/usr/share/gap/pkg/openmath/doc/chap2.html is in gap-openmath 11.3.1+ds-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 | <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>GAP (openmath) - Chapter 2: OpenMath functionality in GAP</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<meta name="generator" content="GAPDoc2HTML" />
<link rel="stylesheet" type="text/css" href="manual.css" />
<script src="manual.js" type="text/javascript"></script>
<script type="text/javascript">overwriteStyle();</script>
</head>
<body class="chap2" onload="jscontent()">
<div class="chlinktop"><span class="chlink1">Goto Chapter: </span><a href="chap0.html">Top</a> <a href="chap1.html">1</a> <a href="chap2.html">2</a> <a href="chap3.html">3</a> <a href="chapBib.html">Bib</a> <a href="chapInd.html">Ind</a> </div>
<div class="chlinkprevnexttop"> <a href="chap0.html">[Top of Book]</a> <a href="chap0.html#contents">[Contents]</a> <a href="chap1.html">[Previous Chapter]</a> <a href="chap3.html">[Next Chapter]</a> </div>
<p><a id="X83C7040B7B389CA5" name="X83C7040B7B389CA5"></a></p>
<div class="ChapSects"><a href="chap2.html#X83C7040B7B389CA5">2 <span class="Heading"><strong class="pkg">OpenMath</strong> functionality in <strong class="pkg">GAP</strong></span></a>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap2.html#X8393E7C57E539406">2.1 <span class="Heading">Viewing <strong class="pkg">OpenMath</strong> representation of an object</span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X7B1815F078D8312B">2.1-1 OMPrint</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X876AD5BC7A8812C3">2.1-2 OMString</a></span>
</div></div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap2.html#X7EB959397AB2B646">2.2 <span class="Heading">Reading <strong class="pkg">OpenMath</strong> code from streams and strings</span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X7FBDCB3C83BBB115">2.2-1 OMGetObject</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X7BFA1BAB7DA665F4">2.2-2 EvalOMString</a></span>
</div></div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap2.html#X87E11972845542AE">2.3 <span class="Heading">Writing <strong class="pkg">OpenMath</strong> code to streams</span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X79EE2E8B7C83E0F4">2.3-1 IsOpenMathWriter</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X798979EB7E4723A2">2.3-2 OpenMathXMLWriter</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X786D6A987C1FAB0B">2.3-3 OpenMathBinaryWriter</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X84FC6AD5872CBF33">2.3-4 OMPutObject</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X85297E7081470DDF">2.3-5 OMPlainString</a></span>
</div></div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap2.html#X7DFC90B87DC503A1">2.4 <span class="Heading">Utilities</span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X7D6B0843798A19B9">2.4-1 OMTestXML</a></span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap2.html#X834694B784B5850F">2.4-2 OMTestBinary</a></span>
</div></div>
</div>
<h3>2 <span class="Heading"><strong class="pkg">OpenMath</strong> functionality in <strong class="pkg">GAP</strong></span></h3>
<p><a id="X8393E7C57E539406" name="X8393E7C57E539406"></a></p>
<h4>2.1 <span class="Heading">Viewing <strong class="pkg">OpenMath</strong> representation of an object</span></h4>
<p><a id="X7B1815F078D8312B" name="X7B1815F078D8312B"></a></p>
<h5>2.1-1 OMPrint</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMPrint</code>( <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>OMPrint writes the default XML <strong class="pkg">OpenMath</strong> encoding of <strong class="pkg">GAP</strong> object <var class="Arg">obj</var> to the standard output.</p>
<p>One can try it with different <strong class="pkg">GAP</strong> objects to see if they can be converted to <strong class="pkg">OpenMath</strong> and learn how their <strong class="pkg">OpenMath</strong> representation looks like. Here we show the encoding for lists of integers and rationals:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( [ 1, 1/2 ] ); </span>
<OMOBJ>
<OMA>
<OMS cd="list1" name="list"/>
<OMI>1</OMI>
<OMA>
<OMS cd="nums1" name="rational"/>
<OMI>1</OMI>
<OMI>2</OMI>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p>Strings are encoded using <code class="code"><OMSTR></code> tags:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( "This is a string" );</span>
<OMOBJ>
<OMSTR>This is a string</OMSTR>
</OMOBJ>
</pre></div>
<p>Cyclotomics may be encoded in different ways dependently on their properties:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( 1-2*E(4) ); </span>
<OMOBJ>
<OMA>
<OMS cd="complex1" name="complex_cartesian"/>
<OMI>1</OMI>
<OMI>-2</OMI>
</OMA>
</OMOBJ>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(E(3)); </span>
<OMOBJ>
<OMA>
<OMS cd="arith1" name="plus"/>
<OMA>
<OMS cd="arith1" name="times"/>
<OMI>1</OMI>
<OMA>
<OMS cd="algnums" name="NthRootOfUnity"/>
<OMI>3</OMI>
<OMI>1</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p>Various encodings may be used for various types of groups:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( Group( (1,2) ) );</span>
<OMOBJ>
<OMA>
<OMS cd="permgp1" name="group"/>
<OMS cd="permutation1" name="right_compose"/>
<OMA>
<OMS cd="permut1" name="permutation"/>
<OMI>2</OMI>
<OMI>1</OMI>
</OMA>
</OMA>
</OMOBJ>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( Group( [ [ [ 1, 2 ],[ 0, 1 ] ] ] ) );</span>
<OMOBJ>
<OMA>
<OMS cd="group1" name="group_by_generators"/>
<OMA>
<OMS cd="linalg2" name="matrix"/>
<OMA>
<OMS cd="linalg2" name="matrixrow"/>
<OMI>1</OMI>
<OMI>2</OMI>
</OMA>
<OMA>
<OMS cd="linalg2" name="matrixrow"/>
<OMI>0</OMI>
<OMI>1</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint( FreeGroup( 2 ) ); </span>
<OMOBJ>
<OMA>
<OMS cd="fpgroup1" name="free_groupn"/>
<OMI>2</OMI>
</OMA>
</OMOBJ>
</pre></div>
<p>Producing <strong class="pkg">OpenMath</strong> representation of polynomials, one may get a warning:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">x:=Indeterminate(Rationals,"x");; y:=Indeterminate(Rationals,"y");;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(x^2+y);</span>
#I Warning : polynomial will be printed using its default ring
#I because the default OpenMath polynomial ring is not specified
#I or it is not contained in the default OpenMath polynomial ring.
#I You may ignore this or call SetOpenMathDefaultPolynomialRing to fix it.
<OMOBJ>
<OMA>
<OMS cd="polyd1" name="DMP"/>
<OMA id="polyring9qiY2oOaiITWUORb" >
<OMS cd="polyd1" name="poly_ring_d"/>
<OMS cd="setname1" name="Q"/>
<OMI>2</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="SDMP"/>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
<OMI>1</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>2</OMI>
<OMI>0</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p>Indeed, now when another polynomial will be printed, it will belong to a ring with a different identifier (despite <strong class="pkg">GAP</strong> will be able to perform arithmetical operations on these polynomials like when they belong to the same ground ring):</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(x+1);</span>
#I Warning : polynomial will be printed using its default ring
#I because the default OpenMath polynomial ring is not specified
#I or it is not contained in the default OpenMath polynomial ring.
#I You may ignore this or call SetOpenMathDefaultPolynomialRing to fix it.
<OMOBJ>
<OMA>
<OMS cd="polyd1" name="DMP"/>
<OMA id="polyring0LqlkhnCyLldcoBl" >
<OMS cd="polyd1" name="poly_ring_d_named"/>
<OMS cd="setname1" name="Q"/>
<OMV name="x"/>
</OMA>
<OMA>
<OMS cd="polyd1" name="SDMP"/>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>1</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p>Thus, the warning means that it is not guaranteed that the polynomial ring will have the same identifier <code class="code"><OMA id="polyring..." ></code> when another or same polynomial from this ring will be printed next time. If this may constitute a problem, for example, if a list of polynomial is being exchanged with another system and it is crucial that all of them will belong to the same ring, then such ring must be created explicitly and then <code class="code">SetOpenMathDefaultPolynomialRing</code> must be called:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">x:=Indeterminate(Rationals,"x");; y:=Indeterminate(Rationals,"y");;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">R:=PolynomialRing(Rationals,[x,y]);;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">SetOpenMathDefaultPolynomialRing(R);</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(x^2+y);</span>
<OMOBJ>
<OMA>
<OMS cd="polyd1" name="DMP"/>
<OMA id="polyring9eNcBGFHXkjl2kWh" >
<OMS cd="polyd1" name="poly_ring_d"/>
<OMS cd="setname1" name="Q"/>
<OMI>2</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="SDMP"/>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
<OMI>0</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
<OMI>0</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p>Now we can see that both polynomials belong to the ring with the same identifier, and the <strong class="pkg">OpenMath</strong> representation of the 2nd polynomial properly reflects that it belongs to a polynomial ring with two variables.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(x+1); </span>
<OMOBJ>
<OMA>
<OMS cd="polyd1" name="DMP"/>
<OMR href="#polyring9eNcBGFHXkjl2kWh" />
<OMA>
<OMS cd="polyd1" name="SDMP"/>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
<OMI>0</OMI>
</OMA>
<OMA>
<OMS cd="polyd1" name="term"/>
<OMI>1</OMI>
<OMI>0</OMI>
<OMI>0</OMI>
</OMA>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p><a id="X876AD5BC7A8812C3" name="X876AD5BC7A8812C3"></a></p>
<h5>2.1-2 OMString</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMString</code>( <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>OMString returns a string with the default XML <strong class="pkg">OpenMath</strong> encoding of <strong class="pkg">GAP</strong> object <var class="Arg">obj</var>. If used with the <code class="keyw">noomobj</code> option, then initial and final <OMOBJ> tags will be omitted.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMString(42);</span>
"<OMOBJ> <OMI>42</OMI> </OMOBJ>"
<span class="GAPprompt">gap></span> <span class="GAPinput">OMString([1,2]:noomobj); </span>
"<OMA> <OMS cd=\"list1\" name=\"list\"/> <OMI>1</OMI> <OMI>2</OMI> </OMA>"
</pre></div>
<p><a id="X7EB959397AB2B646" name="X7EB959397AB2B646"></a></p>
<h4>2.2 <span class="Heading">Reading <strong class="pkg">OpenMath</strong> code from streams and strings</span></h4>
<p><a id="X7FBDCB3C83BBB115" name="X7FBDCB3C83BBB115"></a></p>
<h5>2.2-1 OMGetObject</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMGetObject</code>( <var class="Arg">stream</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p><var class="Arg">stream</var> is an input stream (see <code class="func">InputTextFile</code> (<span class="RefLink">Reference: InputTextFile</span>), <code class="func">InputTextUser</code> (<span class="RefLink">Reference: InputTextUser</span>), <code class="func">InputTextString</code> (<span class="RefLink">Reference: InputTextString</span>), <code class="func">InputOutputLocalProcess</code> (<span class="RefLink">Reference: InputOutputLocalProcess</span>), <code class="func">InputOutputTCPStream</code> (<a href="/usr/share/gap/pkg/scscp/doc/chap3.html#X7E3D43CF7B049F04"><span class="RefLink">SCSCP: InputOutputTCPStream (for client)</span></a>), <code class="func">InputOutputTCPStream</code> (<a href="/usr/share/gap/pkg/scscp/doc/chap3.html#X7E3D43CF7B049F04"><span class="RefLink">SCSCP: InputOutputTCPStream (for server)</span></a>)) with an <strong class="pkg">OpenMath</strong> object on it. <code class="func">OMGetObject</code> takes precisely one object off <var class="Arg">stream</var> and returns it as a GAP object. Both XML and binary <strong class="pkg">OpenMath</strong> encoding are supported: autodetection is used.</p>
<p>This may be used to retrieve objects from a file. In the following example we demonsrate reading the same content in binary and XML formats using the test files supplied with the package (the package autodetects whether binary or XML encoding is used):</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">txml:=Filename(DirectoriesPackageLibrary("openmath","tst"),"test3.omt");; </span>
<span class="GAPprompt">gap></span> <span class="GAPinput">tbin:=Filename(DirectoriesPackageLibrary("openmath","tst"),"test3.bin");; </span>
<span class="GAPprompt">gap></span> <span class="GAPinput">xstream := InputTextFile( txml );; bstream := InputTextFile( tbin );; </span>
<span class="GAPprompt">gap></span> <span class="GAPinput">x:=OMGetObject(xstream); y:=OMGetObject(bstream);</span>
912873912381273891
912873912381273891
<span class="GAPprompt">gap></span> <span class="GAPinput">x:=OMGetObject(xstream); y:=OMGetObject(bstream);</span>
E(4)
E(4)
<span class="GAPprompt">gap></span> <span class="GAPinput">CloseStream(xstream);CloseStream(bstream);</span>
</pre></div>
<p>To paste an <strong class="pkg">OpenMath</strong> object directly into standard input execute the following command in GAP:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">s:= InputTextUser();; g := OMGetObject(s); CloseStream(s);</span>
<span class="GAPprompt">gap></span> <span class="GAPinput"></span>
</pre></div>
<p>For XML <strong class="pkg">OpenMath</strong>, this function requires that the <strong class="pkg">GAP</strong> package <strong class="pkg">GAPDoc</strong> is available.</p>
<p><a id="X7BFA1BAB7DA665F4" name="X7BFA1BAB7DA665F4"></a></p>
<h5>2.2-2 EvalOMString</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ EvalOMString</code>( <var class="Arg">omstr</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>This function is an analog of <code class="func">EvalString</code> (<span class="RefLink">Reference: EvalString</span>). Its argument <var class="Arg">omstr</var> must be a string containing a single <strong class="pkg">OpenMath</strong> object. <code class="func">EvalOMString</code> will return the <strong class="pkg">GAP</strong> object represented by <var class="Arg">omstr</var>.</p>
<p>If <var class="Arg">omstr</var> contains more <strong class="pkg">OpenMath</strong> objects, the rest will be ignored.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">s:="<OMOBJ><OMS cd=\"setname1\" name=\"Z\"/></OMOBJ>";;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">EvalOMString(s);</span>
Integers
<span class="GAPprompt">gap></span> <span class="GAPinput">G:=SL(2,5);; G=EvalOMString(OMString(G));</span>
true
</pre></div>
<p><a id="X87E11972845542AE" name="X87E11972845542AE"></a></p>
<h4>2.3 <span class="Heading">Writing <strong class="pkg">OpenMath</strong> code to streams</span></h4>
<p>While it is possible to read <strong class="pkg">OpenMath</strong> code directly from a stream, writing <strong class="pkg">OpenMath</strong> to streams uses a different setup. It requires special objects called <strong class="pkg">OpenMath</strong> <em>writers</em>, which encapsulate streams and may be viewed as transducers accepting <strong class="pkg">GAP</strong> objects and writing them to a stream in the XML or binary <strong class="pkg">OpenMath</strong></p>
<p>Such setup makes it possible to re-use the same stream for both binary and XML <strong class="pkg">OpenMath</strong> communication, using different <strong class="pkg">OpenMath</strong> writers in different calls. It also allows to re-use most of the high-level code for <strong class="pkg">GAP</strong> to <strong class="pkg">OpenMath</strong> conversion, having separate methods for generating binary and XML <strong class="pkg">OpenMath</strong> only for low-level output (<strong class="pkg">OpenMath</strong> tags and basic objects). This makes easier adding support to new mathematical objects and private content dictionaries as described in Chapter <a href="chap3.html#X84EBC4EC7D3DC9CB"><span class="RefLink">3</span></a> since it does not require changing the low-level functionality.</p>
<p><a id="X79EE2E8B7C83E0F4" name="X79EE2E8B7C83E0F4"></a></p>
<h5>2.3-1 IsOpenMathWriter</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ IsOpenMathWriter</code></td><td class="tdright">( category )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ IsOpenMathXMLWriter</code></td><td class="tdright">( category )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ IsOpenMathBinaryWriter</code></td><td class="tdright">( category )</td></tr></table></div>
<p><code class="func">IsOpenMathWriter</code>is a category for <strong class="pkg">OpenMath</strong> writers. It has two subcategories: <code class="func">IsOpenMathXMLWriter</code> and <code class="func">IsOpenMathBinaryWriter</code>.</p>
<p><a id="X798979EB7E4723A2" name="X798979EB7E4723A2"></a></p>
<h5>2.3-2 OpenMathXMLWriter</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OpenMathXMLWriter</code>( <var class="Arg">s</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>for a stream <var class="Arg">s</var>, returns an object in the category <code class="func">IsOpenMathXMLWriter</code> (<a href="chap2.html#X79EE2E8B7C83E0F4"><span class="RefLink">2.3-1</span></a>).</p>
<p><a id="X786D6A987C1FAB0B" name="X786D6A987C1FAB0B"></a></p>
<h5>2.3-3 OpenMathBinaryWriter</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OpenMathBinaryWriter</code>( <var class="Arg">s</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>for a stream <var class="Arg">s</var>, returns an object in the category <code class="func">OpenMathBinaryWriter</code>.</p>
<p><a id="X84FC6AD5872CBF33" name="X84FC6AD5872CBF33"></a></p>
<h5>2.3-4 OMPutObject</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMPutObject</code>( <var class="Arg">stream</var>, <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMPutObjectNoOMOBJtags</code>( <var class="Arg">stream</var>, <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p><code class="func">OMPutObject</code> writes (appends) the XML <strong class="pkg">OpenMath</strong> encoding of the <strong class="pkg">GAP</strong> object <var class="Arg">obj</var> to output stream <var class="Arg">stream</var> (see <code class="func">InputTextFile</code> (<span class="RefLink">Reference: InputTextFile</span>), <code class="func">OutputTextUser</code> (<span class="RefLink">Reference: OutputTextUser</span>), <code class="func">OutputTextString</code> (<span class="RefLink">Reference: OutputTextString</span>), <code class="func">InputOutputTCPStream</code> (<a href="/usr/share/gap/pkg/scscp/doc/chap3.html#X7E3D43CF7B049F04"><span class="RefLink">SCSCP: InputOutputTCPStream (for client)</span></a>), <code class="func">InputOutputTCPStream</code> (<a href="/usr/share/gap/pkg/scscp/doc/chap3.html#X7E3D43CF7B049F04"><span class="RefLink">SCSCP: InputOutputTCPStream (for server)</span></a>)).</p>
<p>The second version does the same but without <OMOBJ> tags, what may be useful for assembling complex <strong class="pkg">OpenMath</strong> objects.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">g := [[1,2],[1,0]];;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">t := "";</span>
""
<span class="GAPprompt">gap></span> <span class="GAPinput">s := OutputTextString(t, true);;</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">w:=OpenMathXMLWriter( s );</span>
<OpenMath XML writer to OutputTextString(0)>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPutObject(w, g);</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">CloseStream(s);</span>
<span class="GAPprompt">gap></span> <span class="GAPinput">Print(t);</span>
<OMOBJ>
<OMA>
<OMS cd="linalg2" name="matrix"/>
<OMA>
<OMS cd="linalg2" name="matrixrow"/>
<OMI>1</OMI>
<OMI>2</OMI>
</OMA>
<OMA>
<OMS cd="linalg2" name="matrixrow"/>
<OMI>1</OMI>
<OMI>0</OMI>
</OMA>
</OMA>
</OMOBJ>
</pre></div>
<p><a id="X85297E7081470DDF" name="X85297E7081470DDF"></a></p>
<h5>2.3-5 OMPlainString</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMPlainString</code>( <var class="Arg">string</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p><code class="func">OMPlainString</code> wraps the string into a <strong class="pkg">GAP</strong> object of a special kind called an <strong class="pkg">OpenMath</strong> plain string. Internally such object is represented as a string, but <code class="func">OMPutObject</code> (<a href="chap2.html#X84FC6AD5872CBF33"><span class="RefLink">2.3-4</span></a>) threat it in a different way: instead of converting it into a <OMSTR> object, an <strong class="pkg">OpenMath</strong> plain string will be plainly substituted into the output (this explains its name) without decorating it with <OMSTR> tags.</p>
<p>It is assumed that <strong class="pkg">OpenMath</strong> plain string contains valid <strong class="pkg">OpenMath</strong> code; no actual validation is performed during its creation. Such functionality may be useful to compose some <strong class="pkg">OpenMath</strong> code at the <strong class="pkg">GAP</strong> level to communicate it to the other system, in particular, to send there symbols which are not supported by <strong class="pkg">GAP</strong>, for example:</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">s:=OMPlainString("<OMS cd=\"nums1\" name=\"pi\"/>");</span>
<OMS cd="nums1" name="pi"/>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMPrint(s); </span>
<OMOBJ>
<OMS cd="nums1" name="pi"/>
</OMOBJ>
</pre></div>
<p><a id="X7DFC90B87DC503A1" name="X7DFC90B87DC503A1"></a></p>
<h4>2.4 <span class="Heading">Utilities</span></h4>
<p><a id="X7D6B0843798A19B9" name="X7D6B0843798A19B9"></a></p>
<h5>2.4-1 OMTestXML</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMTestXML</code>( <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMTest</code>( <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Converts <var class="Arg">obj</var> to XML <strong class="pkg">OpenMath</strong> and back. Returns true if and only if <var class="Arg">obj</var> is unchanged (as a <strong class="pkg">GAP</strong> object) by this operation. The <strong class="pkg">OpenMath</strong> standard does not stipulate that converting to and from <strong class="pkg">OpenMath</strong> should be the identity function so this is a useful diagnostic tool.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMTestXML([[1..10],[1/2,2+E(4)],ZmodnZObj(2,6),(1,2),true,"string"]); </span>
true
</pre></div>
<p><code class="func">OMTest</code> is a synonym to <code class="func">OMTestXML</code></p>
<p><a id="X834694B784B5850F" name="X834694B784B5850F"></a></p>
<h5>2.4-2 OMTestBinary</h5>
<div class="func"><table class="func" width="100%"><tr><td class="tdleft"><code class="func">‣ OMTestBinary</code>( <var class="Arg">obj</var> )</td><td class="tdright">( function )</td></tr></table></div>
<p>Converts <var class="Arg">obj</var> to binary <strong class="pkg">OpenMath</strong> and back. Returns true if and only if <var class="Arg">obj</var> is unchanged (as a <strong class="pkg">GAP</strong> object) by this operation. The <strong class="pkg">OpenMath</strong> standard does not stipulate that converting to and from <strong class="pkg">OpenMath</strong> should be the identity function so this is a useful diagnostic tool.</p>
<div class="example"><pre>
<span class="GAPprompt">gap></span> <span class="GAPinput">OMTestBinary([[1..10],[1/2,2+E(4)],ZmodnZObj(2,6),(1,2),true,"string"]); </span>
true
</pre></div>
<div class="chlinkprevnextbot"> <a href="chap0.html">[Top of Book]</a> <a href="chap0.html#contents">[Contents]</a> <a href="chap1.html">[Previous Chapter]</a> <a href="chap3.html">[Next Chapter]</a> </div>
<div class="chlinkbot"><span class="chlink1">Goto Chapter: </span><a href="chap0.html">Top</a> <a href="chap1.html">1</a> <a href="chap2.html">2</a> <a href="chap3.html">3</a> <a href="chapBib.html">Bib</a> <a href="chapInd.html">Ind</a> </div>
<hr />
<p class="foot">generated by <a href="http://www.math.rwth-aachen.de/~Frank.Luebeck/GAPDoc">GAPDoc2HTML</a></p>
</body>
</html>
|