modelverse/kernel/rules/to_python.alc

include "primitives.alh"
include "modelling.alh"
include "object_operations.alh"
include "random.alh"

Boolean function main(model : Element):
	String result
	Element nodes
	String node
	Element edges
	String edge
	String new_node
	String source
	String destination
	String name
	Element to_explore
	Element rules
	String rule
	String value
	Element explored

	explored = set_create()
	result = "root, = yield [('RR', [])]\n"
	nodes = allInstances(model, "Rules/Root")
	while (set_len(nodes) > 0):
		node = set_pop(nodes)
		source = string_replace(node, "/", "_")
		result = result + source + " = root\n"

		// Keep following outgoing edges to find matching nodes
		to_explore = set_create()
		set_add(to_explore, node)

		while (set_len(to_explore) > 0):
			// Still explore more!
			node = set_pop(to_explore)
			source = string_replace(node, "/", "_")

			edges = allOutgoingAssociationInstances(model, node, "Rules/Edge")
			while (set_len(edges) > 0):
				edge = set_pop(edges)
				new_node = readAssociationDestination(model, edge)
				if (value_eq(read_attribute(model, new_node, "match"), True)):
					// Is a match node, so fetch the value on the edge
					name = read_attribute(model, edge, "value")
					destination = string_replace(new_node, "/", "_")
					if (set_in(explored, destination)):
						// Already visited this one in another way, so try to merge!
						String rand
						rand = random_string(10)
						result = result + rand + ", = yield [('RD', [" + source + ", " + name + "])]\n"
						result = result + "if " + rand + " != " + destination + ":\n"
						// If the values don't agree, this is not a correct match, and we say that this element remains unmatched (i.e., assign None)
						result = result + "\t" + destination + " = None\n"
					else:
						// First visit to this element, so just assign
						result = result + destination + ", = yield [('RD', [" + source + ", " + name + "])]\n"
						set_add(explored, destination)

						String value
						value = read_attribute(model, new_node, "value")
						if (element_neq(value, read_root())):
							// Match node has a value we should compare as well!
							// Read out the value from the Modelverse
							result = result + destination + "_V, = yield [('RV', [" + destination + "])]\n"

						set_add(to_explore, new_node)

	rules = allInstances(model, "Rules/Rule")
	while (set_len(rules) > 0):
		// Check if this rule is applicable
		rule = set_pop(rules)

		// Fetch all elements with a "match" label and check that they are not None (and possibly, that they have a value)
		result = result + "if (True "
		nodes = allAssociationDestinations(model, rule, "Rules/contains")
		while (set_len(nodes) > 0):
			node = set_pop(nodes)
			if (value_eq(read_attribute(model, node, "match"), True)):
				// We should match on this node:
				value = read_attribute(model, node, "value")
				if (bool_and(read_type(model, node) == "Rules/NAC", element_eq(value, read_root()))):
					result = result + " and " + string_replace(node, "/", "_") + " is None "
				else:
					result = result + " and " + string_replace(node, "/", "_") + " is not None "

				if (element_neq(value, read_root())):
					// Got a value, so match that as well
					// But check if it is an action element (first character == !)
					String sign

					if (read_type(model, node) == "Rules/NAC"):
						sign = "!="
					else:
						sign = "=="

					if (string_get(value, 0) == "!"):
						result = result + " and " + string_replace(node, "/", "_") + "_V['value'] " + sign + " '" + string_replace(value, "!", "") + "'"
					else:
						result = result + " and " + string_replace(node, "/", "_") + "_V " + sign + " " + value

		result = result + "): pass # Execute rule " + string_replace(rule, "/", "_") + "\n"

	log("Got result:")
	log(result)
	return True!