• Fri Mar 28, 2003
  • dlp1r18N.tar.gz ( N#1 )
  
  
• To be done :
  • dlp1r20C.tar.gz (object model + misc.)
  • agent / viewpoint arg's
  • ....

Contents

• Getting Started
  • DLP@cs.vu.nl
  • DownLoad
  • Installation
  • Compilation
  • Execution
• Program Examples
  • DLP Examples
  • DLP + VRML Examples
  • DLP + VRML + WASP Examples
• Builtins / Libraries
  • Core Builtin Predicates
  • TCP / IP Networking Predicates
  • N::F Storage / Retrieval Predicates
  • Regular Expression Library Predicates
  • JavaScript Interface Library Predicates
  • DLP / XML : Extensible Markup Language
  • Vector / Quaternion Predicate Library
  • VRML External Authoring Interface Library
• Multi-Threaded Objects
  • Syntax Summary
  • ....
• Foreign Language Interface
  • Java / DLP
  • JavaScript / DLP

Download

	dlp1r18N/
		bin/
			dlp		## command line execution
			dlpc		## compiler shell script (Cygwin / Linux / Solaris)
		classes/
			dlpsys.jar	## pre-compiled libraries and run-time system
		examples/
			README.txt
			....
			*.pl		## DLP program examples
			makefile	## for the compilation of the DLP examples
			setvars.j140	## environment variable settings (Linux / Solaris)
			setvars.cygw	## environment variable settings (Cygwin)
			....
		lib/
			execomp.qlf	## compiler front-end / back-end

• Cygwin / Linux / Solaris / Windows :
  • classes / dlpsys.zip
    Contains the dlpsys.jar file. Download dlpsys.zip, unzip the file, and put dlpsys.jar in directory classes. The main reason for distributing dlpsys.jar like this is that many browsers have a MIME type for jar files that is not suitable for downloading jar files.
  • lib / execomp.zip
    Contains the execomp.qlf file. Download, unzip and copy the execomp.qlf to lib / execomp.qlf
• Cygwin / Linux / Solaris :
  • bin / dlpc
    DLP compiler shell script
• Linux / Solaris :
  • examples / setvars.j140
    Overview environment variable settings (Linux / Solaris).
• Cygwin :
  • examples / setvars.cygw
    Overview environment variable settings (Cygwin).
• Win2000 command shell script ...
  • bin / dlpc.bat
    bin / dlp.bat
    (Change the settings of the environment variables in dlp.bat, dlpc.bat according to your local configuration)

Installation

• Unzip the downloaded distribution:

   gunzip dlp1r18N.tar.gz 

• Untar the archive:

   tar -xvf dlp1r18N.tar 

  This will create a "dlp1r18N" subdirectory in the current directory.
• Adjust the required environment variable settings as described in one of the setvars files. The settings refer to the jikes compiler : remove the jikes lines in case you prefer SUN's javac compiler. Jikes is a fast Java to JVM compiler developed by IBM. See the Jikes Home page for more information.
• Change the first line in file bin/dlpc, examples/pxdemo and examples/setvars.j140 or examples/setvars.cygw with respect to the location of the bash shell on your local configuration.
• The implementation requires (currently) SWI Prolog version 3.3.10 or higher ( Local Copy ).
• Running a DLP program that is compiled to the JVM requires at least the Java Runtime Environment. The JRE distribution contains the JVM, core classes and several other files, but not the compiler, debugger and a number of other tools.
• Compiling and debugging DLP programs requires a full Java SDK installation. This distribution includes the JRE.
  Each 1.4.X, 1.3.X, and 1.2.X J2SE download link lists both a JRE and full Java SDK distribution for several platforms.

Compilation

 dlpc prog.pl 

Execution

• Command line execution
  After compiling a DLP source file that contains for example an object objectname with method main, start the program by means of the command :

   dlp objectname 

  Execution will be transferred to method main in object objectname. The command "dlp" is basically a wrapper which starts dlpmain.class with the specified objectname. This class file as well as the dlpbrow.class and dlpcons.class files (see next 2 paragraphs) are included in the classes/dlpsys.jar file of the distribution.
  
  
• Execution of DLP in a browser with an output stream area
  In case you have written a DLP program example, e.g. like the bounded buffer example and would like to run it in a browser (without VRML), create a file as shown below :
  
  <html>
  <body>
  <applet archive="dlpsys.jar, pxbuff.jar" code="dlpbrow.class" width=500 height=500>
  <param name="object" value="pxbuff">
  <param name="line" value="80">
  <param name="rows" value="25">
  <param name="cols" value="80">
  </applet>
  </body>
  </html>
  
  The applet tag tells your browser that there are two jar files involved : dlpsys.jar , which contains all the pre-compiled DLP libraries including the dlpbrow.class, and your pxbuff.jar file, containing your program specific class files. If the jar files are not located in the same directory as your html file that contains the above-mentioned definitions, add the corresponding (relative) URLs.
  In addition, the applet tag tells your browser to start dlpbrow.class. This class file will read the parameter value as mentioned in the param name=object entry (alternative: param name=ostart entry in version 1r18K(8) or higher) in order to determine which method / object to start: in this example method main in object pxbuff. As opposed to dlpcons.class (see below), the dlpbrow.class creates a Java TextArea like output stream. The number of rows and columns of the TextArea can be adjusted by means of the param rows and param cols entries.
  When executing DLP methods like text_area(Stream) and set_output(Stream) as illustrated in the bounded buffer program, all subsequent output statements write their output to the TextArea like output stream in your browser. In case you don't invoke the text_area(Stream) and set_output(Stream) methods all output will be written to the browser Java console.
  If the optional param line entry is mentioned, dlpbrow creates a Java TextField like input field. Use the DLP built-in predicate text_field / 1 to specify to which queue input lines are sent for further asynchronous processing. Example : browser I/O.
  
  
• Execution of DLP + VRML browser plug-in without an output stream area
  Executing a DLP program in the context of a browser VRML plug-in (see for example the rotation program at the DLP+VRML examples page) requires the following html definitions :
  
  <html>
  <body>
  <embed src="root.wrl" width="900" height="600">
  <applet archive="dlpsys.jar , rotation.jar" code="dlpcons.class" MAYSCRIPT>
  <param name="command" value="applet_console('ide')">
  <param name="object" value="rotation">
  </applet>
  </body>
  </html>
  
  These definitions are essentially the same as in the previous paragraph. However, the applet tag contains a reference to the dlpcons.class file instead of the dlpbrow.class file. When using the dlpcons.class file, no TextArea like output stream is created and DLP output will always be written to the browser Java console. An example of the root.wrl file can be found at the DLP+VRML examples page.
  
  
• Error Messages
  The browser Java console as well as the VRML plug-in console are important in order to determine whether particular errors occurred.
  In Netscape Communicator, click "Communicator" -> "Tools" -> "Java Console".
  In Microsoft Internet Explorer, click "View" -> "Java Console". In case "View" doesn't show a "Java Console" option, activate the console by means of : "Tools" -> "Internet Options" -> "Advanced" : the "Microsoft VM" section contains the "Java Console enabled" checkbox.
  Using the Blaxxun VRML plug-in, click right mouse button in VRML area -> "Settings" -> "Console".
  
  
• Last but not least ...
  Check the cache settings of your browser and VRML plug-in. When you change your DLP or VRML code, it's not very useful that a browser or VRML plug-in reload the files from their cache. In addition, browser Refresh / Reload buttons will often fetch the class files from cache.
  However, when changing your cache settings to "Every visit to the page" (IExplorer) or "Every time" (Netscape), the class files are for some browser configurations still fetched from a cache : exit your browser and restart. Similar remarks with respect to VRML plug-ins. Use "Empty Cache now ..." (Blaxxun) to be sure that your new VRML specifications are loaded.

Summary of Built-ins

Arithmetic comparison

• +Eval =:= +Eval (arithmetic equal)
• +Eval =\= +Eval (arithmetic not equal)
• +Eval > +Eval (arithmetic greater than)
• +Eval >= +Eval (arithmetic greater than or equal)
• +Eval < +Eval (arithmetic less than)
• +Eval =< +Eval (arithmetic less than or equal)

Arithmetic evaluation

• LogVar is Expression (evaluate expression)
  Arithmetic functors :
  • '+'/2
  • '-'/1
  • '-'/2
  • '*'/2
  • '/'/2
  • '//'/2
  • '**'/2
    
  • '<<'/2 (bit shl)
  • '>>'/2 (bit shr)
  • '\'/2 (bit neg)
  • '/\'/2 (bit and)
  • '\/'/2 (bit ior)
    
  • abs/1
  • mod/2
  • rem/2
  • acos/1
  • asin/1
  • atan/1
  • cos/1
  • sin/1
  • tan/1
  • exp/1
  • log/1
  • random/0
  • round/1
  • sign/1
  • sqrt/1
  • truncate/1

Atomic term processing

• atom_chars (+Atom, ?CharList)
  atom_chars (?Atom, +CharList)
• atom_codes (+Atom, ?CodeList)
  atom_codes (?Atom, +CodeList)
• atom_concat (+Atom1, +Atom2, ?NewAtom)
• atom_list_concat (+AtomList, ?NewAtom)
• atom_length (+Atom, ?Length)
• atom_number(+Atom, ?Number)
  atom_number(?Atom, +Number)
• char_code (+Char, ?Code)
  char_code (?Char, +Code)
• number_chars (+Number, ?CharList)
  number_chars (?Number, +CharList)
• number_codes (+Number, ?CodeList)
  number_codes (?Number, +CodeList)

• compare(R, Term1, Term2). The first argument R will be unified with
  • '<', when Term1 'term-precedes' Term2
  • '=', when Term1 is identical to Term2
  • '>', when Term2 'term-precedes' Term1
  Predicate compare/3 is used by the term comparison predicates.
• numbervars(Term, N0, NL)
• memory(-TotalKBs, -FreeKBs). Get the total number of KBytes and the currently available free KBytes.
• sleep(+Msecs). Suspend the execution of the current thread for Msecs milliseconds.
• get_system_property(+Key, -Value)
  set_system_property(+Key, +NewValue, -OldValue)
  Java run-time system property predicates.
• stack_trace/0. Show the method/predicate continuations until the current point of execution.
• text_area(BrowserStream). Argument BrowserStream will be unified with a Java TextArea like stream.
  Combining this predicate with set_output(BrowserStream) redirects the output of a program to the corresponding BrowserStream, otherwise program output will be written to the browser "Java Console".
• text_field(InputQueueName). Asynchronous browser input from a TextField like input line is sent to the queue as an atom. Example : Browser I/O.
  Input in DLP (and Java), like browser or socket input, is usually processed by a separate thread. Instead of all kinds of detailed I/O control facilities as found in programming languages like C or C++, I/O in DLP (and Java) is handled by a thread that communicates its I/O results to other threads in a multi-threaded safe way.
• trace/0. Turn trace mode on. All method calls will be displayed (non-interactively).
• notrace/0. Turn trace mode off.
• ...

TCP / IP Networking

• Host Identification
  • host_address(+HostName, -InternetAddress).
  • local_host(-HostName, -InternetAddress).
  • code_base_host(-HostName).
    Unifies HostName with the name of the host from which the current program objects are loaded.
    When running in a browser HostName will be unified with the name of the originating host.
    However, note that some browser configurations don't allow for the retrieval of the name
    of the host and will generate a security exception.
• Server Predicates
  • tcp_server(+ServerPort, -ServerSocket).
  • tcp_accept(+ServerSocket, -ServerStreamIn, -ServerStreamOut).
  • tcp_accept(+ServerSocket, -ServerStreamIn, -ServerStreamOut, -ClientHostName).
• Client Predicates
  • tcp_client(+ServerHostName, +ServerPort, -ClientStreamIn, -ClientStreamOut). (TBD)
  • tcp_client(+ServerHostName, +ServerPort, +TimeOut, -ClientStreamIn, -ClientStreamOut).
• Bi-Directional Client / Server Communication
  • tcp_get_term(+StreamIn, ?Term).
  • tcp_put_term(+StreamOut, +Term).
  • ....
• Closing Client / Server Connection
  • tcp_close(+Socket).
  • tcp_close(+Stream).
• Networking Examples
  • Source code distributed DLP client-server example. In addition, the DLP client object in this client-server example can talk to a SICStus-Prolog server or SWI-Prolog server program.

EAI Node::Field like Storage-Retrieval / Synchronization Predicates

Get / Set Field Predicates :

• set_field(+GlobalFieldName, +Term)
• get_field(+GlobalFieldName, ?Term)
• get_field_block(+GlobalFieldName, ?Term)
• get_field_reset(+GlobalFieldName, ?Term)
• get_field_event(+GlobalFieldName, ?Term)

• set_field(+NodeName, +FieldName, +Term)
• get_field(+NodeName, +FieldName, ?Term)
• get_field_block(+NodeName, +FieldName, ?Term)
• get_field_reset(+NodeName, +FieldName, ?Term)
• get_field_event(+NodeName, +FieldName, ?Term)

Get / Set Queue Predicates :

• new_queue(+GlobalQueueName, +MaxSize)
• set_queue(+GlobalQueueName, +Term)
• get_queue(+GlobalQueueName, ?Term)

• queue_full(+GlobalQueueName)
• queue_empty(+GlobalQueueName)
• queue_length(+GlobalQueueName, -CurrentLength)

• new_queue(+NodeName, +QueueName, +MaxSize)
• set_queue(+NodeName, +QueueName, +Term)
• get_queue(+NodeName, +QueueName, ?Term)

• queue_full(+NodeName, +QueueName)
• queue_empty(+NodeName, +QueueName)
• queue_length(+NodeName, +QueueName, -CurrentLength)

Conditional Queue Lookup Predicates :

• accept_queue_term ( +GlobalQueueName, +AcceptExpressionList, -Term )
• accept_queue_term ( +NodeName, +QueueName, +AcceptExpressionList, -Term )
  Accept the first entry in the queue that satifies one of the AcceptExpressions in the AcceptExpressionList.
  ( building block for new DLP accept/n implementation )

Get / Set Array Predicates :

• new_array(+NameSpace, +ArrayName, +Dim1)
• get_array(+NameSpace, +ArrayName, +Idx1, ?Elem)
• set_array(+NameSpace, +ArrayName, +Idx1, +Elem)

• new_array(+NameSpace, +ArrayName, +Dim1, +Dim2)
• get_array(+NameSpace, +ArrayName, +Idx1, +Idx2, ?Elem)
• set_array(+NameSpace, +ArrayName, +Idx1, +Idx2, +Elem)

• new_array(+NameSpace, +ArrayName, +Dim1, +Dim2, +Dim3)
• get_array(+NameSpace, +ArrayName, +Idx1, +Idx2, +Idx3, ?Elem)
• set_array(+NameSpace, +ArrayName, +Idx1, +Idx2, +Idx3, +Elem)

• NameSpace and ArrayName are atoms.
• Array elements must be explicitly initialized.

Fine-grained Multi-threaded Synchronization

• join(+NameSpace:SyncTerm, +NumberOfThreads)
  Initialization of the synchronization barrier
• join(+NameSpace:SyncTerm)
  Wait until all NumberOfThreads reach their join/1
• NameSpace:SyncTerm must be ground.

Program Examples / Sources

• Set / Get Field Predicates : poll versus sync example.
• NodeName based queue example.

DLP Regular Expression Library Predicates

• Remarks

  • rexlib requires Java SDK 1.4.X
  • see the java.util.regex package for more information.
  • rexlib not available in 1r18N (temporarily)
  
  

• Program Examples / Sources

  • introductory pattern matching examples.
  
  

• Pattern Predicates

  • compile_pattern ( +RegExpPattern , -PatternRef )
    RegExpPattern is an atom.
    PatternRef is a foreign language object reference term.
    Compiles the given regular expression into a pattern.
  • compile_pattern ( +RegExpPattern , +PatternFlagList , -PatternRef )
    PatternFlagList is a list of one or more pattern compilation options:
    [ canon_eq, case_insensitive, comments, dotall, multiline, unicode_case, unix_lines ]
    Compiles the given regular expression into a pattern with the given flags.
    
    
  • pattern_matches ( +RegExpPattern , +InputAtomOrString )
    pattern_matches ( +RegExpPattern , +InputAtomOrString , -Boolean )
    Compiles the given regular expression and matches the given input against it.
    Predicate pattern_matches / 2 either succeeds or fails, pattern_matches / 3 returns the atom true or false.
    Predicate pattern_matches / [2,3] is defined as a convenience for when a regular expression is used only once.
    
    
  • split_input ( +PatternRef , +InputAtomOrString , -AtomList )
    split_input ( +PatternRef , +InputAtomOrString , +MaxListLength , -AtomList )
    Splits the given input sequence around matches of this pattern.
  
  

• Pattern Matcher Creation

  • pattern_matcher ( +PatternRef , +InputAtomOrString , -Matcher )
    Creates a matcher that will match the given input against this pattern, many matchers can share the same pattern specification.
    Matcher is a matcher foreign language object reference term.
  
  

• URL's ....

  • url_open ( +URL , -URLRef )
  • url_read_line ( +URLRef , -LineString )
  • url_close ( +URLRef )
    Predicates are part of dlplib, not rexlib (Docs will be moved accordingly).
    (to be extended)
  
  

• Matcher Predicates

  • replacement_buffer ( +BufferSize, -BufferRef)
  • append_replacement ( +Matcher , +BufferRef , +Replacement )
    append_replacement ( +Matcher , +BufferRef , +Replacement , -MatcherOut )
    Non-terminal append-and-replace.
  • append_tail ( +Matcher , +BufferIn , -AtomOut )
    Terminal append-and-replace.
    
    
  • end_index ( +Matcher , -Index )
    Returns the index of the last character matched, plus one.
  • end_index ( +Matcher , +GroupNumber , -Index )
    Returns the index of the last character, plus one, of the subsequence captured by the given group during the previous match operation.
    GroupNumber = [ 0 ... GroupCount - 1 ]. See also group_count / 2.
    
    
  • find_next ( +Matcher )
    find_next ( +Matcher , -Boolean )
    Finds the next subsequence of the input sequence that matches the pattern.
  • find_starting_at ( +Matcher , +Index )
    find_starting_at ( +Matcher , +Index , -Boolean )
    Finds the next subsequence of the input sequence that matches the pattern, starting at the specified index.
    
    
  • group ( +Matcher , -Atom )
    Returns the input subsequence matched by the previous match
  • group ( +Matcher , +GroupNumber , -Atom )
    Returns the input subsequence captured by the given group during the previous match operation
  • group_count ( +Matcher , -GroupCount )
    Returns the number of capturing groups in this matcher's pattern
    
    
  • looking_at ( +Matcher )
    looking_at ( +Matcher , -Boolean )
    Starting at the beginning, match the input sequence against the pattern.
  • matches ( +Matcher )
    matches ( +Matcher , -Boolean )
    Matches the entire input sequence against the pattern.
    
    
  • replace_all (+Matcher , +Replacement , -Atom )
    Replaces every subsequence of the input sequence that matches the pattern with the given replacement.
  • replace_first ( +Matcher , +Replacement , -Atom )
    Replaces the first subsequence of the input sequence that matches the pattern with the given replacement.
    
    
  • reset_matcher ( +MatcherIn , -MatcherOut )
    Resets this matcher.
  • reset_matcher ( +MatcherIn , +InputAtomOrString , -MatcherOut )
    Resets this matcher with a new input sequence.
    
    
  • start_index ( +Matcher , -Index )
    Returns the start index of the previous match.
  • start_index ( +Matcher , +GroupNumber , -Index )
    Returns the start index of the subsequence captured by the given group during the previous match operation.

Atom / String Predicates

• Atom/String Predicates
  • atom_to_string ( +Atom , ?String )
  • string_to_atom ( +String , ?Atom )
    
    
  • new_string_buffer ( -StringBuffer )
  • new_string_buffer ( +Length , -StringBuffer )
    
    
  • string ( ?Term )
    Succeeds when Term is a string.
  • string_char_at ( +String , +Index , ?Char )
    Char is a single character atom.
  • string_code_at ( +String , +Index , ?Code )
    Code is an integer.
  • string_compare_to ( +String1 , +String2 , ?Result )
    Result: < 0 | == 0 | > 0
  • string_buffer_to_atom ( +StringBuffer , ?Atom )
  • string_buffer_to_string ( +StringBuffer , ?String )
  • string_length ( +String , -Length )
  • substring ( +String , +BeginIndex , +EndIndex , -SubString )
  • ...
    
    
  • strings should be built-in :
    • <@ , >@ , =<@ , >=@ , == / 2 , \== / 2
    • = / 2 , \= / 2
    • "write_term" output method
    • type testing: string(Term)
    • copy_term / 2 .
    • FLI : StrTerm
  • ...
• Program Examples / Sources
  • see also the regular expression library.
  • the source code of the string predicates.
  • ....

DLP / JavaScript Interface

• DLP methods (object jsilib)
  • get_window ( -JSObject )
  • call ( +JSObject, +JSMethodName, +ArgList, -Result )
    (t.b.d. arrays < = > lists)
  • eval ( +JSObject, +Evaluate, -Result )
    see member example w.r.t. netscape/explorer remarks.
  • get_member ( +JSObject, +Member, -Result )
  • set_member ( +JSObject, +Member, +Value )
  • get_slot ( +Member, +Index, -Value) (netscape)
    set_slot ( +Member, +Index, +Value) (netscape)
    (use call/4 for a portable solution)
• JS method (part of object dlpbrow / dlpcons)
  • applet.set_queue("namespace", "queuename", term)
  • var applet = window.document.applets['dlpbrow'];
    var applet = window.document.applets['dlpcons'];
    Parameters namespace, queuename are strings.
    Parameter term is an integer, float, double, or string :
    a string is either :
    • "term:" + "aValidTermString"
    • "atom:" + "anAtom" (explicit atom)
    • or any other string (implicit atom)
• Examples / Sources :
  • query example source and script code ( exec program )
  • form example source and script code ( exec program )
  • member example source code ( exec program )
  • library source code.
• JS / DLP interface is based on the JS / Java LiveConnect interface.
  See the following JavaScript links for more information.

DLP / XML : Extensible Markup Language Predicates

• under construction.

Multi-threaded Objects (Syntax Summary)

• program examples :
  • multi-threaded (binary) semaphore objects
  • multi-threaded producer / buffer / consumer objects
• declaration of objects :
  • :-object name .
  • :-object name : [ base ].
  • :-object name : [ base1, base2, ... ].
  • :-end_object name .
• declaration non-logical variables (nlv's) :
  var i=0, j=[1,2,3], k=f(a,b,c).
• destructive assignment :
  nlv := Term
  nlv := Expression (simplification)
  other nlv occurrences are replaced by their current value.
• object creation :
  ObjectRef := new(ObjectNameOrConstructor)
• method invocation :
  ObjectRef <- method(...)
• accept statement :
  accept (AcceptExpression1, AcceptExpression2, ...)
  • accept expression:
    • method(...) <== [Guard] ==> Body
    • method(...) <== [Guard]
    • method(...) ==> Body
    • method(...)
    • any
  • accept guard:
    • callable term
  • accept body:
    • callable term
• channels :
  Channels in DLP provide a way to express synchronous interactions between independently executing active objects. The following DLP language constructs deal with channel communication:
  • channel creation : C := new(channel)
  • channel output : C ! OutTerm
  • channel input : C ? InTerm
  
  Synchronization:
  • Invocation of a channel input statement will block until a client thread executes a channel output statement.
  • Invocation of a channel output statement will block until a server thread executes a channel input statement with an InTerm that unifies with the OutTerm of the current channel output statement.
  • If an input term and an output term are not unifiable, the server side will backtrack until a channel input statement has an InTerm that unifies with the OutTerm of the current channel output statement.
  
  Examples:
  channel example 1 and example 2.
• ...

DLP Foreign Language Interface

FLI Program Example

• Source Code
  • DLP code pxflin.pl
  • Java code pxjint.java
• Compilation
  • dlpc pxflin.pl pxjint.java
• Execution
  • dlp pxflin

Term Dereferencing

• Word dt = Word.deref (Word t)

Term Creation

• IntTerm it = Word.new_int (int)
• FltTerm ft = Word.new_flt (double)
• ForTerm ft = Word.new_for (Object ref)
  foreign object reference term
• FunTerm ft = Word.new_fun (SymTerm func, Word [ ] args)
  FunTerm ft = Word.new_fun (SymTerm func, Word arg1)
  FunTerm ft = Word.new_fun (SymTerm func, Word arg1, Word arg2)
  FunTerm ft = Word.new_fun (SymTerm func, Word arg1, Word arg2, Word arg3)
• LstTerm lt = Word.new_lst (Word head, Word tail)
• NilTerm nt = Word.new_nil ()
• SymTerm st = Word.new_sym ("String".intern())

Term Type Tests

• boolean it = Word.int_term (Word w)
• boolean ft = Word.flt_term (Word w)
• boolean ft = Word.for_term (Word w)
• boolean ft = Word.fun_term (Word w)
• boolean lt = Word.lst_term (Word w)
• boolean nt = Word.nil_term (Word w)
• boolean st = Word.sym_term (Word w)
• boolean vt = Word.var_term (Word w)

Term Type Casts

• IntTerm it = Word.int_cast (Word w)
• FltTerm ft = Word.flt_cast (Word w)
• ForTerm ft = Word.for_cast (Word w)
• FunTerm ft = Word.fun_cast (Word w)
• LstTerm lt = Word.lst_cast (Word w)
• SymTerm st = Word.sym_cast (Word w)
• VarTerm vt = Word.var_cast (Word w)

Term Value Retrieval

• int i = Word.int_val (Word it)
• double f = Word.flt_val (Word ft)
• Object o = Word.for_val (Word ft)
• String n = Word.fun_name (Word ft)
• int argc = Word.fun_argc (Word ft)
• Word argv [ ] = Word.fun_argv (Word ft)
• Word argv = Word.fun_argi (Word ft, int argi)
• Word head = Word.lst_head (Word lt)
• Word tail = Word.lst_tail (Word lt)
• String s = Word.sym_val (Word st)

Vectors / Quaternions (vectorlib)

• Predicates
  • vector_dot_product(vector(X1,Y1,Z1), vector(X2,Y2,Z2), V1DotV2)
  • vector_cross_product(vector(X1,Y1,Z1), vector(X2,Y2,Z2), vector(XN,YN,ZN))
  • vector_cross_product(vector(X1,Y1,Z1), vector(X2,Y2,Z2), vector(XN,YN,ZN), AngleV12)
  • quaternion_to_rotation(quaternion(W1,X1,Y1,Z1), rotation(X,Y,Z,R))
  • rotation_to_quaternion(rotation(X1,Y1,Z1,R1), quaternion(W,X,Y,Z))
  • unit_vector(vector(VX,VY,VZ), vector(UX,UY,UZ))
  • unit_quaternion(quaternion(W1,X1,Y1,Z1), quaternion(W,X,Y,Z))
  • direction_vector(position(X1,Y1,Z1), position(X2,Y2,Z2), vector(Ux,Uy,Uz))
  • quaternion_product(quaternion(W1,X1,Y1,Z1), quaternion(W2,X2,Y2,Z2), quaternion(W,X,Y,Z))
  • slerp(F, quaternion(W1,X1,Y1,Z1), quaternion(W2,X2,Y2,Z2), quaternion(W,X,Y,Z))
    
    
  • cosine_law(A, B, C, AngleAB)
  • vector_rotation(vector(X,Y,Z), R, vector(Ux,Uy,Uz))
  • position_rotation(position(X,Y,Z), R, position(Px,Py,Pz))
• The vectorlib library source code.

DLP / EAI: VRML External Authoring Interface Library (Summary)

• Examples / Sources

  • General VRML / X3D Info.
  • Introductory DLP+VRML examples.
  • More advanced DLP+VRML WASP examples.
  
  

• VRML Browser Predicates

  • loadURL( +URL )
  • getWorldURL( -URL )
  • setDescription( +Description )
    Description is an atom
  • setTimerInterval( +NewMsecs , -OldMsecs )
  • beginUpdate / 0, endUpdate / 0
    
    
  • createVrmlFromString( +VrmlAtom , -ObjectRefList)
  • createVrmlFromString( +VrmlAtom , +ParentObject , -ObjectRefList)
    ObjectRefList is a Foreign Object Reference List.
    See also the addChildren and removeChildren predicates.
  • createVrmlFromURL( +URL , +NotifyNode , +NotifyField )
    
    
  • addRoute( +FromObject, +EventOutFieldName , +ToObject , +EventInFieldName )
  • deleteRoute( +FromObject, +EventOutFieldName, +ToObject, +EventInFieldName )
  
  

• VRML Event Observers

  • eventObserverQueue ( +Object, +FieldName, +QueueName )
    Object/FieldName events are sent to QueueName as a term:
    FieldName(EventValue, EventTime, Object)
  • Not available (in the current EAI SDK : EventOut.unAdvise) :
    removeEventObserverQueue ( +Object, +FieldName, +QueueName )
  
  

• Agent / Object Coordinates

  • getPosition( +Object , -X , -Y , -Z )
  • setPosition( +Object , +X , +Y , +Z )
  • getRotation( +Object , -X , -Y , -Z , -R )
  • setRotation( +Object , +X , +Y , +Z , +R )
  • getViewpointPosition( +Agent , -X , -Y , -Z )
  • setViewpointPosition( +Agent , +X , +Y , +Z )
  • getViewpointOrientation( +Agent , -X , -Y , -Z , -R )
  • setViewpointOrientation( +Agent , +X , +Y , +Z , +R )
    X, Y, Z, and R values are integers or floats
  
  

• Single Field Predicates

  • getSFBool(+Object, +Field, -Bool)
  • setSFBool(+Object, +Field, +Bool)
    Bool is an atom : 'true' or 'false'
  • getSFFloat(+Object, +Field, -Float)
  • setSFFloat(+Object, +Field, +Float)
  • getSFInt32(+Object, +Field, -Int32)
  • setSFInt32(+Object, +Field, +Int32)
  
  
  • getSFString(+Object, +Field, -Atom)
  • setSFString(+Object, +Field, +Atom)
  • setSFString(+Object, +Field, +Format, +ArgList)
  
  
  • getSFColor(+Object, +Field, -R,-G,-B)
  • setSFColor(+Object, +Field, +R,+G,+B)
    R, G, and B values are integers or floats
  • getSFNode(+Object, +Field, -ObjectRef)
  • setSFNode(+Object, +Field, +NameOrRef)
  • getSFRotation(+Object, +Field, -X,-Y,-Z, -R)
  • setSFRotation(+Object, +Field, +X,+Y,+Z, +R)
  • getSFTime(+Object, +Field, -Time)
  • setSFTime(+Object, +Field, +Time)
  
  
  • getSFVec2f(+Object, +Field, -X,-Y)
  • setSFVec2f(+Object, +Field, +X,+Y)
  • getSFVec3f(+Object, +Field, -X,-Y,-Z)
  • setSFVec3f(+Object, +Field, +X,+Y,+Z)
  
  

• Multi Field Predicates

  • getMFFloat(+Object, +Field, -FloatList)
  • setMFFloat(+Object, +Field, +FloatList)
  • getMFInt32(+Object, +Field, -IntegerList)
  • setMFInt32(+Object, +Field, +IntegerList)
  
  
  • getMFString(+Object, +Field, -AtomList)
  • setMFString(+Object, +Field, +AtomList)
  • setMFString(+Object, +Field, +Format, +ArgList)
  
  
  • getMFColor(+Object, +Field, -RGBList)
  • setMFColor(+Object, +Field, +RGBList)
    RGBList = [ sfcolor(R1,G1,B1), sfcolor(R2,G2,B2), .... ]
  • getMFNode(+Object, +Field, -ObjectRefList)
  • setMFNode(+Object, +Field, +ObjectRefList)
  • getMFRotation(+Object, +Field, -XYZRList)
  • setMFRotation(+Object, +Field, +XYZRList)
    XYZRList = [ sfrotation(X1,Y1,Z1,R1), sfrotation(X2,Y2,Z2,R2), .... ]
  
  
  • getMFVec2f(+Object, +Field, -XYList)
  • setMFVec2f(+Object, +Field, +XYList)
    XYList = [ sfvec2f(X1,Y1), sfvec2f(X2,Y2), .... ]
  • getMFVec3f(+Object, +Field, -XYZList)
  • setMFVec3f(+Object, +Field, +XYZList)
    XYZList = [ sfvec3f(X1,Y1,Z1), sfvec3f(X2,Y2,Z2), .... ]
  
  

• Add / Remove Children Predicates

  • addChildren( +ParentObject, +ObjectRefList )
  • removeChildren( +ParentObject, +ObjectRefList )
  
  

• Single / Multi - Field Predicates

  • getFieldType( +Object, +Field, ?Type)
  • getFieldValue( +Object, +Field, ?Value)
  • setFieldValue( +Object, +Field, +Value)
    sf structures : sfbool(B), sfcolor(R,G,B), sffloat(F), sfint32(I), sfnode(N), sfrotation(X,Y,Z,R), sfstring(A), sftime(T), sfvec2f(X,Y), sfvec3f(X,Y,Z).
    mf structures : mfcolor(SFColorList), mffloat(FloatList), mfint32(Int32List), mfnode(NodeList), mfrotation(SFRotationList), mfstring(AtomList), mftime(TimeList) (not in EAI SDK), mfvec2f(SFVec2fList), mfvec3f(SFVec3fList).
  
  

• Miscellaneous

  • distance2D(+X1, +Z1, +X2, +Z2, -Distance)
  • distance3D(+X1, +Y1, +Z1, +X2, +Y2, +Z2, -Distance)
  
  
  • intersection(+Ax1,+Az1, +Ax2,+Az2, +Bx1,+Bz1, +Bx2,+Bz2, -CD, -Ua,-Ub, -Xi,-Zi)
    La line segment from (Ax1,Az1) to (Ax2,Az2)
    Lb line segment from (Bx1,Bz1) to (Bx2,Bz2)
    If CD =:= 0 then the La, Lb line segments are parallel.
    If CD =\= 0 and 0 =< Ua =< 1, La segment contains intersection point,
    If CD =\= 0 and 0 =< Ub =< 1, Lb segment contains intersection point,
    If CD =\= 0 and Ua as well as Ub lie within the [0..1] range then the
    intersection point is within both the La and Lb segments.
    Xi, Zi : if CD =\= 0, the intersection point coordinates.
  
  
  • vector_dot_product(+X1,+Y1,+Z1, +X2,+Y2,+Z2, -Angle12, -V1dotV2)
    V1 dot V2 = | V1 | . | V2 | . cos (Angle12)
  • vector_cross_product(+X1,+Y1,+Z1, +X2,+Y2,+Z2, -XN,-YN,-ZN, -Angle12, -VNSize)
    | VN | = | V1 cross V2 | = | V1 | . | V2 | . sin (Angle12)