enum TokenOffset [src]

A relative token index.

Fields

zero = 0

Members

init (Function)
toAbsolute (Function)
toOptional (Function)

Source

  pub const TokenOffset = enum(i32) {
    zero = 0,
    _,

    pub fn init(base: TokenIndex, destination: TokenIndex) TokenOffset {
        const base_i64: i64 = base;
        const destination_i64: i64 = destination;
        return @enumFromInt(destination_i64 - base_i64);
    }

    pub fn toOptional(to: TokenOffset) OptionalTokenOffset {
        const result: OptionalTokenOffset = @enumFromInt(@intFromEnum(to));
        assert(result != .none);
        return result;
    }

    pub fn toAbsolute(offset: TokenOffset, base: TokenIndex) TokenIndex {
        return @intCast(@as(i64, base) + @intFromEnum(offset));
    }
}  