diff options
Diffstat (limited to 'lib/ic/doc/src/ch_basic_idl.xml')
| -rw-r--r-- | lib/ic/doc/src/ch_basic_idl.xml | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/lib/ic/doc/src/ch_basic_idl.xml b/lib/ic/doc/src/ch_basic_idl.xml new file mode 100644 index 0000000000..d993fa3594 --- /dev/null +++ b/lib/ic/doc/src/ch_basic_idl.xml @@ -0,0 +1,163 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE chapter SYSTEM "chapter.dtd"> + +<chapter> + <header> + <copyright> + <year>2002</year><year>2009</year> + <holder>Ericsson AB. All Rights Reserved.</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + </legalnotice> + + <title>OMG IDL</title> + <prepared></prepared> + <docno></docno> + <date>2002-07-15</date> + <rev></rev> + <file>ch_basic_idl.xml</file> + </header> + + <section> + <title>OMG IDL - Overview</title> + <p>The purpose of OMG IDL, <em>Interface Definition Language</em>, mapping + is to act as translator between platforms and languages. An IDL + specification is supposed to describe data types, object types etc.</p> + <p>Since the <c>C</c> and <c>Java</c> IC backends only supports a subset of the + IDL types supported by the other backends, the mapping is divided into + different parts. For more information about IDL to Erlang mapping, + i.e., <c>CORBA</c>, plain Erlang and generic Erlang Server, see the Orber + User's Guide. How to use the plain Erlang and generic Erlang Server is + found in this User's Guide.</p> + + <section> + <title>Reserved Compiler Names and Keywords</title> + <p>The use of some names is strongly discouraged due to + ambiguities. However, the use of some names is prohibited + when using the Erlang mapping , as they are strictly reserved for IC.</p> + <p>IC reserves all identifiers starting with <c>OE_</c> and <c>oe_</c> + for internal use.</p> + <p>Note also, that an identifier in IDL can contain alphabetic, + digits and underscore characters, but the first character + <em>must</em> be alphabetic. + </p> + <p>Using underscores in IDL names can lead to ambiguities + due to the name mapping described above. It is advisable to + avoid the use of underscores in identifiers.</p> + <p>The OMG defines a set of reserved words, shown below, for use as keywords. + These may <em>not</em> be used as, for example, identifiers.</p> + <table> + <row> + <cell align="left" valign="middle">abstract</cell> + <cell align="left" valign="middle">double</cell> + <cell align="left" valign="middle">local</cell> + <cell align="left" valign="middle">raises</cell> + <cell align="left" valign="middle">typedef</cell> + </row> + <row> + <cell align="left" valign="middle">any</cell> + <cell align="left" valign="middle">exception</cell> + <cell align="left" valign="middle">long</cell> + <cell align="left" valign="middle">readonly</cell> + <cell align="left" valign="middle">unsigned</cell> + </row> + <row> + <cell align="left" valign="middle">attribute</cell> + <cell align="left" valign="middle">enum</cell> + <cell align="left" valign="middle">module</cell> + <cell align="left" valign="middle">sequence</cell> + <cell align="left" valign="middle">union</cell> + </row> + <row> + <cell align="left" valign="middle">boolean</cell> + <cell align="left" valign="middle">factory</cell> + <cell align="left" valign="middle">native</cell> + <cell align="left" valign="middle">short</cell> + <cell align="left" valign="middle">ValueBase</cell> + </row> + <row> + <cell align="left" valign="middle">case</cell> + <cell align="left" valign="middle">FALSE</cell> + <cell align="left" valign="middle">Object</cell> + <cell align="left" valign="middle">string</cell> + <cell align="left" valign="middle">valuetype</cell> + </row> + <row> + <cell align="left" valign="middle">char</cell> + <cell align="left" valign="middle">fixed</cell> + <cell align="left" valign="middle">octet</cell> + <cell align="left" valign="middle">struct</cell> + <cell align="left" valign="middle">void</cell> + </row> + <row> + <cell align="left" valign="middle">const</cell> + <cell align="left" valign="middle">float</cell> + <cell align="left" valign="middle">oneway</cell> + <cell align="left" valign="middle">supports</cell> + <cell align="left" valign="middle">wchar</cell> + </row> + <row> + <cell align="left" valign="middle">context</cell> + <cell align="left" valign="middle">in</cell> + <cell align="left" valign="middle">out</cell> + <cell align="left" valign="middle">switch</cell> + <cell align="left" valign="middle">wstring</cell> + </row> + <row> + <cell align="left" valign="middle">custom</cell> + <cell align="left" valign="middle">inout</cell> + <cell align="left" valign="middle">private</cell> + <cell align="left" valign="middle">TRUE</cell> + <cell align="left" valign="middle"></cell> + </row> + <row> + <cell align="left" valign="middle">default</cell> + <cell align="left" valign="middle">interface</cell> + <cell align="left" valign="middle">public</cell> + <cell align="left" valign="middle">truncatable</cell> + <cell align="left" valign="middle"></cell> + </row> + <tcaption>OMG IDL keywords</tcaption> + </table> + <p>The keywords listed above must be written exactly as shown. Any usage + of identifiers that collide with a keyword is illegal. For example, + <em>long</em> is a valid keyword; <em>Long</em> and <em>LONG</em> are + illegal as keywords and identifiers. But, since the OMG must be able + to expand the IDL grammar, it is possible to use <em>Escaped Identifiers</em>. For example, it is not unlikely that <c>native</c> + have been used in IDL-specifications as identifiers. One option is to + change all occurrences to <c>myNative</c>. Usually, it is necessary + to change programming language code that depends upon that IDL as well. + Since Escaped Identifiers just disable type checking (i.e. if it is a reserved + word or not) and leaves everything else unchanged, it is only necessary to + update the IDL-specification. To escape an identifier, simply prefix it + with <c>_</c>. The following IDL-code is illegal:</p> + <code type="none"> +typedef string native; +interface i { + void foo(in native Arg); + }; +}; + </code> + <p>With Escaped Identifiers the code will look like:</p> + <code type="none"> +typedef string _native; +interface i { + void foo(in _native Arg); + }; +}; + </code> + </section> + </section> +</chapter> + |