key: string]: number}?} allowed A list of allowed options. If
* given only allowed arguments are returned.
* @param {boolean?} error If true, raises an exception if not allowed options
* are found.
* @return {EnvList} The attribute list.
*/
export function keyvalOptions(attrib: string,
allowed: {[key: string]: number} = null,
error: boolean = false): EnvList {
let def: EnvList = readKeyval(attrib);
if (allowed) {
for (let key of Object.keys(def)) {
if (!allowed.hasOwnProperty(key)) {
if (error) {
throw new TexError('InvalidOption', 'Invalid option: %1', key);
}
delete def[key];
}
}
}
return def;
}
/**
* Implementation of the keyval function from https://www.ctan.org/pkg/keyval
* @param {string} text The optional parameter string for a package or
* command.
* @return {EnvList} Set of options as key/value pairs.
*/
function readKeyval(text: string): EnvList {
let options: EnvList = {};
let rest = text;
let end, key, val;
while (rest) {
[key, end, rest] = readValue(rest, ['=', ',']);
if (end === '=') {
[val, end, rest] = readValue(rest, [',']);
val = (val === 'false' || val === 'true') ?
JSON.parse(val) : val;
options[key] = val;
} else if (key) {
options[key] = true;
}
}
return options;
}
/**
* Removes pairs of outer braces.
* @param {string} text The string to clean.
* @param {number} count The number of outer braces to slice off.
* @return {string} The cleaned string.
*/
function removeBraces(text: string, count: number): string {
while (count > 0) {
text = text.trim().slice(1, -1);
count--;
}
return text.trim();
}
/**
* Read a value from the given string until an end parameter is reached or
* string is exhausted.
* @param {string} text The string to process.
* @param {string[]} end List of possible end characters.
* @return {[string, string, string]} The collected value, the actual end
* character, and the rest of the string still to parse.
*/
function readValue(text: string, end: string[]): [string, string, string] {
let length = text.length;
let braces = 0;
let value = '';
let index = 0;
let start = 0; // Counter for the starting left braces.
let startCount = true; // Flag for counting starting left braces.
let stopCount = false; // If true right braces are found directly
// after starting braces, but no other char yet.
while (index < length) {
let c = text[index++];
switch (c) {
case ' ': // Ignore spaces.
break;
case '{':
if (startCount) { // Count start left braces at start.
start++;
} else {
stopCount = false;
if (start > braces) { // Some start left braces have been closed.
start = braces;
}
}
braces++;
break;
case '}':
if (braces) { // Closing braces.
braces--;
}
if (startCount || stopCount) { // Closing braces at the start.
start--;
stopCount = true; // Continue to close braces.
}
startCount = false; // Stop counting start left braces.
break;
default:
if (!braces && end.indexOf(c) !== -1) { // End character reached.
return [stopCount ? 'true' : // If Stop count is true we
// have balanced braces, only.
removeBraces(value, start), c, text.slice(index)];
}
startCount = false;
stopCount = false;
}
value += c;
}
if (braces) {
throw new TexError('ExtraOpenMissingClose',
'Extra open brace or missing close brace');
}
return [stopCount ? 'true' : removeBraces(value, start), '', text.slice(index)];
}
}
export default ParseUtil;