You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
4.4 KiB
136 lines
4.4 KiB
2 years ago
|
const FOLD_FLOW = 'flow';
|
||
|
const FOLD_BLOCK = 'block';
|
||
|
const FOLD_QUOTED = 'quoted';
|
||
|
/**
|
||
|
* Tries to keep input at up to `lineWidth` characters, splitting only on spaces
|
||
|
* not followed by newlines or spaces unless `mode` is `'quoted'`. Lines are
|
||
|
* terminated with `\n` and started with `indent`.
|
||
|
*/
|
||
|
function foldFlowLines(text, indent, mode = 'flow', { indentAtStart, lineWidth = 80, minContentWidth = 20, onFold, onOverflow } = {}) {
|
||
|
if (!lineWidth || lineWidth < 0)
|
||
|
return text;
|
||
|
const endStep = Math.max(1 + minContentWidth, 1 + lineWidth - indent.length);
|
||
|
if (text.length <= endStep)
|
||
|
return text;
|
||
|
const folds = [];
|
||
|
const escapedFolds = {};
|
||
|
let end = lineWidth - indent.length;
|
||
|
if (typeof indentAtStart === 'number') {
|
||
|
if (indentAtStart > lineWidth - Math.max(2, minContentWidth))
|
||
|
folds.push(0);
|
||
|
else
|
||
|
end = lineWidth - indentAtStart;
|
||
|
}
|
||
|
let split = undefined;
|
||
|
let prev = undefined;
|
||
|
let overflow = false;
|
||
|
let i = -1;
|
||
|
let escStart = -1;
|
||
|
let escEnd = -1;
|
||
|
if (mode === FOLD_BLOCK) {
|
||
|
i = consumeMoreIndentedLines(text, i);
|
||
|
if (i !== -1)
|
||
|
end = i + endStep;
|
||
|
}
|
||
|
for (let ch; (ch = text[(i += 1)]);) {
|
||
|
if (mode === FOLD_QUOTED && ch === '\\') {
|
||
|
escStart = i;
|
||
|
switch (text[i + 1]) {
|
||
|
case 'x':
|
||
|
i += 3;
|
||
|
break;
|
||
|
case 'u':
|
||
|
i += 5;
|
||
|
break;
|
||
|
case 'U':
|
||
|
i += 9;
|
||
|
break;
|
||
|
default:
|
||
|
i += 1;
|
||
|
}
|
||
|
escEnd = i;
|
||
|
}
|
||
|
if (ch === '\n') {
|
||
|
if (mode === FOLD_BLOCK)
|
||
|
i = consumeMoreIndentedLines(text, i);
|
||
|
end = i + endStep;
|
||
|
split = undefined;
|
||
|
}
|
||
|
else {
|
||
|
if (ch === ' ' &&
|
||
|
prev &&
|
||
|
prev !== ' ' &&
|
||
|
prev !== '\n' &&
|
||
|
prev !== '\t') {
|
||
|
// space surrounded by non-space can be replaced with newline + indent
|
||
|
const next = text[i + 1];
|
||
|
if (next && next !== ' ' && next !== '\n' && next !== '\t')
|
||
|
split = i;
|
||
|
}
|
||
|
if (i >= end) {
|
||
|
if (split) {
|
||
|
folds.push(split);
|
||
|
end = split + endStep;
|
||
|
split = undefined;
|
||
|
}
|
||
|
else if (mode === FOLD_QUOTED) {
|
||
|
// white-space collected at end may stretch past lineWidth
|
||
|
while (prev === ' ' || prev === '\t') {
|
||
|
prev = ch;
|
||
|
ch = text[(i += 1)];
|
||
|
overflow = true;
|
||
|
}
|
||
|
// Account for newline escape, but don't break preceding escape
|
||
|
const j = i > escEnd + 1 ? i - 2 : escStart - 1;
|
||
|
// Bail out if lineWidth & minContentWidth are shorter than an escape string
|
||
|
if (escapedFolds[j])
|
||
|
return text;
|
||
|
folds.push(j);
|
||
|
escapedFolds[j] = true;
|
||
|
end = j + endStep;
|
||
|
split = undefined;
|
||
|
}
|
||
|
else {
|
||
|
overflow = true;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
prev = ch;
|
||
|
}
|
||
|
if (overflow && onOverflow)
|
||
|
onOverflow();
|
||
|
if (folds.length === 0)
|
||
|
return text;
|
||
|
if (onFold)
|
||
|
onFold();
|
||
|
let res = text.slice(0, folds[0]);
|
||
|
for (let i = 0; i < folds.length; ++i) {
|
||
|
const fold = folds[i];
|
||
|
const end = folds[i + 1] || text.length;
|
||
|
if (fold === 0)
|
||
|
res = `\n${indent}${text.slice(0, end)}`;
|
||
|
else {
|
||
|
if (mode === FOLD_QUOTED && escapedFolds[fold])
|
||
|
res += `${text[fold]}\\`;
|
||
|
res += `\n${indent}${text.slice(fold + 1, end)}`;
|
||
|
}
|
||
|
}
|
||
|
return res;
|
||
|
}
|
||
|
/**
|
||
|
* Presumes `i + 1` is at the start of a line
|
||
|
* @returns index of last newline in more-indented block
|
||
|
*/
|
||
|
function consumeMoreIndentedLines(text, i) {
|
||
|
let ch = text[i + 1];
|
||
|
while (ch === ' ' || ch === '\t') {
|
||
|
do {
|
||
|
ch = text[(i += 1)];
|
||
|
} while (ch && ch !== '\n');
|
||
|
ch = text[i + 1];
|
||
|
}
|
||
|
return i;
|
||
|
}
|
||
|
|
||
|
export { FOLD_BLOCK, FOLD_FLOW, FOLD_QUOTED, foldFlowLines };
|