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| 1 | +use crate::error_message; |
| 2 | +use crate::ifn::IFn; |
| 3 | +use crate::iterable::Iterable; |
| 4 | +use crate::persistent_list::PersistentList; |
| 5 | +use crate::protocol::{Protocol, ProtocolCastable}; |
| 6 | +use crate::type_tag::TypeTag; |
| 7 | +use crate::value::{ToValue, Value}; |
| 8 | +use std::rc::Rc; |
| 9 | + |
| 10 | +/// (more x) |
| 11 | +/// for rest, returns possibly empty sequence after the first |
| 12 | +/// TODO: support for strings |
| 13 | +#[derive(Debug, Clone)] |
| 14 | +pub struct MoreFn {} |
| 15 | +impl ToValue for MoreFn { |
| 16 | + fn to_value(&self) -> Value { |
| 17 | + Value::IFn(Rc::new(self.clone())) |
| 18 | + } |
| 19 | +} |
| 20 | +impl IFn for MoreFn { |
| 21 | + fn invoke(&self, args: Vec<Rc<Value>>) -> Value { |
| 22 | + if args.len() != 1 { |
| 23 | + return error_message::wrong_arg_count(1, args.len()); |
| 24 | + } |
| 25 | + match args.get(0).unwrap().try_as_protocol::<Iterable>() { |
| 26 | + Some(iterable) => match iterable.iter().collect::<Vec<Rc<Value>>>().split_first() { |
| 27 | + Some((_, more)) => { |
| 28 | + Value::PersistentList(more.to_vec().into_iter().collect::<PersistentList>()) |
| 29 | + } |
| 30 | + _ => Value::PersistentList(vec![].into_iter().collect::<PersistentList>()), |
| 31 | + }, |
| 32 | + _ => error_message::type_mismatch(TypeTag::ISeq, args.get(0).unwrap()), |
| 33 | + } |
| 34 | + } |
| 35 | +} |
| 36 | + |
| 37 | +#[cfg(test)] |
| 38 | +mod tests { |
| 39 | + mod more_tests { |
| 40 | + use crate::ifn::IFn; |
| 41 | + use crate::persistent_list::PersistentList; |
| 42 | + use crate::persistent_vector::PersistentVector; |
| 43 | + use crate::rust_core::more::MoreFn; |
| 44 | + use crate::value::Value; |
| 45 | + use std::rc::Rc; |
| 46 | + |
| 47 | + #[test] |
| 48 | + fn more_on_empty_iterable() { |
| 49 | + let more = MoreFn {}; |
| 50 | + let args = vec![Rc::new(Value::PersistentList( |
| 51 | + vec![].into_iter().collect::<PersistentList>(), |
| 52 | + ))]; |
| 53 | + assert_eq!( |
| 54 | + Value::PersistentList(vec![].into_iter().collect::<PersistentList>()), |
| 55 | + more.invoke(args) |
| 56 | + ); |
| 57 | + } |
| 58 | + |
| 59 | + #[test] |
| 60 | + fn more_on_iterable_with_one_value_list() { |
| 61 | + let more = MoreFn {}; |
| 62 | + let args = vec![Rc::new(Value::PersistentList( |
| 63 | + vec![Rc::new(Value::Boolean(true))] |
| 64 | + .into_iter() |
| 65 | + .collect::<PersistentList>(), |
| 66 | + ))]; |
| 67 | + assert_eq!( |
| 68 | + Value::PersistentList(vec![].into_iter().collect::<PersistentList>()), |
| 69 | + more.invoke(args) |
| 70 | + ); |
| 71 | + } |
| 72 | + |
| 73 | + #[test] |
| 74 | + fn more_on_iterable_with_three_value_list() { |
| 75 | + let more = MoreFn {}; |
| 76 | + let args = vec![Rc::new(Value::PersistentList( |
| 77 | + vec![ |
| 78 | + Rc::new(Value::I32(1)), |
| 79 | + Rc::new(Value::I32(2)), |
| 80 | + Rc::new(Value::I32(3)), |
| 81 | + ] |
| 82 | + .into_iter() |
| 83 | + .collect::<PersistentList>(), |
| 84 | + ))]; |
| 85 | + assert_eq!( |
| 86 | + Value::PersistentList( |
| 87 | + vec![Rc::new(Value::I32(2)), Rc::new(Value::I32(3))] |
| 88 | + .into_iter() |
| 89 | + .collect::<PersistentList>() |
| 90 | + ), |
| 91 | + more.invoke(args) |
| 92 | + ); |
| 93 | + } |
| 94 | + |
| 95 | + #[test] |
| 96 | + #[should_panic] |
| 97 | + fn more_on_non_iterable_value() { |
| 98 | + let more = MoreFn {}; |
| 99 | + let args = vec![Rc::new(Value::Nil)]; |
| 100 | + assert_eq!(Value::Nil, more.invoke(args)); |
| 101 | + } |
| 102 | + } |
| 103 | +} |
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