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diff --git a/lib/erl_interface/doc/src/erl_eterm.xml b/lib/erl_interface/doc/src/erl_eterm.xml deleted file mode 100644 index 295760b4e6..0000000000 --- a/lib/erl_interface/doc/src/erl_eterm.xml +++ /dev/null @@ -1,776 +0,0 @@ -<?xml version="1.0" encoding="utf-8" ?> -<!DOCTYPE cref SYSTEM "cref.dtd"> - -<cref> - <header> - <copyright> - <year>1996</year><year>2016</year> - <holder>Ericsson AB. All Rights Reserved.</holder> - </copyright> - <legalnotice> - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. - - </legalnotice> - - <title>erl_eterm</title> - <prepared>Torbjörn Törnkvist</prepared> - <responsible>Torbjörn Törnkvist</responsible> - <docno></docno> - <approved>Bjarne Däcker</approved> - <checked>Torbjörn Törnkvist</checked> - <date>1998-07-03</date> - <rev>A</rev> - <file>erl_eterm.xml</file> - </header> - <lib>erl_eterm</lib> - <libsummary>Functions for Erlang term construction.</libsummary> - <description> - <note><p>The support for VxWorks is deprecated as of OTP 22, and - will be removed in OTP 23.</p></note> - <note><p>The old legacy <c>erl_interface</c> library (functions - with prefix <c>erl_</c>) is deprecated as of OTP 22, and will be - removed in OTP 23. This does not apply to the <c>ei</c> - library. Reasonably new <c>gcc</c> compilers will issue deprecation - warnings. In order to disable these warnings, define the macro - <c>EI_NO_DEPR_WARN</c>.</p></note> - - <p>This module provides functions for creating and manipulating - Erlang terms.</p> - - <p>An Erlang term is represented by a C structure of type - <c>ETERM</c>. Applications should not reference any fields - in this structure directly, as it can be changed in future releases - to provide faster and more compact term storage. Instead, - applications should use the macros and functions provided.</p> - - <p>Each of the following macros takes a single <c>ETERM</c> pointer as an - argument. The macros return a non-zero value if the test is true, - otherwise <c>0</c>.</p> - - <taglist> - <tag><c>ERL_IS_INTEGER(t)</c></tag> - <item>True if <c>t</c> is an integer.</item> - <tag><c>ERL_IS_UNSIGNED_INTEGER(t)</c></tag> - <item>True if <c>t</c> is an integer.</item> - <tag><c>ERL_IS_FLOAT(t)</c></tag> - <item>True if <c>t</c> is a floating point number.</item> - <tag><c>ERL_IS_ATOM(t)</c></tag> - <item>True if <c>t</c> is an atom.</item> - <tag><c>ERL_IS_PID(t)</c></tag> - <item>True if <c>t</c> is a pid (process identifier).</item> - <tag><c>ERL_IS_PORT(t)</c></tag> - <item>True if <c>t</c> is a port.</item> - <tag><c>ERL_IS_REF(t)</c></tag> - <item>True if <c>t</c> is a reference.</item> - <tag><c>ERL_IS_TUPLE(t)</c></tag> - <item>True if <c>t</c> is a tuple.</item> - <tag><c>ERL_IS_BINARY(t)</c></tag> - <item>True if <c>t</c> is a binary.</item> - <tag><c>ERL_IS_LIST(t)</c></tag> - <item>True if <c>t</c> is a list with zero or more - elements.</item> - <tag><c>ERL_IS_EMPTY_LIST(t)</c></tag> - <item>True if <c>t</c> is an empty list.</item> - <tag><c>ERL_IS_CONS(t)</c></tag> - <item>True if <c>t</c> is a list with at least one - element.</item> - </taglist> - - <p>The following macros can be used for retrieving parts of Erlang - terms. None of these do any type checking. Results are undefined - if you pass an <c>ETERM*</c> containing the wrong type. For example, - passing a tuple to <c>ERL_ATOM_PTR()</c> likely results in garbage.</p> - - <taglist> - <tag><c>char *ERL_ATOM_PTR(t)</c></tag> - <item></item> - <tag><c>char *ERL_ATOM_PTR_UTF8(t)</c></tag> - <item>A string representing atom <c>t</c>.</item> - <tag><c>int ERL_ATOM_SIZE(t)</c></tag> - <item></item> - <tag><c>int ERL_ATOM_SIZE_UTF8(t)</c></tag> - <item>The length (in bytes) of atom <c>t</c>.</item> - <tag><c>void *ERL_BIN_PTR(t)</c></tag> - <item>A pointer to the contents of <c>t</c>.</item> - <tag><c>int ERL_BIN_SIZE(t)</c></tag> - <item>The length (in bytes) of binary object <c>t</c>.</item> - <tag><c>int ERL_INT_VALUE(t)</c></tag> - <item>The integer of <c>t</c>.</item> - <tag><c>unsigned int ERL_INT_UVALUE(t)</c></tag> - <item>The unsigned integer value of <c>t</c>.</item> - <tag><c>double ERL_FLOAT_VALUE(t)</c></tag> - <item>The floating point value of <c>t</c>.</item> - <tag><c>ETERM *ERL_PID_NODE(t)</c></tag> - <item></item> - <tag><c>ETERM *ERL_PID_NODE_UTF8(t)</c></tag> - <item>The node in pid <c>t</c>.</item> - <tag><c>int ERL_PID_NUMBER(t)</c></tag> - <item>The sequence number in pid <c>t</c>.</item> - <tag><c>int ERL_PID_SERIAL(t)</c></tag> - <item>The serial number in pid <c>t</c>.</item> - <tag><c>int ERL_PID_CREATION(t)</c></tag> - <item>The creation number in pid <c>t</c>.</item> - <tag><c>int ERL_PORT_NUMBER(t)</c></tag> - <item>The sequence number in port <c>t</c>.</item> - <tag><c>int ERL_PORT_CREATION(t)</c></tag> - <item>The creation number in port <c>t</c>.</item> - <tag><c>ETERM *ERL_PORT_NODE(t)</c></tag> - <item></item> - <tag><c>ETERM *ERL_PORT_NODE_UTF8(t)</c></tag> - <item>The node in port <c>t</c>.</item> - <tag><c>int ERL_REF_NUMBER(t)</c></tag> - <item>The first part of the reference number in ref <c>t</c>. - Use only for compatibility.</item> - <tag><c>int ERL_REF_NUMBERS(t)</c></tag> - <item>Pointer to the array of reference numbers in ref - <c>t</c>.</item> - <tag><c>int ERL_REF_LEN(t)</c></tag> - <item>The number of used reference numbers in ref - <c>t</c>.</item> - <tag><c>int ERL_REF_CREATION(t)</c></tag> - <item>The creation number in ref <c>t</c>.</item> - <tag><c>int ERL_TUPLE_SIZE(t)</c></tag> - <item>The number of elements in tuple <c>t</c>.</item> - <tag><c>ETERM *ERL_CONS_HEAD(t)</c></tag> - <item>The head element of list <c>t</c>.</item> - <tag><c>ETERM *ERL_CONS_TAIL(t)</c></tag> - <item>A list representing the tail elements of list - <c>t</c>.</item> - </taglist> - </description> - - <funcs> - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_cons(head, tail)</nametext></name> - <fsummary>Prepend a term to the head of a list.</fsummary> - <type> - <v>ETERM *head;</v> - <v>ETERM *tail;</v> - </type> - <desc> - <p>Concatenates two Erlang terms, prepending <c>head</c> - onto <c>tail</c> and thereby creating a - <c>cons</c> cell. - To make a proper list, <c>tail</c> is always to be a list - or an empty list. Notice that <c>NULL</c> is not a valid list.</p> - <list type="bulleted"> - <item><c>head</c> is the new term to be added.</item> - <item><c>tail</c> is the existing list to which - <c>head</c> is concatenated.</item> - </list> - <p>The function returns a new list.</p> - <p><c>ERL_CONS_HEAD(list)</c> and - <c>ERL_CONS_TAIL(list)</c> - can be used to retrieve the head and tail components - from the list. <c>erl_hd(list)</c> and - <c>erl_tl(list)</c> do - the same thing, but check that the argument really is a list.</p> - <p><em>Example:</em></p> - <code type="none"><![CDATA[ -ETERM *list,*anAtom,*anInt; -anAtom = erl_mk_atom("madonna"); -anInt = erl_mk_int(21); -list = erl_mk_empty_list(); -list = erl_cons(anAtom, list); -list = erl_cons(anInt, list); - ... /* do some work */ -erl_free_compound(list); - ]]></code> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_copy_term(term)</nametext></name> - <fsummary>Create a copy of an Erlang term.</fsummary> - <type> - <v>ETERM *term;</v> - </type> - <desc> - <p>Creates and returns a copy of the Erlang term - <c>term</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_element(position, tuple)</nametext></name> - <fsummary>Extract an element from an Erlang tuple.</fsummary> - <type> - <v>int position;</v> - <v>ETERM *tuple;</v> - </type> - <desc> - <p>Extracts a specified element from an Erlang tuple.</p> - <list type="bulleted"> - <item><c>position</c> specifies which element to retrieve - from <c>tuple</c>. The elements are numbered starting - from 1.</item> - <item><c>tuple</c> is an Erlang term containing at least - <c>position</c> elements.</item> - </list> - <p>Returns a new Erlang term corresponding to the requested element, or - <c>NULL</c> if <c>position</c> was greater - than the arity of <c>tuple</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_hd(list)</nametext></name> - <fsummary>Extract the first element from a list.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Extracts the first element from a list.</p> - <p><c>list</c> is an Erlang term containing a list.</p> - <p>Returns an Erlang term corresponding to the head - head element in the list, or a <c>NULL</c> pointer if - <c>list</c> was not a list.</p> - </desc> - </func> - - <func> - <name since=""><ret>void</ret><nametext>erl_init(NULL, 0)</nametext></name> - <fsummary>Initialization routine.</fsummary> - <type> - <v>void *NULL;</v> - <v>int 0;</v> - </type> - <desc> - <p>This function must be called before any of the others in the - <c>Erl_Interface</c> library to initialize the - library functions. The arguments must be specified as - <c>erl_init(NULL,0)</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>int</ret><nametext>erl_iolist_length(list)</nametext></name> - <fsummary>Return the length of an I/O list.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Returns the length of an I/O list.</p> - <p><c>list</c> is an Erlang term containing an I/O list.</p> - <p>Returns the length of <c>list</c>, or - <c>-1</c> if <c>list</c> is not an I/O list.</p> - <p>For the definition of an I/O list, see - <seealso marker="#erl_iolist_to_binary"> - <c>erl_iolist_to_binary</c></seealso>.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_iolist_to_binary(term)</nametext></name> - <fsummary>Convert an I/O list to a binary.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Converts an I/O list to a binary term.</p> - <p><c>list</c> is an Erlang term containing a list.</p> - <p>Returns an Erlang binary term, or <c>NULL</c> if - <c>list</c> was not an I/O list.</p> - <p>Informally, an I/O list is a deep list of characters and - binaries that can be sent to an Erlang port. In BNF, an I/O - list is formally defined as follows:</p> - <code type="none"><![CDATA[ -iolist ::= [] - | Binary - | [iohead | iolist] - ; -iohead ::= Binary - | Byte (integer in the range [0..255]) - | iolist - ; - ]]></code> - </desc> - </func> - - <func> - <name since=""><ret>char *</ret><nametext>erl_iolist_to_string(list)</nametext></name> - <fsummary>Convert an I/O list to a <c>NULL</c>-terminated string.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Converts an I/O list to a <c>NULL</c>-terminated C string.</p> - <p><c>list</c> is an Erlang term containing an I/O list. - The I/O list must not contain the integer 0, as C strings may not - contain this value except as a terminating marker.</p> - <p>Returns a pointer to a dynamically allocated - buffer containing a string. If <c>list</c> is not an I/O - list, or if <c>list</c> contains the integer 0, - <c>NULL</c> is returned. It - is the caller's responsibility to free the allocated buffer - with <c>erl_free()</c>.</p> - <p>For the definition of an I/O list, see - <seealso marker="#erl_iolist_to_binary"> - <c>erl_iolist_to_binary</c></seealso>.</p> - </desc> - </func> - - <func> - <name since=""><ret>int</ret><nametext>erl_length(list)</nametext></name> - <fsummary>Determine the length of a list.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Determines the length of a proper list.</p> - <p><c>list</c> is an Erlang term containing a proper list. - In a proper list, all tails except the last point to another list - cell, and the last tail points to an empty list.</p> - <p>Returns <c>-1</c> if <c>list</c> is not a proper - list.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_atom(string)</nametext></name> - <fsummary>Create an atom.</fsummary> - <type> - <v>const char *string;</v> - </type> - <desc> - <p>Creates an atom.</p> - <p><c>string</c> is the sequence of characters that will be - used to create the atom.</p> - <p>Returns an Erlang term containing an atom. Notice that it is - the caller's responsibility to ensure that <c>string</c> - contains a valid name for an atom.</p> - <p><c>ERL_ATOM_PTR(atom)</c> and - <c>ERL_ATOM_PTR_UTF8(atom)</c> - can be used to retrieve the atom name (as a <c>NULL</c>-terminated string). - <c>ERL_ATOM_SIZE(atom)</c> - and <c>ERL_ATOM_SIZE_UTF8(atom)</c> return the length - of the atom name.</p> - <note> - <p>The UTF-8 variants were introduced in Erlang/OTP R16 and the - string returned by <c>ERL_ATOM_PTR(atom)</c> was not - <c>NULL</c>-terminated on older releases.</p> - </note> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_binary(bptr, size)</nametext></name> - <fsummary>Create a binary object.</fsummary> - <type> - <v>char *bptr;</v> - <v>int size;</v> - </type> - <desc> - <p>Produces an Erlang binary object from a - buffer containing a sequence of bytes.</p> - <list type="bulleted"> - <item><c>bptr</c> is a pointer to a buffer containing - data to be converted.</item> - <item><c>size</c> indicates the length of - <c>bptr</c>.</item> - </list> - <p>Returns an Erlang binary object.</p> - <p><c>ERL_BIN_PTR(bin)</c> retrieves a pointer to - the binary data. <c>ERL_BIN_SIZE(bin)</c> retrieves the - size.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_empty_list()</nametext></name> - <fsummary>Create an empty Erlang list.</fsummary> - <desc> - <p>Creates and returns an empty Erlang list. - Notice that <c>NULL</c> is not used to represent an empty list; - Use this function instead.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_estring(string, len)</nametext></name> - <fsummary>Create an Erlang string.</fsummary> - <type> - <v>char *string;</v> - <v>int len;</v> - </type> - <desc> - <p>Creates a list from a sequence of bytes.</p> - <list type="bulleted"> - <item><c>string</c> is a buffer containing a sequence of - bytes. The buffer does not need to be <c>NULL</c>-terminated.</item> - <item><c>len</c> is the length of - <c>string</c>.</item> - </list> - <p>Returns an Erlang list object corresponding to - the character sequence in <c>string</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_float(f)</nametext></name> - <fsummary>Create an Erlang float.</fsummary> - <type> - <v>double f;</v> - </type> - <desc> - <p>Creates an Erlang float.</p> - <p><c>f</c> is a value to be converted to an Erlang - float.</p> - <p>Returns an Erlang float object with the value - specified in <c>f</c> or <c>NULL</c> if - <c>f</c> is not finite.</p> - <p><c>ERL_FLOAT_VALUE(t)</c> can be used to retrieve the - value from an Erlang float.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_int(n)</nametext></name> - <fsummary>Create an Erlang integer.</fsummary> - <type> - <v>int n;</v> - </type> - <desc> - <p>Creates an Erlang integer.</p> - <p><c>n</c> is a value to be converted to an Erlang - integer.</p> - <p>Returns an Erlang integer object with the - value specified in <c>n</c>.</p> - <p><c>ERL_INT_VALUE(t)</c> can be used to retrieve the - value from an Erlang integer.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_list(array, arrsize)</nametext></name> - <fsummary>Create a list from an array.</fsummary> - <type> - <v>ETERM **array;</v> - <v>int arrsize;</v> - </type> - <desc> - <p>Creates an Erlang list from an array of Erlang terms, such - that each element in the list corresponds to one element in - the array.</p> - <list type="bulleted"> - <item><c>array</c> is an array of Erlang terms.</item> - <item><c>arrsize</c> is the number of elements in - <c>array</c>.</item> - </list> - <p>The function creates an Erlang list object, whose length - <c>arrsize</c> and whose elements are taken from the - terms in <c>array</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_long_ref(node, n1, n2, n3, creation)</nametext></name> - <fsummary>Create an Erlang reference.</fsummary> - <type> - <v>const char *node;</v> - <v>unsigned int n1, n2, n3;</v> - <v>unsigned int creation;</v> - </type> - <desc> - <p>Creates an Erlang reference, with 82 bits.</p> - <list type="bulleted"> - <item><c>node</c> is the name of the C-node.</item> - <item><c>n1</c>, <c>n2</c>, and - <c>n3</c> can be seen as one big number - <c>n1*2^64+n2*2^32+n3</c>, which is to be chosen - uniquely for each reference created for a given C-node.</item> - <item><c>creation</c> is an arbitrary number.</item> - </list> - <p>Notice that <c>n3</c> and <c>creation</c> - are limited in precision, so only the low 18 and 2 bits of these - numbers are used.</p> - <p>Returns an Erlang reference object.</p> - <p><c>ERL_REF_NODE(ref)</c>, - <c>ERL_REF_NUMBERS(ref)</c>, - <c>ERL_REF_LEN(ref)</c>, and - <c>ERL_REF_CREATION(ref)</c> can be used to retrieve the - values used to create the reference.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_pid(node, number, serial, creation)</nametext></name> - <fsummary>Create a process identifier.</fsummary> - <type> - <v>const char *node;</v> - <v>unsigned int number;</v> - <v>unsigned int serial;</v> - <v>unsigned int creation;</v> - </type> - <desc> - <p>Creates an Erlang process identifier (pid). The - resulting pid can be used by Erlang processes wishing to - communicate with the C-node.</p> - <list type="bulleted"> - <item><c>node</c> is the name of the C-node.</item> - <item><c>number</c>, <c>serial</c>, and - <c>creation</c> are - arbitrary numbers. Notice that these are limited in - precision, so only the low 15, 3, and 2 bits of these numbers - are used.</item> - </list> - <p>Returns an Erlang pid object.</p> - <p><c>ERL_PID_NODE(pid)</c>, - <c>ERL_PID_NUMBER(pid)</c>, - <c>ERL_PID_SERIAL(pid)</c>, and - <c>ERL_PID_CREATION(pid)</c> - can be used to retrieve the four values used to create the pid.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_port(node, number, creation)</nametext></name> - <fsummary>Create a port identifier.</fsummary> - <type> - <v>const char *node;</v> - <v>unsigned int number;</v> - <v>unsigned int creation;</v> - </type> - <desc> - <p>Creates an Erlang port identifier.</p> - <list type="bulleted"> - <item><c>node</c> is the name of the C-node.</item> - <item><c>number</c> and <c>creation</c> are - arbitrary numbers. Notice that these are limited in - precision, so only the low 18 and 2 bits of these numbers - are used.</item> - </list> - <p>Returns an Erlang port object.</p> - <p><c>ERL_PORT_NODE(port)</c>, - <c>ERL_PORT_NUMBER(port)</c>, - and <c>ERL_PORT_CREATION</c> can be used to retrieve the - three values used to create the port.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_ref(node, number, creation)</nametext></name> - <fsummary>Create an old Erlang reference.</fsummary> - <type> - <v>const char *node;</v> - <v>unsigned int number;</v> - <v>unsigned int creation;</v> - </type> - <desc> - <p>Creates an old Erlang reference, with - only 18 bits - use <c>erl_mk_long_ref</c> instead.</p> - <list type="bulleted"> - <item><c>node</c> is the name of the C-node.</item> - <item><c>number</c> is to be chosen uniquely for each - reference created for a given C-node.</item> - <item><c>creation</c> is an arbitrary number.</item> - </list> - <p>Notice that <c>number</c> and <c>creation</c> - are limited in precision, so only the low 18 and 2 bits of these - numbers are used.</p> - <p>Returns an Erlang reference object.</p> - <p><c>ERL_REF_NODE(ref)</c>, - <c>ERL_REF_NUMBER(ref)</c>, and - <c>ERL_REF_CREATION(ref)</c> can be used to retrieve the - three values used to create the reference.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_string(string)</nametext></name> - <fsummary>Create a string.</fsummary> - <type> - <v>char *string;</v> - </type> - <desc> - <p>Creates a list from a <c>NULL</c>-terminated string.</p> - <p><c>string</c> is a <c>NULL</c>-terminated sequence of - characters - (that is, a C string) from which the list will be created.</p> - <p>Returns an Erlang list.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_tuple(array, arrsize)</nametext></name> - <fsummary>Create an Erlang tuple from an array.</fsummary> - <type> - <v>ETERM **array;</v> - <v>int arrsize;</v> - </type> - <desc> - <p>Creates an Erlang tuple from an array of Erlang terms.</p> - <list type="bulleted"> - <item><c>array</c> is an array of Erlang terms.</item> - <item><c>arrsize</c> is the number of elements in - <c>array</c>.</item> - </list> - <p>The function creates an Erlang tuple, whose arity is - <c>size</c> and whose elements are taken from the terms - in <c>array</c>.</p> - <p>To retrieve the size of a tuple, either use function - <c>erl_size</c> (which checks the type of the - checked term and works for a binary as well as for a tuple) or - <c>ERL_TUPLE_SIZE(tuple)</c> returns the arity of a tuple. - <c>erl_size()</c> does the same thing, but it checks - that the argument is a tuple. - <c>erl_element(index,tuple)</c> returns the element - corresponding to a given position in the tuple.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_uint(n)</nametext></name> - <fsummary>Create an unsigned integer.</fsummary> - <type> - <v>unsigned int n;</v> - </type> - <desc> - <p>Creates an Erlang unsigned integer.</p> - <p><c>n</c> is a value to be converted to an Erlang - unsigned integer.</p> - <p>Returns an Erlang unsigned integer object with - the value specified in <c>n</c>.</p> - <p><c>ERL_INT_UVALUE(t)</c> can be used to retrieve the - value from an Erlang unsigned integer.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_mk_var(name)</nametext></name> - <fsummary>Create an Erlang variable.</fsummary> - <type> - <v>char *name;</v> - </type> - <desc> - <p>Creates an unbound Erlang variable. The variable can later be bound - through pattern matching or assignment.</p> - <p><c>name</c> specifies a name for the variable.</p> - <p>Returns an Erlang variable object with the - name <c>name</c>.</p> - </desc> - </func> - - <func> - <name since=""><ret>int</ret><nametext>erl_print_term(stream, term)</nametext></name> - <fsummary>Print an Erlang term.</fsummary> - <type> - <v>FILE *stream;</v> - <v>ETERM *term;</v> - </type> - <desc> - <p>Prints the specified Erlang term to the specified output stream.</p> - <list type="bulleted"> - <item><c>stream</c> indicates where the function is to - send its output.</item> - <item><c>term</c> is the Erlang term to print.</item> - </list> - <p>Returns the number of characters written on success, otherwise a - negative value.</p> - </desc> - </func> - - <func> - <name since=""><ret>void</ret><nametext>erl_set_compat_rel(release_number)</nametext></name> - <fsummary>Set the Erl_Interface library in compatibility mode.</fsummary> - <type> - <v>unsigned release_number;</v> - </type> - <desc> - <p>By default, the <c>Erl_Interface</c> library is only - guaranteed to be compatible with other Erlang/OTP components from the - same release as the <c>Erl_Interface</c> library itself. - For example, <c>Erl_Interface</c> from Erlang/OTP R10 - is not compatible - with an Erlang emulator from Erlang/OTP R9 by default.</p> - <p>A call to <c>erl_set_compat_rel(release_number)</c> sets - the <c>Erl_Interface</c> library in compatibility mode of - release <c>release_number</c>. Valid range of - <c>release_number</c> - is [7, current release]. This makes it possible to - communicate with Erlang/OTP components from earlier releases.</p> - <note> - <p>If this function is called, it may only be called once - directly after the call to function - <seealso marker="#erl_init">erl_init()</seealso>.</p> - </note> - <warning> - <p>You may run into trouble if this feature is used - carelessly. Always ensure that all communicating - components are either from the same Erlang/OTP release, or - from release X and release Y where all components - from release Y are in compatibility mode of release X.</p> - </warning> - </desc> - </func> - - <func> - <name since=""><ret>int</ret><nametext>erl_size(term)</nametext></name> - <fsummary>Return the arity of a tuple or binary.</fsummary> - <type> - <v>ETERM *term;</v> - </type> - <desc> - <p>Returns either the arity of an Erlang tuple or the - number of bytes in an Erlang binary object.</p> - <p><c>term</c> is an Erlang tuple or an Erlang binary - object.</p> - <p>Returns the size of <c>term</c> as described - above, or <c>-1</c> if <c>term</c> is not one of the two - supported types.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_tl(list)</nametext></name> - <fsummary>Extract the tail from a list.</fsummary> - <type> - <v>ETERM *list;</v> - </type> - <desc> - <p>Extracts the tail from a list.</p> - <p><c>list</c> is an Erlang term containing a list.</p> - <p>Returns an Erlang list corresponding to the - original list minus the first element, or <c>NULL</c> pointer if - <c>list</c> was not a list.</p> - </desc> - </func> - - <func> - <name since=""><ret>ETERM *</ret><nametext>erl_var_content(term, name)</nametext></name> - <fsummary>Extract the content of a variable.</fsummary> - <type> - <v>ETERM *term;</v> - <v>char *name;</v> - </type> - <desc> - <p>Returns the contents of the specified variable in an Erlang term.</p> - <list type="bulleted"> - <item><c>term</c> is an Erlang term. In order for this - function to succeed, - <c>term</c> must either be an Erlang variable with - the specified name, or it must be an Erlang list or tuple - containing a variable with the specified name. Other Erlang - types cannot contain variables.</item> - <item><c>name</c> is the name of an Erlang variable. - </item> - </list> - <p>Returns the Erlang object corresponding to the value of - <c>name</c> in <c>term</c>. If no variable - with the name <c>name</c> is found in - <c>term</c>, or if <c>term</c> is - not a valid Erlang term, <c>NULL</c> is returned.</p> - </desc> - </func> - </funcs> -</cref> |