import type { Reader } from "../../font/binary/reader.ts";
import type { Tag, uint16 } from "../../types.ts";
/** Language system record */
export interface LangSysRecord {
    langSysTag: Tag;
    langSys: LangSys;
}
/** Language system table */
export interface LangSys {
    /** Required feature index (0xFFFF if none) */
    requiredFeatureIndex: uint16;
    /** Feature indices */
    featureIndices: uint16[];
}
/** Script record */
export interface ScriptRecord {
    scriptTag: Tag;
    script: Script;
}
/** Script table */
export interface Script {
    /** Default language system (may be null) */
    defaultLangSys: LangSys | null;
    /** Language system records */
    langSysRecords: LangSysRecord[];
}
/** Script list table */
export interface ScriptList {
    scripts: ScriptRecord[];
}
/** Feature record */
export interface FeatureRecord {
    featureTag: Tag;
    feature: Feature;
}
/** Feature table */
export interface Feature {
    /** Feature parameters offset (usually 0) */
    featureParamsOffset: uint16;
    /** Lookup indices */
    lookupListIndices: uint16[];
}
/** Feature list table */
export interface FeatureList {
    features: FeatureRecord[];
}
/** Lookup table header */
export interface LookupHeader {
    lookupType: uint16;
    lookupFlag: uint16;
    subtableOffsets: uint16[];
    /** Mark filtering set (if UseMarkFilteringSet flag is set) */
    markFilteringSet?: uint16;
}
/** Lookup flags */
export declare const LookupFlag: {
    readonly RightToLeft: 1;
    readonly IgnoreBaseGlyphs: 2;
    readonly IgnoreLigatures: 4;
    readonly IgnoreMarks: 8;
    readonly UseMarkFilteringSet: 16;
    readonly MarkAttachmentTypeMask: 65280;
};
/** Extract mark attachment type from lookup flag */
export declare function getMarkAttachmentType(lookupFlag: uint16): number;
/** Parse ScriptList */
export declare function parseScriptList(reader: Reader): ScriptList;
/** Parse FeatureList */
export declare function parseFeatureList(reader: Reader): FeatureList;
/** Parse lookup headers (does not parse subtables) */
export declare function parseLookupHeaders(reader: Reader): LookupHeader[];
/**
 * Find script in script list by tag
 * @param scriptList - The script list to search
 * @param scriptTag - The script tag to find (e.g., 'latn', 'arab')
 * @returns The script table if found, null otherwise
 */
export declare function findScript(scriptList: ScriptList, scriptTag: Tag): Script | null;
/**
 * Find language system in script by tag
 * @param script - The script table to search
 * @param langSysTag - The language system tag to find (e.g., 'ENG', 'ARA'), or null for default
 * @returns The language system table if found, or the default language system if langSysTag is null or not found
 */
export declare function findLangSys(script: Script, langSysTag: Tag | null): LangSys | null;
/**
 * Get feature by index from feature list
 * @param featureList - The feature list to retrieve from
 * @param index - The zero-based feature index
 * @returns The feature record at the specified index, or null if index is out of bounds
 */
export declare function getFeature(featureList: FeatureList, index: number): FeatureRecord | null;