Abstract:
Example embodiments are directed towards graphical user interfaces for declarative specification languages that express the logic of a computation without describing its control flow. These user interfaces are based on a visual representation of specifications where geometric proximity may be the sole determinant of the resulting configuration. Modularity is improved as each proximal grouping is functionally independent of others. Moreover, a system that executes such specifications may treat groupings independently and execute them in parallel.

Description:
BACKGROUND 
     Specification languages are formal languages used during software development to describe what the system is supposed to do without unnecessary details about how it is to be accomplished. Many of these specification languages have a visual representation, e.g. a graph, which is designed to make them more accessible and improve readability. 
       FIG. 1A  provides an example of a graph representation of a specification language in the form of a finite state machine, which may e.g. be employed by a computer game software developer. Specifically, the example provided in  FIG. 1A  illustrates a virtual shooting game in which game characters may execute specific behaviors based on their environment. Each circle  11 ,  13  and  15  may represent an action taken by the game character, while the transitions between actions may be provided by data indications represented by directed edges  12 ,  14 ,  16  and  18 . 
     Thus, in the example provided by  FIG. 1A , a game character may initially be configured to perform the patrol action  11 . If the game character receives a data indication that a visual of a target has been obtained and the target is not close  12 , the game character may transition to the shooting action  13 . If a data indication specifies that a target visual is no longer obtained  14 , the game character may transition back to a patrol action  11 . Similarly, if the game character is currently executing a patrol action  11  and a data indication that a target visual which is close  18  is obtained, the game character may transition to a stabbing action  15 . Once a data indication is received that a target visual is no longer obtained  16 , the game character may transition back to a patrol action  11 . Finally, if the game character is currently in the shoot action  13 , and a data indication that the target is close  17  is obtained, then it may transition to the stab action  15 . Conversely, if the game character is currently in the stab action  15 , and a data indication that the target is not close  19  is obtained, then it may transition to the shoot action  13 . 
       FIG. 1B  provides another example of a graph representation of a specification language in the form of a decision tree. In the decision tree of  FIG. 1B , data indications are represented by decision nodes  20  and  22 , while actions are represented by leaf nodes  21 ,  23 , and  25 . Transitions from decision nodes to leaf nodes may be provided by the directed edges interconnecting the nodes. 
     Initially, a game character may be configured to wait for a data indication as to whether or not a visual of a target is obtained  20 . If the decision from the visual data indicator  20  is negative, the game character may be configured to execute a patrol command  21 . Thereafter, the game character may be configured to restart this transition process from the root node  20  of the decision tree. If the decision from the visual data indicator  20  is positive the game character may transition to a second data indication where a determination of whether or not the target is close may be made  22 . If the decision from the closeness data indicator  22  is positive, the game character may transition to a shooting action  25  and thereafter restart at the root node  20 . If the decision from the closeness data indicator  22  is negative, the game character may transition to a stabbing action  23  and thereafter restart at the root node  20 . 
     SUMMARY 
     In the examples provided by  FIGS. 1A and 1B , the altering of any action, data indication, and/or transition will have an impact on the entire finite state machine or decision tree. Specifically, if adding a state or data indication to either the finite state machine or decision tree, the transitions between the added state or data indication and other states or data indications may need to be configured as well. Furthermore, both the finite state machine and the decision tree have the limitation of allowing only a single state or action to occur at any given time. 
     Example embodiments presented herein may provide a graphical user interface with a visual representation of a specification language, which may be employed as a plug in component by software developers. The declarative nature of the specification language satisfies the desirable property of expressing the logic of a computation without its control flow, i.e. what the system is supposed to do but not necessarily how it is to be done. Moreover, in the specification language, states and actions may be represented by predicates, and transitions between actions and data indications may be expressed independently of one another and without the use of directed graph edges. Thus, the software developer may have the flexibility to alter parts of the specification without having to alter the entire representation. Finally, the specification may also represent the execution of multiple actions or data indications at any given time. 
     Some example embodiments may be directed towards a method for declarative specification. The method may comprise receiving an adjustment input through a user interface. The adjustment input may indicate a change in a spatial relationship of a first predicate with respect to a second predicate. The method may further comprise altering a declarative specification as a function of the adjustment input. 
     Some example embodiments may be directed towards a system for declarative specification. The system may comprise a receiving unit that may be configured to receive an adjustment input through a user interface. The adjustment input may indicate a change in a spatial relationship of a first predicate with respect to a second predicate. The system may further comprise a processing unit that may be configured to alter a declarative specification as a function of the adjustment input. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments. 
         FIGS. 1A and 1B  are illustrative examples of visual representations of specification languages; 
         FIG. 2  is a schematic of a user interface featuring predicates, according to some of the example embodiments; 
         FIG. 3  is an illustrative example of predicate alteration, according to some of the example embodiments; 
         FIG. 4  is a schematic of a hierarchical predicate, according to some of the example embodiments; 
         FIG. 5  is a schematic of a system which may use some of the example embodiments; and 
         FIG. 6  is a block diagram of a declarative unit, according to some of the example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular components, elements, techniques, etc. in order to provide a thorough understanding of the example embodiments. However, the example embodiments may be practiced in other manners that depart from these specific details. In other instances, detailed descriptions of well-known methods and elements are omitted so as not to obscure the description of the example embodiments. 
     Some example embodiments presented herein are directed towards visual representations of declarative specifications. Through the use of adjustment inputs to the visual representation, the target system may be altered in real time.  FIG. 2  illustrates a graphical user interface which may provide visual representations of declarative specifications, according to some of the example embodiments. The user interface may comprise a spilt screen, or two separate screens. The first section of the spilt screen may feature a declaration specification area  37 . The second section of the split screen may provide a view of the real time execution  39  of the specification represented by the visual representation  37 . Thus, a software developer may alter or amend the program via the declaration specification area  37  while viewing the effects of the alteration in the real time execution screen  39 . It should be appreciated that a software developer may also provide declarative specifications offline as well. Thus, declarative specifications may be performed at least in part in real time. 
     A number of predicates are illustrated in the declaration specification area  37  as an example. Utilizing the virtual shooting game example of  FIGS. 1A and 1B , the predicates of  FIG. 2  are arranged to demonstrate the same character behaviour as previously discussed. For example, in the predicate grouping  27  a visual data indication predicate  28  is grouped in close proximity to an attack predicate  29 . Thus, if the game character obtains a visual of a target, the game character may initiate an attack behavior. 
     A user or software developer may specify this declarative specification, or logical relationship between two or more predicates, by moving the predicate icons on a screen. For example, a user may employ a click and/or drag operation in grouping the predicates, thereby providing the declarative specification. It should also be appreciated that a user may form predicate groupings by moving the various predicates with the use of a touch screen input system. The user interface may receive information regarding a declarative relationship via an adjustment input from a user. The adjustment input may indicate a spatial relationship, or change in such a relationship, between one or more predicates. Thus, predicates that are touching or are in close proximity may form a declarative specification relationship. The proximity value in which two predicates are determined to be in a functional relation may be user programmable. It should also be appreciated that the flow of declarative specification of two or more predicates may be determined from top to bottom, left to right, or any other configuration which may be user programmable. 
     It should also be appreciated that declaration specifications or predicate groupings may comprise any number of predicates or levels. For example, in predicate grouping  31  a no visual data indicator  32  may be grouped with a no attack predicate  33 , which may in turn be grouped with a patrol action predicate  35 . Thus, if the no visual data indication  32  yields a positive result, the no attack predicate  33  may be evoked, and simultaneously the patrol action predicate  35  may be evoked or executed. Therefore, if the game character does not have a visual of a target, the game character may be configured to patrol. As an additional example, in predicate grouping  34 , an item data indicator  36  may be grouped with a take action predicate  38 . Thus, if the game character receives a positive data indication that an item is in sight, the game character may execute a taking action on the item. 
     As can be seen in  FIG. 2 , all of the declaration specifications or predicate groupings are independent of one another. Therefore, if a software developer were to add an additional predicate grouping, alterations to the pre-existing predicate groupings would not have to be made. In contrast, if changes were made to any node of the finite state machine or decision tree of  FIGS. 1A and 1B , respectively, relationships among other nodes will have to be altered as well. Furthermore, it should be appreciated that the three example predicate groupings of  FIG. 2  may all be executed simultaneously. The simultaneous execution of nodes is not possible with the finite state machine or decision tree visualizations. 
     In some example embodiments, changes or alterations to pre-existing predicates may also be provided.  FIG. 3  provides three examples of sub-parameterized predicates. A sub-parameterized predicate is a predicate in which one or more predicate parameters can be provided or modified. 
     As shown in  FIG. 3 , a distance data indicator may be altered to change a value of a data threshold which determines when an object is close (icon  41 ). Specifically, a distance threshold  43  may be altered by selecting a distance value from a range of distances. The selection may be provided via a scroll bar  44  representing the different distance values and a lever  46  representing the selected value. 
     It should also be appreciated that a range of data values may be selected. For example, a distance data indicator  47  may be defined by a threshold data range  49 , which determines when an object is proximate. The threshold data range may be selected via a scroll bar  50  and a plurality of levers  52  and  54 . Thus, if an item or target falls within the selected range the predicate associated with the data indicator may yield a positive result. 
     It should further be appreciated that predicate alteration may be provided for action predicates. For example, a shoot rounds action predicate  57  may be altered in terms of the number of rounds to fire if an attack predicate  55  and a not close data indicator  56  is found to be true. The number of rounds used for shooting may be altered via a scroll bar  58  and lever  60 . It should also be appreciated that the use of scroll bars and levers are provided merely as examples and any other form of indicating a data alteration may be provided. For example, a user may type a data threshold value into a data field. It should further be appreciated that type boxes or drop down menus may also be used to alter predicate types as shown by modified predicate  59  of  FIG. 3 . In fact, any type of predicate, e.g. actions and data indications, may be altered in any manner, e.g. predicate type and threshold values. 
     In some example embodiments, predicates may be hierarchical as shown in  FIG. 4  where different aspects of an attacking behavior are defined within a single hierarchical attacking behavior predicate  61 . For example, if an attack predicate  62  is executed and a not close data indicator  63  is positive, a shooting action predicate  65  may be executed. Similarly, if an attack predicate  62  is executed and a close data indicator  67  is positive, a stabbing action predicate  69  may be executed. Using hierarchical predicates may simplify declaration specifications for a user by abstracting away the attack predicate  62  from all rules inside the hierarchical attacking behavior  61 . Also, instead of having to define all of the different options for an attacking behavior, such a behavior may already be defined in a library as a hierarchical predicate. It should be appreciated that in some example embodiments a user may have the flexibility to create his or her own hierarchical predicates as well as edit pre-existing hierarchical predicates stored in a library. It should further be appreciated that any type of predicate may be defined in a hierarchical manner and that a hierarchical predicate may comprise any number of predicate groupings, where the predicate groupings may comprise any number of levels. 
       FIG. 5  illustrates an overview of a system which may utilize the example embodiments. A user interface  71  may provide the visual representation of the specification language and receive any alteration or programming information from a user or software developer. The received information may be in the form of an adjustment input. The adjustment input may indicate a change in a spatial relationship between two predicates, e.g. two predicates placed in close proximity to one another in either a vertical or horizontal position. It should be appreciated that the adjustment input may also indicate an alteration in a pre-existing predicate, as discussed above. A declarative unit  73  may be configured to receive data from the user interface  71  and provide the declarative specifications  77 . The declarative specifications  77  may e.g. be in the form of propositional or first-order logical formulas where predicates placed in vertical proximity form conjunctions and predicates placed in horizontal proximity form implications. The declarative unit  73  may thereafter assign the declarative specifications  77  to the target system or program  75 , which may have an effect on that system&#39;s behavior. This effect may e.g. be caused by the declarative specifications  77  serving as the input to a propositional or first-order logical inference mechanism that is part of the target system  75 . 
       FIG. 6  illustrates an example of a declarative unit  73 . The declarative unit  73  may comprise any number of information units  79 , which may be able to transmit or receive any number or type of signals or data. It should be appreciated that the declarative unit  73  may alternatively comprise a single transceiver port. The information units or transceiver port may be in the form of any input/output communications port known in the art. 
     The declarative unit  73  may also comprise at least one memory unit  83 . The memory unit  83  may be configured to store received, transmitted, and/or measured data, executable program instructions, and/or a programming library. At least one memory unit  83  may be any suitable type of computer readable memory and may be of volatile and/or non-volatile type. The declarative unit  73  may also comprise a processing unit  81 . The processing unit  81  may be any suitable type of computation unit, e.g. a microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), or application specific integrated circuit (ASIC). 
     In some example embodiments the processing unit  81  may be configured to apply the declarative specifications based on the adjustment input from the user. The processing unit  81  may further be configured to send instructions or the declarative specifications to the target system  75 . 
     Example embodiments comprising interactive visualization of specification languages have been provided herein. Using the example embodiments, a user may modify a program in real time through the use of declarative specification. It should be appreciated that while the example embodiments have been explained with the use of a game environment, the embodiments may be utilized in various other applications. 
     For example, the example embodiments may be utilized for facility control or management. Specifically, a facility manager may utilize the user interface of  FIG. 2  to define declarative specifications using predicates which define actions dealing with facility control. For example, the turning off of the lights of a facility may be provided as an action predicate which may be grouped with a data indicator predicate specifying a time of day or period of non-movement within the building. It should be appreciated that any other forms of facility control may be defined by predicates and managed through declarative specification, according to some of the example embodiments presented herein. 
     Another application may be the specification of the underlying logic of PC, web, or smart phone applications. Graphical user interface elements such as buttons would be represented by data indication predicates and their grouping with action predicates would control what the button does. This embodiment could enable users without programming experience to develop such applications. 
     Other example application of the embodiments may be various forms of automation. For example, a mechanical device, industrial robotic equipment, or toy robot may be controlled using the user interface and predicates defining mechanical movement in response to data sensing. Furthermore, any form of rule based system (e.g., income tax applications) may also be controlled or implemented using the embodiments discussed herein. It should also be appreciated that the example embodiments presented herein may also be used for educational purposes. Specifically, declarative specification may be used to introduce a pupil to software programming, while the user interface of  FIG. 2  may be utilized to show the pupil the effects of the programming in real time. Finally, one may want to integrate the graphical user interface  71  and declarative unit  73  within the target system  75  in order to create a system where the end user has the ability to configure the system itself through the methods described above or variants thereof. 
     The foregoing description of the example embodiments have been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives to the provided embodiments. The examples discussed herein were chosen and described in order to explain the principles and the nature of various example embodiments and its practical application to enable one skilled in the art to utilize the example embodiments in various manners and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. 
     It should be noted that the word “comprising” does not necessarily exclude the presence of other elements or steps than those listed and the words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the example embodiments may be implemented at least in part by means of both hardware and software, and that several “means”, “units” or “devices” may be represented by the same item of hardware. 
     Some example embodiments may comprise a portable or non-portable telephone, media player, Personal Communications System (PCS) terminal, Personal Data Assistant (PDA), laptop computer, palmtop receiver, camera, television, and/or any appliance that comprises a transducer designed to transmit and/or receive radio, television, microwave, telephone and/or radar signals. 
     The various example embodiments described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, and executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.