Bruno BELANYI
0a4966ae95
It can both evaluate and print the given expression. It uses `click` to parse its CLI options.
51 lines
1.1 KiB
Python
Executable file
51 lines
1.1 KiB
Python
Executable file
#! /usr/bin/env python
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import click
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from calculator.eval import Evaluator
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from calculator.parse import parse_infix, parse_postfix, parse_prefix
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from calculator.print import Printer
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STR_TO_PARSER = {
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"infix": parse_infix,
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"prefix": parse_prefix,
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"postfix": parse_postfix,
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}
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@click.group(invoke_without_command=True, chain=True)
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@click.option(
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"--expr-type",
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default="infix",
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type=click.Choice(["infix", "prefix", "postfix"], case_sensitive=False),
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)
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@click.pass_context
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def cli(ctx, expr_type):
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ctx.ensure_object(dict)
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ctx.obj["input"] = STR_TO_PARSER[expr_type](
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input(f"Input your {expr_type} expression: ")
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)
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if ctx.invoked_subcommand is None:
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ctx.invoke(eval_tree)
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@cli.command(name="print")
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@click.pass_context
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def print_tree(ctx):
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"""
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Print the parsed AST.
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"""
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Printer().print(ctx.obj["input"])
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@cli.command(name="eval")
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@click.pass_context
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def eval_tree(ctx):
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"""
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Evaluate the parsed expression.
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"""
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print(Evaluator().visit_and_get_value(ctx.obj["input"]))
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if __name__ == "__main__":
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cli(obj={})
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