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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 85d5c18c9d83a1d54eecc4c2ad4dce63194107c6 authored by R. David Murray on 03 December 2017, 23:51:41 UTC, committed by GitHub on 03 December 2017, 23:51:41 UTC 
bpo-27240 Rewrite the email header folding algorithm. (#3488)
 
The original algorithm tried to delegate the folding to the tokens so
that those tokens whose folding rules differed could specify the
differences.  However, this resulted in a lot of duplicated code because
most of the rules were the same.

The new algorithm moves all folding logic into a set of functions
external to the token classes, but puts the information about which
tokens can be folded in which ways on the tokens...with the exception of
mime-parameters, which are a special case (which was not even
implemented in the old folder).

This algorithm can still probably be improved and hopefully simplified
somewhat.

Note that some of the test expectations are changed.  I believe the
changes are toward more desirable and consistent behavior: in general
when (re) folding a line the canonical version of the tokens is
generated, rather than preserving errors or extra whitespace.
1 parent 29ba688
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Tip revision: 85d5c18c9d83a1d54eecc4c2ad4dce63194107c6 authored by R. David Murray on 03 December 2017, 23:51:41 UTC
bpo-27240 Rewrite the email header folding algorithm. (#3488)
Tip revision: 85d5c18
rotatingtree.h 
/* "Rotating trees" (Armin Rigo)
 *
 * Google "splay trees" for the general idea.
 *
 * It's a dict-like data structure that works best when accesses are not
 * random, but follow a strong pattern.  The one implemented here is for
 * access patterns where the same small set of keys is looked up over
 * and over again, and this set of keys evolves slowly over time.
 */

#include <stdlib.h>

#define EMPTY_ROTATING_TREE       ((rotating_node_t *)NULL)

typedef struct rotating_node_s rotating_node_t;
typedef int (*rotating_tree_enum_fn) (rotating_node_t *node, void *arg);

struct rotating_node_s {
    void *key;
    rotating_node_t *left;
    rotating_node_t *right;
};

void RotatingTree_Add(rotating_node_t **root, rotating_node_t *node);
rotating_node_t* RotatingTree_Get(rotating_node_t **root, void *key);
int RotatingTree_Enum(rotating_node_t *root, rotating_tree_enum_fn enumfn,
                      void *arg);
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