stdlib/public/core/Tuple.swift.gyb

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

// Generate comparison functions for tuples up to some reasonable arity.

% for arity in range(2,7):
%   typeParams = [chr(ord("A") + i) for i in range(arity)]
%   tupleT = "({})".format(",".join(typeParams))

%   equatableTypeParams = ", ".join(["{} : Equatable".format(c) for c in typeParams])

/// Returns `true` iff each component of `lhs` is equal to the corresponding
/// component of `rhs`.
public func == <${equatableTypeParams}>(lhs: ${tupleT}, rhs: ${tupleT}) -> Bool {
  guard lhs.0 == rhs.0 else { return false }
  /*tail*/ return (
    ${", ".join("lhs.{}".format(i) for i in range(1, arity))}
  ) == (
    ${", ".join("rhs.{}".format(i) for i in range(1, arity))}
  )
}

/// Returns `true` iff any component of `lhs` is not equal to the corresponding
/// component of `rhs`.
public func != <${equatableTypeParams}>(lhs: ${tupleT}, rhs: ${tupleT}) -> Bool {
  guard lhs.0 == rhs.0 else { return true }
  /*tail*/ return (
    ${", ".join("lhs.{}".format(i) for i in range(1, arity))}
  ) != (
    ${", ".join("rhs.{}".format(i) for i in range(1, arity))}
  )
}

%   comparableTypeParams = ", ".join(["{} : Comparable".format(c) for c in typeParams])
%   for op in ["<", ">"]:
%     for opeq in ["", "="]:
/// A [lexicographical order](https://en.wikipedia.org/wiki/Lexicographical_order)
/// over tuples of `Comparable` elements.
///
/// Given two tuples `(a1, a2, ..., aN)` and `(b1, b2, ..., bN)`, the
/// first tuple is `${op}${opeq}` the second tuple iff `a1 ${op} b1` or
/// (`a1 == b1` and `(a2, ..., aN) ${op}${opeq} (b2, ..., bN)`).
public func ${op}${opeq} <${comparableTypeParams}>(lhs: ${tupleT}, rhs: ${tupleT}) -> Bool {
  if lhs.0 != rhs.0 { return lhs.0 ${op}${opeq} rhs.0 }
  /*tail*/ return (
    ${", ".join("lhs.{}".format(i) for i in range(1, arity))}
  ) ${op}${opeq} (
    ${", ".join("rhs.{}".format(i) for i in range(1, arity))}
  )
}
%     end
%   end
% end