ハッシュのデータ構造

id:shckorさんコメント消しちゃってスミマセン！
ハッシュキーは「数値」だ。Perlのソースが手元にあったのでハッシュのデータ構造を見てみたらハッシュキーは32bit unsigned int valueだそうだ。

/* typedefs to eliminate some typing */

typedef struct he HE;

typedef struct hek HEK;
/* entry in hash value chain */

struct he {

    HE		*hent_next;	/* next entry in chain */

    HEK		*hent_hek;	/* hash key */

    SV		*hent_val;	/* scalar value that was hashed */

};
/* hash key -- defined separately for use as shared pointer */

struct hek {

    U32		hek_hash;	/* hash of key */

    I32		hek_len;	/* length of hash key */

    char	hek_key[1];	/* variable-length hash key */

};
/* hash structure: */

/* This structure must match the beginning of struct xpvmg in sv.h. */

struct xpvhv {

    char *	xhv_array;	/* pointer to malloced string */

    STRLEN	xhv_fill;	/* how full xhv_array currently is */

    STRLEN	xhv_max;	/* subscript of last element of xhv_array */

    IV		xhv_keys;	/* how many elements in the array */

    NV		xnv_nv;		/* numeric value, if any */

    MAGIC*	xmg_magic;	/* magic for scalar array */

    HV*		xmg_stash;	/* class package */
    I32		xhv_riter;	/* current root of iterator */

    HE		*xhv_eiter;	/* current entry of iterator */

    PMOP	*xhv_pmroot;	/* list of pm's for this package */

    char	*xhv_name;	/* name, if a symbol table */

};