Package localsolver.modeler

Class LSPModeler

  • All Implemented Interfaces:
    java.lang.AutoCloseable
    public class LSPModeler
extends java.lang.Object
implements java.lang.AutoCloseable
    Modeler environment. Main class of the modeler library which enables the creation and manipulation of a virtual machine that can load and execute programs written in the LSP language. The creation of an LSPModeler environment results in the creation of a dedicated LocalSolver environment as well. For more information on how to use the solver's API, see the LocalSolver class.
    Since:
    10.0
    See Also:
    LocalSolver, LSPModule

    • Constructor Detail

      • LSPModeler

        public LSPModeler()
        Constructs a complete modeler environment. Main class of the modeler library which enables the creation and manipulation of a virtual machine that can load and execute programs written in the LSP language.
        See Also:
        LocalSolver

    • Method Detail

      • delete

        public void delete()
        Deletes this modeler environment. All references bound to this modeler will be automatically freed. This also includes solvers created using the createSolver().

      • close

        public void close()
        Specified by:
        close in interface java.lang.AutoCloseable

      • loadModule

        public LSPModule loadModule​(java.lang.String moduleName,
                            java.lang.String filePath)
        Loads the module written LSP at the indicated location. The loaded module will take the name specified in parameter. Unlike getModule(java.lang.String), this method ignores all paths indicated by addModuleLookupPath(java.lang.String), and if a module with a similar name is already loaded, an exception will be thrown. Once loaded, the variables of the module can be manipulated through the associated LSPModule object.
        Parameters:
        moduleName - Name taken by the module once loaded.
        filePath - Path to the module file.
        Returns:
        Module created.
        See Also:
        LSPModule

      • createModule

        public LSPModule createModule​(java.lang.String moduleName)
        Creates an empty module with the given name. The variables of the module can then be manipulated through the associated LSPModule object.
        Parameters:
        moduleName - Module name.
        Returns:
        Module created.
        See Also:
        LSPModule

      • getModule

        public LSPModule getModule​(java.lang.String moduleName)
        Returns the module with the given name. User modules can be accessed as well as builtin modules like the JSON module or the CSV module. If the module is not loaded, this method attempts to load it from the paths specified by addModuleLookupPath(java.lang.String). The variables of the module can then be manipulated through the associated LSPModule object.
        Parameters:
        moduleName - Module name.
        Returns:
        Module loaded.
        See Also:
        LSPModule

      • addModuleLookupPath

        public void addModuleLookupPath​(java.lang.String path)
        Adds a new lookup path for modules. The paths specified when calling this method are taken into account when the LSP virtual machine loads a module, either by a direct call to the getModule(java.lang.String) method, or indirectly when loading a dependency to another module. By default, the lookup path contains at least the current runtime folder.
        Parameters:
        path - New path to consider for modules.

      • clearModuleLookupPaths

        public void clearModuleLookupPaths()

        Deletes all paths used to search for modules. This method deletes all the paths previously added by addModuleLookupPath(java.lang.String) method, as well as the default location(s) (including the current execution folder).

        Important note: after calling this method, you must at least add a path with addModuleLookupPath(java.lang.String). Without a path, you won't be able to load any LSP modules other than the native ones supplied by the virtual machine.

      • createFunction

        public LSPFunction createFunction​(java.lang.String name,
                                  LSPFunctor functor)
        Creates an external LSPFunction. The argument must be derived from LSPFunctor. When the function is called, the modeler instance will be made accessible to the function, as well as the arguments. For instance, the following example creates a simple function that accepts two arguments and returns the sum of both values. The generated function is then exposed in an LSP module under the name "myCustomFunction". 
         public class MyCustomFunction extends LSPFunctor {
     @Override
     LSPValue call(LSPModeler modeler, List<LSPValue> arguments) override {
         return modeler.createDouble(arguments.get(0).asDouble() + arguments.get(1).asDouble());
     }
 }
 
 MyCustomFunction customFunctor = new MyCustomFunction();
 module.setFunction("myCustomFunction", modeler.createFunction(customFunctor));
        Note: This method should only be used to expose functions used during the modeling process. You should not use this method to create a function that will be used during the resolution as an external function. In this case, you should instead use the solver API directly (see LSIntExternalFunction or LSDoubleExternalFunction)
        Parameters:
        name - Name of the function. The name is only used to identify the function in the generated stack trace when an exception occurs. Once created, the function can be associated with any variable in any module, regardless of its name.
        functor - Implementation of the external function.
        Returns:
        Function created.
        See Also:
        LSPFunctor, LSPFunction

      • createFunction

        public LSPFunction createFunction​(LSPFunctor functor)
        Creates an external LSPFunction. The argument must be derived from LSPFunctor. When the function is called, the modeler instance will be made accessible to the function, as well as the arguments. For instance, the following example creates a simple function that accepts two arguments and returns the sum of both values. The generated function is then exposed in an LSP module under the name "myCustomFunction". 
         public class MyCustomFunction extends LSPFunctor {
     @Override
     LSPValue call(LSPModeler modeler, List<LSPValue> arguments) override {
         return modeler.createDouble(arguments.get(0).asDouble() + arguments.get(1).asDouble());
     }
 }
 
 MyCustomFunction customFunctor = new MyCustomFunction();
 module.setFunction("myCustomFunction", modeler.createFunction(customFunctor));
        Note: This method should only be used to expose functions used during the modeling process. You should not use this method to create a function that will be used during the resolution as an external function. In this case, you should instead use the solver API directly (see LSIntExternalFunction or LSDoubleExternalFunction)
        Parameters:
        functor - Implementation of the external function.
        Returns:
        Function created.
        See Also:
        LSPFunctor, LSPFunction

      • createMap

        public <E> LSPMap createMap​(java.util.List<E> values)
        Creates a LSPMap and fills it with the contents of the provided list. The keys in the map will correspond to the indices of the values in the list. This method only supports types that can be added to a LSPMap (such as integer, double, strings, LSExpression, LSPMap, LSPModule or LSPFunction) A map is a data structure mapping keys to values that can also be used as an array-like structure. The map can be assigned to any variable in a module with LSPModule.setMap(java.lang.String, localsolver.modeler.LSPMap) or can be part of another map with LSPMap.setMap(java.lang.String, localsolver.modeler.LSPMap).
        Parameters:
        values - List of values to place in the map.
        Returns:
        Map created containing all the values in the list.

      • createNil

        public LSPValue createNil()
        Creates a nil value.
        Returns:
        Created nil value.
        See Also:
        LSPValue

      • createBool

        public LSPValue createBool​(boolean value)
        Creates a boolean value. Please note that there is no dedicated type for booleans in the modeler. They are simulated with integers: 1 denotes true and 0 denotes false. The created value can be assigned to any variable in a module with LSPModule.setValue(java.lang.String, localsolver.modeler.LSPValue) or can be part of a map as key or value.
        Returns:
        Created boolean value.
        See Also:
        LSPValue

      • getStdOut

        public java.io.PrintStream getStdOut()
        Returns the stream used by the modeler for its standard output methods like print or println. The default stream used by the modeler corresponds to the Java standard output, retrieved with System.out.
        Returns:
        The stream used by the modeler for its standard output or null if the standard output is disabled.

      • setStdOut

        public void setStdOut​(java.io.PrintStream stream)
        Sets the stream used by the modeler for its standard output methods like print or println. The default is to redirect all the modeler's outputs to the Java standard output. If the given stream is null, the standard output of the modeler will be disabled and all calls to the print/println related functions will do nothing.
        Parameters:
        stream - Stream to use for the standard output or null to disable standard output.

      • getStdErr

        public java.io.PrintStream getStdErr()
        Returns the stream used by the modeler for its standard error output. The default stream used by the modeler corresponds to the Java standard error output, retrieved with System.err.
        Returns:
        The stream used by the modeler for its standard error output or null if the standard error output is disabled.

      • setStdErr

        public void setStdErr​(java.io.PrintStream stream)
        Sets the stream used by the modeler for its standard error output. The default is to redirect the standard error output stream to the Java standard error output stream. If the given stream is null, the standard error output of the modeler will be disabled.
        Parameters:
        stream - Stream to use for the standard error output or null to disable standard error output.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object