use rhai::{
Dynamic, Engine, EvalAltResult, ImmutableString, LexError, ParseErrorType, Position, Scope, INT,
};
#[test]
fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
engine.run("while false {}")?;
engine.disable_symbol("while");
assert!(matches!(
*engine.compile("while false {}").expect_err("should error").0,
ParseErrorType::Reserved(err) if err == "while"
));
assert!(matches!(
*engine.compile("let while = 0").expect_err("should error").0,
ParseErrorType::Reserved(err) if err == "while"
));
engine.register_custom_syntax(
&[
"exec", "[", "$ident$", "$symbol$", "$int$", "]", "->", "$block$", "while", "$expr$",
],
true,
|context, inputs| {
let var_name = inputs[0].get_variable_name().unwrap().to_string();
let op = inputs[1].get_literal_value::<ImmutableString>().unwrap();
let max = inputs[2].get_literal_value::<INT>().unwrap();
let stmt = &inputs[3];
let condition = &inputs[4];
context.scope_mut().push(var_name.clone(), 0 as INT);
let mut count: INT = 0;
loop {
let done = match op.as_str() {
"<" => count >= max,
"<=" => count > max,
">" => count <= max,
">=" => count < max,
"==" => count != max,
"!=" => count == max,
_ => return Err(format!("Unsupported operator: {}", op).into()),
};
if done {
break;
}
context.eval_expression_tree(stmt)?;
count += 1;
context
.scope_mut()
.push(format!("{}{}", var_name, count), count);
let stop = !context
.eval_expression_tree(condition)?
.as_bool()
.map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"bool".to_string(),
err.to_string(),
condition.position(),
))
})?;
if stop {
break;
}
}
Ok(count.into())
},
)?;
assert!(matches!(
*engine
.run("let foo = (exec [x<<15] -> { x += 2 } while x < 42) * 10;")
.expect_err("should error"),
EvalAltResult::ErrorRuntime(_, _)
));
assert_eq!(
engine.eval::<INT>(
"
let x = 0;
let foo = (exec [x<15] -> { x += 2 } while x < 42) * 10;
foo
"
)?,
150
);
assert_eq!(
engine.eval::<INT>(
"
let x = 0;
exec [x<100] -> { x += 1 } while x < 42;
x
"
)?,
42
);
assert_eq!(
engine.eval::<INT>(
"
exec [x<100] -> { x += 1 } while x < 42;
x
"
)?,
42
);
assert_eq!(
engine.eval::<INT>(
"
let foo = 123;
exec [x<15] -> { x += 1 } while x < 42;
foo + x + x1 + x2 + x3
"
)?,
144
);
assert_eq!(
*engine
.register_custom_syntax(&["!"], false, |_, _| Ok(Dynamic::UNIT))
.expect_err("should error")
.0,
ParseErrorType::BadInput(LexError::ImproperSymbol(
"!".to_string(),
"Improper symbol for custom syntax at position #1: '!'".to_string()
))
);
engine
.register_custom_syntax(&["test1", "$block$"], true, |_, _| Ok(Dynamic::UNIT))?
.register_custom_syntax(&["test2", "}"], true, |_, _| Ok(Dynamic::UNIT))?
.register_custom_syntax(&["test3", ";"], true, |_, _| Ok(Dynamic::UNIT))?;
assert_eq!(engine.eval::<INT>("test1 { x = y + z; } 42")?, 42);
assert_eq!(engine.eval::<INT>("test2 } 42")?, 42);
assert_eq!(engine.eval::<INT>("test3; 42")?, 42);
engine.register_custom_syntax(
&["var", "$ident$", "=", "$expr$"],
true,
|context, inputs| {
let var_name = inputs[0].get_variable_name().unwrap().to_string();
let expr = &inputs[1];
let value = context.eval_expression_tree(expr)?;
if !context.scope().is_constant(&var_name).unwrap_or(false) {
context.scope_mut().set_value(var_name, value);
Ok(Dynamic::UNIT)
} else {
Err(format!("variable {} is constant", var_name).into())
}
},
)?;
let mut scope = Scope::new();
assert_eq!(
engine.eval_with_scope::<INT>(&mut scope, "var foo = 42; foo")?,
42
);
assert_eq!(scope.get_value::<INT>("foo"), Some(42));
assert_eq!(scope.len(), 1);
assert_eq!(
engine.eval_with_scope::<INT>(&mut scope, "var foo = 123; foo")?,
123
);
assert_eq!(scope.get_value::<INT>("foo"), Some(123));
assert_eq!(scope.len(), 1);
Ok(())
}
#[test]
fn test_custom_syntax_raw() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
engine.register_custom_syntax_raw(
"hello",
|stream, _| match stream.len() {
0 => unreachable!(),
1 => Ok(Some("$ident$".into())),
2 => match stream[1].as_str() {
"world" => Ok(Some("$$hello".into())),
"kitty" => Ok(None),
s => Err(LexError::ImproperSymbol(s.to_string(), String::new())
.into_err(Position::NONE)
.into()),
},
_ => unreachable!(),
},
true,
|context, inputs| {
context.scope_mut().push("foo", 999 as INT);
Ok(match inputs[0].get_variable_name().unwrap() {
"world"
if inputs
.last()
.unwrap()
.get_literal_value::<ImmutableString>()
.map_or(false, |s| s == "$$hello") =>
{
0 as INT
}
"world" => 123 as INT,
"kitty" if inputs.len() > 1 => 999 as INT,
"kitty" => 42 as INT,
_ => unreachable!(),
}
.into())
},
);
assert_eq!(engine.eval::<INT>("hello world")?, 0);
assert_eq!(engine.eval::<INT>("hello kitty")?, 42);
assert_eq!(
engine.eval::<INT>("let foo = 0; (hello kitty) + foo")?,
1041
);
assert_eq!(engine.eval::<INT>("(hello kitty) + foo")?, 1041);
assert_eq!(
*engine.compile("hello hey").expect_err("should error").0,
ParseErrorType::BadInput(LexError::ImproperSymbol("hey".to_string(), "".to_string()))
);
Ok(())
}