| 1 |
<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
|
| 2 |
<page>
|
| 3 |
|
| 4 |
<title>CDuce memento</title>
|
| 5 |
<banner> CDuce memento </banner>
|
| 6 |
|
| 7 |
<!-- ********* Left panel ********* -->
|
| 8 |
<navig>
|
| 9 |
<toc/>
|
| 10 |
<box>
|
| 11 |
<p>
|
| 12 |
This page briefly presents the syntax of the CDuce language.
|
| 13 |
</p>
|
| 14 |
|
| 15 |
<ul>
|
| 16 |
<li><a href="/cgi-bin/cduce">Online demo</a></li>
|
| 17 |
<li><a href="/">Home page</a></li>
|
| 18 |
</ul>
|
| 19 |
</box>
|
| 20 |
</navig>
|
| 21 |
|
| 22 |
<!-- ********* Main panel ********* -->
|
| 23 |
|
| 24 |
<main>
|
| 25 |
|
| 26 |
<box title="Identifiers" link="id">
|
| 27 |
<ul>
|
| 28 |
<li> Type and Pattern identifiers: words formed by of unicode letters and and
|
| 29 |
the underscore "_" character, starting by a capitalized letter. </li>
|
| 30 |
|
| 31 |
<li> value identifiers: words formed by of unicode letters and the underscore "
|
| 32 |
_" character, starting by a capitalized letter or underscore.</li>
|
| 33 |
</ul>
|
| 34 |
</box>
|
| 35 |
|
| 36 |
<box title="Scalars" link="scalars">
|
| 37 |
<ul>
|
| 38 |
<li>Large integers:
|
| 39 |
<ul>
|
| 40 |
<li>Values: <duce>0,1,2,3,...</duce> </li>
|
| 41 |
<li>Types: intervals <duce>-*--10, 20--30, 50--*, ...</duce>,
|
| 42 |
singletons <duce>0,1,2,3,...</duce> </li>
|
| 43 |
<li>Operators: <duce>+,-,/,*,div,mod, int_of</duce> </li>
|
| 44 |
</ul>
|
| 45 |
</li>
|
| 46 |
<li>Unicode characters:
|
| 47 |
<ul>
|
| 48 |
<li>Values: <duce>'a','b','c'...</duce> </li>
|
| 49 |
<li>Types: intervals <duce>'a'--'z', '0'--'9'</duce>,
|
| 50 |
singletons <duce>'a','b','c',...</duce> </li>
|
| 51 |
</ul>
|
| 52 |
</li>
|
| 53 |
<li>Symbolic atoms:
|
| 54 |
<ul>
|
| 55 |
<li>Values: <duce>`A, `B, `a, `b, `true, `false, ...</duce> </li>
|
| 56 |
<li>Types: singletons <duce>`A, `B, ...</duce> </li>
|
| 57 |
</ul>
|
| 58 |
</li>
|
| 59 |
</ul>
|
| 60 |
</box>
|
| 61 |
|
| 62 |
<box title="Operators" link="op">
|
| 63 |
<ul>
|
| 64 |
<li>Infix:
|
| 65 |
<br/> <duce>@</duce> : String,String -> String
|
| 66 |
<br/> <duce>+,*,-,div,mod</duce> : Integer,Integer -> Integer
|
| 67 |
<br/> <duce>=, <<, <=, >>, >= </duce> :
|
| 68 |
Integer,Integer -> Bool = <duce>`true | `false</duce>
|
| 69 |
</li>
|
| 70 |
<li>Prefix:
|
| 71 |
<br/><duce>load_xml,load_html, dump_to_file</duce> : String -> Any
|
| 72 |
<br/><duce>print_xml</duce> : Any -> String
|
| 73 |
<br/><duce>print</duce> : String -> []
|
| 74 |
<br/><duce>int_of</duce> : [('0'--'9')+] -> Integer
|
| 75 |
<br/><duce>string_of</duce> : Integer -> String
|
| 76 |
</li>
|
| 77 |
<li>Postfix:
|
| 78 |
<br/><duce>?,*,+,??,*?,+?</duce> : for regexp
|
| 79 |
</li>
|
| 80 |
</ul>
|
| 81 |
</box>
|
| 82 |
|
| 83 |
<box title="Pairs" link="pair">
|
| 84 |
<ul>
|
| 85 |
<li>Expressions: <duce>(e1,e2)</duce> </li>
|
| 86 |
<li>Types and patterns: <duce>(t1,t2)</duce> </li>
|
| 87 |
<li>Note: tuples are right-associative pairs; e.g.:
|
| 88 |
<duce>(1,2,3)=(1,(2,3))</duce> </li>
|
| 89 |
<li>When a capture variable appears on both side of a pair pattern,
|
| 90 |
the two captured values are paired
|
| 91 |
together (e.g. <duce>match (1,2,3) with (x,(_,x)) -> x ==>
|
| 92 |
(1,3)</duce>). </li>
|
| 93 |
</ul>
|
| 94 |
</box>
|
| 95 |
|
| 96 |
<box title="Sequences" link="seq">
|
| 97 |
<ul>
|
| 98 |
<li>Expressions: <duce>[ 1 2 3 ]</duce>,
|
| 99 |
which is syntactic sugar for <duce>(1,(2,(3,`nil)))</duce> </li>
|
| 100 |
<li>A sub-sequence can be escaped by !: <duce>[ 1 2 ![ 3 4 ] 5
|
| 101 |
]</duce> is then equal to <duce>[ 1 2 3 4 5 ]</duce> . </li>
|
| 102 |
<li>Types and patterns : <duce>[ R ]</duce> where <duce>R</duce> is
|
| 103 |
a regular expression built on types and patterns:
|
| 104 |
<ul>
|
| 105 |
<li>A type or a pattern is a regexp by itself, matching a single
|
| 106 |
element of the sequence </li>
|
| 107 |
<li>Postfix repetition operators: <duce>*,+,?</duce>
|
| 108 |
and the ungreedy variants (for patterns) <duce>*?, +?
|
| 109 |
,??</duce></li>
|
| 110 |
<li>Concatenation of regexps</li>
|
| 111 |
<li>For patterns, sequence capture variable <duce>x::R</duce> </li>
|
| 112 |
</ul>
|
| 113 |
</li>
|
| 114 |
<li>It is possible to specify a tail, for expressions, types, and patterns;
|
| 115 |
e.g.: <duce>[ x::Int*; q ]</duce> </li>
|
| 116 |
<li>Map: <duce>map e with p1 -> e1 | ... | pn -> en</duce>.
|
| 117 |
Each element of e must be matched. </li>
|
| 118 |
<li>Transform: <duce>transform e with p1 -> e1 | ... | pn -> en</duce>.
|
| 119 |
Unmatched elements are discarded; each branch returns a sequence
|
| 120 |
and all the resulting sequences are concatenated together. </li>
|
| 121 |
<li>Operators: concatenation <duce>e1 @ e2 = [ !e1 !e2 ]</duce>,
|
| 122 |
flattening <duce>flatten e = transform e with x -> x</duce>.
|
| 123 |
</li>
|
| 124 |
</ul>
|
| 125 |
</box>
|
| 126 |
|
| 127 |
<box title="Record" link="record">
|
| 128 |
<ul>
|
| 129 |
<li>Records litteral <duce>{ l1 = e1; ...; ln = en }</duce></li>
|
| 130 |
<li>Types: <duce>{| l1 = t1; ...; ln = tn |}</duce> (closed, no more
|
| 131 |
fields allowed), <duce>>{ l1 = t1; ...; ln = tn }</duce> (open,
|
| 132 |
any other field allowed). Optional fields: <duce>li =? ti</duce>
|
| 133 |
instead of <duce>li = ti</duce>.</li>
|
| 134 |
<li>Record concatenation: <duce>e1 + e2</duce>
|
| 135 |
(priority to the fields from the right argument) </li>
|
| 136 |
<li>Field removal: <duce>e1 \ l</duce> (does nothing if the
|
| 137 |
field <duce>l</duce> is not present)</li>
|
| 138 |
<li>Field access: <duce>e1 . l</duce></li>
|
| 139 |
<li>Record: <duce>{ l1 = p1; ...; ln = pn }</duce></li>
|
| 140 |
</ul>
|
| 141 |
</box>
|
| 142 |
|
| 143 |
<box title="Strings" link="string">
|
| 144 |
<ul>
|
| 145 |
<li>Strings are actually sequences of characters.</li>
|
| 146 |
<li>Expressions: <duce>"abc", [ 'abc' ], [ 'a' 'b' 'c' ]</duce>. </li>
|
| 147 |
<li>Operators: <duce>string_of, print, dump_to_file</duce></li>
|
| 148 |
<li><duce>PCDATA</duce> means <duce>Char*</duce> inside regular expressions</li>
|
| 149 |
</ul>
|
| 150 |
</box>
|
| 151 |
|
| 152 |
<box title="XML elements" link="xml">
|
| 153 |
<ul>
|
| 154 |
<li>Expressions: <duce> <(tag) (attr)>content</duce> </li>
|
| 155 |
<li>If the tag is an atom <duce>`X</duce>, it can be written
|
| 156 |
<duce>X</duce> (without the <duce>(..)</duce>).
|
| 157 |
Similarly, parenthesis and curly braces may be omitted
|
| 158 |
when attr is a record <duce>l1=e1;...;ln=en</duce>.
|
| 159 |
E.g: <duce><a href="abc">[ 'abc' ]</duce>.</li>
|
| 160 |
<li>Types and patterns: same notations.</li>
|
| 161 |
<li>Operators: <duce>load_xml : String -> Any; print_xml : Any -> String</duce>
|
| 162 |
</li>
|
| 163 |
</ul>
|
| 164 |
</box>
|
| 165 |
|
| 166 |
<box title="Functions" link="fun">
|
| 167 |
<ul>
|
| 168 |
<li>Expressions:
|
| 169 |
<ul>
|
| 170 |
<li>General form: <duce>fun f (t1->s1;...;tn->sn)
|
| 171 |
p1 -> e1 | ... | pn -> en</duce> (<duce>f</duce> is optional) </li>
|
| 172 |
<li>Simple function: <duce>fun f (p : t) : s = e</duce>,
|
| 173 |
equivalent to <duce>fun f (t -> s) p -> e</duce> </li>
|
| 174 |
<li>Multiple arguments: <duce>fun f (p1 : t1, p2 : t2,...) : s =
|
| 175 |
e</duce>, equivalent to <duce>fun f ((p1,p2,...):(t1,t2,...)) : s
|
| 176 |
= e</duce> </li>
|
| 177 |
</ul>
|
| 178 |
</li>
|
| 179 |
<li>Types: <duce>t -> s</duce> </li>
|
| 180 |
</ul>
|
| 181 |
</box>
|
| 182 |
|
| 183 |
<box title="Pattern matching, exceptions, ..." link="match">
|
| 184 |
<ul>
|
| 185 |
<li>Type restriction: <duce>(e : t)</duce> (forgets any more precise
|
| 186 |
type for <duce>e</duce>) </li>
|
| 187 |
<li>Pattern matching: <duce>match e with p1 -> e1 | ... | pn ->
|
| 188 |
en</duce></li>
|
| 189 |
<li>Local binding: <duce>let p = e1 in e2</duce>, equivalent to
|
| 190 |
<duce>match e1 with p -> e2</duce>;
|
| 191 |
<duce>let p : t = e1 in e2</duce> equivalent to
|
| 192 |
<duce>let p = (e1 : t) in e2</duce> </li>
|
| 193 |
<li>If-then-else: <duce>if e1 then e2 else e3</duce>, equivalent to
|
| 194 |
<duce>match e1 with `true -> e2 | `false -> e3</duce></li>
|
| 195 |
<li>Exceptions: <ul>
|
| 196 |
<li>Raise exception: <duce>raise e</duce></li>
|
| 197 |
<li>Handle exception: <duce>try e with p1 -> e1 | ... | pn ->
|
| 198 |
en</duce></li>
|
| 199 |
</ul> </li>
|
| 200 |
</ul>
|
| 201 |
</box>
|
| 202 |
|
| 203 |
<box title="More about types and patterns" link="type">
|
| 204 |
<ul>
|
| 205 |
<li>Boolean connectives: <duce>&,|,\</duce> (<duce>|</duce> is
|
| 206 |
first-match). </li>
|
| 207 |
<li>Empty and universal types: <duce>Empty,Any</duce> or
|
| 208 |
<duce>_</duce>.</li>
|
| 209 |
<li>Recursive types and patterns: <duce>t where T1 = t2 and ... and
|
| 210 |
Tn = tn</duce>.</li>
|
| 211 |
<li>Capture variable: <duce>x</duce>. </li>
|
| 212 |
<li>Default values: <duce>(x := c)</duce>. </li>
|
| 213 |
</ul>
|
| 214 |
</box>
|
| 215 |
<meta>
|
| 216 |
<p>
|
| 217 |
This page has been generated by a CDuce program.
|
| 218 |
</p>
|
| 219 |
<p>
|
| 220 |
<b>Todo</b>: toplevel phrases.
|
| 221 |
</p>
|
| 222 |
<p><a href="/">Home page</a> - <a href="mailto:Alain.Frisch@ens.fr">Webmaster</a>
|
| 223 |
</p>
|
| 224 |
</meta>
|
| 225 |
|
| 226 |
</main>
|
| 227 |
</page>
|
Parent Directory
| 
Revision Log