RString Struct Reference

Ruby's String. More...

#include <rstring.h>

Data Fields
struct RBasic	basic
	Basic part, including flags and class.
long	len
	Length of the string, not including terminating NUL character.
union {
struct {
char *   ptr
	Pointer to the contents of the string. More...
union {
long   capa
	Capacity of *ptr. More...
VALUE   shared
	Parent of the string. More...
}   aux
	Auxiliary info. More...
}   heap
	Strings that use separated memory region for contents use this pattern. More...
struct {
char   ary [1]
}   embed
	Embedded contents. More...
}	as
	String's specific fields.

Detailed Description

Ruby's String.

A string in ruby conceptually has these information:

• Encoding of the string.
• Length of the string.
• Contents of the string.

It is worth noting that a string is not an array of characters in ruby. It has never been. In 1.x a string was an array of integers. Since 2.x a string is no longer an array of anything. A string is a string – just like a Time is not an integer.

Definition at line 196 of file rstring.h.

Field Documentation

ary

char RString::ary[1]

Definition at line 251 of file rstring.h.

[union]

union { ... } RString::as

String's specific fields.

Referenced by rb_str_resize().

[union]

union { ... } RString::aux

Auxiliary info.

basic

struct RBasic RString::basic

Basic part, including flags and class.

Definition at line 199 of file rstring.h.

capa

long RString::capa

Capacity of *ptr.

A continuous memory region of at least capa bytes is expected to exist at *ptr. This can be bigger than len.

Definition at line 232 of file rstring.h.

[struct]

struct { ... } RString::embed

Embedded contents.

[struct]

struct { ... } RString::heap

Strings that use separated memory region for contents use this pattern.

len

long RString::len

Length of the string, not including terminating NUL character.

Note

This is in bytes.

Definition at line 206 of file rstring.h.

ptr

char* RString::ptr

Pointer to the contents of the string.

In the old days each string had dedicated memory regions. That is no longer true today, but there still are strings of such properties. This field could be used to point such things.

Definition at line 222 of file rstring.h.

Referenced by rb_check_id_cstr(), rb_check_symbol_cstr(), rb_enc_interned_str(), rb_enc_interned_str_cstr(), rb_enc_str_buf_cat(), rb_enc_str_new(), rb_enc_str_new_cstr(), rb_enc_str_new_static(), rb_external_str_new(), rb_external_str_new_cstr(), rb_external_str_new_with_enc(), rb_filesystem_str_new(), rb_filesystem_str_new_cstr(), rb_interned_str(), rb_interned_str_cstr(), rb_locale_str_new(), rb_locale_str_new_cstr(), rb_str_buf_cat_ascii(), rb_str_buf_new_cstr(), rb_str_cat(), rb_str_cat_cstr(), rb_str_conv_enc_opts(), rb_str_new(), rb_str_new_cstr(), rb_str_new_static(), rb_str_new_with_class(), rb_str_resize(), rb_string_value(), rb_string_value_cstr(), rb_string_value_ptr(), rb_usascii_str_new(), rb_usascii_str_new_cstr(), rb_usascii_str_new_static(), rb_utf8_str_new(), rb_utf8_str_new_cstr(), and rb_utf8_str_new_static().

shared

VALUE RString::shared

Parent of the string.

Nowadays strings can share their contents each other, constructing gigantic nest of objects. This situation is called "shared", and this is the field to control such properties.

Definition at line 240 of file rstring.h.

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The documentation for this struct was generated from the following file:

• include/ruby/internal/core/rstring.h (61f34568037f0948491bf8bf2b00c6c39ee3537b)