diff options
Diffstat (limited to 'lib/stdlib/doc/src/erl_pp.xml')
| -rw-r--r-- | lib/stdlib/doc/src/erl_pp.xml | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/lib/stdlib/doc/src/erl_pp.xml b/lib/stdlib/doc/src/erl_pp.xml new file mode 100644 index 0000000000..6b15c5afd3 --- /dev/null +++ b/lib/stdlib/doc/src/erl_pp.xml @@ -0,0 +1,178 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>1996</year> + <year>2007</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. + + The Initial Developer of the Original Code is Ericsson AB. + </legalnotice> + + <title>erl_pp</title> + <prepared>Robert Virding</prepared> + <responsible>Bjarne Däcker</responsible> + <docno>1</docno> + <approved>Bjarne Däcker</approved> + <checked></checked> + <date>97-01-24</date> + <rev>B</rev> + <file>erl_pp.sgml</file> + </header> + <module>erl_pp</module> + <modulesummary>The Erlang Pretty Printer</modulesummary> + <description> + <p>The functions in this module are used to generate + aesthetically attractive representations of abstract + forms, which are suitable for printing. All functions return (possibly deep) + lists of characters and generate an error if the form is wrong.</p> + <p>All functions can have an optional argument which specifies a hook + that is called if an attempt is made to print an unknown form.</p> + </description> + <funcs> + <func> + <name>form(Form) -> DeepCharList</name> + <name>form(Form, HookFunction) -> DeepCharList</name> + <fsummary>Pretty print a form</fsummary> + <type> + <v>Form = term()</v> + <v>HookFunction = see separate description below.</v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>Pretty prints a + <c>Form</c> which is an abstract form of a type which is + returned by <c>erl_parse:parse_form</c>.</p> + </desc> + </func> + <func> + <name>attribute(Attribute) -> DeepCharList</name> + <name>attribute(Attribute, HookFunction) -> DeepCharList</name> + <fsummary>Pretty print an attribute</fsummary> + <type> + <v>Attribute = term()</v> + <v>HookFunction = see separate description below.</v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>The same as <c>form</c>, but only for the attribute + <c>Attribute</c>.</p> + </desc> + </func> + <func> + <name>function(Function) -> DeepCharList</name> + <name>function(Function, HookFunction) -> DeepCharList</name> + <fsummary>Pretty print a function</fsummary> + <type> + <v>Function = term()</v> + <v>HookFunction = see separate description below.</v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>The same as <c>form</c>, but only for the function + <c>Function</c>.</p> + </desc> + </func> + <func> + <name>guard(Guard) -> DeepCharList</name> + <name>guard(Guard, HookFunction) -> DeepCharList</name> + <fsummary>Pretty print a guard</fsummary> + <type> + <v>Form = term()</v> + <v>HookFunction = see separate description below.</v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>The same as <c>form</c>, but only for the guard test + <c>Guard</c>.</p> + </desc> + </func> + <func> + <name>exprs(Expressions) -> DeepCharList</name> + <name>exprs(Expressions, HookFunction) -> DeepCharList</name> + <name>exprs(Expressions, Indent, HookFunction) -> DeepCharList</name> + <fsummary>Pretty print <c>Expressions</c></fsummary> + <type> + <v>Expressions = term()</v> + <v>HookFunction = see separate description below.</v> + <v>Indent = integer()</v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>The same as <c>form</c>, but only for the sequence of + expressions in <c>Expressions</c>.</p> + </desc> + </func> + <func> + <name>expr(Expression) -> DeepCharList</name> + <name>expr(Expression, HookFunction) -> DeepCharList</name> + <name>expr(Expression, Indent, HookFunction) -> DeepCharList</name> + <name>expr(Expression, Indent, Precedence, HookFunction) ->-> DeepCharList</name> + <fsummary>Pretty print one <c>Expression</c></fsummary> + <type> + <v>Expression = term()</v> + <v>HookFunction = see separate description below.</v> + <v>Indent = integer()</v> + <v>Precedence = </v> + <v>DeepCharList = [char()|DeepCharList]</v> + </type> + <desc> + <p>This function prints one expression. It is useful for implementing hooks (see below).</p> + </desc> + </func> + </funcs> + + <section> + <title>Unknown Expression Hooks</title> + <p>The optional argument <c>HookFunction</c>, shown in the functions described above, defines a function which is called when an unknown form occurs where there + should be a valid expression. It can have the following formats:</p> + <taglist> + <tag><c>Function</c></tag> + <item> + <p>The hook function is called by:</p> + <code type="none"> +Function(Expr, + CurrentIndentation, + CurrentPrecedence, + HookFunction) </code> + </item> + <tag><c>none</c></tag> + <item> + <p>There is no hook function</p> + </item> + </taglist> + <p>The called hook function should return a (possibly deep) list + of characters. <c>expr/4</c> is useful in a hook. + </p> + <p>If <c>CurrentIndentation</c> is negative, there will be no line + breaks and only a space is used as a separator.</p> + </section> + + <section> + <title>Bugs</title> + <p>It should be possible to have hook functions for unknown forms + at places other than expressions.</p> + </section> + + <section> + <title>See Also</title> + <p><seealso marker="io">io(3)</seealso>, + <seealso marker="erl_parse">erl_parse(3)</seealso>, + <seealso marker="erl_eval">erl_eval(3)</seealso></p> + </section> +</erlref> + |