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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 };
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