marked-variables
Version:
Variable extension for Marked.js
350 lines (306 loc) • 11.7 kB
JavaScript
import { Parser as MathParser } from 'expr-eval';
import { romanize } from 'romans';
import writtenNumber from 'written-number';
let varsQueue = [];
const globalVarsList = {};
let globalPageNumber = 0;
// Regex
// url or <url> "title" or 'title' or (title)
const linkRegex = /^([^<\s][^\s]*|<.*?>)(?: ("(?:\\"|[^"])*"|'(?:\\'|[^'])*'|\((?:\\\(|\\\)|[^()])*\)))?$/m;
const varCallRegex = /([!$]?)\[((?!\s*\])(?:\\.|[^\[\]\\])+)\]/g; // Matches [var] or ![var] or $[var]
//Limit math features to simple items
const mathParser = new MathParser({
operators : {
// These default to true, but are included to be explicit
add : true,
subtract : true,
multiply : true,
divide : true,
power : true,
round : true,
floor : true,
ceil : true,
abs : true,
sin : false, cos : false, tan : false, asin : false, acos : false,
atan : false, sinh : false, cosh : false, tanh : false, asinh : false,
acosh : false, atanh : false, sqrt : false, cbrt : false, log : false,
log2 : false, ln : false, lg : false, log10 : false, expm1 : false,
log1p : false, trunc : false, join : false, sum : false, indexOf : false,
'-' : false, '+' : false, exp : false, not : false, length : false,
'!' : false, sign : false, random : false, fac : false, min : false,
max : false, hypot : false, pyt : false, pow : false, atan2 : false,
'if' : false, gamma : false, roundTo : false, map : false, fold : false,
filter : false,
remainder : false, factorial : false,
comparison : false, concatenate : false,
logical : false, assignment : false,
array : false, fndef : false
}
});
// Add sign function
mathParser.functions.sign = function (a) {
if(a >= 0) return '+';
return '-';
};
// Add signed function
mathParser.functions.signed = function (a) {
if(a >= 0) return `+${a}`;
return `${a}`;
};
// Add Roman numeral functions
mathParser.functions.toRomans = function (a) {
return romanize(a);
};
mathParser.functions.toRomansUpper = function (a) {
return romanize(a).toUpperCase();
};
mathParser.functions.toRomansLower = function (a) {
return romanize(a).toLowerCase();
};
// Add character functions
mathParser.functions.toChar = function (a) {
if(a <= 0) return a;
const genChars = function (i) {
return (i > 26 ? genChars(Math.floor((i - 1) / 26)) : '') + 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'[(i - 1) % 26];
};
return genChars(a);
};
mathParser.functions.toCharUpper = function (a) {
return mathParser.functions.toChar(a).toUpperCase();
};
mathParser.functions.toCharLower = function (a) {
return mathParser.functions.toChar(a).toLowerCase();
};
// Add word functions
mathParser.functions.toWords = function (a) {
return writtenNumber(a);
};
mathParser.functions.toWordsUpper = function (a) {
return mathParser.functions.toWords(a).toUpperCase();
};
mathParser.functions.toWordsLower = function (a) {
return mathParser.functions.toWords(a).toLowerCase();
};
mathParser.functions.toWordsCaps = function (a) {
const words = mathParser.functions.toWords(a).split(' ');
return words.map((word)=>{
return word.replace(/(?:^|\b|\s)(\w)/g, function(w, index) {
return index === 0 ? w.toLowerCase() : w.toUpperCase();
});
}).join(' ');
};
// Normalize variable names; trim edge spaces and shorten blocks of whitespace to 1 space
const normalizeVarNames = (label)=>{
return label.trim().replace(/\s+/g, ' ');
};
const replaceVar = function(prefix, label, allowUnresolved=false) {
//v=====--------------------< HANDLE MATH >-------------------=====v//
const mathRegex = /[a-z]+\(|[+\-*/^(),]/g;
const matches = label.split(mathRegex);
const mathVars = matches.filter((match)=>isNaN(match))?.map((s)=>s.trim()); // Capture any variable names
let replacedLabel = label;
if(prefix[0] == '$' && mathVars?.[0] !== label.trim()) {// If there was mathy stuff not captured, let's do math!
mathVars?.forEach((variable)=>{
const foundVar = lookupVar(variable, globalPageNumber);
if(foundVar && foundVar.resolved && foundVar.content && !isNaN(foundVar.content)) // Only subsitute math values if fully resolved, not empty strings, and numbers
replacedLabel = replacedLabel.replaceAll(new RegExp(`(?<!\\w)(${variable})(?!\\w)`, 'g'), foundVar.content);
});
try {
return mathParser.evaluate(replacedLabel);
} catch (error) {
return undefined; // Return undefined if invalid math result
}
}
//^=====--------------------< HANDLE MATH >-------------------=====^//
const foundVar = lookupVar(label, globalPageNumber);
if(!foundVar || (!foundVar.resolved && !allowUnresolved))
return undefined; // Return undefined if not found, or parially-resolved vars are not allowed
if(prefix[0] == '$') // Variable <================================
return foundVar.content;
const linkMatch = foundVar.content.match(linkRegex);
const href = linkMatch ? linkMatch[1] : null; //TODO: TRIM OFF < > IF PRESENT
const title = linkMatch ? linkMatch[2]?.slice(1, -1) : null;
if(!prefix[0] && href) // Link <================================
return `[${label}](${href}${title ? ` "${title}"` : ''})`;
if(prefix[0] == '!' && href) // Image <================================
return `![${label}](${href} ${title ? ` "${title}"` : ''})`;
};
const lookupVar = function(label, index) {
while (index >= 0) {
if(globalVarsList[index]?.[label] !== undefined)
return globalVarsList[index][label];
index--;
}
//If normal lookup failed, attempt hoisting from later
index = Object.keys(globalVarsList).length; // Move index to start from last page
while (index >= 0) {
if(globalVarsList[index]?.[label] !== undefined)
return globalVarsList[index][label];
index--;
}
return undefined;
};
const processVariableQueue = function() {
let resolvedOne = true;
let finalLoop = false;
while (resolvedOne || finalLoop) { // Loop through queue until no more variable calls can be resolved
resolvedOne = false;
for (const item of varsQueue) {
if(item.type == 'text')
continue;
if(item.type == 'varDefBlock') {
let match;
let resolved = true;
let tempContent = item.content;
while (match = varCallRegex.exec(item.content)) { // Check for any variable calls within this definition (i.e. [var]: $[nestedVar])
const value = replaceVar(match[1], match[2]);
if(value == undefined)
resolved = false;
else
tempContent = tempContent.replaceAll(match[0], value);
}
if(resolved == true || item.content != tempContent) {
resolvedOne = true;
item.content = tempContent;
}
globalVarsList[globalPageNumber][item.varName] = {
content : item.content,
resolved : resolved
};
if(resolved)
item.type = 'resolved';
}
if(item.type == 'varCall') {
const value = replaceVar(item.prefix, item.varName, finalLoop); // final loop will just use the best value so far
if(value == undefined)
continue;
resolvedOne = true;
item.content = value;
item.type = 'text';
}
}
varsQueue = varsQueue.filter((item)=>item.type !== 'resolved'); // Remove any fully-resolved variable definitions
if(finalLoop)
break;
if(!resolvedOne)
finalLoop = true;
}
varsQueue = varsQueue.filter((item)=>item.type !== 'varDefBlock');
};
export function markedVariables() {
return {
hooks : {
preprocess(src) {
const existing = globalVarsList[globalPageNumber] || {}; // Clear variables for current page (except externally-injected) before processing
globalVarsList[globalPageNumber] = Object.fromEntries(
Object.entries(existing)
.filter(([_, value]) => value?.external)
.map(([key, value]) => [key, { ...value, external: undefined }])
);
varsQueue = []; // Start with an empty queue of variables to parse
const codeBlockSkip = /^(?: {4}[^\n]+(?:\n(?: *(?:\n|$))*)?)+|^ {0,3}(`{3,}(?=[^`\n]*(?:\n|$))|~{3,})(?:[^\n]*)(?:\n|$)(?:|(?:[\s\S]*?)(?:\n|$))(?: {0,3}\2[~`]* *(?=\n|$))|`[^`]*?`/;
const varLabelRegex = /([!$]?)\[((?!\s*\])(?:\\.|[^\[\]\\])+)\]/; // Matches [var] or ![var] or $[var], 3[4]
const blockDefRegex = /:((?:\n? *[^\s].*)+)(?=\n+|$)/; // Matches : block definitions, 3[4]: 5
const inlineDefRegex = /\(([^\n]+)\)/; // Matches (inline definitions), 3[4](6)
const combinedRegex = new RegExp(`(${codeBlockSkip.source})|${varLabelRegex.source}(?:${blockDefRegex.source}|${inlineDefRegex.source})?`, 'gm');
let lastIndex = 0;
let match;
while ((match = combinedRegex.exec(src)) !== null) {
const isLineStart = match.index === 0 || src[match.index - 1] === '\n';
const prefix = match[3];
const label = match[4] ? normalizeVarNames(match[4]) : null;
// Format any matches into tokens and store
if(match.index > lastIndex) { // Any non-variable stuff
varsQueue.push(
{ type : 'text',
content : src.slice(lastIndex, match.index)
});
}
if(match[1]) {
varsQueue.push(
{ type : 'text',
content : match[0]
});
}
else if(isLineStart && match[5]) { // Block Definition
const content = match[5].trim().replace(/[ \t]+/g, ' '); // Normalize text content (except newlines for block-level content)
varsQueue.push(
{ type : 'varDefBlock',
prefix : prefix,
varName : label,
content : content
});
}
else if(match[6]) { // Inline Definition
let content = match[6] || null;
// In case of nested (), find the correct matching end )
let level = 0;
let i;
for (i = 0; i < content.length; i++) {
if(content[i] === '\\') {
i++;
} else if(content[i] === '(') {
level++;
} else if(content[i] === ')') {
level--;
if(level < 0)
break;
}
}
combinedRegex.lastIndex = combinedRegex.lastIndex - (content.length - i);
content = content.slice(0, i).trim().replace(/\s+/g, ' ');
varsQueue.push(
{ type : 'varDefBlock',
prefix : prefix,
varName : label,
content : content
});
varsQueue.push(
{ type : 'varCall',
prefix : prefix,
varName : label
});
}
else if(match[4]) { // Variable Call
varsQueue.push(
{ type : 'varCall',
prefix : prefix,
varName : label,
content : `${prefix}[${label}]` // Keep original `$[var]` in case not defined anywhere
});
}
lastIndex = combinedRegex.lastIndex;
}
if(lastIndex < src.length) {
varsQueue.push(
{ type : 'text',
varName : null,
content : src.slice(lastIndex)
});
}
processVariableQueue();
const output = varsQueue.map((item)=>item.content).join('');
return output;
}
}
}
};
export function setMarkedVariable(name, content, page=0) {
if (page < 0) return;
if(!globalVarsList[ page ]) globalVarsList[ page ] = {};
globalVarsList[ page ][ name ] = {
content : content,
resolved : true,
external : true
};
};
export function getMarkedVariable(name, page=0) {
const lookup = lookupVar(name, page);
if(lookup?.resolved) { // Not sure if it can ever be unresolved here, something to check later
return lookup.content;
}
return undefined;
}
export function setMarkedVariablePage(pageNumber) {
globalPageNumber = pageNumber;
}