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
 780     <refentry id="def-union">
 781       <refnamediv>
 782         <refname>def-union</refname>
 783         <refpurpose>Defines a foreign union type.
 784         </refpurpose>
 785         <refclass>Macro</refclass>
 786       </refnamediv>
 787       <refsynopsisdiv>
 788         <title>Syntax</title>
 789         <synopsis>
 790           <function>def-union</function> <replaceable>name &amp;rest fields</replaceable>
 791         </synopsis>
 792       </refsynopsisdiv>
 793       <refsect1>
 794         <title>Arguments and Values</title>
 795         <variablelist>
 796           <varlistentry>
 797             <term><parameter>name</parameter></term>
 798             <listitem>
 799               <para>A name of the new union type.
 800               </para>
 801             </listitem>
 802           </varlistentry>
 803           <varlistentry>
 804             <term><parameter>fields</parameter></term>
 805             <listitem>
 806               <para>A list of fields of the union.
 807               </para>
 808             </listitem>
 809           </varlistentry>
 810         </variablelist>
 811       </refsect1>
 812       <refsect1>
 813         <title>Description</title>
 814         <para>
 815           Defines a foreign union type.
 816         </para>
 817       </refsect1>
 818       <refsect1>
 819         <title>Examples</title>
 820         <programlisting>
 821 (def-union test-union
 822   (a-char :char)
 823   (an-int :int))
 824
 825 (let ((u (allocate-foreign-object 'test-union))
 826   (setf (get-slot-value u 'test-union 'an-int) (+ 65 (* 66 256)))
 827   (prog1
 828     (ensure-char-character (get-slot-value u 'test-union 'a-char))
 829     (free-foreign-object u)))
 830 => #\A
 831         </programlisting>
 832       </refsect1>
 833       <refsect1>
 834         <title>Side Effects</title>
 835         <para>Defines a new foreign type.</para>
 836       </refsect1>
 837       <refsect1>
 838         <title>Affected by</title>
 839         <para>None.</para>
 840       </refsect1>
 841       <refsect1>
 842         <title>Exceptional Situations</title>
 843         <para>None.</para>
 844       </refsect1>
 845     </refentry>
 846
 847
 848 </reference>
 849
 850 <reference>
 851     <title>Objects</title>
 852 <partintro>
 853 <title>Overview</title>
 854     <para>
 855       Objects are entities that can allocated, referred to by pointers, and
 856 can be freed.
 857     </para>
 858 </partintro>
 859
 860
 861     <refentry id="allocate-foreign-object">
 862       <refnamediv>
 863         <refname>allocate-foreign-object</refname>
 864         <refpurpose>Allocates an instance of a foreign object.
 865         </refpurpose>
 866         <refclass>Macro</refclass>
 867       </refnamediv>
 868       <refsynopsisdiv>
 869         <title>Syntax</title>
 870         <synopsis>
 871           <function>allocate-foreign-object</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
 872         </synopsis>
 873       </refsynopsisdiv>
 874       <refsect1>
 875         <title>Arguments and Values</title>
 876         <variablelist>
 877           <varlistentry>
 878             <term><parameter>type</parameter></term>
 879             <listitem>
 880               <para>A type of foreign object to allocate.
 881               </para>
 882             </listitem>
 883           </varlistentry>
 884           <varlistentry>
 885             <term><returnvalue>ptr</returnvalue></term>
 886             <listitem>
 887               <para>A pointer to the foreign object.
 888               </para>
 889             </listitem>
 890           </varlistentry>
 891         </variablelist>
 892       </refsect1>
 893       <refsect1>
 894         <title>Description</title>
 895         <para>
 896           Allocates an instance of a foreign object. It returns a pointer to the object.
 897         </para>
 898       </refsect1>
 899       <refsect1>
 900         <title>Examples</title>
 901         <programlisting>
 902 (def-struct ab (a :int) (b :double))
 903 (allocate-foreign-object ab)
 904 => #&lt;ptr&gt;
 905         </programlisting>
 906       </refsect1>
 907       <refsect1>
 908         <title>Side Effects</title>
 909         <para>None.</para>
 910       </refsect1>
 911       <refsect1>
 912         <title>Affected by</title>
 913         <para>None.</para>
 914       </refsect1>
 915       <refsect1>
 916         <title>Exceptional Situations</title>
 917         <para>None.</para>
 918       </refsect1>
 919     </refentry>
 920
 921
 922     <refentry id="free-foreign-object">
 923       <refnamediv>
 924         <refname>free-foreign-object</refname>
 925         <refpurpose>Frees memory that was allocated for a foreign boject.
 926         </refpurpose>
 927         <refclass>Macro</refclass>
 928       </refnamediv>
 929       <refsynopsisdiv>
 930         <title>Syntax</title>
 931         <synopsis>
 932           <function>free-foreign-object</function> <replaceable>ptr</replaceable>
 933         </synopsis>
 934       </refsynopsisdiv>
 935       <refsect1>
 936         <title>Arguments and Values</title>
 937         <variablelist>
 938           <varlistentry>
 939             <term><parameter>ptr</parameter></term>
 940             <listitem>
 941               <para>A pointer to the allocated foreign object to free.
 942               </para>
 943             </listitem>
 944           </varlistentry>
 945         </variablelist>
 946       </refsect1>
 947       <refsect1>
 948         <title>Description</title>
 949         <para>
 950           Frees the memory used by the allocation of a foreign object.
 951         </para>
 952       </refsect1>
 953       <refsect1>
 954         <title>Side Effects</title>
 955         <para>None.</para>
 956       </refsect1>
 957       <refsect1>
 958         <title>Affected by</title>
 959         <para>None.</para>
 960       </refsect1>
 961       <refsect1>
 962         <title>Exceptional Situations</title>
 963         <para>None.</para>
 964       </refsect1>
 965     </refentry>
 966
 967
 968     <refentry id="pointer-address">
 969       <refnamediv>
 970         <refname>pointer-address</refname>
 971         <refpurpose>Returns the address of a pointer.
 972         </refpurpose>
 973         <refclass>Macro</refclass>
 974       </refnamediv>
 975       <refsynopsisdiv>
 976         <title>Syntax</title>
 977         <synopsis>
 978           <function>pointer-address</function> <replaceable>ptr</replaceable> => <returnvalue>address</returnvalue>
 979         </synopsis>
 980       </refsynopsisdiv>
 981       <refsect1>
 982         <title>Arguments and Values</title>
 983         <variablelist>
 984           <varlistentry>
 985             <term><parameter>ptr</parameter></term>
 986             <listitem>
 987               <para>A pointer to a foreign object.
 988               </para>
 989             </listitem>
 990           </varlistentry>
 991           <varlistentry>
 992             <term><parameter>address</parameter></term>
 993             <listitem>
 994               <para>An integer representing the pointer's address.
 995               </para>
 996             </listitem>
 997           </varlistentry>
 998         </variablelist>
 999       </refsect1>
1000       <refsect1>
1001         <title>Description</title>
1002         <para>
1003           Returns the address as an integer of a pointer.
1004         </para>
1005       </refsect1>
1006       <refsect1>
1007         <title>Side Effects</title>
1008         <para>None.</para>
1009       </refsect1>
1010       <refsect1>
1011         <title>Affected by</title>
1012         <para>None.</para>
1013       </refsect1>
1014       <refsect1>
1015         <title>Exceptional Situations</title>
1016         <para>None.</para>
1017       </refsect1>
1018     </refentry>
1019
1020
1021     <refentry id="deref-pointer">
1022       <refnamediv>
1023         <refname>deref-pointer</refname>
1024         <refpurpose>Deferences a pointer.
1025         </refpurpose>
1026         <refclass>Macro</refclass>
1027       </refnamediv>
1028       <refsynopsisdiv>
1029         <title>Syntax</title>
1030         <synopsis>
1031           <function>deref-pointer</function> <replaceable>ptr type</replaceable> => <returnvalue>value</returnvalue>
1032         </synopsis>
1033       </refsynopsisdiv>
1034       <refsect1>
1035         <title>Arguments and Values</title>
1036         <variablelist>
1037           <varlistentry>
1038             <term><parameter>ptr</parameter></term>
1039             <listitem>
1040               <para>A pointer to a foreign object.
1041               </para>
1042             </listitem>
1043           </varlistentry>
1044           <varlistentry>
1045             <term><parameter>type</parameter></term>
1046             <listitem>
1047               <para>A foreign type of the object being pointed to.
1048               </para>
1049             </listitem>
1050           </varlistentry>
1051           <varlistentry>
1052             <term><returnvalue>value</returnvalue></term>
1053             <listitem>
1054               <para>The value of the object where the pointer points.
1055               </para>
1056             </listitem>
1057           </varlistentry>
1058         </variablelist>
1059       </refsect1>
1060       <refsect1>
1061         <title>Description</title>
1062         <para>
1063           Returns the object to which a pointer points.
1064         </para>
1065       </refsect1>
1066       <refsect1>
1067         <title>Examples</title>
1068         <para>
1069 <programlisting>
1070 (let ((intp (allocate-foreign-object :int)))
1071   (setf (deref-pointer intp :int) 10)
1072   (prog1
1073     (deref-pointer intp :int)
1074     (free-foreign-object intp)))
1075 => 10
1076 </programlisting>
1077         </para>
1078       </refsect1>
1079       <refsect1>
1080         <title>Side Effects</title>
1081         <para>None.</para>
1082       </refsect1>
1083       <refsect1>
1084         <title>Affected by</title>
1085         <para>None.</para>
1086       </refsect1>
1087       <refsect1>
1088         <title>Exceptional Situations</title>
1089         <para>None.</para>
1090       </refsect1>
1091     </refentry>
1092
1093     <refentry id="ensure-char-character">
1094       <refnamediv>
1095         <refname>ensure-char-character</refname>
1096         <refpurpose>Ensures that a dereferenced :char pointer is
1097 a character.
1098         </refpurpose>
1099         <refclass>Macro</refclass>
1100       </refnamediv>
1101       <refsynopsisdiv>
1102         <title>Syntax</title>
1103         <synopsis>
1104           <function>ensure-char-character</function> <replaceable>object</replaceable> => <returnvalue>char</returnvalue>
1105         </synopsis>
1106       </refsynopsisdiv>
1107       <refsect1>
1108         <title>Arguments and Values</title>
1109         <variablelist>
1110           <varlistentry>
1111             <term><parameter>object</parameter></term>
1112             <listitem>
1113               <para>Either a character or a integer specifying a character code.
1114               </para>
1115             </listitem>
1116           </varlistentry>
1117           <varlistentry>
1118             <term><returnvalue>char</returnvalue></term>
1119             <listitem>
1120               <para>A character.
1121               </para>
1122             </listitem>
1123           </varlistentry>
1124         </variablelist>
1125       </refsect1>
1126       <refsect1>
1127         <title>Description</title>
1128         <para>
1129           Ensures that an object obtained by dereferencing a
1130 <constant>:char</constant> pointer is a character.
1131         </para>
1132       </refsect1>
1133       <refsect1>
1134         <title>Examples</title>
1135         <para>
1136 <programlisting>
1137 (let ((fs (convert-to-foreign-string "a")))
1138   (prog1
1139     (ensure-char-character (deref-pointer fs :char))
1140     (free-foreign-object fs)))
1141 => #\a
1142 </programlisting>
1143         </para>
1144       </refsect1>
1145       <refsect1>
1146         <title>Side Effects</title>
1147         <para>None.</para>
1148       </refsect1>
1149       <refsect1>
1150         <title>Affected by</title>
1151         <para>None.</para>
1152       </refsect1>
1153       <refsect1>
1154         <title>Exceptional Situations</title>
1155         <para>Depending upon the implementation and what &uffi; expects, this
1156 macro may signal an error if the object is not a character or
1157 integer.</para>
1158       </refsect1>
1159     </refentry>
1160
1161     <refentry id="ensure-char-integer">
1162       <refnamediv>
1163         <refname>ensure-char-integer</refname>
1164         <refpurpose>Ensures that a dereferenced :char pointer is
1165 an integer.
1166         </refpurpose>
1167         <refclass>Macro</refclass>
1168       </refnamediv>
1169       <refsynopsisdiv>
1170         <title>Syntax</title>
1171         <synopsis>
1172           <function>ensure-char-integer</function> <replaceable>object</replaceable> => <returnvalue>int</returnvalue>
1173         </synopsis>
1174       </refsynopsisdiv>
1175       <refsect1>
1176         <title>Arguments and Values</title>
1177         <variablelist>
1178           <varlistentry>
1179             <term><parameter>object</parameter></term>
1180             <listitem>
1181               <para>Either a character or a integer specifying a character code.
1182               </para>
1183             </listitem>
1184           </varlistentry>
1185           <varlistentry>
1186             <term><returnvalue>int</returnvalue></term>
1187             <listitem>
1188               <para>An integer.
1189               </para>
1190             </listitem>
1191           </varlistentry>
1192         </variablelist>
1193       </refsect1>
1194       <refsect1>
1195         <title>Description</title>
1196         <para>
1197           Ensures that an object obtained by dereferencing a
1198 <constant>:char</constant> pointer is an integer.
1199         </para>
1200       </refsect1>
1201       <refsect1>
1202         <title>Examples</title>
1203         <para>
1204 <programlisting>
1205 (let ((fs (convert-to-foreign-string "a")))
1206   (prog1
1207     (ensure-char-integer (deref-pointer fs :char))
1208     (free-foreign-object fs)))
1209 => 96
1210 </programlisting>
1211         </para>
1212       </refsect1>
1213       <refsect1>
1214         <title>Side Effects</title>
1215         <para>None.</para>
1216       </refsect1>
1217       <refsect1>
1218         <title>Affected by</title>
1219         <para>None.</para>
1220       </refsect1>
1221       <refsect1>
1222         <title>Exceptional Situations</title>
1223         <para>Depending upon the implementation and what &uffi; expects, this
1224 macro may signal an error if the object is not a character or
1225 integer.</para>
1226       </refsect1>
1227     </refentry>
1228
1229     <refentry id="make-null-pointer">
1230       <refnamediv>
1231         <refname>make-null-pointer</refname>
1232         <refpurpose>Create a &null; pointer.
1233         </refpurpose>
1234         <refclass>Macro</refclass>
1235       </refnamediv>
1236       <refsynopsisdiv>
1237         <title>Syntax</title>
1238         <synopsis>
1239           <function>make-null-pointer</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
1240         </synopsis>
1241       </refsynopsisdiv>
1242       <refsect1>
1243         <title>Arguments and Values</title>
1244         <variablelist>
1245           <varlistentry>
1246             <term><parameter>type</parameter></term>
1247             <listitem>
1248               <para>A type of object to which the pointer refers.
1249               </para>
1250             </listitem>
1251           </varlistentry>
1252           <varlistentry>
1253             <term><parameter>ptr</parameter></term>
1254             <listitem>
1255               <para>The &null; pointer of type <parameter>type</parameter>.
1256               </para>
1257             </listitem>
1258           </varlistentry>
1259         </variablelist>
1260       </refsect1>
1261       <refsect1>
1262         <title>Description</title>
1263         <para>
1264           Creates a &null; pointer of a specified type.
1265         </para>
1266       </refsect1>
1267       <refsect1>
1268         <title>Side Effects</title>
1269         <para>None.</para>
1270       </refsect1>
1271       <refsect1>
1272         <title>Affected by</title>
1273         <para>None.</para>
1274       </refsect1>
1275       <refsect1>
1276         <title>Exceptional Situations</title>
1277         <para>None.</para>
1278       </refsect1>
1279     </refentry>
1280
1281
1282     <refentry id="null-pointer-p">
1283       <refnamediv>
1284         <refname>null-pointer-p</refname>
1285         <refpurpose>Tests a pointer for &null; value.
1286         </refpurpose>
1287         <refclass>Macro</refclass>
1288       </refnamediv>
1289       <refsynopsisdiv>
1290         <title>Syntax</title>
1291         <synopsis>
1292           <function>null-pointer-p</function> <replaceable>ptr</replaceable> => <returnvalue>is-null</returnvalue>
1293         </synopsis>
1294       </refsynopsisdiv>
1295       <refsect1>
1296         <title>Arguments and Values</title>
1297         <variablelist>
1298           <varlistentry>
1299             <term><parameter>ptr</parameter></term>
1300             <listitem>
1301               <para>A foreign object pointer.
1302               </para>
1303             </listitem>
1304           </varlistentry>
1305           <varlistentry>
1306             <term><returnvalue>is-null</returnvalue></term>
1307             <listitem>
1308               <para>The boolean flag.
1309               </para>
1310             </listitem>
1311           </varlistentry>
1312         </variablelist>
1313       </refsect1>
1314       <refsect1>
1315         <title>Description</title>
1316         <para>
1317           A predicate testing if a pointer is has a &null; value.
1318         </para>
1319       </refsect1>
1320       <refsect1>
1321         <title>Side Effects</title>
1322         <para>None.</para>
1323       </refsect1>
1324       <refsect1>
1325         <title>Affected by</title>
1326         <para>None.</para>
1327       </refsect1>
1328       <refsect1>
1329         <title>Exceptional Situations</title>
1330         <para>None.</para>
1331       </refsect1>
1332     </refentry>
1333
1334
1335     <refentry id="null-cstring-pointer">
1336       <refnamediv>
1337         <refname>+null-cstring-pointer+</refname>
1338         <refpurpose>A constant &null; cstring pointer.
1339         </refpurpose>
1340         <refclass>Constant</refclass>
1341       </refnamediv>
1342       <refsect1>
1343         <title>Description</title>
1344         <para>
1345           A &null; cstring pointer. This can be used for testing
1346 if a cstring returned by a function is &null;.
1347         </para>
1348       </refsect1>
1349     </refentry>
1350
1351 </reference>
1352
1353     <reference>
1354       <title>Strings</title>
1355 <partintro>
1356 <title>Overview</title>
1357 <para>
1358           &uffi; has functions to two types of <varname>C</varname>-compatible
1359           strings, <emphasis>cstring</emphasis> and <emphasis>foreign</emphasis> strings.
1360 cstrings are used as parameters to and from functions. An implementation, such as CMUCL,
1361 may not convert these to a foreign type for efficiency sake. Thus, it is not
1362 possible to "allocate" a cstring. In contrast, foreign strings
1363 always need to have memory for them.
1364         </para>
1365 </partintro>
1366
1367     <refentry id="convert-from-cstring">
1368       <refnamediv>
1369         <refname>convert-from-cstring</refname>
1370         <refpurpose>Converts a cstring to a Lisp string.
1371         </refpurpose>
1372         <refclass>Macro</refclass>
1373       </refnamediv>
1374       <refsynopsisdiv>
1375         <title>Syntax</title>
1376         <synopsis>
1377           <function>convert-from-cstring</function> <replaceable>cstring</replaceable> => <returnvalue>string</returnvalue>
1378         </synopsis>
1379       </refsynopsisdiv>
1380       <refsect1>
1381         <title>Arguments and Values</title>
1382         <variablelist>
1383           <varlistentry>
1384             <term><parameter>cstring</parameter></term>
1385             <listitem>
1386               <para>A cstring.
1387               </para>
1388             </listitem>
1389           </varlistentry>
1390           <varlistentry>
1391             <term><returnvalue>string</returnvalue></term>
1392             <listitem>
1393               <para>A Lisp string.
1394               </para>
1395             </listitem>
1396           </varlistentry>
1397         </variablelist>
1398       </refsect1>
1399       <refsect1>
1400         <title>Description</title>
1401         <para>
1402           Converts a Lisp string to a <constant>cstring</constant>. This is
1403 most often used when processing the results of a foreign function
1404 that returns a cstring.
1405         </para>
1406       </refsect1>
1407       <refsect1>
1408         <title>Side Effects</title>
1409         <para>None.</para>
1410       </refsect1>
1411       <refsect1>
1412         <title>Affected by</title>
1413         <para>None.</para>
1414       </refsect1>
1415       <refsect1>
1416         <title>Exceptional Situations</title>
1417         <para>None.</para>
1418       </refsect1>
1419     </refentry>
1420
1421
1422     <refentry id="convert-to-cstring">
1423       <refnamediv>
1424         <refname>convert-to-cstring</refname>
1425         <refpurpose>Converts a Lisp string to a cstring.
1426         </refpurpose>
1427         <refclass>Macro</refclass>
1428       </refnamediv>
1429       <refsynopsisdiv>
1430         <title>Syntax</title>
1431         <synopsis>
1432           <function>convert-to-cstring</function> <replaceable>string</replaceable> => <returnvalue>cstring</returnvalue>
1433         </synopsis>
1434       </refsynopsisdiv>
1435       <refsect1>
1436         <title>Arguments and Values</title>
1437         <variablelist>
1438           <varlistentry>
1439             <term><parameter>string</parameter></term>
1440             <listitem>
1441               <para>A Lisp string.
1442               </para>
1443             </listitem>
1444           </varlistentry>
1445           <varlistentry>
1446             <term><returnvalue>cstring</returnvalue></term>
1447             <listitem>
1448               <para>A cstring.
1449               </para>
1450             </listitem>
1451           </varlistentry>
1452         </variablelist>
1453       </refsect1>
1454       <refsect1>
1455         <title>Description</title>
1456         <para>
1457           Converts a Lisp string to a
1458           <varname>cstring</varname>. The
1459           <varname>cstring</varname> should be freed with
1460           <function>free-cstring</function>.
1461         </para>
1462       </refsect1>
1463       <refsect1>
1464         <title>Side Effects</title>
1465         <para>None.</para>
1466       </refsect1>
1467       <refsect1>
1468         <title>Affected by</title>
1469         <para>None.</para>
1470       </refsect1>
1471       <refsect1>
1472         <title>Exceptional Situations</title>
1473         <para>None.</para>
1474       </refsect1>
1475     </refentry>
1476
1477
1478     <refentry id="free-cstring">
1479       <refnamediv>
1480         <refname>free-cstring</refname>
1481         <refpurpose>Free memory used by cstring.
1482         </refpurpose>
1483         <refclass>Macro</refclass>
1484       </refnamediv>
1485       <refsynopsisdiv>
1486         <title>Syntax</title>
1487         <synopsis>
1488           <function>free-cstring</function> <replaceable>cstring</replaceable>
1489         </synopsis>
1490       </refsynopsisdiv>
1491       <refsect1>
1492         <title>Arguments and Values</title>
1493         <variablelist>
1494           <varlistentry>
1495             <term><parameter>cstring</parameter></term>
1496             <listitem>
1497               <para>A cstring.
1498               </para>
1499             </listitem>
1500           </varlistentry>
1501         </variablelist>
1502       </refsect1>
1503       <refsect1>
1504         <title>Description</title>
1505         <para>
1506           Frees any memory possibly allocated by
1507           <function>convert-to-cstring</function>.
1508         </para>
1509       </refsect1>
1510       <refsect1>
1511         <title>Side Effects</title>
1512         <para>None.</para>
1513       </refsect1>
1514       <refsect1>
1515         <title>Affected by</title>
1516         <para>None.</para>
1517       </refsect1>
1518       <refsect1>
1519         <title>Exceptional Situations</title>
1520         <para>None.</para>
1521       </refsect1>
1522     </refentry>
1523
1524
1525     <refentry id="with-cstring">
1526       <refnamediv>
1527         <refname>with-cstring</refname>
1528         <refpurpose>Binds a newly created cstring.
1529         </refpurpose>
1530         <refclass>Macro</refclass>
1531       </refnamediv>
1532       <refsynopsisdiv>
1533         <title>Syntax</title>
1534         <synopsis>
1535           <function>with-cstring</function> <replaceable>(cstring string) {body}</replaceable>
1536         </synopsis>
1537       </refsynopsisdiv>
1538       <refsect1>
1539         <title>Arguments and Values</title>
1540         <variablelist>
1541           <varlistentry>
1542             <term><parameter>cstring</parameter></term>
1543             <listitem>
1544               <para>A symbol naming the cstring to be created.
1545               </para>
1546             </listitem>
1547           </varlistentry>
1548           <varlistentry>
1549             <term><parameter>string</parameter></term>
1550             <listitem>
1551               <para>A Lisp string that will be translated to a cstring.
1552               </para>
1553             </listitem>
1554           </varlistentry>
1555           <varlistentry>
1556             <term><parameter>body</parameter></term>
1557             <listitem>
1558               <para>The body of where the cstring will be bound.
1559               </para>
1560             </listitem>
1561           </varlistentry>
1562         </variablelist>
1563       </refsect1>
1564       <refsect1>
1565         <title>Description</title>
1566         <para>
1567           Binds a lexical variable to a newly allocated <varname>cstring</varname>. Automatically frees <varname>cstring</varname>.
1568         </para>
1569       </refsect1>
1570       <refsect1>
1571         <title>Examples</title>
1572         <para>
1573             <programlisting>
1574 (def-function ("getenv" c-getenv)
1575    ((name :cstring))
1576    :returning :cstring)
1577
1578 (defun getenv (key)
1579   "Returns an environment variable, or NIL if it does not exist"
1580   (check-type key string)
1581   (with-cstring (key-cstring key)
1582     (convert-from-cstring (c-getenv key-cstring))))
1583             </programlisting>
1584           </para>
1585         </refsect1>
1586       <refsect1>
1587         <title>Side Effects</title>
1588         <para>None.</para>
1589       </refsect1>
1590       <refsect1>
1591         <title>Affected by</title>
1592         <para>None.</para>
1593       </refsect1>
1594       <refsect1>
1595         <title>Exceptional Situations</title>
1596         <para>None.</para>
1597       </refsect1>
1598     </refentry>
1599
1600
1601     <refentry id="convert-from-foreign-string">
1602       <refnamediv>
1603         <refname>convert-from-foreign-string</refname>
1604         <refpurpose>Converts a foreign string into a Lisp string.
1605         </refpurpose>
1606         <refclass>Macro</refclass>
1607       </refnamediv>
1608       <refsynopsisdiv>
1609         <title>Syntax</title>
1610         <synopsis>
1611           <function>convert-from-foreign-string</function> <replaceable>foreign-string &amp;key length null-terminated-p</replaceable> => <returnvalue>string</returnvalue>
1612         </synopsis>
1613       </refsynopsisdiv>
1614       <refsect1>
1615         <title>Arguments and Values</title>
1616         <variablelist>
1617           <varlistentry>
1618             <term><parameter>foreign-string</parameter></term>
1619             <listitem>
1620               <para>A foreign string.
1621               </para>
1622             </listitem>
1623           </varlistentry>
1624           <varlistentry>
1625             <term><parameter>length</parameter></term>
1626             <listitem>
1627               <para>The length of the foreign string to
1628 convert. The default is the length of the string until a &null;
1629 character is reached.
1630               </para>
1631             </listitem>
1632           </varlistentry>
1633           <varlistentry>
1634             <term><parameter>null-terminated-p</parameter></term>
1635             <listitem>
1636               <para>A boolean flag with a default value of &t; When true,
1637 the string is converted until the first &null; character is reached.
1638               </para>
1639             </listitem>
1640           </varlistentry>
1641           <varlistentry>
1642             <term><returnvalue>string</returnvalue></term>
1643             <listitem>
1644               <para>A Lisp string.
1645               </para>
1646             </listitem>
1647           </varlistentry>
1648         </variablelist>
1649       </refsect1>
1650       <refsect1>
1651         <title>Description</title>
1652         <para>
1653           Returns a Lisp string from a foreign string.
1654 Can translated ASCII and binary strings.
1655         </para>
1656       </refsect1>
1657       <refsect1>
1658         <title>Side Effects</title>
1659         <para>None.</para>
1660       </refsect1>
1661       <refsect1>
1662         <title>Affected by</title>
1663         <para>None.</para>
1664       </refsect1>
1665       <refsect1>
1666         <title>Exceptional Situations</title>
1667         <para>None.</para>
1668       </refsect1>
1669     </refentry>
1670
1671
1672     <refentry id="convert-to-foreign-string">
1673       <refnamediv>
1674         <refname>convert-to-foreign-string</refname>
1675         <refpurpose>Converts a Lisp string to a foreign string.
1676         </refpurpose>
1677         <refclass>Macro</refclass>
1678       </refnamediv>
1679       <refsynopsisdiv>
1680         <title>Syntax</title>
1681         <synopsis>
1682           <function>convert-to-foreign-string</function> <replaceable>string</replaceable> => <returnvalue>foreign-string</returnvalue>
1683         </synopsis>
1684       </refsynopsisdiv>
1685       <refsect1>
1686         <title>Arguments and Values</title>
1687         <variablelist>
1688           <varlistentry>
1689             <term><parameter>string</parameter></term>
1690             <listitem>
1691               <para>A Lisp string.
1692               </para>
1693             </listitem>
1694           </varlistentry>
1695           <varlistentry>
1696             <term><returnvalue>foreign-string</returnvalue></term>
1697             <listitem>
1698               <para>A foreign string.
1699               </para>
1700             </listitem>
1701           </varlistentry>
1702         </variablelist>
1703       </refsect1>
1704       <refsect1>
1705         <title>Description</title>
1706         <para>
1707           Converts a Lisp string to a foreign string. Memory should be
1708           freed with <function>free-foreign-object</function>.
1709         </para>
1710       </refsect1>
1711       <refsect1>
1712         <title>Side Effects</title>
1713         <para>None.</para>
1714       </refsect1>
1715       <refsect1>
1716         <title>Affected by</title>
1717         <para>None.</para>
1718       </refsect1>
1719       <refsect1>
1720         <title>Exceptional Situations</title>
1721         <para>None.</para>
1722       </refsect1>
1723     </refentry>
1724
1725
1726
1727     <refentry id="allocate-foreign-string">
1728       <refnamediv>
1729         <refname>allocate-foreign-string</refname>
1730         <refpurpose>Allocates space for a foreign string.
1731         </refpurpose>
1732         <refclass>Macro</refclass>
1733       </refnamediv>
1734       <refsynopsisdiv>
1735         <title>Syntax</title>
1736         <synopsis>
1737           <function>allocate-foreign-string</function> <replaceable>size &amp;key unsigned</replaceable> => <returnvalue>foreign-string</returnvalue>
1738         </synopsis>
1739       </refsynopsisdiv>
1740       <refsect1>
1741         <title>Arguments and Values</title>
1742         <variablelist>
1743           <varlistentry>
1744             <term><parameter>size</parameter></term>
1745             <listitem>
1746               <para>The size of the space to be allocated in bytes.
1747               </para>
1748             </listitem>
1749           </varlistentry>
1750           <varlistentry>
1751             <term><parameter>unsigned</parameter></term>
1752             <listitem>
1753               <para>A boolean flag with a default value of &t;. When true,
1754 marks the pointer as an <constant>:unsigned-char</constant>.
1755               </para>
1756             </listitem>
1757           </varlistentry>
1758           <varlistentry>
1759             <term><returnvalue>foreign-string</returnvalue></term>
1760             <listitem>
1761               <para>A foreign string which has undefined contents.
1762               </para>
1763             </listitem>
1764           </varlistentry>
1765         </variablelist>
1766       </refsect1>
1767       <refsect1>
1768         <title>Description</title>
1769         <para>
1770           Allocates space for a foreign string. Memory should
1771           be freed with <function>free-foreign-object</function>.
1772         </para>
1773       </refsect1>
1774       <refsect1>
1775         <title>Side Effects</title>
1776         <para>None.</para>
1777       </refsect1>
1778       <refsect1>
1779         <title>Affected by</title>
1780         <para>None.</para>
1781       </refsect1>
1782       <refsect1>
1783         <title>Exceptional Situations</title>
1784         <para>None.</para>
1785       </refsect1>
1786     </refentry>
1787
1788   </reference>
1789
1790   <reference>
1791       <title>Functions &amp; Libraries</title>
1792
1793       <refentry id="def-function">
1794         <refnamediv>
1795           <refname>def-function</refname>
1796         <refpurpose>Declares a function.
1797         </refpurpose>
1798         <refclass>Macro</refclass>
1799       </refnamediv>
1800       <refsynopsisdiv>
1801         <title>Syntax</title>
1802         <synopsis>
1803           <function>def-function</function> <replaceable>name args &amp;key module returning</replaceable>
1804         </synopsis>
1805       </refsynopsisdiv>
1806       <refsect1>
1807         <title>Arguments and Values</title>
1808         <variablelist>
1809           <varlistentry>
1810             <term><parameter>name</parameter></term>
1811             <listitem>
1812               <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.
1813               </para>
1814             </listitem>
1815           </varlistentry>
1816           <varlistentry>
1817             <term><parameter>args</parameter></term>
1818             <listitem>
1819               <para>A list of argument declarations. If &nil;, indicates that the function does not take any arguments.
1820               </para>
1821             </listitem>
1822           </varlistentry>
1823           <varlistentry>
1824             <term><parameter>module</parameter></term>
1825             <listitem>
1826               <para>A string specifying which module (or library) that the foreign function resides. (Required by Lispworks)</para>
1827             </listitem>
1828           </varlistentry>
1829           <varlistentry>
1830             <term><returnvalue>returning</returnvalue></term>
1831             <listitem>
1832               <para>A declaration specifying the result type of the
1833 foreign function. If <constant>:void</constant> indicates module does not return any value.
1834               </para>
1835             </listitem>
1836           </varlistentry>
1837         </variablelist>
1838       </refsect1>
1839       <refsect1>
1840         <title>Description</title>
1841         <para>Declares a foreign function.
1842         </para>
1843       </refsect1>
1844       <refsect1>
1845         <title>Examples</title>
1846         <programlisting>
1847 (def-function "gethostname"
1848   ((name (* :unsigned-char))
1849    (len :int))
1850   :returning :int)
1851         </programlisting>
1852       </refsect1>
1853       <refsect1>
1854         <title>Side Effects</title>
1855         <para>None.</para>
1856       </refsect1>
1857       <refsect1>
1858         <title>Affected by</title>
1859         <para>None.</para>
1860       </refsect1>
1861       <refsect1>
1862         <title>Exceptional Situations</title>
1863         <para>None.</para>
1864       </refsect1>
1865     </refentry>
1866
1867       <refentry id="load-foreign-library">
1868         <refnamediv>
1869           <refname>load-foreign-library</refname>
1870         <refpurpose>Loads a foreign library.
1871         </refpurpose>
1872         <refclass>Function</refclass>
1873       </refnamediv>
1874       <refsect1>
1875         <title>Syntax</title>
1876 <synopsis>
1877           <function>load-foreign-library</function> <replaceable>filename &amp;key module supporting-libraries</replaceable> => <returnvalue>success</returnvalue>
1878 </synopsis>
1879       </refsect1>
1880       <refsect1>
1881         <title>Arguments and Values</title>
1882         <variablelist>
1883           <varlistentry>
1884             <term><parameter>filename</parameter></term>
1885             <listitem>
1886               <para>A string or pathname specifying the library location
1887 in the filesystem. At least one implementation (&lw;) can not
1888 accept a logical pathname.
1889               </para>
1890             </listitem>
1891           </varlistentry>
1892           <varlistentry>
1893             <term><parameter>module</parameter></term>
1894             <listitem>
1895               <para>A string designating the name of the module to apply
1896 to functions in this library. (Required for Lispworks)
1897               </para>
1898             </listitem>
1899           </varlistentry>
1900           <varlistentry>
1901             <term><parameter>supporting-libraries</parameter></term>
1902             <listitem>
1903               <para>A list of strings naming the libraries required to
1904 link the foreign library. (Required by CMUCL)
1905               </para>
1906             </listitem>
1907           </varlistentry>
1908           <varlistentry>
1909             <term><returnvalue>success</returnvalue></term>
1910             <listitem>
1911               <para>A boolean flag, &t; if the library was able to be
1912 loaded successfully or if the library has been previously loaded,
1913 otherwise &nil;.
1914               </para>
1915             </listitem>
1916           </varlistentry>
1917         </variablelist>
1918       </refsect1>
1919       <refsect1>
1920         <title>Description</title>
1921         <para>Loads a foreign library. Applies a module name to functions
1922 within the library. Ensures that a library is only loaded once during
1923 a session.
1924         </para>
1925       </refsect1>
1926       <refsect1>
1927         <title>Examples</title>
1928         <programlisting>
1929   (load-foreign-library #p"/usr/lib/libmysqlclient.so"
1930                         :module "mysql"
1931                         :supporting-libraries '("c"))
1932     => T
1933         </programlisting>
1934       </refsect1>
1935       <refsect1>
1936         <title>Side Effects</title>
1937         <para>Loads the foreign code into the Lisp system.
1938         </para>
1939       </refsect1>
1940       <refsect1>
1941         <title>Affected by</title>
1942         <para>Ability to load the file.</para>
1943       </refsect1>
1944       <refsect1>
1945         <title>Exceptional Situations</title>
1946         <para>None.</para>
1947       </refsect1>
1948     </refentry>
1949
1950 </reference>
1951
1952