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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 17:35:20 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 17:35:20 +0000
commite106bf94eff07d9a59771d9ccc4406421e18ab64 (patch)
treeedb6545500e39df9c67aa918a6125bffc8ec1aee /examples/prompts/regular-language.py
parentInitial commit. (diff)
downloadprompt-toolkit-e106bf94eff07d9a59771d9ccc4406421e18ab64.tar.xz
prompt-toolkit-e106bf94eff07d9a59771d9ccc4406421e18ab64.zip
Adding upstream version 3.0.36.upstream/3.0.36upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+#!/usr/bin/env python
+"""
+This is an example of "prompt_toolkit.contrib.regular_languages" which
+implements a little calculator.
+
+Type for instance::
+
+ > add 4 4
+ > sub 4 4
+ > sin 3.14
+
+This example shows how you can define the grammar of a regular language and how
+to use variables in this grammar with completers and tokens attached.
+"""
+import math
+
+from prompt_toolkit import prompt
+from prompt_toolkit.completion import WordCompleter
+from prompt_toolkit.contrib.regular_languages.compiler import compile
+from prompt_toolkit.contrib.regular_languages.completion import GrammarCompleter
+from prompt_toolkit.contrib.regular_languages.lexer import GrammarLexer
+from prompt_toolkit.lexers import SimpleLexer
+from prompt_toolkit.styles import Style
+
+operators1 = ["add", "sub", "div", "mul"]
+operators2 = ["cos", "sin"]
+
+
+def create_grammar():
+ return compile(
+ r"""
+ (\s* (?P<operator1>[a-z]+) \s+ (?P<var1>[0-9.]+) \s+ (?P<var2>[0-9.]+) \s*) |
+ (\s* (?P<operator2>[a-z]+) \s+ (?P<var1>[0-9.]+) \s*)
+ """
+ )
+
+
+example_style = Style.from_dict(
+ {
+ "operator": "#33aa33 bold",
+ "number": "#ff0000 bold",
+ "trailing-input": "bg:#662222 #ffffff",
+ }
+)
+
+
+if __name__ == "__main__":
+ g = create_grammar()
+
+ lexer = GrammarLexer(
+ g,
+ lexers={
+ "operator1": SimpleLexer("class:operator"),
+ "operator2": SimpleLexer("class:operator"),
+ "var1": SimpleLexer("class:number"),
+ "var2": SimpleLexer("class:number"),
+ },
+ )
+
+ completer = GrammarCompleter(
+ g,
+ {
+ "operator1": WordCompleter(operators1),
+ "operator2": WordCompleter(operators2),
+ },
+ )
+
+ try:
+ # REPL loop.
+ while True:
+ # Read input and parse the result.
+ text = prompt(
+ "Calculate: ", lexer=lexer, completer=completer, style=example_style
+ )
+ m = g.match(text)
+ if m:
+ vars = m.variables()
+ else:
+ print("Invalid command\n")
+ continue
+
+ print(vars)
+ if vars.get("operator1") or vars.get("operator2"):
+ try:
+ var1 = float(vars.get("var1", 0))
+ var2 = float(vars.get("var2", 0))
+ except ValueError:
+ print("Invalid command (2)\n")
+ continue
+
+ # Turn the operator string into a function.
+ operator = {
+ "add": (lambda a, b: a + b),
+ "sub": (lambda a, b: a - b),
+ "mul": (lambda a, b: a * b),
+ "div": (lambda a, b: a / b),
+ "sin": (lambda a, b: math.sin(a)),
+ "cos": (lambda a, b: math.cos(a)),
+ }[vars.get("operator1") or vars.get("operator2")]
+
+ # Execute and print the result.
+ print("Result: %s\n" % (operator(var1, var2)))
+
+ elif vars.get("operator2"):
+ print("Operator 2")
+
+ except EOFError:
+ pass