Merge or update a JSONGrammar

from __future__ import annotations

from copy import deepcopy
from pathlib import Path

from gemseo.core.grammars.errors import InvalidDataError
from gemseo.core.grammars.json_grammar import JSONGrammar

PATH_TO_PARENT_DIRECTORY = Path(__file__).parent

Create the JSON grammars

The first grammar has the elements name1 and name2 that shall be integers. The second grammar has the elements name2 and name3 that shall be strings.

grammar_1 = JSONGrammar("grammar_1")
grammar_1.update_from_file(PATH_TO_PARENT_DIRECTORY / "grammar_1.json")

grammar_2 = JSONGrammar("grammar_2")
grammar_2.update_from_file(PATH_TO_PARENT_DIRECTORY / "grammar_2.json")

Keep a pristine copy of the first grammar such that we can experiment more than once on it.

grammar_1_copy = deepcopy(grammar_1)

Update without merge

By default, the update method acts like for a dictionary, i.e. an already existing key has its value overriden. Here the value for the element name2 is now string.

grammar_1.update(grammar_2)
print(repr(grammar_1))

On validation, the allowed type is only the one from the second grammar.

try:
    grammar_1.validate({"name2": 0})
except InvalidDataError:
    pass

grammar_1.validate({"name2": "a string"})

Update with merge

First use the initial grammar from its copy.

grammar_1 = grammar_1_copy

When merging elements, an already existing element of the grammar will have both the old and the new value.

grammar_1.update(grammar_2, merge=True)
print(repr(grammar_1))

On validation, the allowed types can be any of the types from the original grammars, here either integer or string.

grammar_1.validate({"name2": 0})
grammar_1.validate({"name2": "a string"})