[ новости /+++ | форум | теги | ]

NAME
     xfn_compound_names - XFN compound syntax: an overview of XFN
     model for compound name parsing

DESCRIPTION
     Each naming system in an XFN federation has a naming conven-
     tion.  XFN  defines  a standard model of expressing compound
     name syntax that covers a large number of specific name syn-
     taxes and is expressed in terms of  syntax properties of the
     naming convention.

     The model uses the attributes  in  the  following  table  to
     describe  properties  of the syntax. Unless otherwise quali-
     fied, these syntax attributes   have  attribute  identifiers
     that  use  the  FN_ID_STRING format. A context that supports
     the XFN standard syntax model has an attribute set  contain-
     ing    the     fn_syntax_type    (with   identifier   format
     FN_ID_STRING) attribute with  the  value  "standard"  (ASCII
     attribute syntax).

     These are the interfaces:

     #include <xfn/xfn.h>
     FN_attrset_t *fn_ctx_get_syntax_attrs(FN_ctx_t *ctx,
     const FN_composite_name_t *name,
     FN_status_t *status);
     FN_compound_name_t *fn_compound_name_from_syntax_attrs( const FN_attrset_t *aset,
     const FN_string_t *name, FN_status_t *status);

     fn_syntax_type
           Its value is the ASCII string "standard"  if the  con-
           text supports the XFN standard syntax model. Its value
           is an implementation-specific value if another  syntax
           model is supported.

     fn_std_syntax_direction
           Its value is an ASCII string, one of  "left_to_right",
           "right_to_left",  or  "flat".  This determines whether
           the order of components in a compound name string goes
           from  left  to  right,  right  to left, or whether the
           namespace is flat (in other words,  not  hierarchical;
           em all names are atomic).

     fn_std_syntax_separator
           Its value is the separator string for this  name  syn-
           tax.   This   attribute   is   required   unless   the
           fn_std_syntax_direction is "flat".

     fn_std_syntax_escape
           If present, its value is the escape  string  for  this
           name syntax.

     fn_std_syntax_case_insensitive
           If this attribute is present, it indicates that  names
           that  differ only in case are considered identical. If
           this attribute is absent, it indicates  that  case  is
           significant. If a value is present, it is ignored.

     fn_std_syntax_begin_quote
           If present, its value is the  begin-quote  string  for
           this  syntax.  There  can  be multiple values for this
           attribute.

     fn_std_syntax_end_quote
           If present, its value is the end-quote string for this
           syntax.  There  can be multiple values for this attri-
           bute.

     fn_std_syntax_ava_separator
           If present, its value is the attribute value assertion
           separator string for this syntax.

     fn_std_syntax_typeval_separator
           If present, its value  is   the  attribute  type-value
           separator string for this syntax.

     fn_std_syntax_code_sets
           If present, its value identifies the code sets of  the
           string  representation for this syntax. Its value con-
           sists of a structure containing an array of code  sets
           supported  by  the  context;  the  first member of the
           array is the preferred code set of  the  context.  The
           values  for  the  code  sets are defined in the X/Open
           code set registry. If this attribute is  not  present,
           or  if  the  value  is empty,  the default code set is
           ISO 646 (same encoding as ASCII).

     fn_std_syntax_locale_info
           If present, identifies  locale  information,  such  as
           character  set  information, of the string representa-
           tion for this syntax. The interpretation of its  value
           is implementation-dependent.

     The XFN standard syntax attributes are interpreted according
     to the following rules:

     1. In a string without quotes or escapes,  any  instance  of
        the separator string delimits two atomic names.

     2. A separator, quotation or escape  string  is  escaped  if
        preceded immediately (on the left) by the escape string.

     3. A non-escaped begin-quote which precedes a component must
        be  matched  by a non-escaped end-quote at the end of the
        component.  Quotes  embedded  in  non-quoted  names   are
        treated  as  simple  characters  and  do  not  need to be
        matched. An unmatched quotation  fails  with  the  status
        code  FN_E_ILLEGAL_NAME.

     4. If there are multiple values  for  begin-quote  and  end-
        quote,  a specific begin-quote value must be matched with
        its  corresponding end-quote value.

     5. When the separator appears between a (non-escaped)  begin
        quote and the end quote, it is ignored.

     6. When the separator is escaped, it is ignored. An  escaped
        begin-quote or end-quote string is not treated as a  quo-
        tation mark. An escaped escape string is not  treated  as
        an escape string.

     7. A non-escaped escape string appearing  within  quotes  is
        interpreted  as  an  escape  string.  This can be used to
        embed an end-quote within a quoted string.

     After constructing  a  compound  name  from  a  string,  the
     resulting  component  atoms have one level of escape strings
     and  quotations interpreted and consumed.

     fn_ctx_get_syntax_attrs()  is  used  to  obtain  the  syntax
     attributes associated with a context.

     fn_compound_name_from_syntax() is used to construct  a  com-
     pound  name object using the string form of the name and the
     syntax attributes of the name.

ERRORS
     FN_E_ILLEGAL_NAME
           The name supplied to the operation  was  not  a  well-
           formed   component according to the name syntax of the
           context.

     FN_E_INCOMPATIBLE_CODE_SETS
           Code set mismatches that occur during the construction
           of  the compound name's string form are resolved in an
           implementation-dependent way. When  an  implementation
           discovers  that  a  compound  name has components with
           incompatible code sets, it returns this error code.

     FN_E_INVALID_SYNTAX_ATTRS
           The syntax attributes supplied are invalid or insuffi-
           cient to fully specify the syntax.

     FN_E_SYNTAX_NOT_SUPPORTED
           The syntax specified is not supported.

USAGE
     Most applications treat names as  opaque  data.  Hence,  the
     majority  of  clients  of the XFN interface will not need to
     parse compound names  from  specific  naming  systems.  Some
     applications, however, such as browsers, need such capabili-
     ties. These applications would use fn_ctx_get_syntax_attrs()
     to obtain the syntax-related attributes of a context and, if
     the context uses the XFN standard  syntax  model,  it  would
     examine these attributes to determine the name syntax of the
     context.

SEE ALSO
     FN_attribute_t(3XFN),                    FN_attrset_t(3XFN),
     FN_compound_name_t(3XFN),             FN_identifier_t(3XFN),
     FN_string_t(3XFN) fn_ctx_get_syntax_attrs (3XFN), xfn(3XFN)

NOTES
     The implementation of XFN in this Solaris release  is  based
     on  the  X/Open preliminary specification. It is likely that
     there will be minor changes to these interfaces  to  reflect
     changes in the final version of this specification. The next
     minor release of Solaris will offer binary compatibility for
     applications  developed using the current interfaces. As the
     interfaces evolve toward  standardization,  it  is  possible
     that  future  releases  of Solaris will require minor source
     code  changes  to  applications  that  have  been  developed
     against the preliminary specification.

Партнёры:

Хостинг: