import { ParserError } from './error';
import { MessageFormatElement } from './types';
export interface Position {
    /** Offset in terms of UTF-16 *code unit*. */
    offset: number;
    line: number;
    /** Column offset in terms of unicode *code point*. */
    column: number;
}
export interface ParserOptions {
    /**
     * Whether to treat HTML/XML tags as string literal
     * instead of parsing them as tag token.
     * When this is false we only allow simple tags without
     * any attributes
     */
    ignoreTag?: boolean;
    /**
     * Should `select`, `selectordinal`, and `plural` arguments always include
     * the `other` case clause.
     */
    requiresOtherClause?: boolean;
    /**
     * Whether to parse number/datetime skeleton
     * into Intl.NumberFormatOptions and Intl.DateTimeFormatOptions, respectively.
     */
    shouldParseSkeletons?: boolean;
    /**
     * Capture location info in AST
     * Default is false
     */
    captureLocation?: boolean;
    /**
     * Instance of Intl.Locale to resolve locale-dependent skeleton
     */
    locale?: Intl.Locale;
}
export type Result<T, E> = {
    val: T;
    err: null;
} | {
    val: null;
    err: E;
};
export declare class Parser {
    private message;
    private position;
    private locale?;
    private ignoreTag;
    private requiresOtherClause;
    private shouldParseSkeletons?;
    constructor(message: string, options?: ParserOptions);
    parse(): Result<MessageFormatElement[], ParserError>;
    private parseMessage;
    /**
     * A tag name must start with an ASCII lower/upper case letter. The grammar is based on the
     * [custom element name][] except that a dash is NOT always mandatory and uppercase letters
     * are accepted:
     *
     * ```
     * tag ::= "<" tagName (whitespace)* "/>" | "<" tagName (whitespace)* ">" message "</" tagName (whitespace)* ">"
     * tagName ::= [a-z] (PENChar)*
     * PENChar ::=
     *     "-" | "." | [0-9] | "_" | [a-z] | [A-Z] | #xB7 | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x37D] |
     *     [#x37F-#x1FFF] | [#x200C-#x200D] | [#x203F-#x2040] | [#x2070-#x218F] | [#x2C00-#x2FEF] |
     *     [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
     * ```
     *
     * [custom element name]: https://html.spec.whatwg.org/multipage/custom-elements.html#valid-custom-element-name
     * NOTE: We're a bit more lax here since HTML technically does not allow uppercase HTML element but we do
     * since other tag-based engines like React allow it
     */
    private parseTag;
    /**
     * This method assumes that the caller has peeked ahead for the first tag character.
     */
    private parseTagName;
    private parseLiteral;
    tryParseLeftAngleBracket(): string | null;
    /**
     * Starting with ICU 4.8, an ASCII apostrophe only starts quoted text if it immediately precedes
     * a character that requires quoting (that is, "only where needed"), and works the same in
     * nested messages as on the top level of the pattern. The new behavior is otherwise compatible.
     */
    private tryParseQuote;
    private tryParseUnquoted;
    private parseArgument;
    /**
     * Advance the parser until the end of the identifier, if it is currently on
     * an identifier character. Return an empty string otherwise.
     */
    private parseIdentifierIfPossible;
    private parseArgumentOptions;
    private tryParseArgumentClose;
    /**
     * See: https://github.com/unicode-org/icu/blob/af7ed1f6d2298013dc303628438ec4abe1f16479/icu4c/source/common/messagepattern.cpp#L659
     */
    private parseSimpleArgStyleIfPossible;
    private parseNumberSkeletonFromString;
    /**
     * @param nesting_level The current nesting level of messages.
     *     This can be positive when parsing message fragment in select or plural argument options.
     * @param parent_arg_type The parent argument's type.
     * @param parsed_first_identifier If provided, this is the first identifier-like selector of
     *     the argument. It is a by-product of a previous parsing attempt.
     * @param expecting_close_tag If true, this message is directly or indirectly nested inside
     *     between a pair of opening and closing tags. The nested message will not parse beyond
     *     the closing tag boundary.
     */
    private tryParsePluralOrSelectOptions;
    private tryParseDecimalInteger;
    private offset;
    private isEOF;
    private clonePosition;
    /**
     * Return the code point at the current position of the parser.
     * Throws if the index is out of bound.
     */
    private char;
    private error;
    /** Bump the parser to the next UTF-16 code unit. */
    private bump;
    /**
     * If the substring starting at the current position of the parser has
     * the given prefix, then bump the parser to the character immediately
     * following the prefix and return true. Otherwise, don't bump the parser
     * and return false.
     */
    private bumpIf;
    /**
     * Bump the parser until the pattern character is found and return `true`.
     * Otherwise bump to the end of the file and return `false`.
     */
    private bumpUntil;
    /**
     * Bump the parser to the target offset.
     * If target offset is beyond the end of the input, bump the parser to the end of the input.
     */
    private bumpTo;
    /** advance the parser through all whitespace to the next non-whitespace code unit. */
    private bumpSpace;
    /**
     * Peek at the *next* Unicode codepoint in the input without advancing the parser.
     * If the input has been exhausted, then this returns null.
     */
    private peek;
}