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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;
- if (lineWidth < minContentWidth)
- minContentWidth = 0;
- 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, indent.length);
- 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, indent.length);
- end = i + indent.length + 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, indent) {
- let end = i;
- let start = i + 1;
- let ch = text[start];
- while (ch === ' ' || ch === '\t') {
- if (i < start + indent) {
- ch = text[++i];
- }
- else {
- do {
- ch = text[++i];
- } while (ch && ch !== '\n');
- end = i;
- start = i + 1;
- ch = text[start];
- }
- }
- return end;
- }
- export { FOLD_BLOCK, FOLD_FLOW, FOLD_QUOTED, foldFlowLines };
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