rhai/tests/syntax.rs
2020-12-15 19:23:30 +08:00

138 lines
3.9 KiB
Rust

use rhai::{Dynamic, Engine, EvalAltResult, LexError, ParseError, ParseErrorType, Position, INT};
#[test]
fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
engine.consume("while false {}")?;
// Disable 'while' and make sure it still works with custom syntax
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", "|", "$ident$", "|", "->", "$block$", "while", "$expr$",
],
1,
|context, inputs| {
let var_name = inputs[0].get_variable_name().unwrap().to_string();
let stmt = inputs.get(1).unwrap();
let condition = inputs.get(2).unwrap();
context.scope_mut().push(var_name, 0 as INT);
loop {
context.eval_expression_tree(stmt)?;
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(Dynamic::UNIT)
},
)?;
assert_eq!(
engine.eval::<INT>(
r"
let x = 0;
exec |x| -> { x += 1 } while x < 42;
x
"
)?,
42
);
assert_eq!(
engine.eval::<INT>(
r"
exec |x| -> { x += 1 } while x < 42;
x
"
)?,
42
);
// The first symbol must be an identifier
assert_eq!(
*engine
.register_custom_syntax(&["!"], 0, |_, _| Ok(Dynamic::UNIT))
.expect_err("should error")
.0,
ParseErrorType::BadInput(LexError::ImproperSymbol(
"!".to_string(),
"Improper symbol for custom syntax at position #1: '!'".to_string()
))
);
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" | "kitty" => Ok(None),
s => Err(ParseError(
Box::new(ParseErrorType::BadInput(LexError::ImproperSymbol(
s.to_string(),
"".to_string(),
))),
Position::NONE,
)),
},
_ => unreachable!(),
},
1,
|context, inputs| {
context.scope_mut().push("foo", 999 as INT);
Ok(match inputs[0].get_variable_name().unwrap() {
"world" => 123 as INT,
"kitty" => 42 as INT,
_ => unreachable!(),
}
.into())
},
);
assert_eq!(engine.eval::<INT>("hello world")?, 123);
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(())
}