Printing

To print the models obtained by the meta-system in the command line, one can define a custom Python function or use one of the available print functions.

Show statements

To specify the atoms that you wish to include as shown check the show statements section.

Default printing

By default, if no print function is specified, the models will be printed using the default output of the solver.

Available print functions

All available print functions are listed in the API documentation.

Create your own print function

To define a custom print function, you can create a Python script that contains the function. The function should take a model and a Meta System as input and print the desired output to stdout.

The script and the function can then be specified when running the system with the --printer and --python-scripts options.

Example

In the mel, we define a custom print function in melingo/print_functions.py:

import sys

from clingo import Model, SymbolType

from metasp.printing import colored_symbol_str


def mel_printer(model: Model, system) -> None:
    """
    Prints the model as in mel separating the states.

    Args:
        model (Model): The clingo model to be printed.
        system (MetaSystem): The metasp system.
    """
    l = int(system.constants["n"]) + 1
    table = {}
    times = {}
    extra_shown = []

    for sym in model.symbols(theory=True):
        if sym.type == SymbolType.Function and sym.name == "__csp" and len(sym.arguments) == 2:
            if (
                sym.arguments[0].type == SymbolType.Function
                and len(sym.arguments[0].arguments) > 0
                and sym.arguments[0].name == "t"
            ):
                times[sym.arguments[0].arguments[0].number] = sym.arguments[1].number
    for sym in model.symbols(shown=True):
        if sym.type == SymbolType.Function and len(sym.arguments) > 0 and sym.name == "true":
            table.setdefault(sym.arguments[-1].number, []).append(sym.arguments[0])
        else:
            extra_shown.append(sym)
    if len(extra_shown) > 0:
        sys.stdout.write(" Other shown symbols:\n")
        for sym in extra_shown:
            sys.stdout.write(" {}".format(sym))
        sys.stdout.write("\n\n")
    for step in range(l):
        symbols = table.get(step, [])
        sys.stdout.write("State {} \033[94m @{}:\033[0m".format(step, times.get(step, "?")))
        sig = None
        for sym in sorted(symbols):
            if (sym.name, len(sym.arguments), sym.positive) != sig:
                # sys.stdout.write("\n ")
                sig = (sym.name, len(sym.arguments), sym.positive)
            sys.stdout.write(" {}".format(colored_symbol_str(sym)))
        sys.stdout.write("\n")
    sys.stdout.write("\n")