pythonelse.h

#ifndef OTESUNKI_PYTHONELSE_H
#define OTESUNKI_PYTHONELSE_H
  #ifdef PY_FOR
    #undef PY_FOR
  #endif
  
  #ifdef PY_WHL
    #undef PY_WHL
  #endif
  
  #ifdef __STDC__
    #ifdef __STDC_VERSION__
      #if __STDC_VERSION__ >= 199901L
        #include <setjmp.h>
        
        #define PY_WHL(...) PY_FOR(;(__VA_ARGS__);)
        #define PY_FOR(...) \
          for (int _ftv_ = 1; _ftv_; _ftv_ = 0) \
          for (jmp_buf _fbr_, _fbk_, _fct_; _ftv_; _ftv_ = 0) \
          if (setjmp(_fbk_) == 0) \
            if (setjmp(_fbr_) == 1) \
              (void) 0; \
            else \
              for(;;longjmp(_fbk_, 1)) \
                for (__VA_ARGS__) \
                  if (setjmp(_fct_) == 1) \
                    (void) 0; \
                  else \
                    for(;;longjmp(_fbr_, 1)) \
                      for(;;longjmp(_fct_, 1))
      #endif
    #endif
  #endif
  
  #ifndef PY_FOR
    #define PY_P2(foo, bar) PY_P2_(foo, bar)
    #define PY_P2_(foo, bar) foo##bar
    #define PY_WHL(cond) PY_FOR(;(cond);)
    #define PY_FOR(initcondinc) \
      if (1) \
        goto PY_P2(_fib_, __LINE__); \
      else \
        PY_P2(_fel_, __LINE__): if (0) \
          for (;;) \
            if (1) { \
              goto PY_P2(_fel_, __LINE__); \
              PY_P2(_fbr_, __LINE__): break; \
            } else \
              PY_P2(_fib_, __LINE__): \
                for (initcondinc) \
                  if (1) { \
                    goto PY_P2(_fbd_, __LINE__); \
                    PY_P2(_fct_, __LINE__): (void) 0; \
                  } else \
                    for (;;) \
                      if (1) { \
                        goto PY_P2(_fbr_, __LINE__); \
                      } else \
                        for (;;) \
                          if (1) { \
                            goto PY_P2(_fct_, __LINE__); \
                          } else \
                            PY_P2(_fbd_, __LINE__):
  #endif
  
  #ifdef macro
    #undef macro
  #endif

  #ifdef syntax_extension
    #undef syntax_extension
  #endif
  
  #define macro 1
  #define syntax_extension 2

  #ifndef include_as
    #define include_as macro
  #endif

  #if include_as == macro
    
  #else
    #ifdef for
      #undef for
    #endif
    
    #ifdef while
      #undef while
    #endif
    
    #ifdef __STDC__
      #ifdef __STDC_VERSION__
        #if __STDC_VERSION__ >= 199901L
          #define for(...) PY_FOR(__VA_ARGS__)
          #define while(...) PY_WHL(__VA_ARGS__)
        #endif
      #endif
    #endif
    
    #ifndef for
      #define for(initcondinc) PY_FOR(initcondinc)
      #define while(cond) PY_WHL(cond)
    #endif
  #endif
  
  #undef include_as
  #undef syntax_extension
  #undef macro
#endif