Class MacroExpander

src/MacroExpander.ts:29–467

};

export default class MacroExpander implements MacroContextInterface {
    settings: Settings;
    expansionCount: number;
    lexer!: Lexer;
    macros: Namespace<MacroDefinition>;
    stack: Token[];
    mode: Mode;

    constructor(input: string, settings: Settings, mode: Mode) {
        this.settings = settings;
        this.expansionCount = 0;
        this.feed(input);
        // Make new global namespace
        this.macros = new Namespace(macros, settings.macros);
        this.mode = mode;
        this.stack = []; // contains tokens in REVERSE order
    }

    /**
     * Feed a new input string to the same MacroExpander
     * (with existing macros etc.).
     */
    feed(input: string) {
        this.lexer = new Lexer(input, this.settings);
    }

    /**
     * Switches between "text" and "math" modes.
     */
    switchMode(newMode: Mode) {
        this.mode = newMode;
    }

    /**
     * Start a new group nesting within all namespaces.
     */
    beginGroup() {
        this.macros.beginGroup();
    }

    /**
     * End current group nesting within all namespaces.
     */
    endGroup() {
        this.macros.endGroup();
    }

    /**
     * Ends all currently nested groups (if any), restoring values before the
     * groups began.  Useful in case of an error in the middle of parsing.
     */
    endGroups() {
        this.macros.endGroups();
    }

    /**
     * Returns the topmost token on the stack, without expanding it.
     * Similar in behavior to TeX's `\futurelet`.