mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-02 08:45:54 +01:00
Dave Abrahams
29a59944fa
Replaces low-level uses of `Cons` with a first-class `Stack` data structure. Also removes an unused algorithm. Co-authored-by: Jeremy Siek <jsiek@indiana.edu> Possible next step: use `std::stack` instead.
41 lines
895 B
C++
41 lines
895 B
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#ifndef EXECUTABLE_SEMANTICS_INTERPRETER_CONS_LIST_H_
|
|
#define EXECUTABLE_SEMANTICS_INTERPRETER_CONS_LIST_H_
|
|
|
|
namespace Carbon {
|
|
|
|
template <class T>
|
|
struct Stack;
|
|
|
|
template <class T>
|
|
struct Cons {
|
|
friend struct Stack<T>;
|
|
|
|
private:
|
|
Cons(T e, Cons* n) : curr(e), next(n) {}
|
|
|
|
const T curr;
|
|
Cons* const next;
|
|
|
|
// Cons cells are part of a "persistent data structure" and are thus
|
|
// immutable.
|
|
Cons& operator=(const Cons&) = delete;
|
|
Cons& operator=(Cons&&) = delete;
|
|
};
|
|
|
|
template <class T>
|
|
auto Length(Cons<T>* ls) -> unsigned int {
|
|
if (ls) {
|
|
return 1 + Length(ls->next);
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
} // namespace Carbon
|
|
|
|
#endif // EXECUTABLE_SEMANTICS_INTERPRETER_CONS_LIST_H_
|