diff options
Diffstat (limited to 'lib/asn1/doc/src/asn1_ug.xml')
| -rw-r--r-- | lib/asn1/doc/src/asn1_ug.xml | 50 |
1 files changed, 13 insertions, 37 deletions
diff --git a/lib/asn1/doc/src/asn1_ug.xml b/lib/asn1/doc/src/asn1_ug.xml index eb9f000e75..ee54fdffd7 100644 --- a/lib/asn1/doc/src/asn1_ug.xml +++ b/lib/asn1/doc/src/asn1_ug.xml @@ -205,16 +205,13 @@ ok is saved in the <c>People.asn1db</c> file, the generated Erlang code is compiled using the Erlang compiler and loaded into the Erlang runtime system. Now there is a user interface - of encode/2 and decode/2 in the module People, which is invoked by: + for <c>encode/2</c> and <c>decode/2</c> in the module People, + which is invoked by: <br></br> <c><![CDATA['People':encode(<Type name>,<Value>),]]></c> <br></br> or <br></br> -<c><![CDATA['People':decode(<Type name>,<Value>),]]></c> <br></br> - - Alternatively one can use the <c><![CDATA[asn1rt:encode(<Module name> ,<Type name>,<Value>)]]></c> and <c><![CDATA[asn1rt:decode(< Module name>,<Type name>,<Value>)]]></c> calls. - However, they are not as efficient as the previous methods since they - result in an additional <c>apply/3</c> call.</p> +<c><![CDATA['People':decode(<Type name>,<Value>),]]></c></p> <p>Assume there is a network application which receives instances of the ASN.1 defined type Person, modifies and sends them back again:</p> @@ -241,16 +238,14 @@ receive encoding-rules. <br></br> The encoder and the decoder can also be run from - the shell. The following dialogue with the shell illustrates - how the functions - <c>asn1rt:encode/3</c> and <c>asn1rt:decode/3</c> are used.</p> + the shell.</p> <pre> 2> <input>Rockstar = {'Person',"Some Name",roving,50}.</input> {'Person',"Some Name",roving,50} -3> <input>{ok,Bin} = asn1rt:encode('People','Person',Rockstar).</input> +3> <input>{ok,Bin} = 'People':encode('Person',Rockstar).</input> {ok,<<243,17,19,9,83,111,109,101,32,78,97,109,101,2,1,2, 2,1,50>>} -4> <input>{ok,Person} = asn1rt:decode('People','Person',Bin).</input> +4> <input>{ok,Person} = 'People':decode('Person',Bin).</input> {ok,{'Person',"Some Name",roving,50}} 5> </pre> </section> @@ -279,11 +274,8 @@ The encoder and the decoder can also be run from (including the compiler).</p> </item> <item> - <p>The module <c>asn1rt</c> which provides the run-time functions. - However, it is preferable to use the generated <c>encode/2</c> and - <c>decode/2</c> functions in each module, ie. - Module:encode(Type,Value), in favor of the <c>asn1rt</c> - interface.</p> + <p>The module <c>asn1rt_nif</c> which provides the run-time functions + for the ASN.1 decoder for the BER back-end.</p> </item> </list> <p>The reason for the division of the interface into compile-time @@ -384,25 +376,9 @@ asn1ct:decode('H323-MESSAGES','SomeChoiceType',Bytes). </pre> <section> <title>Run-time Functions</title> - <p>A brief description of the major functions is given here. For a - complete description of each function see - <seealso marker="asn1rt"> the Asn1 Reference Manual</seealso>, the <c>asn1rt</c> module.</p> - <p>The generic run-time encode and decode functions can be invoked as below:</p> - <pre> -asn1rt:encode('H323-MESSAGES','SomeChoiceType',{call,"octetstring"}). -asn1rt:decode('H323-MESSAGES','SomeChoiceType',Bytes). </pre> - <p>Or, preferable like:</p> - <pre> -'H323-MESSAGES':encode('SomeChoiceType',{call,"octetstring"}). -'H323-MESSAGES':decode('SomeChoiceType',Bytes). </pre> - <p>The asn1 nif is enabled in two occasions: encoding of - asn1 values when the asn1 spec is compiled with <c>per</c> and - or decode of encoded asn1 values when the asn1 spec is - compiled with <c>ber</c>. In - those cases the nif will be loaded automatically at the first call - to <c>encode</c>/<c>decode</c>. If one doesn't want the performance - overhead of the nif being loaded at the first call it is possible - to load the nif separately by loading the <c>asn1rt_nif</c> module.</p> + <p>When an ASN.1 specification is compiled with the <c>ber</c> + option, the module <c>asn1rt_nif</c> module and the NIF library in + <c>asn1/priv_dir</c> will be needed at run-time.</p> <p>By invoking the function <c>info/0</c> in a generated module, one gets information about which compiler options were used.</p> </section> @@ -414,8 +390,8 @@ asn1rt:decode('H323-MESSAGES','SomeChoiceType',Bytes). </pre> a line number indicating where in the source file the error was detected. If no errors are found, an Erlang ASN.1 module will be created as default.</p> - <p>The run-time encoders and decoders (in the <c>asn1rt</c> module) do - execute within a catch and returns <c>{ok, Data}</c> or + <p>The run-time encoders and decoders execute within a catch and + returns <c>{ok, Data}</c> or <c>{error, {asn1, Description}}</c> where <c>Description</c> is an Erlang term describing the error. </p> |