cst.js
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export { createScalarToken, resolveAsScalar, setScalarValue } from './cst-scalar.js';
export { stringify } from './cst-stringify.js';
export { visit } from './cst-visit.js';
/** The byte order mark */
const BOM = '\u{FEFF}';
/** Start of doc-mode */
const DOCUMENT = '\x02'; // C0: Start of Text
/** Unexpected end of flow-mode */
const FLOW_END = '\x18'; // C0: Cancel
/** Next token is a scalar value */
const SCALAR = '\x1f'; // C0: Unit Separator
/** @returns `true` if `token` is a flow or block collection */
const isCollection = (token) => !!token && 'items' in token;
/** @returns `true` if `token` is a flow or block scalar; not an alias */
const isScalar = (token) => !!token &&
(token.type === 'scalar' ||
token.type === 'single-quoted-scalar' ||
token.type === 'double-quoted-scalar' ||
token.type === 'block-scalar');
/* istanbul ignore next */
/** Get a printable representation of a lexer token */
function prettyToken(token) {
switch (token) {
case BOM:
return '<BOM>';
case DOCUMENT:
return '<DOC>';
case FLOW_END:
return '<FLOW_END>';
case SCALAR:
return '<SCALAR>';
default:
return JSON.stringify(token);
}
}
/** Identify the type of a lexer token. May return `null` for unknown tokens. */
function tokenType(source) {
switch (source) {
case BOM:
return 'byte-order-mark';
case DOCUMENT:
return 'doc-mode';
case FLOW_END:
return 'flow-error-end';
case SCALAR:
return 'scalar';
case '---':
return 'doc-start';
case '...':
return 'doc-end';
case '':
case '\n':
case '\r\n':
return 'newline';
case '-':
return 'seq-item-ind';
case '?':
return 'explicit-key-ind';
case ':':
return 'map-value-ind';
case '{':
return 'flow-map-start';
case '}':
return 'flow-map-end';
case '[':
return 'flow-seq-start';
case ']':
return 'flow-seq-end';
case ',':
return 'comma';
}
switch (source[0]) {
case ' ':
case '\t':
return 'space';
case '#':
return 'comment';
case '%':
return 'directive-line';
case '*':
return 'alias';
case '&':
return 'anchor';
case '!':
return 'tag';
case "'":
return 'single-quoted-scalar';
case '"':
return 'double-quoted-scalar';
case '|':
case '>':
return 'block-scalar-header';
}
return null;
}
export { BOM, DOCUMENT, FLOW_END, SCALAR, isCollection, isScalar, prettyToken, tokenType };