1/*  Part of JPL -- SWI-Prolog/Java interface
    2
    3    Author:        Paul Singleton, Fred Dushin and Jan Wielemaker
    4    E-mail:        paul@jbgb.com
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2004-2020, Paul Singleton
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(jpl,
   36    [   jpl_get_default_jvm_opts/1,
   37        jpl_set_default_jvm_opts/1,
   38        jpl_get_actual_jvm_opts/1,
   39        jpl_pl_lib_version/1,
   40        jpl_c_lib_version/1,
   41        jpl_pl_syntax/1,
   42        jpl_new/3,
   43        jpl_call/4,
   44        jpl_get/3,
   45        jpl_set/3,
   46        jpl_servlet_byref/3,
   47        jpl_servlet_byval/3,
   48        jpl_class_to_classname/2,
   49        jpl_class_to_type/2,
   50        jpl_classname_to_class/2,
   51        jpl_classname_to_type/2, % name does not reflect that it deals with entity names
   52        jpl_datum_to_type/2,
   53        jpl_entityname_to_type/2, % new alias for jpl_classname_to_type/2
   54        jpl_false/1,
   55        jpl_is_class/1,
   56        jpl_is_false/1,
   57        jpl_is_null/1,
   58        jpl_is_object/1,
   59        jpl_is_object_type/1,
   60        jpl_is_ref/1,
   61        jpl_is_true/1,
   62        jpl_is_type/1,
   63        jpl_is_void/1,
   64        jpl_null/1,
   65        jpl_object_to_class/2,
   66        jpl_object_to_type/2,
   67        jpl_primitive_type/1,
   68        jpl_ref_to_type/2,
   69        jpl_true/1,
   70        jpl_type_to_class/2,
   71        jpl_type_to_classname/2, % name does not reflect that it deals with entity names
   72        jpl_type_to_entityname/2, % new alias for jpl_type_to_classname/2
   73        jpl_void/1,
   74        jpl_array_to_length/2,
   75        jpl_array_to_list/2,
   76        jpl_datums_to_array/2,
   77        jpl_enumeration_element/2,
   78        jpl_enumeration_to_list/2,
   79        jpl_hashtable_pair/2,
   80        jpl_iterator_element/2,
   81        jpl_list_to_array/2,
   82        jpl_terms_to_array/2,
   83        jpl_array_to_terms/2,
   84        jpl_map_element/2,
   85        jpl_set_element/2
   86   ]).   87:- autoload(library(apply),[maplist/2]).   88:- use_module(library(debug),[assertion/1, debugging/1,debug/3]).   89:- use_module(library(yall)).   90:- autoload(library(lists),
   91	    [member/2,nth0/3,nth1/3,append/3,flatten/2,select/3]).   92:- autoload(library(shlib),[load_foreign_library/1]).

  101% suppress debugging this library
  102:- set_prolog_flag(generate_debug_info, false).

 jpl_new(+X, +Params, -V) is det

X can be:

• an atomic classname, e.g. 'java.lang.String'
• or an atomic descriptor, e.g. '[I' or 'Ljava.lang.String;'
• or a suitable type, i.e. any class(_,_) or array(_), e.g. class([java,util],['Date'])

If X is an object (non-array) type or descriptor and Params is a list of values or references, then V is the result of an invocation of that type's most specifically-typed constructor to whose respective formal parameters the actual Params are assignable (and assigned).

If X is an array type or descriptor and Params is a list of values or references, each of which is (independently) assignable to the array element type, then V is a new array of as many elements as Params has members, initialised with the respective members of Params.

If X is an array type or descriptor and Params is a non-negative integer N, then V is a new array of that type, with N elements, each initialised to Java's appropriate default value for the type.

If V is literally {Term} then we attempt to convert a new org.jpl7.Term instance to a corresponding term; this is of little obvious use here, but is consistent with jpl_call/4 and jpl_get/3.

  133jpl_new(X, Params, V) :-
  134    (   var(X)
  135    ->  throwme(jpl_new,x_is_var)
  136    ;   jpl_is_type(X)                  % NB Should check for "instantiable type"? Also accepts "double" for example.
  137    ->  Type = X
  138    ;   atom(X)                         % an atom not captured by jpl_is_type/1 e.g. 'java.lang.String', '[L', even "void"
  139    ->  (   jpl_entityname_to_type(X, Type)
  140        ->  true
  141        ;   throwme(jpl_new,x_not_classname(X))
  142        )
  143    ;   throwme(jpl_new,x_not_instantiable(X))
  144    ),
  145    jpl_new_1(Type, Params, Vx),
  146    (   nonvar(V),
  147        V = {Term}  % yucky way of requesting Term->term conversion
  148    ->  (   jni_jref_to_term(Vx, TermX)    % fails if Vx is not a JRef to a org.jpl7.Term
  149        ->  Term = TermX
  150        ;   throwme(jpl_new,not_a_jpl_term(Vx))
  151        )
  152    ;   V = Vx
  153    ).

 jpl_new_1(+Tx, +Params, -Vx)

(serves only jpl_new/3)

Tx can be a class(_,_) or array(_) type.

Params must be a proper list of constructor parameters.

At exit, Vx is bound to a JPL reference to a new, initialised instance of Tx

  166jpl_new_1(class(Ps,Cs), Params, Vx) :-
  167    !,                                      % green (see below)
  168    Tx = class(Ps,Cs),
  169    (   var(Params)
  170    ->  throwme(jpl_new_class,params_is_var)
  171    ;   \+ is_list(Params)
  172    ->  throwme(jpl_new_class,params_is_not_list(Params))
  173    ;   true
  174    ),
  175    length(Params, A),          % the "arity" of the required constructor
  176    jpl_type_to_class(Tx, Cx),  % throws Java exception if class is not found
  177    N = '<init>',               % JNI's constructor naming convention for GetMethodID()
  178    Tr = void,                  % all constructors have this return "type"
  179    findall(
  180        z3(I,MID,Tfps),
  181        jpl_method_spec(Tx, I, N, A, _Mods, MID, Tr, Tfps), % cached
  182        Z3s
  183    ),
  184    (   Z3s == []               % no constructors which require the given qty of parameters?
  185    ->  (   jpl_call(Cx, isInterface, [], @(true))
  186        ->  throwme(jpl_new_class,class_is_interface(Tx))
  187        ;   throwme(jpl_new_class,class_without_constructor(Tx,A))
  188        )
  189    ;   (   catch(
  190                jpl_datums_to_types(Params, Taps),  % infer actual parameter types
  191                % 2020-07-21: make catcher's 1st context arg an "anonvar" instead of a overspecified predicate indicator
  192                error(type_error(acyclic,Te),context(_,Msg)),
  193                throwme(jpl_new_class,acyclic(Te,Msg)) % rethrow
  194            )
  195        ->  true
  196        ;   throwme(jpl_new_class,bad_jpl_datum(Params))
  197        ),
  198        findall(
  199            z3(I,MID,Tfps),                 % select constructors to which actual parameters are assignable
  200            (   member(z3(I,MID,Tfps), Z3s),
  201                jpl_types_fit_types(Taps, Tfps) % assignability test: actual parameter types "fit" formal parameter types?
  202            ),
  203            Z3sA
  204        ),
  205        (   Z3sA == []                      % no type-assignable constructors?
  206        ->  (   Z3s = [_]
  207            ->  throwme(jpl_new_class,single_constructor_mismatch(Tx/A))
  208            ;   throwme(jpl_new_class,any_constructor_mismatch(Params))
  209            )
  210        ;   Z3sA = [z3(I,MID,Tfps)]
  211        ->  true
  212        ;   jpl_z3s_to_most_specific_z3(Z3sA, z3(I,MID,Tfps))
  213        ->  true
  214        ;   throwme(jpl_new_class,constructor_multimatch(Params))
  215        )
  216    ),
  217    catch(
  218        jNewObject(Cx, MID, Tfps, Params, Vx),
  219        error(java_exception(_), 'java.lang.InstantiationException'),
  220        throwme(jpl_new_class,class_is_abstract(Tx)) % Rethrow
  221    ),
  222    jpl_cache_type_of_ref(Tx, Vx).          % since we know it
  223
  224jpl_new_1(array(T), Params, Vx) :-
  225    !,
  226    (   var(Params)
  227    ->  throwme(jpl_new_array,params_is_var)
  228    ;   integer(Params)         % integer I -> array[0..I-1] of default values
  229    ->  (   Params >= 0
  230        ->  Len is Params
  231        ;   throwme(jpl_new_array,params_is_negative(Params))
  232        )
  233    ;   is_list(Params)     % [V1,..VN] -> array[0..N-1] of respective values
  234    ->  length(Params, Len)
  235    ),
  236    jpl_new_array(T, Len, Vx), % NB may throw out-of-memory exception
  237    (   nth0(I, Params, Param),     % nmember fails silently when Params is integer
  238        jpl_set(Vx, I, Param),
  239        fail
  240    ;   true
  241    ),
  242    jpl_cache_type_of_ref(array(T), Vx).   % since we know it
  243
  244jpl_new_1(T, _Params, _Vx) :-       % doomed attempt to create new primitive type instance (formerly a dubious completist feature :-)
  245    jpl_primitive_type(T),
  246    !,
  247    throwme(jpl_new_primitive,primitive_type_requested(T)).
  248  % (   var(Params)
  249  % ->  throwme(jpl_new_primitive,params_is_var)
  250  % ;   Params == []
  251  % ->  jpl_primitive_type_default_value(T, Vx)
  252  % ;   Params = [Param]
  253  % ->  jpl_primitive_type_term_to_value(T, Param, Vx)
  254  % ;   throwme(jpl_new_primitive,params_is_bad(Params))
  255  % ).
  256
  257jpl_new_1(T, _, _) :- throwme(jpl_new_catchall,catchall(T)).

 jpl_new_array(+ElementType, +Length, -NewArray) is det

binds NewArray to a jref to a newly created Java array of ElementType and Length

  264jpl_new_array(boolean, Len, A) :-
  265    jNewBooleanArray(Len, A).
  266jpl_new_array(byte, Len, A) :-
  267    jNewByteArray(Len, A).
  268jpl_new_array(char, Len, A) :-
  269    jNewCharArray(Len, A).
  270jpl_new_array(short, Len, A) :-
  271    jNewShortArray(Len, A).
  272jpl_new_array(int, Len, A) :-
  273    jNewIntArray(Len, A).
  274jpl_new_array(long, Len, A) :-
  275    jNewLongArray(Len, A).
  276jpl_new_array(float, Len, A) :-
  277    jNewFloatArray(Len, A).
  278jpl_new_array(double, Len, A) :-
  279    jNewDoubleArray(Len, A).
  280jpl_new_array(array(T), Len, A) :-
  281    jpl_type_to_class(array(T), C),
  282    jNewObjectArray(Len, C, @(null), A).        % initialise each element to null
  283jpl_new_array(class(Ps,Cs), Len, A) :-
  284    jpl_type_to_class(class(Ps,Cs), C),
  285    jNewObjectArray(Len, C, @(null), A).

 jpl_call(+X, +MethodName:atom, +Params:list(datum), -Result:datum) is det

X should be either

• an object reference, e.g. <jref>(1552320) (for static or instance methods)
• or a classname, e.g. 'java.util.Date' (for static methods only)
• or a descriptor, e.g. 'Ljava.util.Date;' (for static methods only)
• or type, e.g. class([java,util],['Date']) (for static methods only)

MethodName should be a method name (as an atom) (may involve dynamic overload resolution based on inferred types of params)

Params should be a proper list (perhaps empty) of suitable actual parameters for the named method.

The class or object may have several methods with the given name; JPL will resolve (per call) to the most appropriate method based on the quantity and inferred types of Params. This resolution mimics the corresponding static resolution performed by Java compilers.

Finally, an attempt will be made to unify Result with the method's returned value, or with @(void) (the compound term with name @ and argument void) if it has none.

  307jpl_call(X, Mspec, Params, R) :-
  308    (   jpl_object_to_type(X, Type)         % the usual case (goal fails safely if X is var or rubbish)
  309    ->  Obj = X,
  310        Kind = instance
  311    ;   var(X)
  312    ->  throwme(jpl_call,arg1_is_var)
  313    ;   atom(X)
  314    ->  (   jpl_entityname_to_type(X, Type)     % does this attempt to load the class?
  315        ->  (   jpl_type_to_class(Type, ClassObj)
  316            ->  Kind = static
  317            ;   throwme(jpl_call,no_such_class(X))
  318            )
  319        ;   throwme(jpl_call,arg1_is_bad(X))
  320        )
  321    ;   X = class(_,_)
  322    ->  Type = X,
  323        jpl_type_to_class(Type, ClassObj),
  324        Kind = static
  325    ;   X = array(_)
  326    ->  throwme(jpl_call,arg1_is_array(X))
  327    ;   throwme(jpl_call,arg1_is_bad(X))
  328    ),
  329    (   atom(Mspec)                 % the usual case, i.e. a method name
  330    ->  true
  331    ;   var(Mspec)
  332    ->  throwme(jpl_call,mspec_is_var)
  333    ;   throwme(jpl_call,mspec_is_bad(Mspec))
  334    ),
  335    (   is_list(Params)
  336    ->  (   catch(
  337                jpl_datums_to_types(Params, Taps),
  338                % 2020-07-21: make catcher's 1st context arg an "anonvar" instead of a overspecified predicate indicator
  339                error(type_error(acyclic,Te),context(_,Msg)),
  340                throwme(jpl_call,acyclic(Te,Msg)) % rethrow
  341            )
  342        ->  true
  343
  344        ;   throwme(jpl_call,nonconvertible_params(Params))
  345        ),
  346        length(Params, A)
  347    ;   var(Params)
  348    ->  throwme(jpl_call,arg3_is_var)
  349    ;   throwme(jpl_call,arg3_is_bad(Params))
  350    ),
  351    (   Kind == instance
  352    ->  jpl_call_instance(Type, Obj, Mspec, Params, Taps, A, Rx)
  353    ;   jpl_call_static(Type, ClassObj, Mspec, Params, Taps, A, Rx)
  354    ),
  355    (   nonvar(R),
  356        R = {Term}  % yucky way of requesting Term->term conversion
  357    ->  (   jni_jref_to_term(Rx, TermX)    % fails if Rx isn't a JRef to a org.jpl7.Term
  358        ->  Term = TermX
  359        ;   throwme(jpl_call,not_a_jpl_term(Rx))
  360        )
  361    ;   R = Rx
  362    ).

 jpl_call_instance(+ObjectType, +Object, +MethodName, +Params, +ActualParamTypes, +Arity, -Result)

calls the MethodName-d method (instance or static) of Object (which is of ObjectType), which most specifically applies to Params, which we have found to be (respectively) of ActualParamTypes, and of which there are Arity, yielding Result.

  372jpl_call_instance(Type, Obj, Mname, Params, Taps, A, Rx) :-
  373    findall(                    % get remaining details of all accessible methods of Obj's class (as denoted by Type)
  374        z5(I,Mods,MID,Tr,Tfps),
  375        jpl_method_spec(Type, I, Mname, A, Mods, MID, Tr, Tfps),
  376        Z5s
  377    ),
  378    (   Z5s = []
  379    ->  throwme(jpl_call_instance,no_such_method(Mname/A))
  380    ;   findall(
  381            z5(I,Mods,MID,Tr,Tfps),             % those to which Params is assignable
  382            (   member(z5(I,Mods,MID,Tr,Tfps), Z5s),
  383                jpl_types_fit_types(Taps, Tfps) % assignability test: actual param types "fit" formal param types
  384            ),
  385            Z5sA                                % Params-assignable methods
  386        ),
  387        (   Z5sA == []
  388        ->  throwme(jpl_call_instance,param_not_assignable(Params))
  389        ;   Z5sA = [z5(I,Mods,MID,Tr,Tfps)]
  390        ->  true                                % exactly one applicable method
  391        ;   jpl_z5s_to_most_specific_z5(Z5sA, z5(I,Mods,MID,Tr,Tfps))
  392        ->  true                                % exactly one most-specific applicable method
  393        ;   throwme(jpl_call_instance,multiple_most_specific(Mname/Params))
  394        )
  395    ),
  396    (   member(static, Mods)                                        % if the chosen method is static
  397    ->  jpl_object_to_class(Obj, ClassObj),                         % get a java.lang.Class instance which personifies Obj's class
  398        jpl_call_static_method(Tr, ClassObj, MID, Tfps, Params, Rx) % call static method w.r.t. associated Class object
  399    ;   jpl_call_instance_method(Tr, Obj, MID, Tfps, Params, Rx)    % else call (non-static) method w.r.t. object itself
  400    ).

 jpl_call_static(+ClassType, +ClassObject, +MethodName, +Params, +ActualParamTypes, +Arity, -Result)

calls the MethodName-d static method of the class (which is of ClassType, and which is represented by the java.lang.Class instance ClassObject) which most specifically applies to Params, which we have found to be (respectively) of ActualParamTypes, and of which there are Arity, yielding Result.

  411jpl_call_static(Type, ClassObj, Mname, Params, Taps, A, Rx) :-
  412    findall(                    % get all accessible static methods of the class denoted by Type and ClassObj
  413        z5(I,Mods,MID,Tr,Tfps),
  414        (   jpl_method_spec(Type, I, Mname, A, Mods, MID, Tr, Tfps),
  415            member(static, Mods)
  416        ),
  417        Z5s
  418    ),
  419    (   Z5s = []
  420    ->  throwme(jpl_call_static,no_such_method(Mname))
  421    ;   findall(
  422            z5(I,Mods,MID,Tr,Tfps),
  423            (   member(z5(I,Mods,MID,Tr,Tfps), Z5s),
  424                jpl_types_fit_types(Taps, Tfps) % assignability test: actual param types "fit" formal param types
  425            ),
  426            Z5sA                                % Params-assignable methods
  427        ),
  428        (   Z5sA == []
  429        ->  throwme(jpl_call_static,param_not_assignable(Params))
  430        ;   Z5sA = [z5(I,Mods,MID,Tr,Tfps)]
  431        ->  true                % exactly one applicable method
  432        ;   jpl_z5s_to_most_specific_z5(Z5sA, z5(I,Mods,MID,Tr,Tfps))
  433        ->  true                % exactly one most-specific applicable method
  434        ;   throwme(jpl_call_instance,multiple_most_specific(Mname/Params))
  435        )
  436    ),
  437    jpl_call_static_method(Tr, ClassObj, MID, Tfps, Params, Rx).

 jpl_call_instance_method(+Type, +ClassObject, +MethodID, +FormalParamTypes, +Params, -Result)

  442jpl_call_instance_method(void, Class, MID, Tfps, Ps, R) :-
  443    jCallVoidMethod(Class, MID, Tfps, Ps),
  444    jpl_void(R).
  445jpl_call_instance_method(boolean, Class, MID, Tfps, Ps, R) :-
  446    jCallBooleanMethod(Class, MID, Tfps, Ps, R).
  447jpl_call_instance_method(byte, Class, MID, Tfps, Ps, R) :-
  448    jCallByteMethod(Class, MID, Tfps, Ps, R).
  449jpl_call_instance_method(char, Class, MID, Tfps, Ps, R) :-
  450    jCallCharMethod(Class, MID, Tfps, Ps, R).
  451jpl_call_instance_method(short, Class, MID, Tfps, Ps, R) :-
  452    jCallShortMethod(Class, MID, Tfps, Ps, R).
  453jpl_call_instance_method(int, Class, MID, Tfps, Ps, R) :-
  454    jCallIntMethod(Class, MID, Tfps, Ps, R).
  455jpl_call_instance_method(long, Class, MID, Tfps, Ps, R) :-
  456    jCallLongMethod(Class, MID, Tfps, Ps, R).
  457jpl_call_instance_method(float, Class, MID, Tfps, Ps, R) :-
  458    jCallFloatMethod(Class, MID, Tfps, Ps, R).
  459jpl_call_instance_method(double, Class, MID, Tfps, Ps, R) :-
  460    jCallDoubleMethod(Class, MID, Tfps, Ps, R).
  461jpl_call_instance_method(array(_), Class, MID, Tfps, Ps, R) :-
  462    jCallObjectMethod(Class, MID, Tfps, Ps, R).
  463jpl_call_instance_method(class(_,_), Class, MID, Tfps, Ps, R) :-
  464    jCallObjectMethod(Class, MID, Tfps, Ps, R).

 jpl_call_static_method(+Type, +ClassObject, +MethodID, +FormalParamTypes, +Params, -Result)

  469jpl_call_static_method(void, Class, MID, Tfps, Ps, R) :-
  470    jCallStaticVoidMethod(Class, MID, Tfps, Ps),
  471    jpl_void(R).
  472jpl_call_static_method(boolean, Class, MID, Tfps, Ps, R) :-
  473    jCallStaticBooleanMethod(Class, MID, Tfps, Ps, R).
  474jpl_call_static_method(byte, Class, MID, Tfps, Ps, R) :-
  475    jCallStaticByteMethod(Class, MID, Tfps, Ps, R).
  476jpl_call_static_method(char, Class, MID, Tfps, Ps, R) :-
  477    jCallStaticCharMethod(Class, MID, Tfps, Ps, R).
  478jpl_call_static_method(short, Class, MID, Tfps, Ps, R) :-
  479    jCallStaticShortMethod(Class, MID, Tfps, Ps, R).
  480jpl_call_static_method(int, Class, MID, Tfps, Ps, R) :-
  481    jCallStaticIntMethod(Class, MID, Tfps, Ps, R).
  482jpl_call_static_method(long, Class, MID, Tfps, Ps, R) :-
  483    jCallStaticLongMethod(Class, MID, Tfps, Ps, R).
  484jpl_call_static_method(float, Class, MID, Tfps, Ps, R) :-
  485    jCallStaticFloatMethod(Class, MID, Tfps, Ps, R).
  486jpl_call_static_method(double, Class, MID, Tfps, Ps, R) :-
  487    jCallStaticDoubleMethod(Class, MID, Tfps, Ps, R).
  488jpl_call_static_method(array(_), Class, MID, Tfps, Ps, R) :-
  489    jCallStaticObjectMethod(Class, MID, Tfps, Ps, R).
  490jpl_call_static_method(class(_,_), Class, MID, Tfps, Ps, R) :-
  491    jCallStaticObjectMethod(Class, MID, Tfps, Ps, R).

 jpl_get(+X, +Fspec, -V:datum) is det

X can be

• a classname
• or a descriptor
• or an (object or array) type (for static fields)
• or a non-array object (for static and non-static fields)
• or an array (for 'length' pseudo field, or indexed element retrieval)

Fspec can be

• an atomic field name
• or an integral array index (to get an element from an array)
• or a pair I-J of integers (to get a subrange of an array).

Finally, an attempt will be made to unify V with the retrieved value or object reference.

Examples

jpl_get('java.awt.Cursor', 'NE_RESIZE_CURSOR', Q).
Q = 7.

jpl_new(array(class([java,lang],['String'])), [for,while,do,if,then,else,try,catch,finally], A),
jpl_get(A, 3-5, B).
B = [if, then, else].

  523jpl_get(X, Fspec, V) :-
  524    (   jpl_object_to_type(X, Type)
  525    ->  Obj = X,
  526        jpl_get_instance(Type, Type, Obj, Fspec, Vx)   % pass Type twice for FAI
  527    ;   var(X)
  528    ->  throwme(jpl_get,arg1_is_var)
  529    ;   jpl_is_type(X)          % e.g. class([java,lang],['String']), array(int)
  530    ->  Type = X,
  531        (   jpl_type_to_class(Type, ClassObj)
  532        ->  jpl_get_static(Type, ClassObj, Fspec, Vx)
  533        ;   throwme(jpl_get,named_class_not_found(Type))
  534        )
  535    ;   atom(X)
  536    ->  (   jpl_entityname_to_type(X, Type)     % does this attempt to load the class? (NO!)
  537        ->  (   jpl_type_to_class(Type, ClassObj)
  538            ->  jpl_get_static(Type, ClassObj, Fspec, Vx)
  539            ;   throwme(jpl_get,named_class_not_found(Type))
  540            )
  541        ;   throwme(jpl_get,arg1_is_bad(X))
  542        )
  543    ;   throwme(jpl_get,arg1_is_bad_2(X))
  544    ),
  545    (   nonvar(V),
  546        V = {Term}  % yucky way of requesting Term->term conversion
  547    ->  (   jni_jref_to_term(Vx, TermX)    % fails if Rx is not a JRef to a org.jpl7.Term
  548        ->  Term = TermX
  549        ;   throwme(jpl_get,not_a_jpl_term(X))
  550        )
  551    ;   V = Vx
  552    ).

 jpl_get_static(+Type:type, +ClassObject:jref, +FieldName:atom, -Value:datum) is det

ClassObject is an instance of java.lang.Class which represents the same class as Type; Value (Vx below) is guaranteed unbound on entry, and will, before exit, be unified with the retrieved value

  564jpl_get_static(Type, ClassObj, Fname, Vx) :-
  565    (   atom(Fname)             % assume it's a field name
  566    ->  true
  567    ;   var(Fname)
  568    ->  throwme(jpl_get_static,arg2_is_var)
  569    ;   throwme(jpl_get_static,arg2_is_bad(Fname))
  570    ),
  571  % get static fields of the denoted class
  572    findall(
  573        z4(I,Mods,FID,Tf),
  574        (   jpl_field_spec(Type, I, Fname, Mods, FID, Tf),
  575            member(static, Mods)
  576        ),
  577        Z4s
  578    ),
  579    (   Z4s = []
  580    ->  throwme(jpl_get_static,no_such_field(Fname))
  581    ;   Z4s = [z4(I,_Mods,FID,Tf)]
  582    ->  jpl_get_static_field(Tf, ClassObj, FID, Vx)
  583    ;   throwme(jpl_get_static,multiple_fields(Fname))
  584    ).

 jpl_get_instance(+Type, +Type, +Object, +FieldSpecifier, -Value) is det

  590jpl_get_instance(class(_,_), Type, Obj, Fname, Vx) :-
  591    (   atom(Fname)                 % the usual case
  592    ->  true
  593    ;   var(Fname)
  594    ->  throwme(jpl_get_instance,arg2_is_var)
  595    ;   throwme(jpl_get_instance,arg2_is_bad(Fname))
  596    ),
  597    findall(
  598        z4(I,Mods,FID,Tf),
  599        jpl_field_spec(Type, I, Fname, Mods, FID, Tf),
  600        Z4s
  601    ),
  602    (   Z4s = []
  603    ->  throwme(jpl_get_instance,no_such_field(Fname))
  604    ;   Z4s = [z4(I,Mods,FID,Tf)]
  605    ->  (   member(static, Mods)
  606        ->  jpl_object_to_class(Obj, ClassObj),
  607            jpl_get_static_field(Tf, ClassObj, FID, Vx)
  608        ;   jpl_get_instance_field(Tf, Obj, FID, Vx)
  609        )
  610    ;   throwme(jpl_get_instance,multiple_fields(Fname))
  611    ).
  612
  613
  614jpl_get_instance(array(ElementType), _, Array, Fspec, Vx) :-
  615    (   var(Fspec)
  616    ->  throwme(jpl_get_instance_array,arg2_is_var)
  617    ;   integer(Fspec)
  618    ->  (   Fspec < 0       % lo bound check
  619        ->  throwme(jpl_get_instance_array,arg2_is_bad(Fspec))
  620        ;   jGetArrayLength(Array, Len),
  621            Fspec >= Len    % hi bound check
  622        ->  throwme(jpl_get_instance_array,arg2_is_too_large(Fspec))
  623        ;   jpl_get_array_element(ElementType, Array, Fspec, Vx)
  624        )
  625    ;   Fspec = N-M     % NB should we support e.g. 3-2 -> [] ?
  626    ->  (   integer(N),
  627            integer(M)
  628        ->  (   N >= 0,
  629                M >= N
  630            ->  jGetArrayLength(Array, Len),
  631                (   N >= Len
  632                ->  throwme(jpl_get_instance_array,bad_range_low(N-M))
  633                ;   M >= Len
  634                ->  throwme(jpl_get_instance_array,bad_range_high(N-M))
  635                ;   jpl_get_array_elements(ElementType, Array, N, M, Vx)
  636                )
  637            ;   throwme(jpl_get_instance_array,bad_range_pair_values(N-M))
  638            )
  639        ;   throwme(jpl_get_instance_array,bad_range_pair_types(N-M))
  640        )
  641    ;   atom(Fspec)
  642    ->  (   Fspec == length             % special-case for this solitary array "method"
  643        ->  jGetArrayLength(Array, Vx)
  644        ;   throwme(jpl_get_instance_array,no_such_field(Fspec))
  645        )
  646    ;   throwme(jpl_get_instance_array,wrong_spec(Fspec))
  647    ).

 jpl_get_array_element(+ElementType:type, +Array:jref, +Index, -Vc) is det

Array is a JPL reference to a Java array of ElementType; Vc is (unified with a JPL repn of) its Index-th (numbered from 0) element Java values are now converted to Prolog terms within foreign code

To be done

- more of this could be done within foreign code

  660jpl_get_array_element(Type, Array, Index, Vc) :-
  661    (   (   Type = class(_,_)
  662        ;   Type = array(_)
  663        )
  664    ->  jGetObjectArrayElement(Array, Index, Vr)
  665    ;   jpl_primitive_type(Type)
  666    ->  jni_type_to_xput_code(Type, Xc),
  667        jni_alloc_buffer(Xc, 1, Bp),        % one-element buf for a Type
  668        jpl_get_primitive_array_region(Type, Array, Index, 1, Bp),
  669        jni_fetch_buffer_value(Bp, 0, Vr, Xc),    % zero-th element
  670        jni_free_buffer(Bp)
  671    ),
  672    Vr = Vc.    % redundant since Vc is always (?) unbound at call

 jpl_get_array_elements(+ElementType, +Array, +N, +M, -Vs)

serves only jpl_get_instance/5

Vs will always be unbound on entry

  681jpl_get_array_elements(ElementType, Array, N, M, Vs) :-
  682    (   (   ElementType = class(_,_)
  683        ;   ElementType = array(_)
  684        )
  685    ->  jpl_get_object_array_elements(Array, N, M, Vs)
  686    ;   jpl_get_primitive_array_elements(ElementType, Array, N, M, Vs)
  687    ).
  688
  689
  690jpl_get_instance_field(boolean, Obj, FieldID, V) :-
  691    jGetBooleanField(Obj, FieldID, V).
  692jpl_get_instance_field(byte, Obj, FieldID, V) :-
  693    jGetByteField(Obj, FieldID, V).
  694jpl_get_instance_field(char, Obj, FieldID, V) :-
  695    jGetCharField(Obj, FieldID, V).
  696jpl_get_instance_field(short, Obj, FieldID, V) :-
  697    jGetShortField(Obj, FieldID, V).
  698jpl_get_instance_field(int, Obj, FieldID, V) :-
  699    jGetIntField(Obj, FieldID, V).
  700jpl_get_instance_field(long, Obj, FieldID, V) :-
  701    jGetLongField(Obj, FieldID, V).
  702jpl_get_instance_field(float, Obj, FieldID, V) :-
  703    jGetFloatField(Obj, FieldID, V).
  704jpl_get_instance_field(double, Obj, FieldID, V) :-
  705    jGetDoubleField(Obj, FieldID, V).
  706jpl_get_instance_field(class(_,_), Obj, FieldID, V) :-
  707    jGetObjectField(Obj, FieldID, V).
  708jpl_get_instance_field(array(_), Obj, FieldID, V) :-
  709    jGetObjectField(Obj, FieldID, V).

 jpl_get_object_array_elements(+Array, +LoIndex, +HiIndex, -Vcs) is det

Array should be a (zero-based) array of some object (array or non-array) type; LoIndex is an integer, 0 =< LoIndex < length(Array); HiIndex is an integer, LoIndex-1 =< HiIndex < length(Array); at call, Vcs will be unbound; at exit, Vcs will be a list of (references to) the array's elements [LoIndex..HiIndex] inclusive

  721jpl_get_object_array_elements(Array, Lo, Hi, Vcs) :-
  722    (   Lo =< Hi
  723    ->  Vcs = [Vc|Vcs2],
  724        jGetObjectArrayElement(Array, Lo, Vc),
  725        Next is Lo+1,
  726        jpl_get_object_array_elements(Array, Next, Hi, Vcs2)
  727    ;   Vcs = []
  728    ).

 jpl_get_primitive_array_elements(+ElementType, +Array, +LoIndex, +HiIndex, -Vcs) is det

Array should be a (zero-based) Java array of (primitive) ElementType; Vcs should be unbound on entry, and on exit will be a list of (JPL representations of the values of) the elements [LoIndex..HiIndex] inclusive

  738jpl_get_primitive_array_elements(ElementType, Array, Lo, Hi, Vcs) :-
  739    Size is Hi-Lo+1,
  740    (   Size == 0
  741    ->  Vcs = []
  742    ;   jni_type_to_xput_code(ElementType, Xc),
  743        jni_alloc_buffer(Xc, Size, Bp),
  744        jpl_get_primitive_array_region(ElementType, Array, Lo, Size, Bp),
  745        jpl_primitive_buffer_to_array(ElementType, Xc, Bp, 0, Size, Vcs),
  746        jni_free_buffer(Bp)
  747    ).
  748
  749
  750jpl_get_primitive_array_region(boolean, Array, Lo, S, I) :-
  751    jGetBooleanArrayRegion(Array, Lo, S, jbuf(I,boolean)).
  752jpl_get_primitive_array_region(byte, Array, Lo, S, I) :-
  753    jGetByteArrayRegion(Array, Lo, S, jbuf(I,byte)).
  754jpl_get_primitive_array_region(char, Array, Lo, S, I) :-
  755    jGetCharArrayRegion(Array, Lo, S, jbuf(I,char)).
  756jpl_get_primitive_array_region(short, Array, Lo, S, I) :-
  757    jGetShortArrayRegion(Array, Lo, S, jbuf(I,short)).
  758jpl_get_primitive_array_region(int, Array, Lo, S, I) :-
  759    jGetIntArrayRegion(Array, Lo, S, jbuf(I,int)).
  760jpl_get_primitive_array_region(long, Array, Lo, S, I) :-
  761    jGetLongArrayRegion(Array, Lo, S, jbuf(I,long)).
  762jpl_get_primitive_array_region(float, Array, Lo, S, I) :-
  763    jGetFloatArrayRegion(Array, Lo, S, jbuf(I,float)).
  764jpl_get_primitive_array_region(double, Array, Lo, S, I) :-
  765    jGetDoubleArrayRegion(Array, Lo, S, jbuf(I,double)).
  766
  767
  768jpl_get_static_field(boolean, Array, FieldID, V) :-
  769    jGetStaticBooleanField(Array, FieldID, V).
  770jpl_get_static_field(byte, Array, FieldID, V) :-
  771    jGetStaticByteField(Array, FieldID, V).
  772jpl_get_static_field(char, Array, FieldID, V) :-
  773    jGetStaticCharField(Array, FieldID, V).
  774jpl_get_static_field(short, Array, FieldID, V) :-
  775    jGetStaticShortField(Array, FieldID, V).
  776jpl_get_static_field(int, Array, FieldID, V) :-
  777    jGetStaticIntField(Array, FieldID, V).
  778jpl_get_static_field(long, Array, FieldID, V) :-
  779    jGetStaticLongField(Array, FieldID, V).
  780jpl_get_static_field(float, Array, FieldID, V) :-
  781    jGetStaticFloatField(Array, FieldID, V).
  782jpl_get_static_field(double, Array, FieldID, V) :-
  783    jGetStaticDoubleField(Array, FieldID, V).
  784jpl_get_static_field(class(_,_), Array, FieldID, V) :-
  785    jGetStaticObjectField(Array, FieldID, V).
  786jpl_get_static_field(array(_), Array, FieldID, V) :-
  787    jGetStaticObjectField(Array, FieldID, V).

 jpl_set(+X, +Fspec, +V) is det

sets the Fspec-th field of (class or object) X to value V iff it is assignable

X can be

• a class instance (for static or non-static fields)
• or an array (for indexed element or subrange assignment)
• or a classname, or a class(_,_) or array(_) type (for static fields)
• but not a String (no fields to retrieve)

Fspec can be

• an atomic field name (overloading through shadowing has yet to be handled properly)
• or an array index I (X must be an array object: V is assigned to X[I])
• or a pair I-J of integers (X must be an array object, V must be a list of values: successive members of V are assigned to X[I..J])

V must be a suitable value or object.

  807jpl_set(X, Fspec, V) :-
  808    (   jpl_object_to_type(X, Type)         % the usual case (test is safe if X is var or rubbish)
  809    ->  Obj = X,
  810        catch(
  811            jpl_set_instance(Type, Type, Obj, Fspec, V),    % first 'Type' is for FAI
  812            % 2020-07-21: make catcher's 1st context arg an "anonvar" instead of a overspecified predicate indicator
  813            error(type_error(acyclic,Te),context(_,Msg)),
  814            throwme(jpl_set,acyclic(Te,Msg)) % rethrow
  815        )
  816    ;   var(X)
  817    ->  throwme(jpl_set,arg1_is_var)
  818    ;   (   atom(X)
  819        ->  (   jpl_entityname_to_type(X, Type)          % it's a classname or descriptor...
  820            ->  true
  821            ;   throwme(jpl_set,classname_does_not_resolve(X))
  822            )
  823        ;   (   X = class(_,_)                          % it's a class type...
  824            ;   X = array(_)                            % ...or an array type
  825            )
  826        ->  Type = X
  827        ),
  828        (   jpl_type_to_class(Type, ClassObj)      % ...whose Class object is available
  829        ->  true
  830        ;   throwme(jpl_set,named_class_not_found(Type))
  831        )
  832    ->  catch(
  833            jpl_set_static(Type, ClassObj, Fspec, V),
  834            % 2020-07-21: make catcher's 1st context arg an "anonvar" instead of a overspecified predicate indicator
  835            error(type_error(acyclic,Te),context(_,Msg)),
  836            throwme(jpl_set,acyclic(Te,Msg)) % rethrow
  837        )
  838    ;   throwme(jpl_set,arg1_is_bad(X))
  839    ).

 jpl_set_instance(+Type, +Type, +ObjectReference, +FieldName, +Value) is det

ObjectReference is a JPL reference to a Java object of the class denoted by Type (which is passed twice for first agument indexing);

FieldName should name a public, non-final (static or non-static) field of this object, but could be anything, and is validated here;

Value should be assignable to the named field, but could be anything, and is validated here

  852jpl_set_instance(class(_,_), Type, Obj, Fname, V) :-    % a non-array object
  853    (   atom(Fname)                 % the usual case
  854    ->  true
  855    ;   var(Fname)
  856    ->  throwme(jpl_set_instance_class,arg2_is_var)
  857    ;   throwme(jpl_set_instance_class,arg2_is_bad(Fname))
  858    ),
  859    findall(
  860        z4(I,Mods,FID,Tf),
  861        jpl_field_spec(Type, I, Fname, Mods, FID, Tf),  % public fields of class denoted by Type
  862        Z4s
  863    ),
  864    (   Z4s = []
  865    ->  throwme(jpl_set_instance_class,no_such_field(Fname))
  866    ;   Z4s = [z4(I,Mods,FID,Tf)]
  867    ->  (   member(final, Mods)
  868        ->  throwme(jpl_set_instance_class,field_is_final(Fname))
  869        ;   jpl_datum_to_type(V, Tv)
  870        ->  (   jpl_type_fits_type(Tv, Tf)
  871            ->  (   member(static, Mods)
  872                ->  jpl_object_to_class(Obj, ClassObj),
  873                    jpl_set_static_field(Tf, ClassObj, FID, V)
  874                ;   jpl_set_instance_field(Tf, Obj, FID, V)         % oughta be jpl_set_instance_field?
  875                )
  876            ;   throwme(jpl_set_instance_class,incompatible_value(Tf,V))
  877            )
  878        ;   throwme(jpl_set_instance_class,arg3_is_bad(V))
  879        )
  880    ;   throwme(jpl_set_instance_class,multiple_fields(Fname))  % 'existence'? or some other sort of error maybe?
  881    ).
  882
  883
  884
  885jpl_set_instance(array(Type), _, Obj, Fspec, V) :-
  886    (   is_list(V)                  % a list of array element values
  887    ->  Vs = V
  888    ;   var(V)
  889    ->  throwme(jpl_set_instance_array,arg3_is_var)
  890    ;   Vs = [V]                    % a single array element value
  891    ),
  892    length(Vs, Iv),
  893    (   var(Fspec)
  894    ->  throwme(jpl_set_instance_array,arg2_is_var)
  895    ;   integer(Fspec)          % single-element assignment
  896    ->  (   Fspec < 0
  897        ->  throwme(jpl_set_instance_array,arg2_is_bad(Fspec))
  898        ;   Iv is 1
  899        ->  N is Fspec
  900        ;   Iv is 0
  901        ->  throwme(jpl_set_instance_array,no_values(Fspec,Vs))
  902        ;   throwme(jpl_set_instance_array,more_than_one_value(Fspec,Vs))
  903        )
  904    ;   Fspec = N-M             % element-sequence assignment
  905    ->  (   integer(N),
  906            integer(M)
  907        ->  (   N >= 0,
  908                Size is (M-N)+1,
  909                Size >= 0
  910            ->  (   Size == Iv
  911                ->  true
  912                ;   Size < Iv
  913                ->  throwme(jpl_set_instance_array,too_few_values(N-M,Vs))
  914                ;   throwme(jpl_set_instance_array,too_many_values(N-M,Vs))
  915                )
  916            ;   throwme(jpl_set_instance_array,bad_range_pair_values(N-M))
  917            )
  918        ;   throwme(jpl_set_instance_array,bad_range_pair_types(N-M))
  919        )
  920    ;   atom(Fspec)
  921    ->  (   Fspec == length
  922        ->  throwme(jpl_set_instance_array,cannot_assign_to_final_field)
  923        ;   throwme(jpl_set_instance_array,no_such_field(Fspec))
  924        )
  925    ;   throwme(jpl_set_instance_array,arg2_is_bad_2(Fspec))
  926    ),
  927    jpl_set_array(Type, Obj, N, Iv, Vs).

 jpl_set_static(+Type, +ClassObj, +FieldName, +Value) is det

We can rely on:

• Type being a class/2 type representing some accessible class
• ClassObj being an instance of java.lang.Class which represents the same class as Type but FieldName could be anything, so we validate it here, look for a suitable (static) field of the target class, then call jpl_set_static_field/4 to attempt to assign Value (which could be anything) to it

NB this does not yet handle shadowed fields correctly.

  942jpl_set_static(Type, ClassObj, Fname, V) :-
  943    (   atom(Fname)                     % the usual case
  944    ->  true
  945    ;   var(Fname)
  946    ->  throwme(jpl_set_static,arg2_is_unbound)
  947    ;   throwme(jpl_set_static,arg2_is_bad(Fname))
  948    ),
  949    findall(  % get all static fields of the denoted class
  950        z4(I,Mods,FID,Tf),
  951        (   jpl_field_spec(Type, I, Fname, Mods, FID, Tf),
  952            member(static, Mods)
  953        ),
  954        Z4s
  955    ),
  956    (   Z4s = []
  957    ->  throwme(jpl_set_static,no_such_public_static_field(field,Fname))
  958    ;   Z4s = [z4(I,Mods,FID,Tf)]       % exactly one synonymous field?
  959    ->  (   member(final, Mods)
  960        ->  throwme(jpl_set_static,cannot_assign_final_field(Fname))
  961        ;   jpl_datum_to_type(V, Tv)
  962        ->  (   jpl_type_fits_type(Tv, Tf)
  963            ->  jpl_set_static_field(Tf, ClassObj, FID, V)
  964            ;   throwme(jpl_set_static,value_not_assignable(Tf,V))
  965            )
  966        ;   throwme(jpl_set_static,arg3_is_bad(field_value,V))
  967        )
  968    ;   throwme(jpl_set_static,multiple_matches(field,Fname))
  969    ).

 jpl_set_array(+ElementType, +Array, +Offset, +DatumQty, +Datums) is det

Datums, of which there are DatumQty, are stashed in successive elements of Array which is an array of ElementType starting at the Offset-th (numbered from 0) throws error(type_error(acyclic,_),context(jpl_datum_to_type/2,_))

  979jpl_set_array(T, A, N, I, Ds) :-
  980    (   jpl_datums_to_types(Ds, Tds)        % most specialised types of given values
  981    ->  (   jpl_types_fit_type(Tds, T)      % all assignable to element type?
  982        ->  true
  983        ;   throwme(jpl_set_array,not_all_values_assignable(T,Ds))
  984        )
  985    ;   throwme(jpl_set_array,not_all_values_convertible(T,Ds))
  986    ),
  987    (   (   T = class(_,_)
  988        ;   T = array(_)                    % array elements are objects
  989        )
  990    ->  (   nth0(J, Ds, D),                 % for each datum
  991            Nd is N+J,                      % compute array index
  992            (   D = {Tq}                    % quoted term?
  993            ->  jni_term_to_jref(Tq, D2)    % convert to a JPL reference to a corresponding org.jpl7.Term object
  994            ;   D = D2
  995            ),
  996            jSetObjectArrayElement(A, Nd, D2),
  997            fail                            % iterate
  998        ;   true
  999        )
 1000    ;   jpl_primitive_type(T)               % array elements are primitive values
 1001    ->  jni_type_to_xput_code(T, Xc),
 1002        jni_alloc_buffer(Xc, I, Bp),        % I-element buf of required primitive type
 1003        jpl_set_array_1(Ds, T, 0, Bp),
 1004        jpl_set_elements(T, A, N, I, Bp),
 1005        jni_free_buffer(Bp)
 1006    ;
 1007        % T is neither a class, nor an array type nor a primitive type
 1008        throwme(jpl_set_array,element_type_unknown(array_element_type,T))
 1009    ).

 jpl_set_array_1(+Values, +Type, +BufferIndex, +BufferPointer) is det

successive members of Values are stashed as (primitive) Type from the BufferIndex-th element (numbered from 0) onwards of the buffer indicated by BufferPointer

NB this could be done more efficiently (?) within foreign code...

 1020jpl_set_array_1([], _, _, _).
 1021jpl_set_array_1([V|Vs], Tprim, Ib, Bp) :-
 1022    jni_type_to_xput_code(Tprim, Xc),
 1023    jni_stash_buffer_value(Bp, Ib, V, Xc),
 1024    Ibnext is Ib+1,
 1025    jpl_set_array_1(Vs, Tprim, Ibnext, Bp).
 1026
 1027
 1028jpl_set_elements(boolean, Obj, N, I, Bp) :-
 1029    jSetBooleanArrayRegion(Obj, N, I, jbuf(Bp,boolean)).
 1030jpl_set_elements(char, Obj, N, I, Bp) :-
 1031    jSetCharArrayRegion(Obj, N, I, jbuf(Bp,char)).
 1032jpl_set_elements(byte, Obj, N, I, Bp) :-
 1033    jSetByteArrayRegion(Obj, N, I, jbuf(Bp,byte)).
 1034jpl_set_elements(short, Obj, N, I, Bp) :-
 1035    jSetShortArrayRegion(Obj, N, I, jbuf(Bp,short)).
 1036jpl_set_elements(int, Obj, N, I, Bp) :-
 1037    jSetIntArrayRegion(Obj, N, I, jbuf(Bp,int)).
 1038jpl_set_elements(long, Obj, N, I, Bp) :-
 1039    jSetLongArrayRegion(Obj, N, I, jbuf(Bp,long)).
 1040jpl_set_elements(float, Obj, N, I, Bp) :-
 1041    jSetFloatArrayRegion(Obj, N, I, jbuf(Bp,float)).
 1042jpl_set_elements(double, Obj, N, I, Bp) :-
 1043    jSetDoubleArrayRegion(Obj, N, I, jbuf(Bp,double)).

 jpl_set_instance_field(+Type, +Obj, +FieldID, +V) is det

We can rely on Type, Obj and FieldID being valid, and on V being assignable (if V is a quoted term then it is converted here)

 1051jpl_set_instance_field(boolean, Obj, FieldID, V) :-
 1052    jSetBooleanField(Obj, FieldID, V).
 1053jpl_set_instance_field(byte, Obj, FieldID, V) :-
 1054    jSetByteField(Obj, FieldID, V).
 1055jpl_set_instance_field(char, Obj, FieldID, V) :-
 1056    jSetCharField(Obj, FieldID, V).
 1057jpl_set_instance_field(short, Obj, FieldID, V) :-
 1058    jSetShortField(Obj, FieldID, V).
 1059jpl_set_instance_field(int, Obj, FieldID, V) :-
 1060    jSetIntField(Obj, FieldID, V).
 1061jpl_set_instance_field(long, Obj, FieldID, V) :-
 1062    jSetLongField(Obj, FieldID, V).
 1063jpl_set_instance_field(float, Obj, FieldID, V) :-
 1064    jSetFloatField(Obj, FieldID, V).
 1065jpl_set_instance_field(double, Obj, FieldID, V) :-
 1066    jSetDoubleField(Obj, FieldID, V).
 1067jpl_set_instance_field(class(_,_), Obj, FieldID, V) :-  % also handles byval term assignments
 1068    (   V = {T}                     % quoted term?
 1069    ->  jni_term_to_jref(T, V2)     % convert to a JPL reference to a corresponding org.jpl7.Term object
 1070    ;   V = V2
 1071    ),
 1072    jSetObjectField(Obj, FieldID, V2).
 1073jpl_set_instance_field(array(_), Obj, FieldID, V) :-
 1074    jSetObjectField(Obj, FieldID, V).

 jpl_set_static_field(+Type, +ClassObj, +FieldID, +V)

We can rely on Type, ClassObj and FieldID being valid, and on V being assignable (if V is a quoted term then it is converted here).

 1082jpl_set_static_field(boolean, Obj, FieldID, V) :-
 1083    jSetStaticBooleanField(Obj, FieldID, V).
 1084jpl_set_static_field(byte, Obj, FieldID, V) :-
 1085    jSetStaticByteField(Obj, FieldID, V).
 1086jpl_set_static_field(char, Obj, FieldID, V) :-
 1087    jSetStaticCharField(Obj, FieldID, V).
 1088jpl_set_static_field(short, Obj, FieldID, V) :-
 1089    jSetStaticShortField(Obj, FieldID, V).
 1090jpl_set_static_field(int, Obj, FieldID, V) :-
 1091    jSetStaticIntField(Obj, FieldID, V).
 1092jpl_set_static_field(long, Obj, FieldID, V) :-
 1093    jSetStaticLongField(Obj, FieldID, V).
 1094jpl_set_static_field(float, Obj, FieldID, V) :-
 1095    jSetStaticFloatField(Obj, FieldID, V).
 1096jpl_set_static_field(double, Obj, FieldID, V) :-
 1097    jSetStaticDoubleField(Obj, FieldID, V).
 1098jpl_set_static_field(class(_,_), Obj, FieldID, V) :-    % also handles byval term assignments
 1099    (   V = {T}                         % quoted term?
 1100    ->  jni_term_to_jref(T, V2)         % convert to a JPL reference to a corresponding org.jpl7.Term object
 1101    ;   V = V2
 1102    ),
 1103    jSetStaticObjectField(Obj, FieldID, V2).
 1104jpl_set_static_field(array(_), Obj, FieldID, V) :-
 1105    jSetStaticObjectField(Obj, FieldID, V).

 jpl_get_default_jvm_opts(-Opts:list(atom)) is det

Returns (as a list of atoms) the options which will be passed to the JVM when it is initialised, e.g. ['-Xrs']

 1113jpl_get_default_jvm_opts(Opts) :-
 1114    jni_get_default_jvm_opts(Opts).

 jpl_set_default_jvm_opts(+Opts:list(atom)) is det

Replaces the default JVM initialisation options with those supplied.

 1121jpl_set_default_jvm_opts(Opts) :-
 1122    is_list(Opts),
 1123    length(Opts, N),
 1124    jni_set_default_jvm_opts(N, Opts).

 jpl_get_actual_jvm_opts(-Opts:list(atom)) is semidet

Returns (as a list of atoms) the options with which the JVM was initialised.

Fails silently if a JVM has not yet been started, and can thus be used to test for this.

 1133jpl_get_actual_jvm_opts(Opts) :-
 1134    jni_get_actual_jvm_opts(Opts).
 1135
 1136% ===========================================================================
 1137% Caching
 1138% ===========================================================================
 1139
 1140% In principle the predicates subject to assert/1 must be declared with the
 1141% dynamic/1 directive. However, they are automatically declared as "dynamic"
 1142% if they appear in an assert/1 call first. Anyway, we declare then dynamic
 1143% right here!
 1144
 1145:- dynamic jpl_field_spec_cache/6.      % document this...
 1146:- dynamic jpl_field_spec_is_cached/1.  % document this...
 1147:- dynamic jpl_method_spec_cache/8. 1148:- dynamic jpl_method_spec_is_cached/1. 1149:- dynamic jpl_iref_type_cache/2.

 jpl_classname_type_cache(-Classname:className, -Type:type)

Classname is the atomic name of Type.

NB may denote a class which cannot be found.

 1157:- dynamic jpl_classname_type_cache/2.

 jpl_class_tag_type_cache(-Class:jref, -Type:jpl_type)

Class is a reference to an instance of java.lang.Class which denotes Type.

We index on Class (a jref) so as to keep these objects around even after an atom garbage collection (if needed once, they are likely to be needed again)

(Is it possble to have different Ref for the same ClassType, which happens once several ClassLoaders become involved?) (Most likely)

 1171:- dynamic jpl_class_tag_type_cache/2.

 jpl_assert(+Fact:term)

Assert a fact listed in jpl_assert_policy/2 with "yes" into the Prolog database.

From the SWI-Prolog manual:

"In SWI-Prolog, querying dynamic predicates has the same performance as static ones. The manipulation predicates are fast."

And:

"By default, a predicate declared dynamic (see dynamic/1) is shared by all threads. Each thread may assert, retract and run the dynamic predicate. Synchronisation inside Prolog guarantees the consistency of the predicate. Updates are logical: visible clauses are not affected by assert/retract after a query started on the predicate. In many cases primitives from section 10.4 should be used to ensure that application invariants on the predicate are maintained.

See also

- https://eu.swi-prolog.org/pldoc/man?section=db

- https://eu.swi-prolog.org/pldoc/man?section=threadlocal

 1196jpl_assert(Fact) :-
 1197    (   jpl_assert_policy(Fact, yes)
 1198    ->  assertz(Fact)
 1199    ;   true
 1200    ).
 1201
 1202% ---
 1203% policies
 1204% ---
 1205
 1206jpl_assert_policy(jpl_field_spec_cache(_,_,_,_,_,_), yes).
 1207jpl_assert_policy(jpl_field_spec_is_cached(_), YN) :-
 1208   jpl_assert_policy(jpl_field_spec_cache(_,_,_,_,_,_), YN).
 1209
 1210jpl_assert_policy(jpl_method_spec_cache(_,_,_,_,_,_,_,_), yes).
 1211jpl_assert_policy(jpl_method_spec_is_cached(_), YN) :-
 1212   jpl_assert_policy(jpl_method_spec_cache(_,_,_,_,_,_,_,_), YN).
 1213
 1214jpl_assert_policy(jpl_class_tag_type_cache(_,_), yes).
 1215jpl_assert_policy(jpl_classname_type_cache(_,_), yes).
 1216jpl_assert_policy(jpl_iref_type_cache(_,_), no).   % must correspond to JPL_CACHE_TYPE_OF_REF in jpl.c

 jpl_tidy_iref_type_cache(+Iref) is det

Delete the cached type info, if any, under Iref.

Called from jpl.c's jni_free_iref() via jni_tidy_iref_type_cache()

 1224jpl_tidy_iref_type_cache(Iref) :-
 1225  % write('[decaching types for iref='), write(Iref), write(']'), nl,
 1226    retractall(jpl_iref_type_cache(Iref,_)),
 1227    true.
 1228
 1229jpl_fergus_find_candidate([], Candidate, Candidate, []).
 1230jpl_fergus_find_candidate([X|Xs], Candidate0, Candidate, Rest) :-
 1231    (   jpl_fergus_greater(X, Candidate0)
 1232    ->  Candidate1 = X,
 1233        Rest = [Candidate0|Rest1]
 1234    ;   Candidate1 = Candidate0,
 1235        Rest = [X|Rest1]
 1236    ),
 1237    jpl_fergus_find_candidate(Xs, Candidate1, Candidate, Rest1).
 1238
 1239
 1240jpl_fergus_greater(z5(_,_,_,_,Tps1), z5(_,_,_,_,Tps2)) :-
 1241    jpl_types_fit_types(Tps1, Tps2).
 1242jpl_fergus_greater(z3(_,_,Tps1), z3(_,_,Tps2)) :-
 1243    jpl_types_fit_types(Tps1, Tps2).

 jpl_fergus_is_the_greatest(+Xs:list(T), -GreatestX:T)

Xs is a list of things for which jpl_fergus_greater/2 defines a partial ordering; GreatestX is one of those, than which none is greater; fails if there is more than one such; this algorithm was contributed to c.l.p by Fergus Henderson in response to my "there must be a better way" challenge: there was, this is it

 1254jpl_fergus_is_the_greatest([X|Xs], Greatest) :-
 1255    jpl_fergus_find_candidate(Xs, X, Greatest, Rest),
 1256    forall(
 1257        member(R, Rest),
 1258        jpl_fergus_greater(Greatest, R)
 1259    ).

 jpl_z3s_to_most_specific_z3(+Zs, -Z)

Zs is a list of arity-matching, type-suitable z3(I,MID,Tfps).

Z is the single most specific element of Zs, i.e. that than which no other z3/3 has a more specialised signature (fails if there is more than one such).

 1269jpl_z3s_to_most_specific_z3(Zs, Z) :-
 1270    jpl_fergus_is_the_greatest(Zs, Z).

 jpl_z5s_to_most_specific_z5(+Zs, -Z)

Zs is a list of arity-matching, type-suitable z5(I,Mods,MID,Tr,Tfps)

Z is the single most specific element of Zs, i.e. that than which no other z5/5 has a more specialised signature (fails if there is more than one such)

 1280jpl_z5s_to_most_specific_z5(Zs, Z) :-
 1281    jpl_fergus_is_the_greatest(Zs, Z).

 jpl_pl_lib_version(-Version)

Version is the fully qualified version identifier of the in-use Prolog component (jpl.pl) of JPL.

It should exactly match the version identifiers of JPL's C (jpl.c) and Java (jpl.jar) components.

Example

?- jpl_pl_lib_version(V).
V = '7.6.1'.

 1297jpl_pl_lib_version(VersionString) :-
 1298    jpl_pl_lib_version(Major, Minor, Patch, Status),
 1299    atomic_list_concat([Major,'.',Minor,'.',Patch,'-',Status], VersionString).

 jpl_pl_lib_version(-Major, -Minor, -Patch, -Status)

Major, Minor, Patch and Status are the respective components of the version identifier of the in-use C component (jpl.c) of JPL.

Example

?- jpl:jpl_pl_lib_version(Major, Minor, Patch, Status).
Major = 7,
Minor = 4,
Patch = 0,
Status = alpha.

 1316jpl_pl_lib_version(7, 6, 1, stable).  % jref as blob

 jpl_c_lib_version(-Version)

Version is the fully qualified version identifier of the in-use C component (jpl.c) of JPL.

It should exactly match the version identifiers of JPL's Prolog (jpl.pl) and Java (jpl.jar) components.

Example

?- jpl_c_lib_version(V).
V = '7.4.0-alpha'.

 jpl_java_lib_version(-Version)

Version is the fully qualified version identifier of the in-use Java component (jpl.jar) of JPL.

Example

?- jpl:jpl_java_lib_version(V).
V = '7.4.0-alpha'.

 jpl_java_lib_version(V)

 1345jpl_java_lib_version(V) :-
 1346    jpl_call('org.jpl7.JPL', version_string, [], V).

 jpl_pl_lib_path(-Path:atom)

 1351jpl_pl_lib_path(Path) :-
 1352    module_property(jpl, file(Path)).

 jpl_c_lib_path(-Path:atom)

 1357jpl_c_lib_path(Path) :-
 1358    shlib:current_library(_, _, Path, jpl, _),
 1359    !.

 jpl_java_lib_path(-Path:atom)

 1364jpl_java_lib_path(Path) :-
 1365    jpl_call('org.jpl7.JPL', jarPath, [], Path).

 jCallBooleanMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rbool:boolean)

 1370jCallBooleanMethod(Obj, MethodID, Types, Params, Rbool) :-
 1371    jni_params_put(Params, Types, ParamBuf),
 1372    jni_func(39, Obj, MethodID, ParamBuf, Rbool).

 jCallByteMethod(+Obj:jref, +MethodID:methodId, +Types, +Params:list(datum), -Rbyte:byte)

 1378jCallByteMethod(Obj, MethodID, Types, Params, Rbyte) :-
 1379    jni_params_put(Params, Types, ParamBuf),
 1380    jni_func(42, Obj, MethodID, ParamBuf, Rbyte).

 jCallCharMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rchar:char)

 1386jCallCharMethod(Obj, MethodID, Types, Params, Rchar) :-
 1387    jni_params_put(Params, Types, ParamBuf),
 1388    jni_func(45, Obj, MethodID, ParamBuf, Rchar).

 jCallDoubleMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rdouble:double)

 1393jCallDoubleMethod(Obj, MethodID, Types, Params, Rdouble) :-
 1394    jni_params_put(Params, Types, ParamBuf),
 1395    jni_func(60, Obj, MethodID, ParamBuf, Rdouble).

 jCallFloatMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rfloat:float)

 1400jCallFloatMethod(Obj, MethodID, Types, Params, Rfloat) :-
 1401    jni_params_put(Params, Types, ParamBuf),
 1402    jni_func(57, Obj, MethodID, ParamBuf, Rfloat).

 jCallIntMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rint:int)

 1407jCallIntMethod(Obj, MethodID, Types, Params, Rint) :-
 1408    jni_params_put(Params, Types, ParamBuf),
 1409    jni_func(51, Obj, MethodID, ParamBuf, Rint).

 jCallLongMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rlong:long)

 1414jCallLongMethod(Obj, MethodID, Types, Params, Rlong) :-
 1415    jni_params_put(Params, Types, ParamBuf),
 1416    jni_func(54, Obj, MethodID, ParamBuf, Rlong).

 jCallObjectMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Robj:jref)

 1421jCallObjectMethod(Obj, MethodID, Types, Params, Robj) :-
 1422    jni_params_put(Params, Types, ParamBuf),
 1423    jni_func(36, Obj, MethodID, ParamBuf, Robj).

 jCallShortMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rshort:short)

 1428jCallShortMethod(Obj, MethodID, Types, Params, Rshort) :-
 1429    jni_params_put(Params, Types, ParamBuf),
 1430    jni_func(48, Obj, MethodID, ParamBuf, Rshort).

 jCallStaticBooleanMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rbool:boolean)

 1435jCallStaticBooleanMethod(Class, MethodID, Types, Params, Rbool) :-
 1436    jni_params_put(Params, Types, ParamBuf),
 1437    jni_func(119, Class, MethodID, ParamBuf, Rbool).

 jCallStaticByteMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rbyte:byte)

 1442jCallStaticByteMethod(Class, MethodID, Types, Params, Rbyte) :-
 1443    jni_params_put(Params, Types, ParamBuf),
 1444    jni_func(122, Class, MethodID, ParamBuf, Rbyte).

 jCallStaticCharMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rchar:char)

 1449jCallStaticCharMethod(Class, MethodID, Types, Params, Rchar) :-
 1450    jni_params_put(Params, Types, ParamBuf),
 1451    jni_func(125, Class, MethodID, ParamBuf, Rchar).

 jCallStaticDoubleMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rdouble:double)

 1456jCallStaticDoubleMethod(Class, MethodID, Types, Params, Rdouble) :-
 1457    jni_params_put(Params, Types, ParamBuf),
 1458    jni_func(140, Class, MethodID, ParamBuf, Rdouble).

 jCallStaticFloatMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rfloat:float)

 1463jCallStaticFloatMethod(Class, MethodID, Types, Params, Rfloat) :-
 1464    jni_params_put(Params, Types, ParamBuf),
 1465    jni_func(137, Class, MethodID, ParamBuf, Rfloat).

 jCallStaticIntMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rint:int)

 1470jCallStaticIntMethod(Class, MethodID, Types, Params, Rint) :-
 1471    jni_params_put(Params, Types, ParamBuf),
 1472    jni_func(131, Class, MethodID, ParamBuf, Rint).

 jCallStaticLongMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rlong:long)

 1477jCallStaticLongMethod(Class, MethodID, Types, Params, Rlong) :-
 1478    jni_params_put(Params, Types, ParamBuf),
 1479    jni_func(134, Class, MethodID, ParamBuf, Rlong).

 jCallStaticObjectMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Robj:jref)

 1484jCallStaticObjectMethod(Class, MethodID, Types, Params, Robj) :-
 1485    jni_params_put(Params, Types, ParamBuf),
 1486    jni_func(116, Class, MethodID, ParamBuf, Robj).

 jCallStaticShortMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum), -Rshort:short)

 1491jCallStaticShortMethod(Class, MethodID, Types, Params, Rshort) :-
 1492    jni_params_put(Params, Types, ParamBuf),
 1493    jni_func(128, Class, MethodID, ParamBuf, Rshort).

 jCallStaticVoidMethod(+Class:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum))

 1498jCallStaticVoidMethod(Class, MethodID, Types, Params) :-
 1499    jni_params_put(Params, Types, ParamBuf),
 1500    jni_void(143, Class, MethodID, ParamBuf).

 jCallVoidMethod(+Obj:jref, +MethodID:methodId, +Types:list(type), +Params:list(datum))

 1505jCallVoidMethod(Obj, MethodID, Types, Params) :-
 1506    jni_params_put(Params, Types, ParamBuf),
 1507    jni_void(63, Obj, MethodID, ParamBuf).

 jFindClass(+ClassName:findclassname, -Class:jref)

 1512jFindClass(ClassName, Class) :-
 1513    jni_func(6, ClassName, Class).

 jGetArrayLength(+Array:jref, -Size:int)

 1518jGetArrayLength(Array, Size) :-
 1519    jni_func(171, Array, Size).

 jGetBooleanArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:boolean_buf)

 1524jGetBooleanArrayRegion(Array, Start, Len, Buf) :-
 1525    jni_void(199, Array, Start, Len, Buf).

 jGetBooleanField(+Obj:jref, +FieldID:fieldId, -Rbool:boolean)

 1530jGetBooleanField(Obj, FieldID, Rbool) :-
 1531    jni_func(96, Obj, FieldID, Rbool).

 jGetByteArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:byte_buf)

 1536jGetByteArrayRegion(Array, Start, Len, Buf) :-
 1537    jni_void(200, Array, Start, Len, Buf).

 jGetByteField(+Obj:jref, +FieldID:fieldId, -Rbyte:byte)

 1542jGetByteField(Obj, FieldID, Rbyte) :-
 1543    jni_func(97, Obj, FieldID, Rbyte).

 jGetCharArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:char_buf)

 1548jGetCharArrayRegion(Array, Start, Len, Buf) :-
 1549    jni_void(201, Array, Start, Len, Buf).

 jGetCharField(+Obj:jref, +FieldID:fieldId, -Rchar:char)

 1554jGetCharField(Obj, FieldID, Rchar) :-
 1555    jni_func(98, Obj, FieldID, Rchar).

 jGetDoubleArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:double_buf)

 1560jGetDoubleArrayRegion(Array, Start, Len, Buf) :-
 1561    jni_void(206, Array, Start, Len, Buf).

 jGetDoubleField(+Obj:jref, +FieldID:fieldId, -Rdouble:double)

 1566jGetDoubleField(Obj, FieldID, Rdouble) :-
 1567    jni_func(103, Obj, FieldID, Rdouble).

 jGetFieldID(+Class:jref, +Name:fieldName, +Type:type, -FieldID:fieldId)

 1572jGetFieldID(Class, Name, Type, FieldID) :-
 1573    jpl_type_to_java_field_descriptor(Type, FD),
 1574    jni_func(94, Class, Name, FD, FieldID).

 jGetFloatArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:float_buf)

 1579jGetFloatArrayRegion(Array, Start, Len, Buf) :-
 1580    jni_void(205, Array, Start, Len, Buf).

 jGetFloatField(+Obj:jref, +FieldID:fieldId, -Rfloat:float)

 1585jGetFloatField(Obj, FieldID, Rfloat) :-
 1586    jni_func(102, Obj, FieldID, Rfloat).

 jGetIntArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:int_buf)

 1591jGetIntArrayRegion(Array, Start, Len, Buf) :-
 1592    jni_void(203, Array, Start, Len, Buf).

 jGetIntField(+Obj:jref, +FieldID:fieldId, -Rint:int)

 1597jGetIntField(Obj, FieldID, Rint) :-
 1598    jni_func(100, Obj, FieldID, Rint).

 jGetLongArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:long_buf)

 1603jGetLongArrayRegion(Array, Start, Len, Buf) :-
 1604    jni_void(204, Array, Start, Len, Buf).

 jGetLongField(+Obj:jref, +FieldID:fieldId, -Rlong:long)

 1609jGetLongField(Obj, FieldID, Rlong) :-
 1610    jni_func(101, Obj, FieldID, Rlong).

 jGetMethodID(+Class:jref, +Name:atom, +Type:type, -MethodID:methodId)

 1615jGetMethodID(Class, Name, Type, MethodID) :-
 1616    jpl_type_to_java_method_descriptor(Type, MD),
 1617    jni_func(33, Class, Name, MD, MethodID).

 jGetObjectArrayElement(+Array:jref, +Index:int, -Obj:jref)

 1622jGetObjectArrayElement(Array, Index, Obj) :-
 1623    jni_func(173, Array, Index, Obj).

 jGetObjectClass(+Object:jref, -Class:jref)

 1628jGetObjectClass(Object, Class) :-
 1629    jni_func(31, Object, Class).

 jGetObjectField(+Obj:jref, +FieldID:fieldId, -RObj:jref)

 1634jGetObjectField(Obj, FieldID, Robj) :-
 1635    jni_func(95, Obj, FieldID, Robj).

 jGetShortArrayRegion(+Array:jref, +Start:int, +Len:int, +Buf:short_buf)

 1640jGetShortArrayRegion(Array, Start, Len, Buf) :-
 1641    jni_void(202, Array, Start, Len, Buf).

 jGetShortField(+Obj:jref, +FieldID:fieldId, -Rshort:short)

 1646jGetShortField(Obj, FieldID, Rshort) :-
 1647    jni_func(99, Obj, FieldID, Rshort).

 jGetStaticBooleanField(+Class:jref, +FieldID:fieldId, -Rbool:boolean)

 1652jGetStaticBooleanField(Class, FieldID, Rbool) :-
 1653    jni_func(146, Class, FieldID, Rbool).

 jGetStaticByteField(+Class:jref, +FieldID:fieldId, -Rbyte:byte)

 1658jGetStaticByteField(Class, FieldID, Rbyte) :-
 1659    jni_func(147, Class, FieldID, Rbyte).

 jGetStaticCharField(+Class:jref, +FieldID:fieldId, -Rchar:char)

 1664jGetStaticCharField(Class, FieldID, Rchar) :-
 1665    jni_func(148, Class, FieldID, Rchar).

 jGetStaticDoubleField(+Class:jref, +FieldID:fieldId, -Rdouble:double)

 1670jGetStaticDoubleField(Class, FieldID, Rdouble) :-
 1671    jni_func(153, Class, FieldID, Rdouble).

 jGetStaticFieldID(+Class:jref, +Name:fieldName, +Type:type, -FieldID:fieldId)

 1676jGetStaticFieldID(Class, Name, Type, FieldID) :-
 1677    jpl_type_to_java_field_descriptor(Type, TD),               % cache this?
 1678    jni_func(144, Class, Name, TD, FieldID).

 jGetStaticFloatField(+Class:jref, +FieldID:fieldId, -Rfloat:float)

 1683jGetStaticFloatField(Class, FieldID, Rfloat) :-
 1684    jni_func(152, Class, FieldID, Rfloat).

 jGetStaticIntField(+Class:jref, +FieldID:fieldId, -Rint:int)

 1689jGetStaticIntField(Class, FieldID, Rint) :-
 1690    jni_func(150, Class, FieldID, Rint).

 jGetStaticLongField(+Class:jref, +FieldID:fieldId, -Rlong:long)

 1695jGetStaticLongField(Class, FieldID, Rlong) :-
 1696    jni_func(151, Class, FieldID, Rlong).

 jGetStaticMethodID(+Class:jref, +Name:methodName, +Type:type, -MethodID:methodId)

 1701jGetStaticMethodID(Class, Name, Type, MethodID) :-
 1702    jpl_type_to_java_method_descriptor(Type, TD),
 1703    jni_func(113, Class, Name, TD, MethodID).

 jGetStaticObjectField(+Class:jref, +FieldID:fieldId, -RObj:jref)

 1708jGetStaticObjectField(Class, FieldID, Robj) :-
 1709    jni_func(145, Class, FieldID, Robj).

 jGetStaticShortField(+Class:jref, +FieldID:fieldId, -Rshort:short)

 1714jGetStaticShortField(Class, FieldID, Rshort) :-
 1715    jni_func(149, Class, FieldID, Rshort).

 jGetSuperclass(+Class1:jref, -Class2:jref)

 1720jGetSuperclass(Class1, Class2) :-
 1721    jni_func(10, Class1, Class2).

 jIsAssignableFrom(+Class1:jref, +Class2:jref)

 1726jIsAssignableFrom(Class1, Class2) :-
 1727    jni_func(11, Class1, Class2, @(true)).

 jNewBooleanArray(+Length:int, -Array:jref)

 1732jNewBooleanArray(Length, Array) :-
 1733    jni_func(175, Length, Array).

 jNewByteArray(+Length:int, -Array:jref)

 1738jNewByteArray(Length, Array) :-
 1739    jni_func(176, Length, Array).

 jNewCharArray(+Length:int, -Array:jref)

 1744jNewCharArray(Length, Array) :-
 1745    jni_func(177, Length, Array).

 jNewDoubleArray(+Length:int, -Array:jref)

 1750jNewDoubleArray(Length, Array) :-
 1751    jni_func(182, Length, Array).

 jNewFloatArray(+Length:int, -Array:jref)

 1756jNewFloatArray(Length, Array) :-
 1757    jni_func(181, Length, Array).

 jNewIntArray(+Length:int, -Array:jref)

 1762jNewIntArray(Length, Array) :-
 1763    jni_func(179, Length, Array).

 jNewLongArray(+Length:int, -Array:jref)