doc/ref.sgml

   1 <!-- -*- DocBook -*- -->
   2
   3
   4 <reference>
   5   <title>Declarations</title>
   6
   7   <partintro>
   8     <sect1>
   9       <title>Overview</title>
  10       <para>Declarations are used to give the compiler optimizing
  11         information about foreign types. Currently, only &cmucl;
  12         supports declarations. On &acl; and &lw;, these expressions
  13         declare the type generically as &t;
  14       </para>
  15     </sect1>
  16   </partintro>
  17
  18       <refentry id="def-type">
  19         <refnamediv>
  20           <refname>def-type</refname>
  21         <refpurpose>Defines a Common Lisp type.
  22         </refpurpose>
  23         <refclass>Macro</refclass>
  24       </refnamediv>
  25       <refsynopsisdiv>
  26         <title>Syntax</title>
  27         <synopsis>
  28           <function>def-type</function> <replaceable>name type</replaceable>
  29         </synopsis>
  30       </refsynopsisdiv>
  31       <refsect1>
  32         <title>Arguments and Values</title>
  33         <variablelist>
  34           <varlistentry>
  35             <term><parameter>name</parameter></term>
  36             <listitem>
  37               <para>A symbol naming the type</para>
  38             </listitem>
  39           </varlistentry>
  40           <varlistentry>
  41             <term><parameter>type</parameter></term>
  42             <listitem>
  43               <para>A form that is evaluated that specifies the &uffi; type.
  44               </para>
  45             </listitem>
  46           </varlistentry>
  47         </variablelist>
  48       </refsect1>
  49       <refsect1>
  50         <title>Description</title>
  51         <para>Defines a Common Lisp type based on a &uffi; type.
  52         </para>
  53       </refsect1>
  54       <refsect1>
  55         <title>Examples</title>
  56         <programlisting>
  57 (def-type char-ptr '(* :char))
  58 ...
  59 (defun foo (ptr)
  60   (declare (type char-ptr ptr))
  61   ...
  62         </programlisting>
  63       </refsect1>
  64       <refsect1>
  65         <title>Side Effects</title>
  66         <para>Defines a new &cl; type.</para>
  67       </refsect1>
  68       <refsect1>
  69         <title>Affected by</title>
  70         <para>None.</para>
  71       </refsect1>
  72       <refsect1>
  73         <title>Exceptional Situations</title>
  74         <para>None.</para>
  75       </refsect1>
  76     </refentry>
  77   </reference>
  78
  79
  80   <reference>
  81     <title>Primitive Types</title>
  82     <partintro>
  83       <title>Overview</title>
  84         <para>
  85           Primitive types have a single value, these include
  86           characters, numbers, and pointers. They are all symbols in
  87           the keyword package.
  88         </para>
  89         <itemizedlist>
  90           <listitem>
  91             <para><constant>:char</constant> - Signed 8-bits. A
  92 dereferenced :char pointer returns an character.</para>
  93           </listitem>
  94           <listitem>
  95             <para><constant>:unsigned-char</constant> - Unsigned 8-bits. A dereferenced :unsigned-char
  96 pointer returns an character.</para>
  97           </listitem>
  98           <listitem>
  99             <para><constant>:byte</constant> - Unsigned 8-bits. A
 100 dereferenced :byte pointer returns an integer.</para>
 101           </listitem>
 102           <listitem>
 103             <para><constant>:short</constant> - Signed 16-bits.</para>
 104           </listitem>
 105           <listitem>
 106             <para><constant>:unsigned-short</constant> - Unsigned 16-bits.</para>
 107           </listitem>
 108           <listitem>
 109             <para><constant>:int</constant> - Signed 32-bits.</para>
 110           </listitem>
 111           <listitem>
 112             <para><constant>:unsigned-int</constant> - Unsigned 32-bits.</para>
 113           </listitem>
 114           <listitem>
 115             <para><constant>:long</constant> - Signed 32-bits.</para>
 116           </listitem>
 117           <listitem>
 118             <para><constant>:unsigned-long</constant> - Unsigned 32-bits.</para>
 119           </listitem>
 120           <listitem>
 121             <para><constant>:float</constant> - 32-bit floating point.</para>
 122           </listitem>
 123           <listitem>
 124             <para><constant>:double</constant> - 64-bit floating point.</para>
 125           </listitem>
 126           <listitem>
 127             <para><constant>:cstring</constant> -
 128 A &null; terminated string used for passing and returning characters strings with a &c; function.
 129             </para>
 130           </listitem>
 131           <listitem>
 132             <para><constant>:void</constant> -
 133 The absence of a value. Used to indicate that a function does not return a value.</para>
 134           </listitem>
 135           <listitem>
 136             <para><constant>:pointer-void</constant> -
 137 Points to a generic object.</para>
 138           </listitem>
 139           <listitem>
 140             <para><constant>*</constant> - Used to declare a pointer to an object</para>
 141           </listitem>
 142         </itemizedlist>
 143       </partintro>
 144
 145       <refentry id="def-constant">
 146         <refnamediv>
 147           <refname>def-constant</refname>
 148         <refpurpose>Binds a symbol to a constant.
 149         </refpurpose>
 150         <refclass>Macro</refclass>
 151       </refnamediv>
 152       <refsynopsisdiv>
 153         <title>Syntax</title>
 154         <synopsis>
 155           <function>def-constant</function> <replaceable>name value &amp;key export</replaceable>
 156         </synopsis>
 157       </refsynopsisdiv>
 158       <refsect1>
 159         <title>Arguments and Values</title>
 160         <variablelist>
 161           <varlistentry>
 162             <term><parameter>name</parameter></term>
 163             <listitem>
 164               <para>A symbol that will be bound to the value.
 165               </para>
 166             </listitem>
 167           </varlistentry>
 168           <varlistentry>
 169             <term><parameter>value</parameter></term>
 170             <listitem>
 171               <para>An evaluated form that is bound the the name.
 172               </para>
 173             </listitem>
 174           </varlistentry>
 175           <varlistentry>
 176             <term><parameter>export</parameter></term>
 177             <listitem>
 178               <para>When &t;, the name is exported from the current package. The default is &nil;</para>
 179             </listitem>
 180           </varlistentry>
 181         </variablelist>
 182       </refsect1>
 183       <refsect1>
 184         <title>Description</title>
 185         <para>
 186           This is a thin wrapper around
 187           <function>defconstant</function>. It evaluates at
 188             compile-time and optionally exports the symbol from the package.
 189         </para>
 190       </refsect1>
 191       <refsect1>
 192         <title>Examples</title>
 193         <programlisting>
 194 (def-constant pi2 (* 2 pi))
 195 (def-constant exported-pi2 (* 2 pi) :export t)
 196         </programlisting>
 197       </refsect1>
 198       <refsect1>
 199         <title>Side Effects</title>
 200         <para>Creates a new special variable..</para>
 201       </refsect1>
 202       <refsect1>
 203         <title>Affected by</title>
 204         <para>None.</para>
 205       </refsect1>
 206       <refsect1>
 207         <title>Exceptional Situations</title>
 208         <para>None.</para>
 209       </refsect1>
 210     </refentry>
 211
 212     <refentry id="def-foreign-type">
 213         <refnamediv>
 214           <refname>def-foreign-type</refname>
 215         <refpurpose>Defines a new foreign type.
 216         </refpurpose>
 217         <refclass>Macro</refclass>
 218       </refnamediv>
 219       <refsect1>
 220         <title>Syntax</title>
 221 <synopsis>
 222           <function>def-foreign-type</function> <replaceable>name type</replaceable>
 223 </synopsis>
 224       </refsect1>
 225       <refsect1>
 226         <title>Arguments and Values</title>
 227         <variablelist>
 228           <varlistentry>
 229             <term><parameter>name</parameter></term>
 230             <listitem>
 231               <para>A symbol naming the new foreign type.
 232               </para>
 233             </listitem>
 234           </varlistentry>
 235           <varlistentry>
 236             <term><parameter>value</parameter></term>
 237             <listitem>
 238               <para>A form that is not evaluated that defines the new
 239 foreign type.
 240               </para>
 241             </listitem>
 242           </varlistentry>
 243         </variablelist>
 244       </refsect1>
 245       <refsect1>
 246         <title>Description</title>
 247         <para>Defines a new foreign type.
 248         </para>
 249       </refsect1>
 250       <refsect1>
 251         <title>Examples</title>
 252         <programlisting>
 253 (def-foreign-type my-generic-pointer :pointer-void)
 254 (def-foreign-type a-double-float :double-float)
 255 (def-foreign-type char-ptr (* :char))
 256         </programlisting>
 257       </refsect1>
 258       <refsect1>
 259         <title>Side Effects</title>
 260         <para>Defines a new foreign type.
 261         </para>
 262       </refsect1>
 263       <refsect1>
 264         <title>Affected by</title>
 265         <para>None.</para>
 266       </refsect1>
 267       <refsect1>
 268         <title>Exceptional Situations</title>
 269         <para>None.</para>
 270       </refsect1>
 271     </refentry>
 272
 273     <refentry id="null-char-p">
 274         <refnamediv>
 275           <refname>null-char-p</refname>
 276         <refpurpose>Tests a character for &null; value.
 277         </refpurpose>
 278         <refclass>Macro</refclass>
 279       </refnamediv>
 280       <refsect1>
 281         <title>Syntax</title>
 282 <synopsis>
 283           <function>null-char-p</function> <replaceable>char</replaceable> => <returnvalue>is-null</returnvalue>
 284 </synopsis>
 285       </refsect1>
 286       <refsect1>
 287         <title>Arguments and Values</title>
 288         <variablelist>
 289           <varlistentry>
 290             <term><parameter>char</parameter></term>
 291             <listitem>
 292               <para>A character or integer.
 293               </para>
 294             </listitem>
 295           </varlistentry>
 296           <varlistentry>
 297             <term><parameter>is-null</parameter></term>
 298             <listitem>
 299               <para>A boolean flag indicating if char is a &null; value.
 300               </para>
 301             </listitem>
 302           </varlistentry>
 303         </variablelist>
 304       </refsect1>
 305       <refsect1>
 306         <title>Description</title>
 307         <para>
 308           A predicate testing if a character or integer is &null;. This
 309 abstracts the difference in implementations where some return a
 310 <computeroutput>character</computeroutput> and some return a
 311 <computeroutput>integer</computeroutput> whence dereferencing a
 312 <computeroutput>C</computeroutput> character pointer.
 313         </para>
 314       </refsect1>
 315       <refsect1>
 316         <title>Examples</title>
 317         <programlisting>
 318 (def-array ca :char)
 319 (let ((fs (convert-to-foreign-string "ab")))
 320    (values (null-char-p (deref-array fs 'ca 0))
 321            (null-char-p (deref-array fs 'ca 2))))
 322 => &nil;
 323    &t;
 324         </programlisting>
 325       </refsect1>
 326       <refsect1>
 327         <title>Side Effects</title>
 328         <para>None.
 329         </para>
 330       </refsect1>
 331       <refsect1>
 332         <title>Affected by</title>
 333         <para>None.</para>
 334       </refsect1>
 335       <refsect1>
 336         <title>Exceptional Situations</title>
 337         <para>None.</para>
 338       </refsect1>
 339     </refentry>
 340   </reference>
 341
 342   <reference>
 343     <title>Aggregate Types</title>
 344     <partintro>
 345       <title>Overview</title>
 346       <para>
 347         Aggregate types are comprised of one or more primitive types.
 348       </para>
 349     </partintro>
 350
 351     <refentry id="def-enum">
 352       <refnamediv>
 353         <refname>def-enum</refname>
 354         <refpurpose>Defines a &c; enumeration.
 355         </refpurpose>
 356         <refclass>Macro</refclass>
 357       </refnamediv>
 358       <refsynopsisdiv>
 359         <title>Syntax</title>
 360         <synopsis>
 361           <function>def-enum</function> <replaceable>name fields &amp;key separator-string</replaceable>
 362         </synopsis>
 363       </refsynopsisdiv>
 364       <refsect1>
 365         <title>Arguments and Values</title>
 366         <variablelist>
 367           <varlistentry>
 368             <term><parameter>name</parameter></term>
 369             <listitem>
 370               <para>A symbol that names the enumeration.
 371               </para>
 372             </listitem>
 373           </varlistentry>
 374           <varlistentry>
 375             <term><parameter>fields</parameter></term>
 376             <listitem>
 377               <para>A list of field defintions. Each definition can be
 378 a symbol or a list of two elements. Symbols get assigned a value of the
 379 current counter which starts at <computeroutput>0</computeroutput> and
 380 increments by <computeroutput>1</computeroutput> for each subsequent symbol. It the field definition is a list, the first position is the symbol and the second
 381 position is the value to assign the the symbol. The current counter gets set
 382 to <computeroutput>1+</computeroutput> this value.
 383               </para>
 384             </listitem>
 385           </varlistentry>
 386           <varlistentry>
 387             <term><parameter>separator-string</parameter></term>
 388             <listitem>
 389               <para>A string that governs the creation of constants. The
 390 default is <computeroutput>"#"</computeroutput>.</para>
 391             </listitem>
 392           </varlistentry>
 393         </variablelist>
 394       </refsect1>
 395       <refsect1>
 396         <title>Description</title>
 397         <para>
 398           Declares a &c; enumeration. It generates constants with integer values for the elements of the enumeration. The symbols for the these constant
 399 values are created by the <function>concatenation</function> of the
 400 enumeration name, separator-string, and field symbol. Also creates
 401 a foreign type with the name <parameter>name</parameter> of type
 402 <constant>:int</constant>.
 403         </para>
 404       </refsect1>
 405       <refsect1>
 406         <title>Examples</title>
 407         <programlisting>
 408 (def-enum abc (:a :b :c))
 409 ;; Creates constants abc#a (1), abc#b (2), abc#c (3) and defines
 410 ;; the foreign type "abc" to be :int
 411
 412 (def-enum efoo (:e1 (:e2 10) :e3) :separator-string "-")
 413 ;; Creates constants efoo-e1 (1), efoo-e2 (10), efoo-e3 (11) and defines
 414 ;; the foreign type efoo to be :int
 415         </programlisting>
 416       </refsect1>
 417       <refsect1>
 418         <title>Side Effects</title>
 419         <para>Creates a :int foreign type, defines constants.</para>
 420       </refsect1>
 421       <refsect1>
 422         <title>Affected by</title>
 423         <para>None.</para>
 424       </refsect1>
 425       <refsect1>
 426         <title>Exceptional Situations</title>
 427         <para>None.</para>
 428       </refsect1>
 429     </refentry>
 430
 431
 432       <refentry id="def-struct">
 433         <refnamediv>
 434           <refname>def-struct</refname>
 435         <refpurpose>Defines a &c; structure.
 436         </refpurpose>
 437         <refclass>Macro</refclass>
 438       </refnamediv>
 439       <refsynopsisdiv>
 440         <title>Syntax</title>
 441         <synopsis>
 442           <function>def-struct</function> <replaceable>name &amp;rest fields</replaceable>
 443         </synopsis>
 444       </refsynopsisdiv>
 445       <refsect1>
 446         <title>Arguments and Values</title>
 447         <variablelist>
 448           <varlistentry>
 449             <term><parameter>name</parameter></term>
 450             <listitem>
 451               <para>A symbol that names the structure.
 452               </para>
 453             </listitem>
 454           </varlistentry>
 455           <varlistentry>
 456             <term><parameter>fields</parameter></term>
 457             <listitem>
 458               <para>A variable number of field defintions. Each definition is a list consisting of a symbol naming the field followed by its foreign type.
 459               </para>
 460             </listitem>
 461           </varlistentry>
 462         </variablelist>
 463       </refsect1>
 464       <refsect1>
 465         <title>Description</title>
 466         <para>
 467           Declares a structure. A special type is available as a slot
 468 in the field. It is a pointer that points to an instance of the parent
 469 structure. It's type is <constant>:pointer-self</constant>.
 470
 471         </para>
 472       </refsect1>
 473       <refsect1>
 474         <title>Examples</title>
 475         <programlisting>
 476 (def-struct foo (a :unsigned-int)
 477                 (b (* :char))
 478                 (c (:array :int 10))
 479                 (next :pointer-self))
 480         </programlisting>
 481       </refsect1>
 482       <refsect1>
 483         <title>Side Effects</title>
 484         <para>Creates a foreign type.</para>
 485       </refsect1>
 486       <refsect1>
 487         <title>Affected by</title>
 488         <para>None.</para>
 489       </refsect1>
 490       <refsect1>
 491         <title>Exceptional Situations</title>
 492         <para>None.</para>
 493       </refsect1>
 494     </refentry>
 495
 496
 497     <refentry id="get-slot-value">
 498       <refnamediv>
 499         <refname>get-slot-value</refname>
 500         <refpurpose>Retrieves a value from a slot of a structure.
 501         </refpurpose>
 502         <refclass>Macro</refclass>
 503       </refnamediv>
 504       <refsynopsisdiv>
 505         <title>Syntax</title>
 506         <synopsis>
 507           <function>get-slot-value</function> <replaceable>obj type field</replaceable> => <returnvalue>value</returnvalue>
 508         </synopsis>
 509       </refsynopsisdiv>
 510       <refsect1>
 511         <title>Arguments and Values</title>
 512         <variablelist>
 513           <varlistentry>
 514             <term><parameter>obj</parameter></term>
 515             <listitem>
 516               <para>A pointer to foreign structure.
 517               </para>
 518             </listitem>
 519           </varlistentry>
 520           <varlistentry>
 521             <term><parameter>type</parameter></term>
 522             <listitem>
 523               <para>A name of the foreign structure.
 524               </para>
 525             </listitem>
 526           </varlistentry>
 527           <varlistentry>
 528             <term><parameter>field</parameter></term>
 529             <listitem>
 530               <para>A name of the desired field in foreign structure.
 531               </para>
 532             </listitem>
 533           </varlistentry>
 534           <varlistentry>
 535             <term><returnvalue>value</returnvalue></term>
 536             <listitem>
 537               <para>The value of the field in the structure.
 538               </para>
 539             </listitem>
 540           </varlistentry>
 541         </variablelist>
 542       </refsect1>
 543       <refsect1>
 544         <title>Description</title>
 545         <para>
 546           Accesses a slot value from a structure.
 547         </para>
 548       </refsect1>
 549       <refsect1>
 550         <title>Examples</title>
 551         <programlisting>
 552 (get-slot-value foo-ptr 'foo-structure 'field-name)
 553         </programlisting>
 554       </refsect1>
 555       <refsect1>
 556         <title>Side Effects</title>
 557         <para>None.</para>
 558       </refsect1>
 559       <refsect1>
 560         <title>Affected by</title>
 561         <para>None.</para>
 562       </refsect1>
 563       <refsect1>
 564         <title>Exceptional Situations</title>
 565         <para>None.</para>
 566       </refsect1>
 567     </refentry>
 568
 569     <refentry id="get-slot-pointer">
 570       <refnamediv>
 571         <refname>get-slot-pointer</refname>
 572         <refpurpose>Retrieves a pointer from a slot of a structure.
 573         </refpurpose>
 574         <refclass>Macro</refclass>
 575       </refnamediv>
 576       <refsynopsisdiv>
 577         <title>Syntax</title>
 578         <synopsis>
 579           <function>get-slot-pointer</function> <replaceable>obj type field</replaceable> => <returnvalue>pointer</returnvalue>
 580         </synopsis>
 581       </refsynopsisdiv>
 582       <refsect1>
 583         <title>Arguments and Values</title>
 584         <variablelist>
 585           <varlistentry>
 586             <term><parameter>obj</parameter></term>
 587             <listitem>
 588               <para>A pointer to foreign structure.
 589               </para>
 590             </listitem>
 591           </varlistentry>
 592           <varlistentry>
 593             <term><parameter>type</parameter></term>
 594             <listitem>
 595               <para>A name of the foreign structure.
 596               </para>
 597             </listitem>
 598           </varlistentry>
 599           <varlistentry>
 600             <term><parameter>field</parameter></term>
 601             <listitem>
 602               <para>A name of the desired field in foreign structure.
 603               </para>
 604             </listitem>
 605           </varlistentry>
 606           <varlistentry>
 607             <term><returnvalue>pointer</returnvalue></term>
 608             <listitem>
 609               <para>The value of the field in the structure.
 610               </para>
 611             </listitem>
 612           </varlistentry>
 613         </variablelist>
 614       </refsect1>
 615       <refsect1>
 616         <title>Description</title>
 617         <para>
 618           This is similar to <function>get-slot-value</function>. It
 619           is used when the value of a slot is a pointer type.
 620         </para>
 621       </refsect1>
 622       <refsect1>
 623         <title>Examples</title>
 624         <programlisting>
 625 (get-slot-pointer foo-ptr 'foo-structure 'my-char-ptr)
 626         </programlisting>
 627       </refsect1>
 628       <refsect1>
 629         <title>Side Effects</title>
 630         <para>None.</para>
 631       </refsect1>
 632       <refsect1>
 633         <title>Affected by</title>
 634         <para>None.</para>
 635       </refsect1>
 636       <refsect1>
 637         <title>Exceptional Situations</title>
 638         <para>None.</para>
 639       </refsect1>
 640     </refentry>
 641
 642
 643     <refentry id="def-array">
 644       <refnamediv>
 645         <refname>def-array</refname>
 646         <refpurpose>Defines a foreign array type.
 647         </refpurpose>
 648         <refclass>Macro</refclass>
 649       </refnamediv>
 650       <refsynopsisdiv>
 651         <title>Syntax</title>
 652         <synopsis>
 653           <function>def-array</function> <replaceable>name type</replaceable>
 654         </synopsis>
 655       </refsynopsisdiv>
 656       <refsect1>
 657         <title>Arguments and Values</title>
 658         <variablelist>
 659           <varlistentry>
 660             <term><parameter>name</parameter></term>
 661             <listitem>
 662               <para>A name of the new foreign type.
 663               </para>
 664             </listitem>
 665           </varlistentry>
 666           <varlistentry>
 667             <term><parameter>type</parameter></term>
 668             <listitem>
 669               <para>The foreign type of the array elements.
 670               </para>
 671             </listitem>
 672           </varlistentry>
 673         </variablelist>
 674       </refsect1>
 675       <refsect1>
 676         <title>Description</title>
 677         <para>
 678           Defines a foreign array type.
 679         </para>
 680       </refsect1>
 681       <refsect1>
 682         <title>Examples</title>
 683         <programlisting>
 684 (def-array byte-array :unsigned-char)
 685         </programlisting>
 686       </refsect1>
 687       <refsect1>
 688         <title>Side Effects</title>
 689         <para>Defines a new foreign type.</para>
 690       </refsect1>
 691       <refsect1>
 692         <title>Affected by</title>
 693         <para>None.</para>
 694       </refsect1>
 695       <refsect1>
 696         <title>Exceptional Situations</title>
 697         <para>None.</para>
 698       </refsect1>
 699     </refentry>
 700
 701
 702     <refentry id="deref-array">
 703       <refnamediv>
 704         <refname>deref-array</refname>
 705         <refpurpose>Deference an array.
 706         </refpurpose>
 707         <refclass>Macro</refclass>
 708       </refnamediv>
 709       <refsynopsisdiv>
 710         <title>Syntax</title>
 711         <synopsis>
 712           <function>deref-array</function> <replaceable>array type positon</replaceable> => <returnvalue>value</returnvalue>
 713         </synopsis>
 714       </refsynopsisdiv>
 715       <refsect1>
 716         <title>Arguments and Values</title>
 717         <variablelist>
 718           <varlistentry>
 719             <term><parameter>array</parameter></term>
 720             <listitem>
 721               <para>A foreign array.
 722               </para>
 723             </listitem>
 724           </varlistentry>
 725           <varlistentry>
 726             <term><parameter>type</parameter></term>
 727             <listitem>
 728               <para>The foreign type of the array.
 729               </para>
 730             </listitem>
 731           </varlistentry>
 732           <varlistentry>
 733             <term><parameter>position</parameter></term>
 734             <listitem>
 735               <para>An integer specifying the position to retrieve from
 736 the array.
 737               </para>
 738             </listitem>
 739           </varlistentry>
 740           <varlistentry>
 741             <term><returnvalue>value</returnvalue></term>
 742             <listitem>
 743               <para>The value stored in the position of the array.
 744               </para>
 745             </listitem>
 746           </varlistentry>
 747         </variablelist>
 748       </refsect1>
 749       <refsect1>
 750         <title>Description</title>
 751         <para>
 752           Dereferences (retrieves) the value of an array element.
 753         </para>
 754       </refsect1>
 755       <refsect1>
 756         <title>Examples</title>
 757         <programlisting>
 758 (def-array ca :char)
 759 (let ((fs (convert-to-foreign-string "ab")))
 760    (values (null-char-p (deref-array fs 'ca 0))
 761            (null-char-p (deref-array fs 'ca 2))))
 762 => &nil;
 763    &t;
 764         </programlisting>
 765       </refsect1>
 766       <refsect1>
 767         <title>Side Effects</title>
 768         <para>None.</para>
 769       </refsect1>
 770       <refsect1>
 771         <title>Affected by</title>
 772         <para>None.</para>
 773       </refsect1>
 774       <refsect1>
 775         <title>Exceptional Situations</title>
 776         <para>None.</para>
 777       </refsect1>
 778     </refentry>
 779 </reference>
 780
 781 <reference>
 782     <title>Objects</title>
 783 <partintro>
 784 <title>Overview</title>
 785     <para>
 786       Objects are entities that can allocated and freed.
 787     </para>
 788 </partintro>
 789
 790
 791     <refentry id="allocate-foreign-object">
 792       <refnamediv>
 793         <refname>allocate-foreign-object</refname>
 794         <refpurpose>Allocates an instance of a foreign object.
 795         </refpurpose>
 796         <refclass>Macro</refclass>
 797       </refnamediv>
 798       <refsynopsisdiv>
 799         <title>Syntax</title>
 800         <synopsis>
 801           <function>allocate-foreign-object</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
 802         </synopsis>
 803       </refsynopsisdiv>
 804       <refsect1>
 805         <title>Arguments and Values</title>
 806         <variablelist>
 807           <varlistentry>
 808             <term><parameter>type</parameter></term>
 809             <listitem>
 810               <para>A type of foreign object to allocate.
 811               </para>
 812             </listitem>
 813           </varlistentry>
 814           <varlistentry>
 815             <term><returnvalue>ptr</returnvalue></term>
 816             <listitem>
 817               <para>A pointer to the foreign object.
 818               </para>
 819             </listitem>
 820           </varlistentry>
 821         </variablelist>
 822       </refsect1>
 823       <refsect1>
 824         <title>Description</title>
 825         <para>
 826           Allocates an instance of a foreign object. It returns a pointer to the object.
 827         </para>
 828       </refsect1>
 829       <refsect1>
 830         <title>Examples</title>
 831         <programlisting>
 832 (def-struct ab (a :int) (b :double))
 833 (allocate-foreign-object ab)
 834 => #&lt;ptr&gt;
 835         </programlisting>
 836       </refsect1>
 837       <refsect1>
 838         <title>Side Effects</title>
 839         <para>None.</para>
 840       </refsect1>
 841       <refsect1>
 842         <title>Affected by</title>
 843         <para>None.</para>
 844       </refsect1>
 845       <refsect1>
 846         <title>Exceptional Situations</title>
 847         <para>None.</para>
 848       </refsect1>
 849     </refentry>
 850
 851
 852     <refentry id="free-foreign-object">
 853       <refnamediv>
 854         <refname>free-foreign-object</refname>
 855         <refpurpose>Frees memory that was allocated for a foreign boject.
 856         </refpurpose>
 857         <refclass>Macro</refclass>
 858       </refnamediv>
 859       <refsynopsisdiv>
 860         <title>Syntax</title>
 861         <synopsis>
 862           <function>free-foreign-object</function> <replaceable>ptr</replaceable>
 863         </synopsis>
 864       </refsynopsisdiv>
 865       <refsect1>
 866         <title>Arguments and Values</title>
 867         <variablelist>
 868           <varlistentry>
 869             <term><parameter>ptr</parameter></term>
 870             <listitem>
 871               <para>A pointer to the allocated foreign object to free.
 872               </para>
 873             </listitem>
 874           </varlistentry>
 875         </variablelist>
 876       </refsect1>
 877       <refsect1>
 878         <title>Description</title>
 879         <para>
 880           Frees the memory used by the allocation of a foreign object.
 881         </para>
 882       </refsect1>
 883       <refsect1>
 884         <title>Side Effects</title>
 885         <para>None.</para>
 886       </refsect1>
 887       <refsect1>
 888         <title>Affected by</title>
 889         <para>None.</para>
 890       </refsect1>
 891       <refsect1>
 892         <title>Exceptional Situations</title>
 893         <para>None.</para>
 894       </refsect1>
 895     </refentry>
 896
 897
 898     <refentry id="pointer-address">
 899       <refnamediv>
 900         <refname>pointer-address</refname>
 901         <refpurpose>Returns the address of a pointer.
 902         </refpurpose>
 903         <refclass>Macro</refclass>
 904       </refnamediv>
 905       <refsynopsisdiv>
 906         <title>Syntax</title>
 907         <synopsis>
 908           <function>pointer-address</function> <replaceable>ptr</replaceable> => <returnvalue>address</returnvalue>
 909         </synopsis>
 910       </refsynopsisdiv>
 911       <refsect1>
 912         <title>Arguments and Values</title>
 913         <variablelist>
 914           <varlistentry>
 915             <term><parameter>ptr</parameter></term>
 916             <listitem>
 917               <para>A pointer to a foreign object.
 918               </para>
 919             </listitem>
 920           </varlistentry>
 921           <varlistentry>
 922             <term><parameter>address</parameter></term>
 923             <listitem>
 924               <para>An integer representing the pointer's address.
 925               </para>
 926             </listitem>
 927           </varlistentry>
 928         </variablelist>
 929       </refsect1>
 930       <refsect1>
 931         <title>Description</title>
 932         <para>
 933           Returns the address as an integer of a pointer.
 934         </para>
 935       </refsect1>
 936       <refsect1>
 937         <title>Side Effects</title>
 938         <para>None.</para>
 939       </refsect1>
 940       <refsect1>
 941         <title>Affected by</title>
 942         <para>None.</para>
 943       </refsect1>
 944       <refsect1>
 945         <title>Exceptional Situations</title>
 946         <para>None.</para>
 947       </refsect1>
 948     </refentry>
 949
 950
 951     <refentry id="deref-pointer">
 952       <refnamediv>
 953         <refname>deref-pointer</refname>
 954         <refpurpose>Deferences a pointer.
 955         </refpurpose>
 956         <refclass>Macro</refclass>
 957       </refnamediv>
 958       <refsynopsisdiv>
 959         <title>Syntax</title>
 960         <synopsis>
 961           <function>deref-pointer</function> <replaceable>ptr type</replaceable> => <returnvalue>value</returnvalue>
 962         </synopsis>
 963       </refsynopsisdiv>
 964       <refsect1>
 965         <title>Arguments and Values</title>
 966         <variablelist>
 967           <varlistentry>
 968             <term><parameter>ptr</parameter></term>
 969             <listitem>
 970               <para>A pointer to a foreign object.
 971               </para>
 972             </listitem>
 973           </varlistentry>
 974           <varlistentry>
 975             <term><parameter>type</parameter></term>
 976             <listitem>
 977               <para>A foreign type of the object being pointed to.
 978               </para>
 979             </listitem>
 980           </varlistentry>
 981           <varlistentry>
 982             <term><parameter>value</parameter></term>
 983             <listitem>
 984               <para>The value of the object where the pointer points.
 985               </para>
 986             </listitem>
 987           </varlistentry>
 988         </variablelist>
 989       </refsect1>
 990       <refsect1>
 991         <title>Description</title>
 992         <para>
 993           Returns the object to which a pointer points.
 994         </para>
 995       </refsect1>
 996       <refsect1>
 997         <title>Examples</title>
 998         <para>
 999 <programlisting>
1000 (let ((fs (convert-to-foreign-string "a")))
1001   (prog1
1002     (ensure-char (deref-pointer fs :char))
1003     (free-foreign-object fs)))
1004 => #\a
1005 </programlisting>
1006         </para>
1007       </refsect1>
1008       <refsect1>
1009         <title>Side Effects</title>
1010         <para>None.</para>
1011       </refsect1>
1012       <refsect1>
1013         <title>Affected by</title>
1014         <para>None.</para>
1015       </refsect1>
1016       <refsect1>
1017         <title>Exceptional Situations</title>
1018         <para>None.</para>
1019       </refsect1>
1020     </refentry>
1021
1022     <refentry id="make-null-pointer">
1023       <refnamediv>
1024         <refname>make-null-pointer</refname>
1025         <refpurpose>Create a &null; pointer.
1026         </refpurpose>
1027         <refclass>Macro</refclass>
1028       </refnamediv>
1029       <refsynopsisdiv>
1030         <title>Syntax</title>
1031         <synopsis>
1032           <function>make-null-pointer</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
1033         </synopsis>
1034       </refsynopsisdiv>
1035       <refsect1>
1036         <title>Arguments and Values</title>
1037         <variablelist>
1038           <varlistentry>
1039             <term><parameter>type</parameter></term>
1040             <listitem>
1041               <para>A type of object to which the pointer refers.
1042               </para>
1043             </listitem>
1044           </varlistentry>
1045           <varlistentry>
1046             <term><parameter>ptr</parameter></term>
1047             <listitem>
1048               <para>The &null; pointer of type <parameter>type</parameter>.
1049               </para>
1050             </listitem>
1051           </varlistentry>
1052         </variablelist>
1053       </refsect1>
1054       <refsect1>
1055         <title>Description</title>
1056         <para>
1057           Creates a &null; pointer of a specified type.
1058         </para>
1059       </refsect1>
1060       <refsect1>
1061         <title>Side Effects</title>
1062         <para>None.</para>
1063       </refsect1>
1064       <refsect1>
1065         <title>Affected by</title>
1066         <para>None.</para>
1067       </refsect1>
1068       <refsect1>
1069         <title>Exceptional Situations</title>
1070         <para>None.</para>
1071       </refsect1>
1072     </refentry>
1073
1074
1075     <refentry id="null-pointer-p">
1076       <refnamediv>
1077         <refname>null-pointer-p</refname>
1078         <refpurpose>Tests a pointer for &null; value.
1079         </refpurpose>
1080         <refclass>Macro</refclass>
1081       </refnamediv>
1082       <refsynopsisdiv>
1083         <title>Syntax</title>
1084         <synopsis>
1085           <function>null-pointer-p</function> <replaceable>ptr</replaceable> => <returnvalue>is-null</returnvalue>
1086         </synopsis>
1087       </refsynopsisdiv>
1088       <refsect1>
1089         <title>Arguments and Values</title>
1090         <variablelist>
1091           <varlistentry>
1092             <term><parameter>ptr</parameter></term>
1093             <listitem>
1094               <para>A foreign object pointer.
1095               </para>
1096             </listitem>
1097           </varlistentry>
1098           <varlistentry>
1099             <term><returnvalue>is-null</returnvalue></term>
1100             <listitem>
1101               <para>The boolean flag.
1102               </para>
1103             </listitem>
1104           </varlistentry>
1105         </variablelist>
1106       </refsect1>
1107       <refsect1>
1108         <title>Description</title>
1109         <para>
1110           A predicate testing if a pointer is has a &null; value.
1111         </para>
1112       </refsect1>
1113       <refsect1>
1114         <title>Side Effects</title>
1115         <para>None.</para>
1116       </refsect1>
1117       <refsect1>
1118         <title>Affected by</title>
1119         <para>None.</para>
1120       </refsect1>
1121       <refsect1>
1122         <title>Exceptional Situations</title>
1123         <para>None.</para>
1124       </refsect1>
1125     </refentry>
1126
1127
1128     <refentry id="null-cstring-pointer">
1129       <refnamediv>
1130         <refname>+null-cstring-pointer+</refname>
1131         <refpurpose>A constant &null; cstring pointer.
1132         </refpurpose>
1133         <refclass>Constant</refclass>
1134       </refnamediv>
1135       <refsect1>
1136         <title>Description</title>
1137         <para>
1138           A &null; cstring pointer. This can be used for testing
1139 if a cstring returned by a function is &null;.
1140         </para>
1141       </refsect1>
1142     </refentry>
1143
1144 </reference>
1145
1146     <reference>
1147       <title>Strings</title>
1148 <partintro>
1149 <title>Overview</title>
1150 <para>
1151           &uffi; has functions to two types of <varname>C</varname>-compatible
1152           strings, <emphasis>cstring</emphasis> and <emphasis>foreign</emphasis> strings.
1153 cstrings are used as parameters to and from functions. An implementation, such as CMUCL,
1154 may not convert these to a foreign type for efficiency sake. Thus, it is not
1155 possible to "allocate" a cstring. In contrast, foreign strings
1156 always need to have memory for them.
1157         </para>
1158 </partintro>
1159
1160     <refentry id="convert-from-cstring">
1161       <refnamediv>
1162         <refname>convert-from-cstring</refname>
1163         <refpurpose>Converts a cstring to a Lisp string.
1164         </refpurpose>
1165         <refclass>Macro</refclass>
1166       </refnamediv>
1167       <refsynopsisdiv>
1168         <title>Syntax</title>
1169         <synopsis>
1170           <function>convert-from-cstring</function> <replaceable>cstring</replaceable> => <returnvalue>string</returnvalue>
1171         </synopsis>
1172       </refsynopsisdiv>
1173       <refsect1>
1174         <title>Arguments and Values</title>
1175         <variablelist>
1176           <varlistentry>
1177             <term><parameter>cstring</parameter></term>
1178             <listitem>
1179               <para>A cstring.
1180               </para>
1181             </listitem>
1182           </varlistentry>
1183           <varlistentry>
1184             <term><returnvalue>string</returnvalue></term>
1185             <listitem>
1186               <para>A Lisp string.
1187               </para>
1188             </listitem>
1189           </varlistentry>
1190         </variablelist>
1191       </refsect1>
1192       <refsect1>
1193         <title>Description</title>
1194         <para>
1195           Converts a Lisp string to a <constant>cstring</constant>. This is
1196 most often used when processing the results of a foreign function
1197 that returns a cstring.
1198         </para>
1199       </refsect1>
1200       <refsect1>
1201         <title>Side Effects</title>
1202         <para>None.</para>
1203       </refsect1>
1204       <refsect1>
1205         <title>Affected by</title>
1206         <para>None.</para>
1207       </refsect1>
1208       <refsect1>
1209         <title>Exceptional Situations</title>
1210         <para>None.</para>
1211       </refsect1>
1212     </refentry>
1213
1214
1215     <refentry id="convert-to-cstring">
1216       <refnamediv>
1217         <refname>convert-to-cstring</refname>
1218         <refpurpose>Converts a Lisp string to a cstring.
1219         </refpurpose>
1220         <refclass>Macro</refclass>
1221       </refnamediv>
1222       <refsynopsisdiv>
1223         <title>Syntax</title>
1224         <synopsis>
1225           <function>convert-to-cstring</function> <replaceable>string</replaceable> => <returnvalue>cstring</returnvalue>
1226         </synopsis>
1227       </refsynopsisdiv>
1228       <refsect1>
1229         <title>Arguments and Values</title>
1230         <variablelist>
1231           <varlistentry>
1232             <term><parameter>string</parameter></term>
1233             <listitem>
1234               <para>A Lisp string.
1235               </para>
1236             </listitem>
1237           </varlistentry>
1238           <varlistentry>
1239             <term><returnvalue>cstring</returnvalue></term>
1240             <listitem>
1241               <para>A cstring.
1242               </para>
1243             </listitem>
1244           </varlistentry>
1245         </variablelist>
1246       </refsect1>
1247       <refsect1>
1248         <title>Description</title>
1249         <para>
1250           Converts a Lisp string to a
1251           <varname>cstring</varname>. The
1252           <varname>cstring</varname> should be freed with
1253           <function>free-cstring</function>.
1254         </para>
1255       </refsect1>
1256       <refsect1>
1257         <title>Side Effects</title>
1258         <para>None.</para>
1259       </refsect1>
1260       <refsect1>
1261         <title>Affected by</title>
1262         <para>None.</para>
1263       </refsect1>
1264       <refsect1>
1265         <title>Exceptional Situations</title>
1266         <para>None.</para>
1267       </refsect1>
1268     </refentry>
1269
1270
1271     <refentry id="free-cstring">
1272       <refnamediv>
1273         <refname>free-cstring</refname>
1274         <refpurpose>Free memory used by cstring.
1275         </refpurpose>
1276         <refclass>Macro</refclass>
1277       </refnamediv>
1278       <refsynopsisdiv>
1279         <title>Syntax</title>
1280         <synopsis>
1281           <function>free-cstring</function> <replaceable>cstring</replaceable>
1282         </synopsis>
1283       </refsynopsisdiv>
1284       <refsect1>
1285         <title>Arguments and Values</title>
1286         <variablelist>
1287           <varlistentry>
1288             <term><parameter>cstring</parameter></term>
1289             <listitem>
1290               <para>A cstring.
1291               </para>
1292             </listitem>
1293           </varlistentry>
1294         </variablelist>
1295       </refsect1>
1296       <refsect1>
1297         <title>Description</title>
1298         <para>
1299           Frees any memory possibly allocated by
1300           <function>convert-to-cstring</function>.
1301         </para>
1302       </refsect1>
1303       <refsect1>
1304         <title>Side Effects</title>
1305         <para>None.</para>
1306       </refsect1>
1307       <refsect1>
1308         <title>Affected by</title>
1309         <para>None.</para>
1310       </refsect1>
1311       <refsect1>
1312         <title>Exceptional Situations</title>
1313         <para>None.</para>
1314       </refsect1>
1315     </refentry>
1316
1317
1318     <refentry id="with-cstring">
1319       <refnamediv>
1320         <refname>with-cstring</refname>
1321         <refpurpose>Binds a newly created cstring.
1322         </refpurpose>
1323         <refclass>Macro</refclass>
1324       </refnamediv>
1325       <refsynopsisdiv>
1326         <title>Syntax</title>
1327         <synopsis>
1328           <function>with-cstring</function> <replaceable>(cstring string) {body}</replaceable>
1329         </synopsis>
1330       </refsynopsisdiv>
1331       <refsect1>
1332         <title>Arguments and Values</title>
1333         <variablelist>
1334           <varlistentry>
1335             <term><parameter>cstring</parameter></term>
1336             <listitem>
1337               <para>A symbol naming the cstring to be created.
1338               </para>
1339             </listitem>
1340           </varlistentry>
1341           <varlistentry>
1342             <term><parameter>string</parameter></term>
1343             <listitem>
1344               <para>A Lisp string that will be translated to a cstring.
1345               </para>
1346             </listitem>
1347           </varlistentry>
1348           <varlistentry>
1349             <term><parameter>body</parameter></term>
1350             <listitem>
1351               <para>The body of where the cstring will be bound.
1352               </para>
1353             </listitem>
1354           </varlistentry>
1355         </variablelist>
1356       </refsect1>
1357       <refsect1>
1358         <title>Description</title>
1359         <para>
1360           Binds a lexical variable to a newly allocated <varname>cstring</varname>. Automatically frees <varname>cstring</varname>.
1361         </para>
1362       </refsect1>
1363       <refsect1>
1364         <title>Examples</title>
1365         <para>
1366             <programlisting>
1367 (def-function ("getenv" c-getenv)
1368    ((name :cstring))
1369    :returning :cstring)
1370
1371 (defun getenv (key)
1372   "Returns an environment variable, or NIL if it does not exist"
1373   (check-type key string)
1374   (with-cstring (key-cstring key)
1375     (convert-from-cstring (c-getenv key-cstring))))
1376             </programlisting>
1377           </para>
1378         </refsect1>
1379       <refsect1>
1380         <title>Side Effects</title>
1381         <para>None.</para>
1382       </refsect1>
1383       <refsect1>
1384         <title>Affected by</title>
1385         <para>None.</para>
1386       </refsect1>
1387       <refsect1>
1388         <title>Exceptional Situations</title>
1389         <para>None.</para>
1390       </refsect1>
1391     </refentry>
1392
1393
1394     <refentry id="convert-from-foreign-string">
1395       <refnamediv>
1396         <refname>convert-from-foreign-string</refname>
1397         <refpurpose>Converts a foreign string into a Lisp string.
1398         </refpurpose>
1399         <refclass>Macro</refclass>
1400       </refnamediv>
1401       <refsynopsisdiv>
1402         <title>Syntax</title>
1403         <synopsis>
1404           <function>convert-from-foreign-string</function> <replaceable>foreign-string &amp;key length null-terminated-p</replaceable> => <returnvalue>string</returnvalue>
1405         </synopsis>
1406       </refsynopsisdiv>
1407       <refsect1>
1408         <title>Arguments and Values</title>
1409         <variablelist>
1410           <varlistentry>
1411             <term><parameter>foreign-string</parameter></term>
1412             <listitem>
1413               <para>A foreign string.
1414               </para>
1415             </listitem>
1416           </varlistentry>
1417           <varlistentry>
1418             <term><parameter>length</parameter></term>
1419             <listitem>
1420               <para>The length of the foreign string to
1421 convert. The default is the length of the string until a &null;
1422 character is reached.
1423               </para>
1424             </listitem>
1425           </varlistentry>
1426           <varlistentry>
1427             <term><parameter>null-terminated-p</parameter></term>
1428             <listitem>
1429               <para>A boolean flag with a default value of &t; When true,
1430 the string is converted until the first &null; character is reached.
1431               </para>
1432             </listitem>
1433           </varlistentry>
1434           <varlistentry>
1435             <term><returnvalue>string</returnvalue></term>
1436             <listitem>
1437               <para>A Lisp string.
1438               </para>
1439             </listitem>
1440           </varlistentry>
1441         </variablelist>
1442       </refsect1>
1443       <refsect1>
1444         <title>Description</title>
1445         <para>
1446           Returns a Lisp string from a foreign string.
1447 Can translated ASCII and binary strings.
1448         </para>
1449       </refsect1>
1450       <refsect1>
1451         <title>Side Effects</title>
1452         <para>None.</para>
1453       </refsect1>
1454       <refsect1>
1455         <title>Affected by</title>
1456         <para>None.</para>
1457       </refsect1>
1458       <refsect1>
1459         <title>Exceptional Situations</title>
1460         <para>None.</para>
1461       </refsect1>
1462     </refentry>
1463
1464
1465     <refentry id="convert-to-foreign-string">
1466       <refnamediv>
1467         <refname>convert-to-foreign-string</refname>
1468         <refpurpose>Converts a Lisp string to a foreign string.
1469         </refpurpose>
1470         <refclass>Macro</refclass>
1471       </refnamediv>
1472       <refsynopsisdiv>
1473         <title>Syntax</title>
1474         <synopsis>
1475           <function>convert-to-foreign-string</function> <replaceable>string</replaceable> => <returnvalue>foreign-string</returnvalue>
1476         </synopsis>
1477       </refsynopsisdiv>
1478       <refsect1>
1479         <title>Arguments and Values</title>
1480         <variablelist>
1481           <varlistentry>
1482             <term><parameter>string</parameter></term>
1483             <listitem>
1484               <para>A Lisp string.
1485               </para>
1486             </listitem>
1487           </varlistentry>
1488           <varlistentry>
1489             <term><returnvalue>foreign-string</returnvalue></term>
1490             <listitem>
1491               <para>A foreign string.
1492               </para>
1493             </listitem>
1494           </varlistentry>
1495         </variablelist>
1496       </refsect1>
1497       <refsect1>
1498         <title>Description</title>
1499         <para>
1500           Converts a Lisp string to a foreign string. Memory should be
1501           freed with <function>free-foreign-object</function>.
1502         </para>
1503       </refsect1>
1504       <refsect1>
1505         <title>Side Effects</title>
1506         <para>None.</para>
1507       </refsect1>
1508       <refsect1>
1509         <title>Affected by</title>
1510         <para>None.</para>
1511       </refsect1>
1512       <refsect1>
1513         <title>Exceptional Situations</title>
1514         <para>None.</para>
1515       </refsect1>
1516     </refentry>
1517
1518
1519
1520     <refentry id="allocate-foreign-string">
1521       <refnamediv>
1522         <refname>allocate-foreign-string</refname>
1523         <refpurpose>Allocates space for a foreign string.
1524         </refpurpose>
1525         <refclass>Macro</refclass>
1526       </refnamediv>
1527       <refsynopsisdiv>
1528         <title>Syntax</title>
1529         <synopsis>
1530           <function>allocate-foreign-string</function> <replaceable>size &amp;key unsigned</replaceable> => <returnvalue>foreign-string</returnvalue>
1531         </synopsis>
1532       </refsynopsisdiv>
1533       <refsect1>
1534         <title>Arguments and Values</title>
1535         <variablelist>
1536           <varlistentry>
1537             <term><parameter>size</parameter></term>
1538             <listitem>
1539               <para>The size of the space to be allocated in bytes.
1540               </para>
1541             </listitem>
1542           </varlistentry>
1543           <varlistentry>
1544             <term><parameter>unsigned</parameter></term>
1545             <listitem>
1546               <para>A boolean flag with a default value of &t;. When true,
1547 marks the pointer as an <constant>:unsigned-char</constant>.
1548               </para>
1549             </listitem>
1550           </varlistentry>
1551           <varlistentry>
1552             <term><returnvalue>foreign-string</returnvalue></term>
1553             <listitem>
1554               <para>A foreign string which has undefined contents.
1555               </para>
1556             </listitem>
1557           </varlistentry>
1558         </variablelist>
1559       </refsect1>
1560       <refsect1>
1561         <title>Description</title>
1562         <para>
1563           Allocates space for a foreign string. Memory should
1564           be freed with <function>free-foreign-object</function>.
1565         </para>
1566       </refsect1>
1567       <refsect1>
1568         <title>Side Effects</title>
1569         <para>None.</para>
1570       </refsect1>
1571       <refsect1>
1572         <title>Affected by</title>
1573         <para>None.</para>
1574       </refsect1>
1575       <refsect1>
1576         <title>Exceptional Situations</title>
1577         <para>None.</para>
1578       </refsect1>
1579     </refentry>
1580
1581   </reference>
1582
1583   <reference>
1584       <title>Functions &amp; Libraries</title>
1585
1586       <refentry id="def-function">
1587         <refnamediv>
1588           <refname>def-function</refname>
1589         <refpurpose>Declares a function.
1590         </refpurpose>
1591         <refclass>Macro</refclass>
1592       </refnamediv>
1593       <refsynopsisdiv>
1594         <title>Syntax</title>
1595         <synopsis>
1596           <function>def-function</function> <replaceable>name args &amp;key module returning</replaceable>
1597         </synopsis>
1598       </refsynopsisdiv>
1599       <refsect1>
1600         <title>Arguments and Values</title>
1601         <variablelist>
1602           <varlistentry>
1603             <term><parameter>name</parameter></term>
1604             <listitem>
1605               <para>A string or list specificying the function name. If it is a string, that names the foreign function. A Lisp name is created by translating #\_ to #\- and by converting to upper-case in case-insensitive Lisp implementations. If it is a list, the first item is a string specifying the foreign function name and the second it is a symbol stating the Lisp name.
1606               </para>
1607             </listitem>
1608           </varlistentry>
1609           <varlistentry>
1610             <term><parameter>args</parameter></term>
1611             <listitem>
1612               <para>A list of argument declarations. If &nil;, indicates that the function does not take any arguments.
1613               </para>
1614             </listitem>
1615           </varlistentry>
1616           <varlistentry>
1617             <term><parameter>module</parameter></term>
1618             <listitem>
1619               <para>A string specifying which module (or library) that the foreign function resides. (Required by Lispworks)</para>
1620             </listitem>
1621           </varlistentry>
1622           <varlistentry>
1623             <term><returnvalue>returning</returnvalue></term>
1624             <listitem>
1625               <para>A declaration specifying the result type of the
1626 foreign function. If <constant>:void</constant> indicates module does not return any value.
1627               </para>
1628             </listitem>
1629           </varlistentry>
1630         </variablelist>
1631       </refsect1>
1632       <refsect1>
1633         <title>Description</title>
1634         <para>Declares a foreign function.
1635         </para>
1636       </refsect1>
1637       <refsect1>
1638         <title>Examples</title>
1639         <programlisting>
1640 (def-function "gethostname"
1641   ((name :cstring)
1642    (len :int))
1643   :returning :int)
1644         </programlisting>
1645       </refsect1>
1646       <refsect1>
1647         <title>Side Effects</title>
1648         <para>None.</para>
1649       </refsect1>
1650       <refsect1>
1651         <title>Affected by</title>
1652         <para>None.</para>
1653       </refsect1>
1654       <refsect1>
1655         <title>Exceptional Situations</title>
1656         <para>None.</para>
1657       </refsect1>
1658     </refentry>
1659
1660       <refentry id="load-foreign-library">
1661         <refnamediv>
1662           <refname>load-foreign-library</refname>
1663         <refpurpose>Loads a foreign library.
1664         </refpurpose>
1665         <refclass>Function</refclass>
1666       </refnamediv>
1667       <refsect1>
1668         <title>Syntax</title>
1669 <synopsis>
1670           <function>load-foreign-library</function> <replaceable>filename &amp;key module supporting-libraries</replaceable> => <returnvalue>success</returnvalue>
1671 </synopsis>
1672       </refsect1>
1673       <refsect1>
1674         <title>Arguments and Values</title>
1675         <variablelist>
1676           <varlistentry>
1677             <term><parameter>filename</parameter></term>
1678             <listitem>
1679               <para>A string or pathname specifying the library location
1680 in the filesystem. At least one implementation (&lw;) can not
1681 accept a logical pathname.
1682               </para>
1683             </listitem>
1684           </varlistentry>
1685           <varlistentry>
1686             <term><parameter>module</parameter></term>
1687             <listitem>
1688               <para>A string designating the name of the module to apply
1689 to functions in this library. (Required for Lispworks)
1690               </para>
1691             </listitem>
1692           </varlistentry>
1693           <varlistentry>
1694             <term><parameter>supporting-libraries</parameter></term>
1695             <listitem>
1696               <para>A list of strings naming the libraries required to
1697 link the foreign library. (Required by CMUCL)
1698               </para>
1699             </listitem>
1700           </varlistentry>
1701           <varlistentry>
1702             <term><returnvalue>success</returnvalue></term>
1703             <listitem>
1704               <para>A boolean flag, &t; if the library was able to be
1705 loaded successfully or if the library has been previously loaded,
1706 otherwise &nil;.
1707               </para>
1708             </listitem>
1709           </varlistentry>
1710         </variablelist>
1711       </refsect1>
1712       <refsect1>
1713         <title>Description</title>
1714         <para>Loads a foreign library. Applies a module name to functions
1715 within the library. Ensures that a library is only loaded once during
1716 a session.
1717         </para>
1718       </refsect1>
1719       <refsect1>
1720         <title>Examples</title>
1721         <programlisting>
1722   (load-foreign-library #p"/usr/lib/libmysqlclient.so"
1723                         :module "mysql"
1724                         :supporting-libraries '("c"))
1725     => T
1726         </programlisting>
1727       </refsect1>
1728       <refsect1>
1729         <title>Side Effects</title>
1730         <para>Loads the foreign code into the Lisp system.
1731         </para>
1732       </refsect1>
1733       <refsect1>
1734         <title>Affected by</title>
1735         <para>Ability to load the file.</para>
1736       </refsect1>
1737       <refsect1>
1738         <title>Exceptional Situations</title>
1739         <para>None.</para>
1740       </refsect1>
1741     </refentry>
1742
1743 </reference>
1744
1745