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-rw-r--r--lib/stdlib/doc/src/Makefile1
-rw-r--r--lib/stdlib/doc/src/c.xml9
-rw-r--r--lib/stdlib/doc/src/filelib.xml29
-rw-r--r--lib/stdlib/doc/src/filename.xml30
-rw-r--r--lib/stdlib/doc/src/gen_server.xml52
-rw-r--r--lib/stdlib/doc/src/gen_statem.xml12
-rw-r--r--lib/stdlib/doc/src/maps.xml94
-rw-r--r--lib/stdlib/doc/src/rand.xml118
-rw-r--r--lib/stdlib/doc/src/ref_man.xml1
-rw-r--r--lib/stdlib/doc/src/specs.xml1
-rw-r--r--lib/stdlib/doc/src/string.xml396
-rw-r--r--lib/stdlib/doc/src/unicode_usage.xml8
-rw-r--r--lib/stdlib/doc/src/uri_string.xml326
13 files changed, 663 insertions, 414 deletions
diff --git a/lib/stdlib/doc/src/Makefile b/lib/stdlib/doc/src/Makefile
index e7ea38c5c3..af27efa6c1 100644
--- a/lib/stdlib/doc/src/Makefile
+++ b/lib/stdlib/doc/src/Makefile
@@ -98,6 +98,7 @@ XML_REF3_FILES = \
sys.xml \
timer.xml \
unicode.xml \
+ uri_string.xml \
win32reg.xml \
zip.xml
diff --git a/lib/stdlib/doc/src/c.xml b/lib/stdlib/doc/src/c.xml
index 7666699183..697e1715e7 100644
--- a/lib/stdlib/doc/src/c.xml
+++ b/lib/stdlib/doc/src/c.xml
@@ -94,6 +94,15 @@
</func>
<func>
+ <name name="erlangrc" arity="1"/>
+ <fsummary>Load an erlang resource file.</fsummary>
+ <desc>
+ <p>Search <c>PathList</c> and load <c>.erlang</c> resource file if
+ found.</p>
+ </desc>
+ </func>
+
+ <func>
<name name="flush" arity="0"/>
<fsummary>Flush any messages sent to the shell.</fsummary>
<desc>
diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml
index 80c4acffdb..5e631aac21 100644
--- a/lib/stdlib/doc/src/filelib.xml
+++ b/lib/stdlib/doc/src/filelib.xml
@@ -45,6 +45,30 @@
<p>For more information about raw filenames, see the
<seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+ <note>
+ <p>
+ Functionality in this module generally assumes valid input and
+ does not necessarily fail on input that does not use a valid
+ encoding, but may instead very likely produce invalid output.
+ </p>
+ <p>
+ File operations used to accept filenames containing
+ null characters (integer value zero). This caused
+ the name to be truncated and in some cases arguments
+ to primitive operations to be mixed up. Filenames
+ containing null characters inside the filename
+ are now <em>rejected</em> and will cause primitive
+ file operations to fail.
+ </p>
+ </note>
+ <warning><p>
+ Currently null characters at the end of the filename
+ will be accepted by primitive file operations. Such
+ filenames are however still documented as invalid. The
+ implementation will also change in the future and
+ reject such filenames.
+ </p></warning>
</description>
<datatypes>
@@ -193,6 +217,11 @@
<p>Other characters represent themselves. Only filenames that
have exactly the same character in the same position match.
Matching is case-sensitive, for example, "a" does not match "A".</p>
+ <p>Directory separators must always be written as <c>/</c>, even on
+ Windows.</p>
+ <p>A character preceded by <c>\</c> loses its special meaning. Note
+ that <c>\</c> must be written as <c>\\</c> in a string literal.
+ For example, "\\?*" will match any filename starting with <c>?</c>.</p>
<p>Notice that multiple "*" characters are allowed
(as in Unix wildcards, but opposed to Windows/DOS wildcards).</p>
<p><em>Examples:</em></p>
diff --git a/lib/stdlib/doc/src/filename.xml b/lib/stdlib/doc/src/filename.xml
index 14fd5ef787..d2608ad542 100644
--- a/lib/stdlib/doc/src/filename.xml
+++ b/lib/stdlib/doc/src/filename.xml
@@ -46,7 +46,10 @@
filename by removing redundant directory separators, use
<seealso marker="#join/1"><c>join/1</c></seealso>.</p>
- <p>The module supports raw filenames in the way that if a binary is
+ <p>
+ The module supports
+ <seealso marker="unicode_usage#notes-about-raw-filenames">raw
+ filenames</seealso> in the way that if a binary is
present, or the filename cannot be interpreted according to the return
value of <seealso marker="kernel:file#native_name_encoding/0">
<c>file:native_name_encoding/0</c></seealso>, a raw filename is also
@@ -56,6 +59,30 @@
(the join operation is performed of course). For more information
about raw filenames, see the
<seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+ <note>
+ <p>
+ Functionality in this module generally assumes valid input and
+ does not necessarily fail on input that does not use a valid
+ encoding, but may instead very likely produce invalid output.
+ </p>
+ <p>
+ File operations used to accept filenames containing
+ null characters (integer value zero). This caused
+ the name to be truncated and in some cases arguments
+ to primitive operations to be mixed up. Filenames
+ containing null characters inside the filename
+ are now <em>rejected</em> and will cause primitive
+ file operations to fail.
+ </p>
+ </note>
+ <warning><p>
+ Currently null characters at the end of the filename
+ will be accepted by primitive file operations. Such
+ filenames are however still documented as invalid. The
+ implementation will also change in the future and
+ reject such filenames.
+ </p></warning>
</description>
<datatypes>
<datatype>
@@ -555,6 +582,7 @@ unsafe</pre>
["a:/","msdev","include"]</pre>
</desc>
</func>
+
</funcs>
</erlref>
diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml
index 7d137fc772..da74e793e6 100644
--- a/lib/stdlib/doc/src/gen_server.xml
+++ b/lib/stdlib/doc/src/gen_server.xml
@@ -60,6 +60,8 @@ gen_server:abcast -----> Module:handle_cast/2
- -----> Module:handle_info/2
+- -----> Module:handle_continue/2
+
- -----> Module:terminate/2
- -----> Module:code_change/3</pre>
@@ -88,6 +90,13 @@ gen_server:abcast -----> Module:handle_cast/2
implies at least two garbage collections (when hibernating and
shortly after waking up) and is not something you want to do
between each call to a busy server.</p>
+
+ <p>If the <c>gen_server</c> process needs to perform an action
+ immediately after initialization or to break the execution of a
+ callback into multiple steps, it can return <c>{continue,Continue}</c>
+ in place of the time-out or hibernation value, which will immediately
+ invoke the <c>handle_continue/2</c> callback.</p>
+
</description>
<funcs>
@@ -610,12 +619,15 @@ gen_server:abcast -----> Module:handle_cast/2
<v>State = term()</v>
<v>Result = {reply,Reply,NewState} | {reply,Reply,NewState,Timeout}</v>
<v>&nbsp;&nbsp;| {reply,Reply,NewState,hibernate}</v>
+ <v>&nbsp;&nbsp;| {reply,Reply,NewState,{continue,Continue}}</v>
<v>&nbsp;&nbsp;| {noreply,NewState} | {noreply,NewState,Timeout}</v>
<v>&nbsp;&nbsp;| {noreply,NewState,hibernate}</v>
+ <v>&nbsp;&nbsp;| {noreply,NewState,{continue,Continue}}</v>
<v>&nbsp;&nbsp;| {stop,Reason,Reply,NewState} | {stop,Reason,NewState}</v>
<v>&nbsp;Reply = term()</v>
<v>&nbsp;NewState = term()</v>
<v>&nbsp;Timeout = int()>=0 | infinity</v>
+ <v>&nbsp;Continue = term()</v>
<v>&nbsp;Reason = term()</v>
</type>
<desc>
@@ -673,9 +685,11 @@ gen_server:abcast -----> Module:handle_cast/2
<v>State = term()</v>
<v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v>
<v>&nbsp;&nbsp;| {noreply,NewState,hibernate}</v>
+ <v>&nbsp;&nbsp;| {noreply,NewState,{continue,Continue}}</v>
<v>&nbsp;&nbsp;| {stop,Reason,NewState}</v>
<v>&nbsp;NewState = term()</v>
<v>&nbsp;Timeout = int()>=0 | infinity</v>
+ <v>&nbsp;Continue = term()</v>
<v>&nbsp;Reason = term()</v>
</type>
<desc>
@@ -690,6 +704,41 @@ gen_server:abcast -----> Module:handle_cast/2
</func>
<func>
+ <name>Module:handle_continue(Continue, State) -> Result</name>
+ <fsummary>Handle a continue instruction.</fsummary>
+ <type>
+ <v>Continue = term()</v>
+ <v>State = term()</v>
+ <v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v>
+ <v>&nbsp;&nbsp;| {noreply,NewState,hibernate}</v>
+ <v>&nbsp;&nbsp;| {noreply,NewState,{continue,Continue}}</v>
+ <v>&nbsp;&nbsp;| {stop,Reason,NewState}</v>
+ <v>&nbsp;NewState = term()</v>
+ <v>&nbsp;Timeout = int()>=0 | infinity</v>
+ <v>&nbsp;Continue = term()</v>
+ <v>&nbsp;Reason = normal | term()</v>
+ </type>
+ <desc>
+ <note>
+ <p>This callback is optional, so callback modules need to
+ export it only if they return <c>{continue,Continue}</c>
+ from another callback. If continue is used and the callback
+ is not implemented, the process will exit with <c>undef</c>
+ error.</p>
+ </note>
+ <p>This function is called by a <c>gen_server</c> process whenever
+ a previous callback returns <c>{continue, Continue}</c>.
+ <c>handle_continue/2</c> is invoked immediately after the previous
+ callback, which makes it useful for performing work after
+ initialization or for splitting the work in a callback in
+ multiple steps, updating the process state along the way.</p>
+ <p>For a description of the other arguments and possible return values,
+ see <seealso marker="#Module:handle_call/3">
+ <c>Module:handle_call/3</c></seealso>.</p>
+ </desc>
+ </func>
+
+ <func>
<name>Module:handle_info(Info, State) -> Result</name>
<fsummary>Handle an incoming message.</fsummary>
<type>
@@ -697,6 +746,7 @@ gen_server:abcast -----> Module:handle_cast/2
<v>State = term()</v>
<v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v>
<v>&nbsp;&nbsp;| {noreply,NewState,hibernate}</v>
+ <v>&nbsp;&nbsp;| {noreply,NewState,{continue,Continue}}</v>
<v>&nbsp;&nbsp;| {stop,Reason,NewState}</v>
<v>&nbsp;NewState = term()</v>
<v>&nbsp;Timeout = int()>=0 | infinity</v>
@@ -726,7 +776,7 @@ gen_server:abcast -----> Module:handle_cast/2
<type>
<v>Args = term()</v>
<v>Result = {ok,State} | {ok,State,Timeout} | {ok,State,hibernate}</v>
- <v>&nbsp;| {stop,Reason} | ignore</v>
+ <v>&nbsp;| {ok,State,{continue,Continue}} | {stop,Reason} | ignore</v>
<v>&nbsp;State = term()</v>
<v>&nbsp;Timeout = int()>=0 | infinity</v>
<v>&nbsp;Reason = term()</v>
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index a7caa71dcb..4a824f073e 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -1329,7 +1329,7 @@ handle_event(_, _, State, Data) ->
<c><anno>T</anno></c> is the time-out time.
<c>{clean_timeout,<anno>T</anno>}</c> works like
just <c>T</c> described in the note above
- and uses a proxy process for <c>T &lt; infinity</c>,
+ and uses a proxy process
while <c>{dirty_timeout,<anno>T</anno>}</c>
bypasses the proxy process which is more lightweight.
</p>
@@ -1339,8 +1339,12 @@ handle_event(_, _, State, Data) ->
with <c>{dirty_timeout,<anno>T</anno>}</c>
to avoid that the calling process dies when the call
times out, you will have to be prepared to handle
- a late reply.
- So why not just let the calling process die?
+ a late reply. Note that there is an odd chance
+ to get a late reply even with
+ <c>{dirty_timeout,infinity}</c> or <c>infinity</c>
+ for example in the event of network problems.
+ So why not just let the calling process die
+ by not catching the exception?
</p>
</note>
<p>
@@ -1851,7 +1855,7 @@ handle_event(_, _, State, Data) ->
</p>
<note>
<p>
- Note that if the <c>gen_statem</c> is started trough
+ Note that if the <c>gen_statem</c> is started through
<seealso marker="proc_lib"><c>proc_lib</c></seealso>
and
<seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>,
diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml
index 8c7270816b..987d92989d 100644
--- a/lib/stdlib/doc/src/maps.xml
+++ b/lib/stdlib/doc/src/maps.xml
@@ -33,16 +33,31 @@
<p>This module contains functions for maps processing.</p>
</description>
+ <datatypes>
+ <datatype>
+ <name name="iterator"/>
+ <desc>
+ <p>An iterator representing the key value associations in a map.</p>
+ <p>Created using <seealso marker="#iterator-1"><c>maps:iterator/1</c></seealso>.</p>
+ <p>Consumed by <seealso marker="#next-1"><c>maps:next/1</c></seealso>,
+ <seealso marker="#filter-2"><c>maps:filter/2</c></seealso>,
+ <seealso marker="#fold-3"><c>maps:fold/3</c></seealso> and
+ <seealso marker="#map-2"><c>maps:map/2</c></seealso>.</p>
+ </desc>
+ </datatype>
+ </datatypes>
+
<funcs>
<func>
<name name="filter" arity="2"/>
<fsummary>Select pairs that satisfy a predicate.</fsummary>
<desc>
- <p>Returns a map <c><anno>Map2</anno></c> for which predicate
- <c><anno>Pred</anno></c> holds true in <c><anno>Map1</anno></c>.</p>
+ <p>Returns a map <c><anno>Map</anno></c> for which predicate
+ <c><anno>Pred</anno></c> holds true in <c><anno>MapOrIter</anno></c>.</p>
<p>The call fails with a <c>{badmap,Map}</c> exception if
- <c><anno>Map1</anno></c> is not a map, or with <c>badarg</c> if
- <c><anno>Pred</anno></c> is not a function of arity 2.</p>
+ <c><anno>MapOrIter</anno></c> is not a map or valid iterator,
+ or with <c>badarg</c> if <c><anno>Pred</anno></c> is not a
+ function of arity 2.</p>
<p><em>Example:</em></p>
<code type="none">
> M = #{a => 2, b => 3, c=> 4, "a" => 1, "b" => 2, "c" => 4},
@@ -76,12 +91,16 @@
<fsummary></fsummary>
<desc>
<p>Calls <c>F(K, V, AccIn)</c> for every <c><anno>K</anno></c> to value
- <c><anno>V</anno></c> association in <c><anno>Map</anno></c> in
+ <c><anno>V</anno></c> association in <c><anno>MapOrIter</anno></c> in
any order. Function <c>fun F/3</c> must return a new
accumulator, which is passed to the next successive call.
This function returns the final value of the accumulator. The initial
accumulator value <c><anno>Init</anno></c> is returned if the map is
empty.</p>
+ <p>The call fails with a <c>{badmap,Map}</c> exception if
+ <c><anno>MapOrIter</anno></c> is not a map or valid iterator,
+ or with <c>badarg</c> if <c><anno>Fun</anno></c> is not a
+ function of arity 3.</p>
<p><em>Example:</em></p>
<code type="none">
> Fun = fun(K,V,AccIn) when is_list(K) -> AccIn + V end,
@@ -169,6 +188,32 @@ false</code>
</func>
<func>
+ <name name="iterator" arity="1"/>
+ <fsummary>Create a map iterator.</fsummary>
+ <desc>
+ <p>Returns a map iterator <c><anno>Iterator</anno></c> that can
+ be used by <seealso marker="#next-1"><c>maps:next/1</c></seealso>
+ to traverse the key-value associations in a map. When iterating
+ over a map, the memory usage is guaranteed to be bounded no matter
+ the size of the map.</p>
+ <p>The call fails with a <c>{badmap,Map}</c> exception if
+ <c><anno>Map</anno></c> is not a map.</p>
+ <p><em>Example:</em></p>
+ <code type="none">
+> M = #{ a => 1, b => 2 }.
+#{a => 1,b => 2}
+> I = maps:iterator(M).
+[{a,1},{b,2}]
+> {K1, V1, I2} = maps:next(I).
+{a,1,[{b,2}]}
+> {K2, V2, I3} = maps:next(I2).
+{b,2,[]}
+> maps:next(I3).
+none</code>
+ </desc>
+ </func>
+
+ <func>
<name name="keys" arity="1"/>
<fsummary></fsummary>
<desc>
@@ -188,12 +233,16 @@ false</code>
<name name="map" arity="2"/>
<fsummary></fsummary>
<desc>
- <p>Produces a new map <c><anno>Map2</anno></c> by calling function
+ <p>Produces a new map <c><anno>Map</anno></c> by calling function
<c>fun F(K, V1)</c> for every <c><anno>K</anno></c> to value
- <c><anno>V1</anno></c> association in <c><anno>Map1</anno></c> in
+ <c><anno>V1</anno></c> association in <c><anno>MapOrIter</anno></c> in
any order. Function <c>fun F/2</c> must return value
<c><anno>V2</anno></c> to be associated with key <c><anno>K</anno></c>
- for the new map <c><anno>Map2</anno></c>.</p>
+ for the new map <c><anno>Map</anno></c>.</p>
+ <p>The call fails with a <c>{badmap,Map}</c> exception if
+ <c><anno>MapOrIter</anno></c> is not a map or valid iterator,
+ or with <c>badarg</c> if <c><anno>Fun</anno></c> is not a
+ function of arity 2.</p>
<p><em>Example:</em></p>
<code type="none">
> Fun = fun(K,V1) when is_list(K) -> V1*2 end,
@@ -234,6 +283,35 @@ false</code>
</func>
<func>
+ <name name="next" arity="1"/>
+ <fsummary>Get the next key and value from an iterator.</fsummary>
+ <desc>
+ <p>Returns the next key-value association in
+ <c><anno>Iterator</anno></c> and a new iterator for the
+ remaining associations in the iterator.
+ </p>
+ <p>
+ If there are no more associations in the iterator,
+ <c>none</c> is returned.
+ </p>
+ <p><em>Example:</em></p>
+ <code type="none">
+> Map = #{a => 1, b => 2, c => 3}.
+#{a => 1,b => 2,c => 3}
+> Iter = maps:iterator(Map).
+[{a,1},{b,2},{c,3}]
+> {_, _, Iter1} = maps:next(Iter).
+{a,1,[{b,2},{c,3}]}
+> {_, _, Iter2} = maps:next(Iter1).
+{b,2,[{c,3}]}
+> {_, _, Iter3} = maps:next(Iter2).
+{c,3,[]}
+> maps:next(Iter3).
+none</code>
+ </desc>
+ </func>
+
+ <func>
<name name="put" arity="3"/>
<fsummary></fsummary>
<desc>
diff --git a/lib/stdlib/doc/src/rand.xml b/lib/stdlib/doc/src/rand.xml
index 89fb858823..21f680a0ee 100644
--- a/lib/stdlib/doc/src/rand.xml
+++ b/lib/stdlib/doc/src/rand.xml
@@ -133,8 +133,9 @@
variable <c>rand_seed</c> to remember the current state.</p>
<p>If a process calls
- <seealso marker="#uniform-0"><c>uniform/0</c></seealso> or
- <seealso marker="#uniform-1"><c>uniform/1</c></seealso> without
+ <seealso marker="#uniform-0"><c>uniform/0</c></seealso>,
+ <seealso marker="#uniform-1"><c>uniform/1</c></seealso> or
+ <seealso marker="#uniform_real-0"><c>uniform_real/0</c></seealso> without
setting a seed first, <seealso marker="#seed-1"><c>seed/1</c></seealso>
is called automatically with the default algorithm and creates a
non-constant seed.</p>
@@ -168,10 +169,17 @@ R3 = rand:uniform(),</pre>
S0 = rand:seed_s(exrop),
{R4, S1} = rand:uniform_s(S0),</pre>
+ <p>Textbook basic form Box-Muller standard normal deviate</p>
+
+ <pre>
+R5 = rand:uniform_real(),
+R6 = rand:uniform(),
+SND0 = math:sqrt(-2 * math:log(R5)) * math:cos(math:pi() * R6)</pre>
+
<p>Create a standard normal deviate:</p>
<pre>
-{SND0, S2} = rand:normal_s(S1),</pre>
+{SND1, S2} = rand:normal_s(S1),</pre>
<p>Create a normal deviate with mean -3 and variance 0.5:</p>
@@ -414,7 +422,8 @@ tests. We suggest to use a sign test to extract a random Boolean value.</pre>
This function may return exactly <c>0.0</c> which can be
fatal for certain applications. If that is undesired
you can use <c>(1.0 - rand:uniform())</c> to get the
- interval <c>0.0 &lt; <anno>X</anno> =&lt; 1.0</c>.
+ interval <c>0.0 &lt; <anno>X</anno> =&lt; 1.0</c>, or instead use
+ <seealso marker="#uniform_real-0"><c>uniform_real/0</c></seealso>.
</p>
<p>
If neither endpoint is desired you can test and re-try
@@ -432,6 +441,42 @@ end.</pre>
</func>
<func>
+ <name name="uniform_real" arity="0"/>
+ <fsummary>Return a random float.</fsummary>
+ <desc><marker id="uniform_real-0"/>
+ <p>
+ Returns a random float
+ uniformly distributed in the value range
+ <c>DBL_MIN =&lt; <anno>X</anno> &lt; 1.0</c>
+ and updates the state in the process dictionary.
+ </p>
+ <p>
+ Conceptually, a random real number <c>R</c> is generated
+ from the interval <c>0 =&lt; R &lt; 1</c> and then the
+ closest rounded down normalized number
+ in the IEEE 754 Double precision format
+ is returned.
+ </p>
+ <note>
+ <p>
+ The generated numbers from this function has got better
+ granularity for small numbers than the regular
+ <seealso marker="#uniform-0"><c>uniform/0</c></seealso>
+ because all bits in the mantissa are random.
+ This property, in combination with the fact that exactly zero
+ is never returned is useful for algoritms doing for example
+ <c>1.0 / <anno>X</anno></c> or <c>math:log(<anno>X</anno>)</c>.
+ </p>
+ </note>
+ <p>
+ See
+ <seealso marker="#uniform_real_s-1"><c>uniform_real_s/1</c></seealso>
+ for more explanation.
+ </p>
+ </desc>
+ </func>
+
+ <func>
<name name="uniform" arity="1"/>
<fsummary>Return a random integer.</fsummary>
<desc><marker id="uniform-1"/>
@@ -460,7 +505,8 @@ end.</pre>
This function may return exactly <c>0.0</c> which can be
fatal for certain applications. If that is undesired
you can use <c>(1.0 - rand:uniform(State))</c> to get the
- interval <c>0.0 &lt; <anno>X</anno> =&lt; 1.0</c>.
+ interval <c>0.0 &lt; <anno>X</anno> =&lt; 1.0</c>, or instead use
+ <seealso marker="#uniform_real_s-1"><c>uniform_real_s/1</c></seealso>.
</p>
<p>
If neither endpoint is desired you can test and re-try
@@ -478,6 +524,68 @@ end.</pre>
</func>
<func>
+ <name name="uniform_real_s" arity="1"/>
+ <fsummary>Return a random float.</fsummary>
+ <desc>
+ <p>
+ Returns, for a specified state, a random float
+ uniformly distributed in the value range
+ <c>DBL_MIN =&lt; <anno>X</anno> &lt; 1.0</c>
+ and updates the state in the process dictionary.
+ </p>
+ <p>
+ Conceptually, a random real number <c>R</c> is generated
+ from the interval <c>0 =&lt; R &lt; 1</c> and then the
+ closest rounded down normalized number
+ in the IEEE 754 Double precision format
+ is returned.
+ </p>
+ <note>
+ <p>
+ The generated numbers from this function has got better
+ granularity for small numbers than the regular
+ <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso>
+ because all bits in the mantissa are random.
+ This property, in combination with the fact that exactly zero
+ is never returned is useful for algoritms doing for example
+ <c>1.0 / <anno>X</anno></c> or <c>math:log(<anno>X</anno>)</c>.
+ </p>
+ </note>
+ <p>
+ The concept implicates that the probability to get
+ exactly zero is extremely low; so low that this function
+ is in fact guaranteed to never return zero. The smallest
+ number that it might return is <c>DBL_MIN</c>, which is
+ 2.0^(-1022).
+ </p>
+ <p>
+ The value range stated at the top of this function
+ description is technically correct, but
+ <c>0.0 =&lt; <anno>X</anno> &lt; 1.0</c>
+ is a better description of the generated numbers'
+ statistical distribution. Except that exactly 0.0
+ is never returned, which is not possible to observe
+ statistically.
+ </p>
+ <p>
+ For example; for all sub ranges
+ <c>N*2.0^(-53) =&lt; X &lt; (N+1)*2.0^(-53)</c>
+ where
+ <c>0 =&lt; integer(N) &lt; 2.0^53</c>
+ the probability is the same.
+ Compare that with the form of the numbers generated by
+ <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso>.
+ </p>
+ <p>
+ Having to generate extra random bits for
+ small numbers costs a little performance.
+ This function is about 20% slower than the regular
+ <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso>
+ </p>
+ </desc>
+ </func>
+
+ <func>
<name name="uniform_s" arity="2"/>
<fsummary>Return a random integer.</fsummary>
<desc>
diff --git a/lib/stdlib/doc/src/ref_man.xml b/lib/stdlib/doc/src/ref_man.xml
index 878a3babc5..68bfddbc71 100644
--- a/lib/stdlib/doc/src/ref_man.xml
+++ b/lib/stdlib/doc/src/ref_man.xml
@@ -93,6 +93,7 @@
<xi:include href="sys.xml"/>
<xi:include href="timer.xml"/>
<xi:include href="unicode.xml"/>
+ <xi:include href="uri_string.xml"/>
<xi:include href="win32reg.xml"/>
<xi:include href="zip.xml"/>
</application>
diff --git a/lib/stdlib/doc/src/specs.xml b/lib/stdlib/doc/src/specs.xml
index 45b207b13d..d559adf9b6 100644
--- a/lib/stdlib/doc/src/specs.xml
+++ b/lib/stdlib/doc/src/specs.xml
@@ -60,6 +60,7 @@
<xi:include href="../specs/specs_sys.xml"/>
<xi:include href="../specs/specs_timer.xml"/>
<xi:include href="../specs/specs_unicode.xml"/>
+ <xi:include href="../specs/specs_uri_string.xml"/>
<xi:include href="../specs/specs_win32reg.xml"/>
<xi:include href="../specs/specs_zip.xml"/>
</specs>
diff --git a/lib/stdlib/doc/src/string.xml b/lib/stdlib/doc/src/string.xml
index 9d5edd9ecf..130fc74a28 100644
--- a/lib/stdlib/doc/src/string.xml
+++ b/lib/stdlib/doc/src/string.xml
@@ -109,10 +109,8 @@
<p>This module has been reworked in Erlang/OTP 20 to
handle <seealso marker="unicode#type-chardata">
<c>unicode:chardata()</c></seealso> and operate on grapheme
- clusters. The <seealso marker="#oldapi"> <c>old
- functions</c></seealso> that only work on Latin-1 lists as input
- are still available but should not be
- used. They will be deprecated in Erlang/OTP 21.
+ clusters. The <c>old functions</c> that only work on Latin-1 lists as input
+ are kept for backwards compatibility reasons but should not be used.
</p>
</description>
@@ -594,7 +592,7 @@ ÖÄÅ</pre>
or <c>both</c>, indicates from which direction characters
are to be removed.
</p>
- <p> Default <c><anno>Characters</anno></c> are the set of
+ <p> Default <c><anno>Characters</anno></c> is the set of
nonbreakable whitespace codepoints, defined as
Pattern_White_Space in
<url href="http://unicode.org/reports/tr31/">Unicode Standard Annex #31</url>.
@@ -631,393 +629,5 @@ ÖÄÅ</pre>
</func>
</funcs>
-
- <section>
- <marker id="oldapi"/>
- <title>Obsolete API functions</title>
- <p>Here follows the function of the old API.
- These functions only work on a list of Latin-1 characters.
- </p>
- <note><p>
- The functions are kept for backward compatibility, but are
- not recommended.
- They will be deprecated in Erlang/OTP 21.
- </p>
- <p>Any undocumented functions in <c>string</c> are not to be used.</p>
- </note>
- </section>
-
- <funcs>
- <func>
- <name name="centre" arity="2"/>
- <name name="centre" arity="3"/>
- <fsummary>Center a string.</fsummary>
- <desc>
- <p>Returns a string, where <c><anno>String</anno></c> is centered in the
- string and surrounded by blanks or <c><anno>Character</anno></c>.
- The resulting string has length <c><anno>Number</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#pad/3"><c>pad/3</c></seealso>.
- </p>
- </desc>
- </func>
-
- <func>
- <name name="chars" arity="2"/>
- <name name="chars" arity="3"/>
- <fsummary>Return a string consisting of numbers of characters.</fsummary>
- <desc>
- <p>Returns a string consisting of <c><anno>Number</anno></c> characters
- <c><anno>Character</anno></c>. Optionally, the string can end with
- string <c><anno>Tail</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="lists#duplicate/2"><c>lists:duplicate/2</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="chr" arity="2"/>
- <fsummary>Return the index of the first occurrence of
- a character in a string.</fsummary>
- <desc>
- <p>Returns the index of the first occurrence of
- <c><anno>Character</anno></c> in <c><anno>String</anno></c>. Returns
- <c>0</c> if <c><anno>Character</anno></c> does not occur.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#find/2"><c>find/2</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="concat" arity="2"/>
- <fsummary>Concatenate two strings.</fsummary>
- <desc>
- <p>Concatenates <c><anno>String1</anno></c> and
- <c><anno>String2</anno></c> to form a new string
- <c><anno>String3</anno></c>, which is returned.</p>
- <p>
- This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use <c>[<anno>String1</anno>, <anno>String2</anno>]</c> as
- <c>Data</c> argument, and call
- <seealso marker="unicode#characters_to_list/2">
- <c>unicode:characters_to_list/2</c></seealso> or
- <seealso marker="unicode#characters_to_binary/2">
- <c>unicode:characters_to_binary/2</c></seealso>
- to flatten the output.
- </p>
- </desc>
- </func>
-
- <func>
- <name name="copies" arity="2"/>
- <fsummary>Copy a string.</fsummary>
- <desc>
- <p>Returns a string containing <c><anno>String</anno></c> repeated
- <c><anno>Number</anno></c> times.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="lists#duplicate/2"><c>lists:duplicate/2</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="cspan" arity="2"/>
- <fsummary>Span characters at start of a string.</fsummary>
- <desc>
- <p>Returns the length of the maximum initial segment of
- <c><anno>String</anno></c>, which consists entirely of characters
- not from <c><anno>Chars</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#take/3"><c>take/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:cspan("\t abcdef", " \t").
-0</code>
- </desc>
- </func>
-
- <func>
- <name name="join" arity="2"/>
- <fsummary>Join a list of strings with separator.</fsummary>
- <desc>
- <p>Returns a string with the elements of <c><anno>StringList</anno></c>
- separated by the string in <c><anno>Separator</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="lists#join/2"><c>lists:join/2</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> join(["one", "two", "three"], ", ").
-"one, two, three"</code>
- </desc>
- </func>
-
- <func>
- <name name="left" arity="2"/>
- <name name="left" arity="3"/>
- <fsummary>Adjust left end of a string.</fsummary>
- <desc>
- <p>Returns <c><anno>String</anno></c> with the length adjusted in
- accordance with <c><anno>Number</anno></c>. The left margin is
- fixed. If <c>length(<anno>String</anno>)</c> &lt;
- <c><anno>Number</anno></c>, then <c><anno>String</anno></c> is padded
- with blanks or <c><anno>Character</anno></c>s.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#pad/2"><c>pad/2</c></seealso> or
- <seealso marker="#pad/3"><c>pad/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:left("Hello",10,$.).
-"Hello....."</code>
- </desc>
- </func>
-
- <func>
- <name name="len" arity="1"/>
- <fsummary>Return the length of a string.</fsummary>
- <desc>
- <p>Returns the number of characters in <c><anno>String</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#length/1"><c>length/1</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="rchr" arity="2"/>
- <fsummary>Return the index of the last occurrence of
- a character in a string.</fsummary>
- <desc>
- <p>Returns the index of the last occurrence of
- <c><anno>Character</anno></c> in <c><anno>String</anno></c>. Returns
- <c>0</c> if <c><anno>Character</anno></c> does not occur.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#find/3"><c>find/3</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="right" arity="2"/>
- <name name="right" arity="3"/>
- <fsummary>Adjust right end of a string.</fsummary>
- <desc>
- <p>Returns <c><anno>String</anno></c> with the length adjusted in
- accordance with <c><anno>Number</anno></c>. The right margin is
- fixed. If the length of <c>(<anno>String</anno>)</c> &lt;
- <c><anno>Number</anno></c>, then <c><anno>String</anno></c> is padded
- with blanks or <c><anno>Character</anno></c>s.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#pad/3"><c>pad/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:right("Hello", 10, $.).
-".....Hello"</code>
- </desc>
- </func>
-
- <func>
- <name name="rstr" arity="2"/>
- <fsummary>Find the index of a substring.</fsummary>
- <desc>
- <p>Returns the position where the last occurrence of
- <c><anno>SubString</anno></c> begins in <c><anno>String</anno></c>.
- Returns <c>0</c> if <c><anno>SubString</anno></c>
- does not exist in <c><anno>String</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#find/3"><c>find/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:rstr(" Hello Hello World World ", "Hello World").
-8</code>
- </desc>
- </func>
-
- <func>
- <name name="span" arity="2"/>
- <fsummary>Span characters at start of a string.</fsummary>
- <desc>
- <p>Returns the length of the maximum initial segment of
- <c><anno>String</anno></c>, which consists entirely of characters
- from <c><anno>Chars</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#take/2"><c>take/2</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:span("\t abcdef", " \t").
-5</code>
- </desc>
- </func>
-
- <func>
- <name name="str" arity="2"/>
- <fsummary>Find the index of a substring.</fsummary>
- <desc>
- <p>Returns the position where the first occurrence of
- <c><anno>SubString</anno></c> begins in <c><anno>String</anno></c>.
- Returns <c>0</c> if <c><anno>SubString</anno></c>
- does not exist in <c><anno>String</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#find/2"><c>find/2</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:str(" Hello Hello World World ", "Hello World").
-8</code>
- </desc>
- </func>
-
- <func>
- <name name="strip" arity="1"/>
- <name name="strip" arity="2"/>
- <name name="strip" arity="3"/>
- <fsummary>Strip leading or trailing characters.</fsummary>
- <desc>
- <p>Returns a string, where leading or trailing, or both, blanks or a
- number of <c><anno>Character</anno></c> have been removed.
- <c><anno>Direction</anno></c>, which can be <c>left</c>, <c>right</c>,
- or <c>both</c>, indicates from which direction blanks are to be
- removed. <c>strip/1</c> is equivalent to
- <c>strip(String, both)</c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#trim/3"><c>trim/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:strip("...Hello.....", both, $.).
-"Hello"</code>
- </desc>
- </func>
-
- <func>
- <name name="sub_string" arity="2"/>
- <name name="sub_string" arity="3"/>
- <fsummary>Extract a substring.</fsummary>
- <desc>
- <p>Returns a substring of <c><anno>String</anno></c>, starting at
- position <c><anno>Start</anno></c> to the end of the string, or to
- and including position <c><anno>Stop</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-sub_string("Hello World", 4, 8).
-"lo Wo"</code>
- </desc>
- </func>
-
- <func>
- <name name="substr" arity="2"/>
- <name name="substr" arity="3"/>
- <fsummary>Return a substring of a string.</fsummary>
- <desc>
- <p>Returns a substring of <c><anno>String</anno></c>, starting at
- position <c><anno>Start</anno></c>, and ending at the end of the
- string or at length <c><anno>Length</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> substr("Hello World", 4, 5).
-"lo Wo"</code>
- </desc>
- </func>
-
- <func>
- <name name="sub_word" arity="2"/>
- <name name="sub_word" arity="3"/>
- <fsummary>Extract subword.</fsummary>
- <desc>
- <p>Returns the word in position <c><anno>Number</anno></c> of
- <c><anno>String</anno></c>. Words are separated by blanks or
- <c><anno>Character</anno></c>s.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#nth_lexeme/3"><c>nth_lexeme/3</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> string:sub_word(" Hello old boy !",3,$o).
-"ld b"</code>
- </desc>
- </func>
-
- <func>
- <name name="to_lower" arity="1" clause_i="1"/>
- <name name="to_lower" arity="1" clause_i="2"/>
- <name name="to_upper" arity="1" clause_i="1"/>
- <name name="to_upper" arity="1" clause_i="2"/>
- <fsummary>Convert case of string (ISO/IEC 8859-1).</fsummary>
- <type variable="String" name_i="1"/>
- <type variable="Result" name_i="1"/>
- <type variable="Char"/>
- <type variable="CharResult"/>
- <desc>
- <p>The specified string or character is case-converted. Notice that
- the supported character set is ISO/IEC 8859-1 (also called Latin 1);
- all values outside this set are unchanged</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso> use
- <seealso marker="#lowercase/1"><c>lowercase/1</c></seealso>,
- <seealso marker="#uppercase/1"><c>uppercase/1</c></seealso>,
- <seealso marker="#titlecase/1"><c>titlecase/1</c></seealso> or
- <seealso marker="#casefold/1"><c>casefold/1</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="tokens" arity="2"/>
- <fsummary>Split string into tokens.</fsummary>
- <desc>
- <p>Returns a list of tokens in <c><anno>String</anno></c>, separated
- by the characters in <c><anno>SeparatorList</anno></c>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> tokens("abc defxxghix jkl", "x ").
-["abc", "def", "ghi", "jkl"]</code>
- <p>Notice that, as shown in this example, two or more
- adjacent separator characters in <c><anno>String</anno></c>
- are treated as one. That is, there are no empty
- strings in the resulting list of tokens.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#lexemes/2"><c>lexemes/2</c></seealso>.</p>
- </desc>
- </func>
-
- <func>
- <name name="words" arity="1"/>
- <name name="words" arity="2"/>
- <fsummary>Count blank separated words.</fsummary>
- <desc>
- <p>Returns the number of words in <c><anno>String</anno></c>, separated
- by blanks or <c><anno>Character</anno></c>.</p>
- <p>This function is <seealso marker="#oldapi">obsolete</seealso>.
- Use
- <seealso marker="#lexemes/2"><c>lexemes/2</c></seealso>.</p>
- <p><em>Example:</em></p>
- <code type="none">
-> words(" Hello old boy!", $o).
-4</code>
- </desc>
- </func>
- </funcs>
-
- <section>
- <title>Notes</title>
- <p>Some of the general string functions can seem to overlap each
- other. The reason is that this string package is the
- combination of two earlier packages and all functions of
- both packages have been retained.</p>
- </section>
-
</erlref>
diff --git a/lib/stdlib/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml
index 26dc46719e..789e063c12 100644
--- a/lib/stdlib/doc/src/unicode_usage.xml
+++ b/lib/stdlib/doc/src/unicode_usage.xml
@@ -719,8 +719,8 @@ Eshell V5.10.1 (abort with ^G)
</section>
<section>
- <title>Unicode Filenames</title>
<marker id="unicode_file_names"/>
+ <title>Unicode Filenames</title>
<p>Most modern operating systems support Unicode filenames in some way.
There are many different ways to do this and Erlang by default treats the
different approaches differently:</p>
@@ -855,8 +855,12 @@ Eshell V5.10.1 (abort with ^G)
</note>
<section>
- <title>Notes About Raw Filenames</title>
<marker id="notes-about-raw-filenames"/>
+ <title>Notes About Raw Filenames</title>
+ <note><p>
+ Note that raw filenames <em>not</em> necessarily are encoded the
+ same way as on the OS level.
+ </p></note>
<p>Raw filenames were introduced together with Unicode filename support
in ERTS 5.8.2 (Erlang/OTP R14B01). The reason &quot;raw
filenames&quot; were introduced in the system was
diff --git a/lib/stdlib/doc/src/uri_string.xml b/lib/stdlib/doc/src/uri_string.xml
new file mode 100644
index 0000000000..21f470e763
--- /dev/null
+++ b/lib/stdlib/doc/src/uri_string.xml
@@ -0,0 +1,326 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+ <header>
+ <copyright>
+ <year>2017</year><year>2017</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>uri_string</title>
+ <prepared>Péter Dimitrov</prepared>
+ <docno>1</docno>
+ <date>2017-10-24</date>
+ <rev>A</rev>
+ </header>
+ <module>uri_string</module>
+ <modulesummary>URI processing functions.</modulesummary>
+ <description>
+ <p>This module contains functions for parsing and handling URIs
+ (<url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>) and
+ form-urlencoded query strings (<url href="https://www.w3.org/TR/html5/forms.html">HTML5</url>).
+ </p>
+ <p>A URI is an identifier consisting of a sequence of characters matching the syntax
+ rule named <em>URI</em> in <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>.
+ </p>
+ <p> The generic URI syntax consists of a hierarchical sequence of components referred
+ to as the scheme, authority, path, query, and fragment:</p>
+ <pre>
+ URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
+ hier-part = "//" authority path-abempty
+ / path-absolute
+ / path-rootless
+ / path-empty
+ scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
+ authority = [ userinfo "@" ] host [ ":" port ]
+ userinfo = *( unreserved / pct-encoded / sub-delims / ":" )
+
+ reserved = gen-delims / sub-delims
+ gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@"
+ sub-delims = "!" / "$" / "&amp;" / "'" / "(" / ")"
+ / "*" / "+" / "," / ";" / "="
+
+ unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
+ </pre><br></br>
+ <p>The interpretation of a URI depends only on the characters used and not on how those
+ characters are represented in a network protocol.</p>
+ <p>The functions implemented by this module cover the following use cases:</p>
+ <list type="bulleted">
+ <item>Parsing URIs into its components and returing a map<br></br>
+ <seealso marker="#parse/1"><c>parse/1</c></seealso>
+ </item>
+ <item>Recomposing a map of URI components into a URI string<br></br>
+ <seealso marker="#recompose/1"><c>recompose/1</c></seealso>
+ </item>
+ <item>Changing inbound binary and percent-encoding of URIs<br></br>
+ <seealso marker="#transcode/2"><c>transcode/2</c></seealso>
+ </item>
+ <item>Transforming URIs into a normalized form<br></br>
+ <seealso marker="#normalize/1"><c>normalize/1</c></seealso>
+ </item>
+ <item>Composing form-urlencoded query strings from a list of key-value pairs<br></br>
+ <seealso marker="#compose_query/1"><c>compose_query/1</c></seealso><br></br>
+ <seealso marker="#compose_query/2"><c>compose_query/2</c></seealso>
+ </item>
+ <item>Dissecting form-urlencoded query strings into a list of key-value pairs<br></br>
+ <seealso marker="#dissect_query/1"><c>dissect_query/1</c></seealso>
+ </item>
+ </list>
+ <p>There are four different encodings present during the handling of URIs:</p>
+ <list type="bulleted">
+ <item>Inbound binary encoding in binaries</item>
+ <item>Inbound percent-encoding in lists and binaries</item>
+ <item>Outbound binary encoding in binaries</item>
+ <item>Outbound percent-encoding in lists and binaries</item>
+ </list>
+ <p>Functions with <c>uri_string()</c> argument accept lists, binaries and
+ mixed lists (lists with binary elements) as input type. All of the functions but
+ <c>transcode/2</c> expects input as lists of unicode codepoints, UTF-8 encoded binaries
+ and UTF-8 percent-encoded URI parts ("%C3%B6" corresponds to the unicode character "ö").</p>
+ <p>Unless otherwise specified the return value type and encoding are the same as the input
+ type and encoding. That is, binary input returns binary output, list input returns a list
+ output but mixed input returns list output.</p>
+ <p>In case of lists there is only percent-encoding. In binaries, however, both binary encoding
+ and percent-encoding shall be considered. <c>transcode/2</c> provides the means to convert
+ between the supported encodings, it takes a <c>uri_string()</c> and a list of options
+ specifying inbound and outbound encodings.</p>
+ <p><url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> does not mandate any specific
+ character encoding and it is usually defined by the protocol or surrounding text. This library
+ takes the same assumption, binary and percent-encoding are handled as one configuration unit,
+ they cannot be set to different values.</p>
+ </description>
+
+ <datatypes>
+ <datatype>
+ <name name="error"/>
+ <desc>
+ <p>Error tuple indicating the type of error. Possible values of the second component:</p>
+ <list type="bulleted">
+ <item><c>invalid_character</c></item>
+ <item><c>invalid_encoding</c></item>
+ <item><c>invalid_input</c></item>
+ <item><c>invalid_map</c></item>
+ <item><c>invalid_percent_encoding</c></item>
+ <item><c>invalid_scheme</c></item>
+ <item><c>invalid_uri</c></item>
+ <item><c>invalid_utf8</c></item>
+ <item><c>missing_value</c></item>
+ </list>
+ <p>The third component is a term providing additional information about the
+ cause of the error.</p>
+ </desc>
+ </datatype>
+ <datatype>
+ <name name="uri_map"/>
+ <desc>
+ <p>Map holding the main components of a URI.</p>
+ </desc>
+ </datatype>
+ <datatype>
+ <name name="uri_string"/>
+ <desc>
+ <p>List of unicode codepoints, a UTF-8 encoded binary, or a mix of the two,
+ representing an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>
+ compliant URI (<em>percent-encoded form</em>).
+ A URI is a sequence of characters from a very limited set: the letters of
+ the basic Latin alphabet, digits, and a few special characters.</p>
+ </desc>
+ </datatype>
+ </datatypes>
+
+ <funcs>
+
+ <func>
+ <name name="compose_query" arity="1"/>
+ <fsummary>Compose urlencoded query string.</fsummary>
+ <desc>
+ <p>Composes a form-urlencoded <c><anno>QueryString</anno></c> based on a
+ <c><anno>QueryList</anno></c>, a list of non-percent-encoded key-value pairs.
+ Form-urlencoding is defined in section
+ 4.10.22.6 of the <url href="https://www.w3.org/TR/html5/forms.html">HTML5</url>
+ specification.
+ </p>
+ <p>See also the opposite operation <seealso marker="#dissect_query/1">
+ <c>dissect_query/1</c></seealso>.
+ </p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input>uri_string:compose_query([{"foo bar","1"},{"city","örebro"}]).</input>
+<![CDATA["foo+bar=1&city=%C3%B6rebro"]]>
+2> <![CDATA[uri_string:compose_query([{<<"foo bar">>,<<"1">>},
+2> {<<"city">>,<<"örebro"/utf8>>}]).]]>
+<![CDATA[<<"foo+bar=1&city=%C3%B6rebro">>]]>
+ </pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="compose_query" arity="2"/>
+ <fsummary>Compose urlencoded query string.</fsummary>
+ <desc>
+ <p>Same as <c>compose_query/1</c> but with an additional
+ <c><anno>Options</anno></c> parameter, that controls the encoding ("charset")
+ used by the encoding algorithm. There are two supported encodings: <c>utf8</c>
+ (or <c>unicode</c>) and <c>latin1</c>.
+ </p>
+ <p>Each character in the entry's name and value that cannot be expressed using
+ the selected character encoding, is replaced by a string consisting of a U+0026
+ AMPERSAND character (<![CDATA[&]]>), a "#" (U+0023) character, one or more ASCII
+ digits representing the Unicode code point of the character in base ten, and
+ finally a ";" (U+003B) character.
+ </p>
+ <p>Bytes that are out of the range 0x2A, 0x2D, 0x2E, 0x30 to 0x39, 0x41 to 0x5A, 0x5F,
+ 0x61 to 0x7A, are percent-encoded (U+0025 PERCENT SIGN character (%) followed by
+ uppercase ASCII hex digits representing the hexadecimal value of the byte).
+ </p>
+ <p>See also the opposite operation <seealso marker="#dissect_query/1">
+ <c>dissect_query/1</c></seealso>.
+ </p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input>uri_string:compose_query([{"foo bar","1"},{"city","örebro"}],</input>
+1> [{encoding, latin1}]).
+<![CDATA["foo+bar=1&city=%F6rebro"
+2> uri_string:compose_query([{<<"foo bar">>,<<"1">>},
+2> {<<"city">>,<<"東京"/utf8>>}], [{encoding, latin1}]).]]>
+<![CDATA[<<"foo+bar=1&city=%26%2326481%3B%26%2320140%3B">>]]>
+ </pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="dissect_query" arity="1"/>
+ <fsummary>Dissect query string.</fsummary>
+ <desc>
+ <p>Dissects an urlencoded <c><anno>QueryString</anno></c> and returns a
+ <c><anno>QueryList</anno></c>, a list of non-percent-encoded key-value pairs.
+ Form-urlencoding is defined in section
+ 4.10.22.6 of the <url href="https://www.w3.org/TR/html5/forms.html">HTML5</url>
+ specification.
+ </p>
+ <p>It is not as strict for its input as the decoding algorithm defined by
+ <url href="https://www.w3.org/TR/html5/forms.html">HTML5</url>
+ and accepts all unicode characters.</p>
+ <p>See also the opposite operation <seealso marker="#compose_query/1">
+ <c>compose_query/1</c></seealso>.
+ </p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input><![CDATA[uri_string:dissect_query("foo+bar=1&city=%C3%B6rebro").]]></input>
+[{"foo bar","1"},{"city","örebro"}]
+2> <![CDATA[uri_string:dissect_query(<<"foo+bar=1&city=%26%2326481%3B%26%2320140%3B">>).]]>
+<![CDATA[[{<<"foo bar">>,<<"1">>},
+ {<<"city">>,<<230,157,177,228,186,172>>}] ]]>
+ </pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="normalize" arity="1"/>
+ <fsummary>Syntax-based normalization.</fsummary>
+ <desc>
+ <p>Transforms <c><anno>URIString</anno></c> into a normalized form
+ using Syntax-Based Normalization as defined by
+ <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>.</p>
+ <p>This function implements case normalization, percent-encoding
+ normalization, path segment normalization and scheme based normalization
+ for HTTP(S) with basic support for FTP, SSH, SFTP and TFTP.</p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input>uri_string:normalize("/a/b/c/./../../g").</input>
+"/a/g"
+2> <![CDATA[uri_string:normalize(<<"mid/content=5/../6">>).]]>
+<![CDATA[<<"mid/6">>]]>
+3> uri_string:normalize("http://localhost:80").
+"https://localhost/"
+ </pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="parse" arity="1"/>
+ <fsummary>Parse URI into a map.</fsummary>
+ <desc>
+ <p>Parses an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>
+ compliant <c>uri_string()</c> into a <c>uri_map()</c>, that holds the parsed
+ components of the <c>URI</c>.
+ If parsing fails, an error tuple is returned.</p>
+ <p>See also the opposite operation <seealso marker="#recompose/1">
+ <c>recompose/1</c></seealso>.</p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input>uri_string:parse("foo://[email protected]:8042/over/there?name=ferret#nose").</input>
+#{fragment => "nose",host => "example.com",
+ path => "/over/there",port => 8042,query => "name=ferret",
+ scheme => foo,userinfo => "user"}
+2> <![CDATA[uri_string:parse(<<"foo://[email protected]:8042/over/there?name=ferret">>).]]>
+<![CDATA[#{host => <<"example.com">>,path => <<"/over/there">>,
+ port => 8042,query => <<"name=ferret">>,scheme => <<"foo">>,
+ userinfo => <<"user">>}]]>
+ </pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="recompose" arity="1"/>
+ <fsummary>Recompose URI.</fsummary>
+ <desc>
+ <p>Creates an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> compliant
+ <c><anno>URIString</anno></c> (percent-encoded), based on the components of
+ <c><anno>URIMap</anno></c>.
+ If the <c><anno>URIMap</anno></c> is invalid, an error tuple is returned.</p>
+ <p>See also the opposite operation <seealso marker="#parse/1">
+ <c>parse/1</c></seealso>.</p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input>URIMap = #{fragment => "nose", host => "example.com", path => "/over/there",</input>
+1> port => 8042, query => "name=ferret", scheme => "foo", userinfo => "user"}.
+#{fragment => "top",host => "example.com",
+ path => "/over/there",port => 8042,query => "?name=ferret",
+ scheme => foo,userinfo => "user"}
+
+2> <input>uri_string:recompose(URIMap).</input>
+"foo://example.com:8042/over/there?name=ferret#nose"</pre>
+ </desc>
+ </func>
+
+ <func>
+ <name name="transcode" arity="2"/>
+ <fsummary>Transcode URI.</fsummary>
+ <desc>
+ <p>Transcodes an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>
+ compliant <c><anno>URIString</anno></c>,
+ where <c><anno>Options</anno></c> is a list of tagged tuples, specifying the inbound
+ (<c>in_encoding</c>) and outbound (<c>out_encoding</c>) encodings. <c>in_encoding</c>
+ and <c>out_encoding</c> specifies both binary encoding and percent-encoding for the
+ input and output data. Mixed encoding, where binary encoding is not the same as
+ percent-encoding, is not supported.
+ If an argument is invalid, an error tuple is returned.</p>
+ <p><em>Example:</em></p>
+ <pre>
+1> <input><![CDATA[uri_string:transcode(<<"foo%00%00%00%F6bar"/utf32>>,]]></input>
+1> [{in_encoding, utf32},{out_encoding, utf8}]).
+<![CDATA[<<"foo%C3%B6bar"/utf8>>]]>
+2> uri_string:transcode("foo%F6bar", [{in_encoding, latin1},
+2> {out_encoding, utf8}]).
+"foo%C3%B6bar"
+ </pre>
+ </desc>
+ </func>
+
+ </funcs>
+</erlref>