Math/modules/MathJax/extensions/TeX/mhchem.js

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/*************************************************************
*
* MathJax/extensions/TeX/mhchem.js
*
* Implements the \ce command for handling chemical formulas
* from the mhchem LaTeX package.
*
* ---------------------------------------------------------------------
*
* Copyright (c) 2011-2012 Design Science, Inc.
*
* 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.
*/
MathJax.Extension["TeX/mhchem"] = {
version: "2.0"
};
MathJax.Hub.Register.StartupHook("TeX Jax Ready",function () {
var TEX = MathJax.InputJax.TeX,
MACROS = TEX.Definitions.macros;
/*
* This is the main class for handing the \ce and related commands.
* Its main method is Parse() which takes the argument to \ce and
* returns the corresponding TeX string.
*/
var CE = MathJax.Object.Subclass({
string: "", // the \ce string being parsed
i: 0, // the current position in the string
tex: "", // the processed TeX result
atom: false, // last processed token is an atom
sup: "", // pending superscript
sub: "", // pending subscript
//
// Store the string when a CE object is created
//
Init: function (string) {this.string = string},
//
// These are the special characters and the methods that
// handle them. All others are passed through verbatim.
//
ParseTable: {
'-': "Minus",
'+': "Plus",
'(': "Open",
')': "Close",
'[': "Open",
']': "Close",
'<': "Less",
'^': "Superscript",
'_': "Subscript",
'*': "Dot",
'.': "Dot",
'=': "Equal",
'#': "Pound",
'$': "Math",
'\\': "Macro",
' ': "Space"
},
//
// Basic arrow names for reactions
//
Arrows: {
'->': "rightarrow",
'<-': "leftarrow",
'<->': "leftrightarrow",
'<=>': "rightleftharpoons",
'<=>>': "Rightleftharpoons",
'^': "uparrow",
'v': "downarrow"
},
//
// Implementations for the various bonds
// (the ~ ones are hacks that don't work well in NativeMML)
//
Bonds: {
'-': "-",
'=': "=",
'#': "\\equiv",
'~': "\\tripledash",
'~-': "\\begin{CEstack}{}\\tripledash\\\\-\\end{CEstack}",
'~=': "\\raise2mu{\\begin{CEstack}{}\\tripledash\\\\-\\\\-\\end{CEstack}}",
'~--': "\\raise2mu{\\begin{CEstack}{}\\tripledash\\\\-\\\\-\\end{CEstack}}",
'-~-': "\\raise2mu{\\begin{CEstack}{}-\\\\\\tripledash\\\\-\\end{CEstack}}",
'...': "{\\cdot}{\\cdot}{\\cdot}",
'....': "{\\cdot}{\\cdot}{\\cdot}{\\cdot}",
'->': "\\rightarrow",
'<-': "\\leftarrow",
'??': "\\text{??}" // unknown bond
},
//
// This converts the CE string to a TeX string.
// It loops through the string and calls the proper
// method depending on the ccurrent character.
//
Parse: function () {
this.tex = ""; this.atom = false;
while (this.i < this.string.length) {
var c = this.string.charAt(this.i);
if (c.match(/[a-z]/i)) {this.ParseLetter()}
else if (c.match(/[0-9]/)) {this.ParseNumber()}
else {this["Parse"+(this.ParseTable[c]||"Other")](c)}
}
this.FinishAtom();
return this.tex;
},
//
// Make an atom name or a down arrow
//
ParseLetter: function () {
this.FinishAtom();
if (this.Match(/^v( |$)/)) {
this.tex += "{\\"+this.Arrows["v"]+"}";
} else {
this.tex += "\\text{"+this.Match(/^[a-z]+/i)+"}";
this.atom = true;
}
},
//
// Make a number of fraction preceeding an atom,
// or a subscript for an atom.
//
ParseNumber: function () {
var n = this.Match(/^\d+/);
if (this.atom && !this.sub) {
this.sub = n;
} else {
this.FinishAtom();
var match = this.Match(/^\/\d+/);
if (match) {
var frac = "\\frac{"+n+"}{"+match.substr(1)+"}";
this.tex += "\\mathchoice{\\textstyle"+frac+"}{"+frac+"}{"+frac+"}{"+frac+"}";
} else {
this.tex += n;
if (this.i < this.string.length) {this.tex += "\\,"}
}
}
},
//
// Make a superscript minus, or an arrow, or a single bond.
//
ParseMinus: function (c) {
if (this.atom && (this.i === this.string.length-1 || this.string.charAt(this.i+1) === " ")) {
this.sup += c;
} else {
this.FinishAtom();
if (this.string.substr(this.i,2) === "->") {this.i += 2; this.AddArrow("->"); return}
else {this.tex += "{-}"}
}
this.i++;
},
//
// Make a superscript plus, or pass it through
//
ParsePlus: function (c) {
if (this.atom) {this.sup += c} else {this.FinishAtom(); this.tex += c}
this.i++;
},
//
// Handle dots and double or triple bonds
//
ParseDot: function (c) {this.FinishAtom(); this.tex += "\\cdot "; this.i++},
ParseEqual: function (c) {this.FinishAtom(); this.tex += "{=}"; this.i++},
ParsePound: function (c) {this.FinishAtom(); this.tex += "{\\equiv}"; this.i++},
//
// Look for (v) or (^), or pass it through
//
ParseOpen: function (c) {
this.FinishAtom();
var match = this.Match(/^\([v^]\)/);
if (match) {this.tex += "{\\"+this.Arrows[match.charAt(1)]+"}"}
else {this.tex += "{"+c; this.i++}
},
//
// Allow ) and ] to get super- and subscripts
//
ParseClose: function (c) {this.FinishAtom(); this.atom = true; this.tex += c+"}"; this.i++},
//
// Make the proper arrow
//
ParseLess: function (c) {
this.FinishAtom();
var arrow = this.Match(/^(<->?|<=>>?)/);
if (!arrow) {this.tex += c; this.i++} else {this.AddArrow(arrow)}
},
//
// Look for a superscript, or an up arrow
//
ParseSuperscript: function (c) {
c = this.string.charAt(++this.i);
if (c === "{") {
this.i++; var m = this.Find("}");
if (m === "-.") {this.sup += "{-}{\\cdot}"} else if (m) {this.sup += CE(m).Parse()}
} else if (c === " " || c === "") {
this.tex += "{\\"+this.Arrows["^"]+"}"; this.i++;
} else {
var n = this.Match(/^(\d+|-\.)/);
if (n) {this.sup += n}
}
},
//
// Look for subscripts
//
ParseSubscript: function (c) {
if (this.string.charAt(++this.i) == "{") {
this.i++; this.sub += CE(this.Find("}")).Parse();
} else {
var n = this.Match(/^\d+/);
if (n) {this.sub += n}
}
},
//
// Look for raw TeX code to include
//
ParseMath: function (c) {
this.FinishAtom();
this.i++; this.tex += this.Find(c);
},
//
// Look for specific macros for bonds
// and allow \} to have subscripts
//
ParseMacro: function (c) {
this.FinishAtom();
this.i++; var match = this.Match(/^([a-z]+|.)/i)||" ";
if (match === "sbond") {this.tex += "{-}"}
else if (match === "dbond") {this.tex += "{=}"}
else if (match === "tbond") {this.tex += "{\\equiv}"}
else if (match === "bond") {
var bond = (this.Match(/^\{.*?\}/)||"");
bond = bond.substr(1,bond.length-2);
this.tex += "{"+(this.Bonds[bond]||"\\text{??}")+"}";
}
else if (match === "{") {this.tex += "{\\{"}
else if (match === "}") {this.tex += "\\}}"; this.atom = true}
else {this.tex += c+match}
},
//
// Ignore spaces
//
ParseSpace: function (c) {this.FinishAtom(); this.i++},
//
// Pass anything else on verbatim
//
ParseOther: function (c) {this.FinishAtom(); this.tex += c; this.i++},
//
// Process an arrow (looking for brackets for above and below)
//
AddArrow: function (arrow) {
var c = this.Match(/^[CT]\[/);
if (c) {this.i--; c = c.charAt(0)}
var above = this.GetBracket(c), below = this.GetBracket(c);
arrow = this.Arrows[arrow];
if (above || below) {
if (below) {arrow += "["+below+"]"}
arrow += "{"+above+"}";
arrow = "\\mathrel{\\x"+arrow+"}";
} else {
arrow = "\\long"+arrow+" ";
}
this.tex += arrow;
},
//
// Handle the super and subscripts for an atom
//
FinishAtom: function () {
if (this.sup || this.sub) {
if (this.sup && this.sub && !this.atom) {
//
// right-justify super- and subscripts when they are before the atom
//
var n = Math.abs(this.sup.length-this.sub.length);
if (n) {
var zeros = "0000000000".substr(0,n);
var script = (this.sup.length > this.sub.length ? "sub" : "sup");
this[script] = "\\phantom{"+zeros+"}" + this[script];
}
}
if (!this.sup) {this.sup = "\\Space{0pt}{0pt}{.2em}"} // forces subscripts to align properly
this.tex += "^{"+this.sup+"}_{"+this.sub+"}";
this.sup = this.sub = "";
}
this.atom = false;
},
//
// Find a bracket group and handle C and T prefixes
//
GetBracket: function (c) {
if (this.string.charAt(this.i) !== "[") {return ""}
this.i++; var bracket = this.Find("]");
if (c === "C") {bracket = "\\ce{"+bracket+"}"} else
if (c === "T") {
if (!bracket.match(/^\{.*\}$/)) {bracket = "{"+bracket+"}"}
bracket = "\\text"+bracket;
};
return bracket;
},
//
// Check if the string matches a regular expression
// and move past it if so, returning the match
//
Match: function (regex) {
var match = regex.exec(this.string.substr(this.i));
if (match) {match = match[0]; this.i += match.length}
return match;
},
//
// Find a particular character, skipping over braced groups
//
Find: function (c) {
var m = this.string.length, i = this.i, braces = 0;
while (this.i < m) {
var C = this.string.charAt(this.i++);
if (C === c && braces === 0) {return this.string.substr(i,this.i-i-1)}
if (C === "{") {braces++} else
if (C === "}") {
if (braces) {braces--}
else {TEX.Error("Extra close brace or missing open brace")}
}
}
if (braces) {TEX.Error("Missing close brace")};
TEX.Error("Can't find closing "+c);
}
});
/***************************************************************************/
//
// Set up the macros for chemistry
//
MACROS.ce = 'CE';
MACROS.cf = 'CE';
MACROS.cee = 'CE';
//
// Include some missing arrows (some are hacks)
//
MACROS.xleftrightarrow = ['xArrow',0x2194,6,6];
MACROS.xrightleftharpoons = ['xArrow',0x21CC,5,7]; // FIXME: doesn't stretch in HTML-CSS output
MACROS.xRightleftharpoons = ['xArrow',0x21CC,5,7]; // FIXME: how should this be handled?
// FIXME: These don't work well in FF NativeMML mode
MACROS.longrightleftharpoons = ["Macro","\\stackrel{\\textstyle{{-}\\!\\!{\\rightharpoonup}}}{\\smash{{\\leftharpoondown}\\!\\!{-}}}"];
MACROS.longRightleftharpoons = ["Macro","\\stackrel{\\textstyle{-}\\!\\!{\\rightharpoonup}}{\\small\\smash\\leftharpoondown}"];
//
// Needed for \bond for the ~ forms
//
MACROS.tripledash = ["Macro","\\raise3mu{\\tiny\\text{-}\\kern2mu\\text{-}\\kern2mu\\text{-}}"];
TEX.Definitions.environment.CEstack = ['Array',null,null,null,'r',null,"0.001em",'T',1]
//
// Add \hyphen used in some mhchem examples
//
MACROS.hyphen = ["Macro","\\text{-}"];
TEX.Parse.Augment({
//
// Implements \ce and friends
//
CE: function (name) {
var arg = this.GetArgument(name);
var tex = CE(arg).Parse();
this.string = tex + this.string.substr(this.i); this.i = 0;
}
});
//
// Indicate that the extension is ready
//
MathJax.Hub.Startup.signal.Post("TeX mhchem Ready");
});
MathJax.Ajax.loadComplete("[MathJax]/extensions/TeX/mhchem.js");