/**
 * Token types as they are produced by the R parser.
 * Not all of them are directly handled by the normalize step.
 * Some of them are also listed as part of the {@link OperatorDatabase}.
 *
 * @see RType
 */
export declare enum RawRType {
    /** T1 */
    NullConst = "NULL_CONST",
    /** T2 */
    NumericConst = "NUM_CONST",
    /** T3 */
    StringConst = "STR_CONST",
    /** T4 */
    EqualAssign = "EQ_ASSIGN",
    /** T5 */
    EqualFormals = "EQ_FORMALS",
    /** T6 */
    EqualSub = "EQ_SUB",
    /** T7 */
    LeftAssign = "LEFT_ASSIGN",
    /** T8 */
    RightAssign = "RIGHT_ASSIGN",
    /** T9 */
    And = "AND",
    /** T10 */
    And2 = "AND2",
    /** T11 */
    Eq = "EQ",
    /** T12 */
    Ge = "GE",
    /** T13 */
    Gt = "GT",
    /** T14 */
    Le = "LE",
    /** T15 */
    Lt = "LT",
    /** T16 */
    Ne = "NE",
    /** T17 */
    Or = "OR",
    /** T18 */
    Or2 = "OR2",
    /** T19 */
    Pipe = "PIPE",
    /** T20 */
    Pipebind = "PIPEBIND",
    /** T21 */
    Special = "SPECIAL",
    /** T22 */
    Plus = "+",
    /** T23 */
    Minus = "-",
    /** T24 */
    Times = "*",
    /** T25 */
    Div = "/",
    /** T26 */
    Colon = ":",
    /** T27 */
    Exclamation = "!",
    /** T28 */
    Exp = "^",
    /** T29 */
    Question = "?",
    /** T30 */
    Tilde = "~",
    /** T31 */
    Break = "BREAK",
    /** T32 */
    Else = "ELSE",
    /** T33 */
    For = "FOR",
    /** T34 */
    ForCondition = "forcond",
    /** T35 */
    If = "IF",
    /** T36 */
    ForIn = "IN",
    /** T37 */
    Next = "NEXT",
    /** T38 */
    Repeat = "REPEAT",
    /** T39 */
    While = "WHILE",
    /** T40 */
    Function = "FUNCTION",
    /** T41 */
    Lambda = "\\\\",
    /** T42 */
    DoubleBracketLeft = "LBB",
    /** T43 */
    Slot = "SLOT",
    /** T44 */
    Dollar = "$",
    /** T45 */
    At = "@",
    /** T46 */
    BracketLeft = "[",
    /** T47 */
    BracketRight = "]",
    /** T48 */
    NsGet = "::",
    /** T49 */
    NsGetInt = ":::",
    /** T50 */
    Symbol = "SYMBOL",
    /** T51 */
    SymbolFunctionCall = "SYMBOL_FUNCTION_CALL",
    /** T52 */
    SymbolPackage = "SYMBOL_PACKAGE",
    /** T53 */
    SymbolSub = "SYMBOL_SUB",
    /** T54 */
    SymbolFormals = "SYMBOL_FORMALS",
    /** T55 */
    Comment = "COMMENT",
    /** T56 */
    LineDirective = "LINE_DIRECTIVE",
    /** T57 */
    ParenLeft = "(",
    /** T58 */
    ParenRight = ")",
    /** T59 */
    Comma = ",",
    /** T60 */
    Semicolon = ";",
    /** T61 */
    BraceLeft = "{",
    /** T62 */
    BraceRight = "}",
    /** T63 */
    Expression = "expr",
    /** T64
     *
     * https://github.com/REditorSupport/languageserver/issues/327
     * https://github.com/REditorSupport/languageserver/pull/328
     */
    ExprOfAssignOrHelp = "expr_or_assign_or_help",
    /**
     * Pre-4.0 version of expr_or_assign_or_help, which was seemingly silently renamed here:
     * https://github.com/wch/r-source/commit/84bbf385f909c0223924c310af6c7c77aa810234
     * (Also see {@link ExprOfAssignOrHelp} documentation for more context.)
     */
    LegacyEqualAssign = "equal_assign",
    /** T65 */
    ExpressionList = "exprlist"
}
/**
 * Types as we use them for our normalized AST.
 * See {@link RNode} for a union type of all normalized AST nodes in-use.
 * For each enum member, the respective normalized AST node should be referenced
 * in the corresponding comment.
 *
 * @see RawRType
 */
export declare enum RType {
    /** {@link RAccess} */
    Access = "RAccess",
    /** {@link RArgument} */
    Argument = "RArgument",
    /** {@link RBinaryOp} */
    BinaryOp = "RBinaryOp",
    /** {@link RExpressionList} */
    ExpressionList = "RExpressionList",
    /** {@link RForLoop} */
    ForLoop = "RForLoop",
    /** {@link RFunctionCall} */
    FunctionCall = "RFunctionCall",
    /** {@link RFunctionDefinition} */
    FunctionDefinition = "RFunctionDefinition",
    /** {@link RIfThenElse} */
    IfThenElse = "RIfThenElse",
    /** {@link RParameter} */
    Parameter = "RParameter",
    /** {@link RPipe} */
    Pipe = "RPipe",
    /** {@link RRepeatLoop} */
    RepeatLoop = "RRepeatLoop",
    /** {@link RUnaryOp} */
    UnaryOp = "RUnaryOp",
    /** {@link RWhileLoop} */
    WhileLoop = "RWhileLoop",
    /** {@link RBreak} */
    Break = "RBreak",
    /** {@link RComment} */
    Comment = "RComment",
    /** {@link RLineDirective} */
    LineDirective = "RLineDirective",
    /** {@link RLogical} */
    Logical = "RLogical",
    /** {@link RNext} */
    Next = "RNext",
    /** {@link RNumber} */
    Number = "RNumber",
    /** {@link RString} */
    String = "RString",
    /** {@link RSymbol} */
    Symbol = "RSymbol",
    /** {@link RDelimiter}.
     * Is not part of the normalized AST but can be found in
     * {@link Source#additionalTokens}.
     */
    Delimiter = "RDelimiter"
}
export declare const ValidRTypes: Set<string>;
export declare const ValidRTypesReverse: {
    [k: string]: string;
};
/**
 * Validates, whether the given type can be used as a symbol in R
 *
 * @see RawRType
 */
export declare function isSymbol(type: string): boolean;