Class: Encoding::Converter

Inherits:
Data show all
Defined in:
transcode.c

Constant Summary collapse

INVALID_MASK =

Mask for invalid byte sequences

INT2FIX(ECONV_INVALID_MASK)
INVALID_REPLACE =

Replace invalid byte sequences

INT2FIX(ECONV_INVALID_REPLACE)
UNDEF_MASK =

Mask for a valid character in the source encoding but no related character(s) in destination encoding.

INT2FIX(ECONV_UNDEF_MASK)
UNDEF_REPLACE =

Replace byte sequences that are undefined in the destination encoding.

INT2FIX(ECONV_UNDEF_REPLACE)
UNDEF_HEX_CHARREF =

Replace byte sequences that are undefined in the destination encoding with an XML hexadecimal character reference. This is valid for XML conversion.

INT2FIX(ECONV_UNDEF_HEX_CHARREF)
PARTIAL_INPUT =

Indicates the source may be part of a larger string. See primitive_convert for an example.

INT2FIX(ECONV_PARTIAL_INPUT)
AFTER_OUTPUT =

Stop converting after some output is complete but before all of the input was consumed. See primitive_convert for an example.

INT2FIX(ECONV_AFTER_OUTPUT)
UNIVERSAL_NEWLINE_DECORATOR =

Decorator for converting CRLF and CR to LF

INT2FIX(ECONV_UNIVERSAL_NEWLINE_DECORATOR)
CRLF_NEWLINE_DECORATOR =

Decorator for converting LF to CRLF

INT2FIX(ECONV_CRLF_NEWLINE_DECORATOR)
CR_NEWLINE_DECORATOR =

Decorator for converting LF to CR

INT2FIX(ECONV_CR_NEWLINE_DECORATOR)
XML_TEXT_DECORATOR =

Escape as XML CharData

INT2FIX(ECONV_XML_TEXT_DECORATOR)
XML_ATTR_CONTENT_DECORATOR =

Escape as XML AttValue

INT2FIX(ECONV_XML_ATTR_CONTENT_DECORATOR)
XML_ATTR_QUOTE_DECORATOR =

Escape as XML AttValue

INT2FIX(ECONV_XML_ATTR_QUOTE_DECORATOR)

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#Encoding::Converter.new(source_encoding, destination_encoding) ⇒ Object #Encoding::Converter.new(source_encoding, destination_encoding, opt) ⇒ Object #Encoding::Converter.new(convpath) ⇒ Object

possible options elements:

hash form:
  :invalid => nil            # raise error on invalid byte sequence (default)
  :invalid => :replace       # replace invalid byte sequence
  :undef => nil              # raise error on undefined conversion (default)
  :undef => :replace         # replace undefined conversion
  :replace => string         # replacement string ("?" or "\uFFFD" if not specified)
  :newline => :universal     # decorator for converting CRLF and CR to LF
  :newline => :crlf          # decorator for converting LF to CRLF
  :newline => :cr            # decorator for converting LF to CR
  :universal_newline => true # decorator for converting CRLF and CR to LF
  :crlf_newline => true      # decorator for converting LF to CRLF
  :cr_newline => true        # decorator for converting LF to CR
  :xml => :text              # escape as XML CharData.
  :xml => :attr              # escape as XML AttValue
integer form:
  Encoding::Converter::INVALID_REPLACE
  Encoding::Converter::UNDEF_REPLACE
  Encoding::Converter::UNDEF_HEX_CHARREF
  Encoding::Converter::UNIVERSAL_NEWLINE_DECORATOR
  Encoding::Converter::CRLF_NEWLINE_DECORATOR
  Encoding::Converter::CR_NEWLINE_DECORATOR
  Encoding::Converter::XML_TEXT_DECORATOR
  Encoding::Converter::XML_ATTR_CONTENT_DECORATOR
  Encoding::Converter::XML_ATTR_QUOTE_DECORATOR

Encoding::Converter.new creates an instance of Encoding::Converter.

Source_encoding and destination_encoding should be a string or Encoding object.

opt should be nil, a hash or an integer.

convpath should be an array. convpath may contain

  • two-element arrays which contain encodings or encoding names, or

  • strings representing decorator names.

Encoding::Converter.new optionally takes an option. The option should be a hash or an integer. The option hash can contain :invalid => nil, etc. The option integer should be logical-or of constants such as Encoding::Converter::INVALID_REPLACE, etc.

:invalid => nil

Raise error on invalid byte sequence. This is a default behavior.

:invalid => :replace

Replace invalid byte sequence by replacement string.

:undef => nil

Raise an error if a character in source_encoding is not defined in destination_encoding. This is a default behavior.

:undef => :replace

Replace undefined character in destination_encoding with replacement string.

:replace => string

Specify the replacement string. If not specified, "uFFFD" is used for Unicode encodings and "?" for others.

:universal_newline => true

Convert CRLF and CR to LF.

:crlf_newline => true

Convert LF to CRLF.

:cr_newline => true

Convert LF to CR.

:xml => :text

Escape as XML CharData. This form can be used as a HTML 4.0 #PCDATA.

  • '&' -> '&'

  • '<' -> '&lt;'

  • '>' -> '&gt;'

  • undefined characters in destination_encoding -> hexadecimal CharRef such as &#xHH;

:xml => :attr

Escape as XML AttValue. The converted result is quoted as "...". This form can be used as a HTML 4.0 attribute value.

  • '&' -> '&amp;'

  • '<' -> '&lt;'

  • '>' -> '&gt;'

  • '"' -> '&quot;'

  • undefined characters in destination_encoding -> hexadecimal CharRef such as &#xHH;

Examples:

# UTF-16BE to UTF-8
ec = Encoding::Converter.new("UTF-16BE", "UTF-8")

# Usually, decorators such as newline conversion are inserted last.
ec = Encoding::Converter.new("UTF-16BE", "UTF-8", :universal_newline => true)
p ec.convpath #=> [[#<Encoding:UTF-16BE>, #<Encoding:UTF-8>],
              #    "universal_newline"]

# But, if the last encoding is ASCII incompatible,
# decorators are inserted before the last conversion.
ec = Encoding::Converter.new("UTF-8", "UTF-16BE", :crlf_newline => true)
p ec.convpath #=> ["crlf_newline",
              #    [#<Encoding:UTF-8>, #<Encoding:UTF-16BE>]]

# Conversion path can be specified directly.
ec = Encoding::Converter.new(["universal_newline", ["EUC-JP", "UTF-8"], ["UTF-8", "UTF-16BE"]])
p ec.convpath #=> ["universal_newline",
              #    [#<Encoding:EUC-JP>, #<Encoding:UTF-8>],
              #    [#<Encoding:UTF-8>, #<Encoding:UTF-16BE>]]

3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
# File 'transcode.c', line 3353

static VALUE
econv_init(int argc, VALUE *argv, VALUE self)
{
    VALUE ecopts;
    volatile VALUE snamev, dnamev;
    const char *sname, *dname;
    rb_encoding *senc, *denc;
    rb_econv_t *ec;
    int ecflags;
    VALUE convpath;

    if (rb_check_typeddata(self, &econv_data_type)) {
        rb_raise(rb_eTypeError, "already initialized");
    }

    if (argc == 1 && !NIL_P(convpath = rb_check_array_type(argv[0]))) {
        ec = rb_econv_init_by_convpath(self, convpath, &sname, &dname, &senc, &denc);
        ecflags = 0;
        ecopts = Qnil;
    }
    else {
        econv_args(argc, argv, &snamev, &dnamev, &sname, &dname, &senc, &denc, &ecflags, &ecopts);
        ec = rb_econv_open_opts(sname, dname, ecflags, ecopts);
    }

    if (!ec) {
        rb_exc_raise(rb_econv_open_exc(sname, dname, ecflags));
    }

    if (!DECORATOR_P(sname, dname)) {
        if (!senc)
            senc = make_dummy_encoding(sname);
        if (!denc)
            denc = make_dummy_encoding(dname);
    }

    ec->source_encoding = senc;
    ec->destination_encoding = denc;

    DATA_PTR(self) = ec;

    return self;
}

Class Method Details

.Encoding::Converter.asciicompat_encoding(string) ⇒ Encoding? .Encoding::Converter.asciicompat_encoding(encoding) ⇒ Encoding?

Returns the corresponding ASCII compatible encoding.

Returns nil if the argument is an ASCII compatible encoding.

"corresponding ASCII compatible encoding" is an ASCII compatible encoding which can represents exactly the same characters as the given ASCII incompatible encoding. So, no conversion undefined error occurs when converting between the two encodings.

Encoding::Converter.asciicompat_encoding("ISO-2022-JP") #=> #<Encoding:stateless-ISO-2022-JP>
Encoding::Converter.asciicompat_encoding("UTF-16BE") #=> #<Encoding:UTF-8>
Encoding::Converter.asciicompat_encoding("UTF-8") #=> nil

Overloads:

  • .Encoding::Converter.asciicompat_encoding(string) ⇒ Encoding?

    Returns:

  • .Encoding::Converter.asciicompat_encoding(encoding) ⇒ Encoding?

    Returns:


2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
# File 'transcode.c', line 2959

static VALUE
econv_s_asciicompat_encoding(VALUE klass, VALUE arg)
{
    const char *arg_name, *result_name;
    rb_encoding *arg_enc, *result_enc;

    enc_arg(&arg, &arg_name, &arg_enc);

    result_name = rb_econv_asciicompat_encoding(arg_name);

    if (result_name == NULL)
        return Qnil;

    result_enc = make_encoding(result_name);

    return rb_enc_from_encoding(result_enc);
}

.Encoding::Converter.search_convpath(source_encoding, destination_encoding) ⇒ Object .Encoding::Converter.search_convpath(source_encoding, destination_encoding, opt) ⇒ Object

Returns a conversion path.

p Encoding::Converter.search_convpath("ISO-8859-1", "EUC-JP")
#=> [[#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>],
#    [#<Encoding:UTF-8>, #<Encoding:EUC-JP>]]

p Encoding::Converter.search_convpath("ISO-8859-1", "EUC-JP", universal_newline: true)
or
p Encoding::Converter.search_convpath("ISO-8859-1", "EUC-JP", newline: :universal)
#=> [[#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>],
#    [#<Encoding:UTF-8>, #<Encoding:EUC-JP>],
#    "universal_newline"]

p Encoding::Converter.search_convpath("ISO-8859-1", "UTF-32BE", universal_newline: true)
or
p Encoding::Converter.search_convpath("ISO-8859-1", "UTF-32BE", newline: :universal)
#=> [[#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>],
#    "universal_newline",
#    [#<Encoding:UTF-8>, #<Encoding:UTF-32BE>]]

3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
# File 'transcode.c', line 3120

static VALUE
econv_s_search_convpath(int argc, VALUE *argv, VALUE klass)
{
    volatile VALUE snamev, dnamev;
    const char *sname, *dname;
    rb_encoding *senc, *denc;
    int ecflags;
    VALUE ecopts;
    VALUE convpath;

    econv_args(argc, argv, &snamev, &dnamev, &sname, &dname, &senc, &denc, &ecflags, &ecopts);

    convpath = Qnil;
    transcode_search_path(sname, dname, search_convpath_i, &convpath);

    if (NIL_P(convpath))
        rb_exc_raise(rb_econv_open_exc(sname, dname, ecflags));

    if (decorate_convpath(convpath, ecflags) == -1)
        rb_exc_raise(rb_econv_open_exc(sname, dname, ecflags));

    return convpath;
}

Instance Method Details

#==(other) ⇒ Boolean

Returns:

  • (Boolean)

3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
# File 'transcode.c', line 3515

static VALUE
econv_equal(VALUE self, VALUE other)
{
    rb_econv_t *ec1 = check_econv(self);
    rb_econv_t *ec2;
    int i;

    if (!rb_typeddata_is_kind_of(other, &econv_data_type)) {
	return Qnil;
    }
    ec2 = DATA_PTR(other);
    if (!ec2) return Qfalse;
    if (ec1->source_encoding_name != ec2->source_encoding_name &&
	strcmp(ec1->source_encoding_name, ec2->source_encoding_name))
	return Qfalse;
    if (ec1->destination_encoding_name != ec2->destination_encoding_name &&
	strcmp(ec1->destination_encoding_name, ec2->destination_encoding_name))
	return Qfalse;
    if (ec1->flags != ec2->flags) return Qfalse;
    if (ec1->replacement_enc != ec2->replacement_enc &&
	strcmp(ec1->replacement_enc, ec2->replacement_enc))
	return Qfalse;
    if (ec1->replacement_len != ec2->replacement_len) return Qfalse;
    if (ec1->replacement_str != ec2->replacement_str &&
	memcmp(ec1->replacement_str, ec2->replacement_str, ec2->replacement_len))
	return Qfalse;

    if (ec1->num_trans != ec2->num_trans) return Qfalse;
    for (i = 0; i < ec1->num_trans; i++) {
        if (ec1->elems[i].tc->transcoder != ec2->elems[i].tc->transcoder)
	    return Qfalse;
    }
    return Qtrue;
}

#convert(source_string) ⇒ Object

Convert source_string and return destination_string.

source_string is assumed as a part of source. i.e. :partial_input=>true is specified internally. finish method should be used last.

ec = Encoding::Converter.new("utf-8", "euc-jp")
puts ec.convert("\u3042").dump     #=> "\xA4\xA2"
puts ec.finish.dump                #=> ""

ec = Encoding::Converter.new("euc-jp", "utf-8")
puts ec.convert("\xA4").dump       #=> ""
puts ec.convert("\xA2").dump       #=> "\xE3\x81\x82"
puts ec.finish.dump                #=> ""

ec = Encoding::Converter.new("utf-8", "iso-2022-jp")
puts ec.convert("\xE3").dump       #=> "".force_encoding("ISO-2022-JP")
puts ec.convert("\x81").dump       #=> "".force_encoding("ISO-2022-JP")
puts ec.convert("\x82").dump       #=> "\e$B$\"".force_encoding("ISO-2022-JP")
puts ec.finish.dump                #=> "\e(B".force_encoding("ISO-2022-JP")

If a conversion error occur, Encoding::UndefinedConversionError or Encoding::InvalidByteSequenceError is raised. Encoding::Converter#convert doesn't supply methods to recover or restart from these exceptions. When you want to handle these conversion errors, use Encoding::Converter#primitive_convert.


3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
# File 'transcode.c', line 3803

static VALUE
econv_convert(VALUE self, VALUE source_string)
{
    VALUE ret, dst;
    VALUE av[5];
    int ac;
    rb_econv_t *ec = check_econv(self);

    StringValue(source_string);

    dst = rb_str_new(NULL, 0);

    av[0] = rb_str_dup(source_string);
    av[1] = dst;
    av[2] = Qnil;
    av[3] = Qnil;
    av[4] = INT2NUM(ECONV_PARTIAL_INPUT);
    ac = 5;

    ret = econv_primitive_convert(ac, av, self);

    if (ret == sym_invalid_byte_sequence ||
        ret == sym_undefined_conversion ||
        ret == sym_incomplete_input) {
        VALUE exc = make_econv_exception(ec);
        rb_exc_raise(exc);
    }

    if (ret == sym_finished) {
        rb_raise(rb_eArgError, "converter already finished");
    }

    if (ret != sym_source_buffer_empty) {
        rb_bug("unexpected result of econv_primitive_convert");
    }

    return dst;
}

#convpathObject

Returns the conversion path of ec.

The result is an array of conversions.

ec = Encoding::Converter.new("ISO-8859-1", "EUC-JP", crlf_newline: true)
p ec.convpath
#=> [[#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>],
#    [#<Encoding:UTF-8>, #<Encoding:EUC-JP>],
#    "crlf_newline"]

Each element of the array is a pair of encodings or a string. A pair means an encoding conversion. A string means a decorator.

In the above example, [#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>] means a converter from ISO-8859-1 to UTF-8. "crlf_newline" means newline converter from LF to CRLF.


3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
# File 'transcode.c', line 3491

static VALUE
econv_convpath(VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    VALUE result;
    int i;

    result = rb_ary_new();
    for (i = 0; i < ec->num_trans; i++) {
        const rb_transcoder *tr = ec->elems[i].tc->transcoder;
        VALUE v;
        if (DECORATOR_P(tr->src_encoding, tr->dst_encoding))
            v = rb_str_new_cstr(tr->dst_encoding);
        else
            v = rb_assoc_new(make_encobj(tr->src_encoding), make_encobj(tr->dst_encoding));
        rb_ary_push(result, v);
    }
    return result;
}

#destination_encodingEncoding

Returns the destination encoding as an Encoding object.

Returns:


3460
3461
3462
3463
3464
3465
3466
3467
# File 'transcode.c', line 3460

static VALUE
econv_destination_encoding(VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    if (!ec->destination_encoding)
        return Qnil;
    return rb_enc_from_encoding(ec->destination_encoding);
}

#finishString

Finishes the converter. It returns the last part of the converted string.

ec = Encoding::Converter.new("utf-8", "iso-2022-jp")
p ec.convert("\u3042")     #=> "\e$B$\""
p ec.finish                #=> "\e(B"

Returns:


3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
# File 'transcode.c', line 3853

static VALUE
econv_finish(VALUE self)
{
    VALUE ret, dst;
    VALUE av[5];
    int ac;
    rb_econv_t *ec = check_econv(self);

    dst = rb_str_new(NULL, 0);

    av[0] = Qnil;
    av[1] = dst;
    av[2] = Qnil;
    av[3] = Qnil;
    av[4] = INT2NUM(0);
    ac = 5;

    ret = econv_primitive_convert(ac, av, self);

    if (ret == sym_invalid_byte_sequence ||
        ret == sym_undefined_conversion ||
        ret == sym_incomplete_input) {
        VALUE exc = make_econv_exception(ec);
        rb_exc_raise(exc);
    }

    if (ret != sym_finished) {
        rb_bug("unexpected result of econv_primitive_convert");
    }

    return dst;
}

#insert_output(string) ⇒ nil

Inserts string into the encoding converter. The string will be converted to the destination encoding and output on later conversions.

If the destination encoding is stateful, string is converted according to the state and the state is updated.

This method should be used only when a conversion error occurs.

ec = Encoding::Converter.new("utf-8", "iso-8859-1")
src = "HIRAGANA LETTER A is \u{3042}."
dst = ""
p ec.primitive_convert(src, dst)    #=> :undefined_conversion
puts "[#{dst.dump}, #{src.dump}]"   #=> ["HIRAGANA LETTER A is ", "."]
ec.insert_output("<err>")
p ec.primitive_convert(src, dst)    #=> :finished
puts "[#{dst.dump}, #{src.dump}]"   #=> ["HIRAGANA LETTER A is <err>.", ""]

ec = Encoding::Converter.new("utf-8", "iso-2022-jp")
src = "\u{306F 3041 3068 2661 3002}" # U+2661 is not representable in iso-2022-jp
dst = ""
p ec.primitive_convert(src, dst)    #=> :undefined_conversion
puts "[#{dst.dump}, #{src.dump}]"   #=> ["\e$B$O$!$H".force_encoding("ISO-2022-JP"), "\xE3\x80\x82"]
ec.insert_output "?"                # state change required to output "?".
p ec.primitive_convert(src, dst)    #=> :finished
puts "[#{dst.dump}, #{src.dump}]"   #=> ["\e$B$O$!$H\e(B?\e$B!#\e(B".force_encoding("ISO-2022-JP"), ""]

Returns:

  • (nil)

4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
# File 'transcode.c', line 4019

static VALUE
econv_insert_output(VALUE self, VALUE string)
{
    const char *insert_enc;

    int ret;

    rb_econv_t *ec = check_econv(self);

    StringValue(string);
    insert_enc = rb_econv_encoding_to_insert_output(ec);
    string = rb_str_encode(string, rb_enc_from_encoding(rb_enc_find(insert_enc)), 0, Qnil);

    ret = rb_econv_insert_output(ec, (const unsigned char *)RSTRING_PTR(string), RSTRING_LEN(string), insert_enc);
    if (ret == -1) {
	rb_raise(rb_eArgError, "too big string");
    }

    return Qnil;
}

#inspectString

Returns a printable version of ec

ec = Encoding::Converter.new("iso-8859-1", "utf-8")
puts ec.inspect    #=> #<Encoding::Converter: ISO-8859-1 to UTF-8>

Returns:


3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
# File 'transcode.c', line 3407

static VALUE
econv_inspect(VALUE self)
{
    const char *cname = rb_obj_classname(self);
    rb_econv_t *ec;

    TypedData_Get_Struct(self, rb_econv_t, &econv_data_type, ec);
    if (!ec)
        return rb_sprintf("#<%s: uninitialized>", cname);
    else {
        const char *sname = ec->source_encoding_name;
        const char *dname = ec->destination_encoding_name;
        VALUE str;
        str = rb_sprintf("#<%s: ", cname);
        econv_description(sname, dname, ec->flags, str);
        rb_str_cat2(str, ">");
        return str;
    }
}

#last_errorException?

Returns an exception object for the last conversion. Returns nil if the last conversion did not produce an error.

"error" means that Encoding::InvalidByteSequenceError and Encoding::UndefinedConversionError for Encoding::Converter#convert and :invalid_byte_sequence, :incomplete_input and :undefined_conversion for Encoding::Converter#primitive_convert.

ec = Encoding::Converter.new("utf-8", "iso-8859-1")
p ec.primitive_convert(src="\xf1abcd", dst="")       #=> :invalid_byte_sequence
p ec.last_error      #=> #<Encoding::InvalidByteSequenceError: "\xF1" followed by "a" on UTF-8>
p ec.primitive_convert(src, dst, nil, 1)             #=> :destination_buffer_full
p ec.last_error      #=> nil

Returns:


4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
# File 'transcode.c', line 4113

static VALUE
econv_last_error(VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    VALUE exc;

    exc = make_econv_exception(ec);
    if (NIL_P(exc))
        return Qnil;
    return exc;
}

#primitive_convert(source_buffer, destination_buffer) ⇒ Object #primitive_convert(source_buffer, destination_buffer, destination_byteoffset) ⇒ Object #primitive_convert(source_buffer, destination_buffer, destination_byteoffset, destination_bytesize) ⇒ Object #primitive_convert(source_buffer, destination_buffer, destination_byteoffset, destination_bytesize, opt) ⇒ Object

possible opt elements:

hash form:
  :partial_input => true           # source buffer may be part of larger source
  :after_output => true            # stop conversion after output before input
integer form:
  Encoding::Converter::PARTIAL_INPUT
  Encoding::Converter::AFTER_OUTPUT

possible results:

:invalid_byte_sequence
:incomplete_input
:undefined_conversion
:after_output
:destination_buffer_full
:source_buffer_empty
:finished

primitive_convert converts source_buffer into destination_buffer.

source_buffer should be a string or nil. nil means an empty string.

destination_buffer should be a string.

destination_byteoffset should be an integer or nil. nil means the end of destination_buffer. If it is omitted, nil is assumed.

destination_bytesize should be an integer or nil. nil means unlimited. If it is omitted, nil is assumed.

opt should be nil, a hash or an integer. nil means no flags. If it is omitted, nil is assumed.

primitive_convert converts the content of source_buffer from beginning and store the result into destination_buffer.

destination_byteoffset and destination_bytesize specify the region which the converted result is stored. destination_byteoffset specifies the start position in destination_buffer in bytes. If destination_byteoffset is nil, destination_buffer.bytesize is used for appending the result. destination_bytesize specifies maximum number of bytes. If destination_bytesize is nil, destination size is unlimited. After conversion, destination_buffer is resized to destination_byteoffset + actually produced number of bytes. Also destination_buffer's encoding is set to destination_encoding.

primitive_convert drops the converted part of source_buffer. the dropped part is converted in destination_buffer or buffered in Encoding::Converter object.

primitive_convert stops conversion when one of following condition met.

  • invalid byte sequence found in source buffer (:invalid_byte_sequence) primitive_errinfo and last_error methods returns the detail of the error.

  • unexpected end of source buffer (:incomplete_input) this occur only when :partial_input is not specified. primitive_errinfo and last_error methods returns the detail of the error.

  • character not representable in output encoding (:undefined_conversion) primitive_errinfo and last_error methods returns the detail of the error.

  • after some output is generated, before input is done (:after_output) this occur only when :after_output is specified.

  • destination buffer is full (:destination_buffer_full) this occur only when destination_bytesize is non-nil.

  • source buffer is empty (:source_buffer_empty) this occur only when :partial_input is specified.

  • conversion is finished (:finished)

example:

ec = Encoding::Converter.new("UTF-8", "UTF-16BE")
ret = ec.primitive_convert(src="pi", dst="", nil, 100)
p [ret, src, dst] #=> [:finished, "", "\x00p\x00i"]

ec = Encoding::Converter.new("UTF-8", "UTF-16BE")
ret = ec.primitive_convert(src="pi", dst="", nil, 1)
p [ret, src, dst] #=> [:destination_buffer_full, "i", "\x00"]
ret = ec.primitive_convert(src, dst="", nil, 1)
p [ret, src, dst] #=> [:destination_buffer_full, "", "p"]
ret = ec.primitive_convert(src, dst="", nil, 1)
p [ret, src, dst] #=> [:destination_buffer_full, "", "\x00"]
ret = ec.primitive_convert(src, dst="", nil, 1)
p [ret, src, dst] #=> [:finished, "", "i"]

3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
# File 'transcode.c', line 3659

static VALUE
econv_primitive_convert(int argc, VALUE *argv, VALUE self)
{
    VALUE input, output, output_byteoffset_v, output_bytesize_v, opt, flags_v;
    rb_econv_t *ec = check_econv(self);
    rb_econv_result_t res;
    const unsigned char *ip, *is;
    unsigned char *op, *os;
    long output_byteoffset, output_bytesize;
    unsigned long output_byteend;
    int flags;

    argc = rb_scan_args(argc, argv, "23:", &input, &output, &output_byteoffset_v, &output_bytesize_v, &flags_v, &opt);

    if (NIL_P(output_byteoffset_v))
        output_byteoffset = 0; /* dummy */
    else
        output_byteoffset = NUM2LONG(output_byteoffset_v);

    if (NIL_P(output_bytesize_v))
        output_bytesize = 0; /* dummy */
    else
        output_bytesize = NUM2LONG(output_bytesize_v);

    if (!NIL_P(flags_v)) {
	if (!NIL_P(opt)) {
	    rb_error_arity(argc + 1, 2, 5);
	}
	flags = NUM2INT(rb_to_int(flags_v));
    }
    else if (!NIL_P(opt)) {
        VALUE v;
        flags = 0;
        v = rb_hash_aref(opt, sym_partial_input);
        if (RTEST(v))
            flags |= ECONV_PARTIAL_INPUT;
        v = rb_hash_aref(opt, sym_after_output);
        if (RTEST(v))
            flags |= ECONV_AFTER_OUTPUT;
    }
    else {
        flags = 0;
    }

    StringValue(output);
    if (!NIL_P(input))
        StringValue(input);
    rb_str_modify(output);

    if (NIL_P(output_bytesize_v)) {
        output_bytesize = RSTRING_EMBED_LEN_MAX;
        if (!NIL_P(input) && output_bytesize < RSTRING_LEN(input))
            output_bytesize = RSTRING_LEN(input);
    }

  retry:

    if (NIL_P(output_byteoffset_v))
        output_byteoffset = RSTRING_LEN(output);

    if (output_byteoffset < 0)
        rb_raise(rb_eArgError, "negative output_byteoffset");

    if (RSTRING_LEN(output) < output_byteoffset)
        rb_raise(rb_eArgError, "output_byteoffset too big");

    if (output_bytesize < 0)
        rb_raise(rb_eArgError, "negative output_bytesize");

    output_byteend = (unsigned long)output_byteoffset +
                     (unsigned long)output_bytesize;

    if (output_byteend < (unsigned long)output_byteoffset ||
        LONG_MAX < output_byteend)
        rb_raise(rb_eArgError, "output_byteoffset+output_bytesize too big");

    if (rb_str_capacity(output) < output_byteend)
        rb_str_resize(output, output_byteend);

    if (NIL_P(input)) {
        ip = is = NULL;
    }
    else {
        ip = (const unsigned char *)RSTRING_PTR(input);
        is = ip + RSTRING_LEN(input);
    }

    op = (unsigned char *)RSTRING_PTR(output) + output_byteoffset;
    os = op + output_bytesize;

    res = rb_econv_convert(ec, &ip, is, &op, os, flags);
    rb_str_set_len(output, op-(unsigned char *)RSTRING_PTR(output));
    if (!NIL_P(input))
        rb_str_drop_bytes(input, ip - (unsigned char *)RSTRING_PTR(input));

    if (NIL_P(output_bytesize_v) && res == econv_destination_buffer_full) {
        if (LONG_MAX / 2 < output_bytesize)
            rb_raise(rb_eArgError, "too long conversion result");
        output_bytesize *= 2;
        output_byteoffset_v = Qnil;
        goto retry;
    }

    if (ec->destination_encoding) {
        rb_enc_associate(output, ec->destination_encoding);
    }

    return econv_result_to_symbol(res);
}

#primitive_errinfoArray

primitive_errinfo returns important information regarding the last error as a 5-element array:

[result, enc1, enc2, error_bytes, readagain_bytes]

result is the last result of primitive_convert.

Other elements are only meaningful when result is :invalid_byte_sequence, :incomplete_input or :undefined_conversion.

enc1 and enc2 indicate a conversion step as a pair of strings. For example, a converter from EUC-JP to ISO-8859-1 converts a string as follows: EUC-JP -> UTF-8 -> ISO-8859-1. So [enc1, enc2] is either ["EUC-JP", "UTF-8"] or ["UTF-8", "ISO-8859-1"].

error_bytes and readagain_bytes indicate the byte sequences which caused the error. error_bytes is discarded portion. readagain_bytes is buffered portion which is read again on next conversion.

Example:

# \xff is invalid as EUC-JP.
ec = Encoding::Converter.new("EUC-JP", "Shift_JIS")
ec.primitive_convert(src="\xff", dst="", nil, 10)
p ec.primitive_errinfo
#=> [:invalid_byte_sequence, "EUC-JP", "UTF-8", "\xFF", ""]

# HIRAGANA LETTER A (\xa4\xa2 in EUC-JP) is not representable in ISO-8859-1.
# Since this error is occur in UTF-8 to ISO-8859-1 conversion,
# error_bytes is HIRAGANA LETTER A in UTF-8 (\xE3\x81\x82).
ec = Encoding::Converter.new("EUC-JP", "ISO-8859-1")
ec.primitive_convert(src="\xa4\xa2", dst="", nil, 10)
p ec.primitive_errinfo
#=> [:undefined_conversion, "UTF-8", "ISO-8859-1", "\xE3\x81\x82", ""]

# partial character is invalid
ec = Encoding::Converter.new("EUC-JP", "ISO-8859-1")
ec.primitive_convert(src="\xa4", dst="", nil, 10)
p ec.primitive_errinfo
#=> [:incomplete_input, "EUC-JP", "UTF-8", "\xA4", ""]

# Encoding::Converter::PARTIAL_INPUT prevents invalid errors by
# partial characters.
ec = Encoding::Converter.new("EUC-JP", "ISO-8859-1")
ec.primitive_convert(src="\xa4", dst="", nil, 10, Encoding::Converter::PARTIAL_INPUT)
p ec.primitive_errinfo
#=> [:source_buffer_empty, nil, nil, nil, nil]

# \xd8\x00\[email protected] is invalid as UTF-16BE because
# no low surrogate after high surrogate (\xd8\x00).
# It is detected by 3rd byte (\00) which is part of next character.
# So the high surrogate (\xd8\x00) is discarded and
# the 3rd byte is read again later.
# Since the byte is buffered in ec, it is dropped from src.
ec = Encoding::Converter.new("UTF-16BE", "UTF-8")
ec.primitive_convert(src="\xd8\x00\[email protected]", dst="", nil, 10)
p ec.primitive_errinfo
#=> [:invalid_byte_sequence, "UTF-16BE", "UTF-8", "\xD8\x00", "\x00"]
p src
#=> "@"

# Similar to UTF-16BE, \x00\[email protected]\x00 is invalid as UTF-16LE.
# The problem is detected by 4th byte.
ec = Encoding::Converter.new("UTF-16LE", "UTF-8")
ec.primitive_convert(src="\x00\[email protected]\x00", dst="", nil, 10)
p ec.primitive_errinfo
#=> [:invalid_byte_sequence, "UTF-16LE", "UTF-8", "\x00\xD8", "@\x00"]
p src
#=> ""

Returns:


3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
# File 'transcode.c', line 3961

static VALUE
econv_primitive_errinfo(VALUE self)
{
    rb_econv_t *ec = check_econv(self);

    VALUE ary;

    ary = rb_ary_new2(5);

    rb_ary_store(ary, 0, econv_result_to_symbol(ec->last_error.result));
    rb_ary_store(ary, 4, Qnil);

    if (ec->last_error.source_encoding)
        rb_ary_store(ary, 1, rb_str_new2(ec->last_error.source_encoding));

    if (ec->last_error.destination_encoding)
        rb_ary_store(ary, 2, rb_str_new2(ec->last_error.destination_encoding));

    if (ec->last_error.error_bytes_start) {
        rb_ary_store(ary, 3, rb_str_new((const char *)ec->last_error.error_bytes_start, ec->last_error.error_bytes_len));
        rb_ary_store(ary, 4, rb_str_new((const char *)ec->last_error.error_bytes_start + ec->last_error.error_bytes_len, ec->last_error.readagain_len));
    }

    return ary;
}

#putbackObject

call-seq

ec.putback                    -> string
ec.putback(max_numbytes)      -> string

Put back the bytes which will be converted.

The bytes are caused by invalid_byte_sequence error. When invalid_byte_sequence error, some bytes are discarded and some bytes are buffered to be converted later. The latter bytes can be put back. It can be observed by Encoding::InvalidByteSequenceError#readagain_bytes and Encoding::Converter#primitive_errinfo.

ec = Encoding::Converter.new("utf-16le", "iso-8859-1")
src = "\x00\xd8\x61\x00"
dst = ""
p ec.primitive_convert(src, dst)   #=> :invalid_byte_sequence
p ec.primitive_errinfo     #=> [:invalid_byte_sequence, "UTF-16LE", "UTF-8", "\x00\xD8", "a\x00"]
p ec.putback               #=> "a\x00"
p ec.putback               #=> ""          # no more bytes to put back

4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
# File 'transcode.c', line 4064

static VALUE
econv_putback(int argc, VALUE *argv, VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    int n;
    int putbackable;
    VALUE str, max;

    rb_scan_args(argc, argv, "01", &max);

    if (NIL_P(max))
        n = rb_econv_putbackable(ec);
    else {
        n = NUM2INT(max);
        putbackable = rb_econv_putbackable(ec);
        if (putbackable < n)
            n = putbackable;
    }

    str = rb_str_new(NULL, n);
    rb_econv_putback(ec, (unsigned char *)RSTRING_PTR(str), n);

    if (ec->source_encoding) {
        rb_enc_associate(str, ec->source_encoding);
    }

    return str;
}

#replacementString

Returns the replacement string.

ec = Encoding::Converter.new("euc-jp", "us-ascii")
p ec.replacement    #=> "?"

ec = Encoding::Converter.new("euc-jp", "utf-8")
p ec.replacement    #=> "\uFFFD"

Returns:


4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
# File 'transcode.c', line 4137

static VALUE
econv_get_replacement(VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    int ret;
    rb_encoding *enc;

    ret = make_replacement(ec);
    if (ret == -1) {
        rb_raise(rb_eUndefinedConversionError, "replacement character setup failed");
    }

    enc = rb_enc_find(ec->replacement_enc);
    return rb_enc_str_new((const char *)ec->replacement_str, (long)ec->replacement_len, enc);
}

#replacement=(string) ⇒ Object

Sets the replacement string.

ec = Encoding::Converter.new("utf-8", "us-ascii", :undef => :replace)
ec.replacement = "<undef>"
p ec.convert("a \u3042 b")      #=> "a <undef> b"

4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
# File 'transcode.c', line 4163

static VALUE
econv_set_replacement(VALUE self, VALUE arg)
{
    rb_econv_t *ec = check_econv(self);
    VALUE string = arg;
    int ret;
    rb_encoding *enc;

    StringValue(string);
    enc = rb_enc_get(string);

    ret = rb_econv_set_replacement(ec,
            (const unsigned char *)RSTRING_PTR(string),
            RSTRING_LEN(string),
            rb_enc_name(enc));

    if (ret == -1) {
        /* xxx: rb_eInvalidByteSequenceError? */
        rb_raise(rb_eUndefinedConversionError, "replacement character setup failed");
    }

    return arg;
}

#source_encodingEncoding

Returns the source encoding as an Encoding object.

Returns:


3445
3446
3447
3448
3449
3450
3451
3452
# File 'transcode.c', line 3445

static VALUE
econv_source_encoding(VALUE self)
{
    rb_econv_t *ec = check_econv(self);
    if (!ec->source_encoding)
        return Qnil;
    return rb_enc_from_encoding(ec->source_encoding);
}