name : resolve-flow-scalar.js import { Scalar } from '../nodes/Scalar.js'; import { resolveEnd } from './resolve-end.js'; function resolveFlowScalar(scalar, strict, onError) { const { offset, type, source, end } = scalar; let _type; let value; const _onError = (rel, code, msg) => onError(offset + rel, code, msg); switch (type) { case 'scalar': _type = Scalar.PLAIN; value = plainValue(source, _onError); break; case 'single-quoted-scalar': _type = Scalar.QUOTE_SINGLE; value = singleQuotedValue(source, _onError); break; case 'double-quoted-scalar': _type = Scalar.QUOTE_DOUBLE; value = doubleQuotedValue(source, _onError); break; /* istanbul ignore next should not happen */ default: onError(scalar, 'UNEXPECTED_TOKEN', `Expected a flow scalar value, but found: ${type}`); return { value: '', type: null, comment: '', range: [offset, offset + source.length, offset + source.length] }; } const valueEnd = offset + source.length; const re = resolveEnd(end, valueEnd, strict, onError); return { value, type: _type, comment: re.comment, range: [offset, valueEnd, re.offset] }; } function plainValue(source, onError) { let badChar = ''; switch (source[0]) { /* istanbul ignore next should not happen */ case '\t': badChar = 'a tab character'; break; case ',': badChar = 'flow indicator character ,'; break; case '%': badChar = 'directive indicator character %'; break; case '|': case '>': { badChar = `block scalar indicator ${source[0]}`; break; } case '@': case '`': { badChar = `reserved character ${source[0]}`; break; } } if (badChar) onError(0, 'BAD_SCALAR_START', `Plain value cannot start with ${badChar}`); return foldLines(source); } function singleQuotedValue(source, onError) { if (source[source.length - 1] !== "'" || source.length === 1) onError(source.length, 'MISSING_CHAR', "Missing closing 'quote"); return foldLines(source.slice(1, -1)).replace(/''/g, "'"); } function foldLines(source) { /** * The negative lookbehind here and in the `re` RegExp is to * prevent causing a polynomial search time in certain cases. * * The try-catch is for Safari, which doesn't support this yet: * https://caniuse.com/js-regexp-lookbehind */ let first, line; try { first = new RegExp('(.*?)(?<![ \t])[ \t]*\r?\n', 'sy'); line = new RegExp('[ \t]*(.*?)(?:(?<![ \t])[ \t]*)?\r?\n', 'sy'); } catch (_) { first = /(.*?)[ \t]*\r?\n/sy; line = /[ \t]*(.*?)[ \t]*\r?\n/sy; } let match = first.exec(source); if (!match) return source; let res = match[1]; let sep = ' '; let pos = first.lastIndex; line.lastIndex = pos; while ((match = line.exec(source))) { if (match[1] === '') { if (sep === '\n') res += sep; else sep = '\n'; } else { res += sep + match[1]; sep = ' '; } pos = line.lastIndex; } const last = /[ \t]*(.*)/sy; last.lastIndex = pos; match = last.exec(source); return res + sep + (match?.[1] ?? ''); } function doubleQuotedValue(source, onError) { let res = ''; for (let i = 1; i < source.length - 1; ++i) { const ch = source[i]; if (ch === '\r' && source[i + 1] === '\n') continue; if (ch === '\n') { const { fold, offset } = foldNewline(source, i); res += fold; i = offset; } else if (ch === '\\') { let next = source[++i]; const cc = escapeCodes[next]; if (cc) res += cc; else if (next === '\n') { // skip escaped newlines, but still trim the following line next = source[i + 1]; while (next === ' ' || next === '\t') next = source[++i + 1]; } else if (next === '\r' && source[i + 1] === '\n') { // skip escaped CRLF newlines, but still trim the following line next = source[++i + 1]; while (next === ' ' || next === '\t') next = source[++i + 1]; } else if (next === 'x' || next === 'u' || next === 'U') { const length = { x: 2, u: 4, U: 8 }[next]; res += parseCharCode(source, i + 1, length, onError); i += length; } else { const raw = source.substr(i - 1, 2); onError(i - 1, 'BAD_DQ_ESCAPE', `Invalid escape sequence ${raw}`); res += raw; } } else if (ch === ' ' || ch === '\t') { // trim trailing whitespace const wsStart = i; let next = source[i + 1]; while (next === ' ' || next === '\t') next = source[++i + 1]; if (next !== '\n' && !(next === '\r' && source[i + 2] === '\n')) res += i > wsStart ? source.slice(wsStart, i + 1) : ch; } else { res += ch; } } if (source[source.length - 1] !== '"' || source.length === 1) onError(source.length, 'MISSING_CHAR', 'Missing closing "quote'); return res; } /** * Fold a single newline into a space, multiple newlines to N - 1 newlines. * Presumes `source[offset] === '\n'` */ function foldNewline(source, offset) { let fold = ''; let ch = source[offset + 1]; while (ch === ' ' || ch === '\t' || ch === '\n' || ch === '\r') { if (ch === '\r' && source[offset + 2] !== '\n') break; if (ch === '\n') fold += '\n'; offset += 1; ch = source[offset + 1]; } if (!fold) fold = ' '; return { fold, offset }; } const escapeCodes = { '0': '\0', a: '\x07', b: '\b', e: '\x1b', f: '\f', n: '\n', r: '\r', t: '\t', v: '\v', N: '\u0085', _: '\u00a0', L: '\u2028', P: '\u2029', ' ': ' ', '"': '"', '/': '/', '\\': '\\', '\t': '\t' }; function parseCharCode(source, offset, length, onError) { const cc = source.substr(offset, length); const ok = cc.length === length && /^[0-9a-fA-F]+$/.test(cc); const code = ok ? parseInt(cc, 16) : NaN; if (isNaN(code)) { const raw = source.substr(offset - 2, length + 2); onError(offset - 2, 'BAD_DQ_ESCAPE', `Invalid escape sequence ${raw}`); return raw; } return String.fromCodePoint(code); } export { resolveFlowScalar };