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| 1 | +use super::super::pyobject::{ |
| 2 | + PyContext, PyFuncArgs, PyObject, PyObjectPayload, PyObjectRef, PyResult, TypeProtocol, |
| 3 | +}; |
| 4 | +use super::super::vm::VirtualMachine; |
| 5 | +use super::objint; |
| 6 | +use super::objtype; |
| 7 | +use num_bigint::ToBigInt; |
| 8 | +use num_traits::ToPrimitive; |
| 9 | + |
| 10 | +#[derive(Debug, Copy, Clone)] |
| 11 | +pub struct RangeType { |
| 12 | + // Unfortunately Rust's built in range type doesn't support things like indexing |
| 13 | + // or ranges where start > end so we need to roll our own. |
| 14 | + pub start: i64, |
| 15 | + pub end: i64, |
| 16 | + pub step: i64, |
| 17 | +} |
| 18 | + |
| 19 | +impl RangeType { |
| 20 | + #[inline] |
| 21 | + pub fn len(&self) -> usize { |
| 22 | + ((self.end - self.start) / self.step).abs() as usize |
| 23 | + } |
| 24 | + |
| 25 | + #[inline] |
| 26 | + pub fn is_empty(&self) -> bool { |
| 27 | + (self.start <= self.end && self.step < 0) || (self.start >= self.end && self.step > 0) |
| 28 | + } |
| 29 | + |
| 30 | + #[inline] |
| 31 | + pub fn forward(&self) -> bool { |
| 32 | + self.start < self.end |
| 33 | + } |
| 34 | + |
| 35 | + #[inline] |
| 36 | + pub fn get(&self, index: i64) -> Option<i64> { |
| 37 | + let result = self.start + self.step * index; |
| 38 | + |
| 39 | + if self.forward() && !self.is_empty() && result < self.end { |
| 40 | + Some(result) |
| 41 | + } else if !self.forward() && !self.is_empty() && result > self.end { |
| 42 | + Some(result) |
| 43 | + } else { |
| 44 | + None |
| 45 | + } |
| 46 | + } |
| 47 | +} |
| 48 | + |
| 49 | +pub fn init(context: &PyContext) { |
| 50 | + let ref range_type = context.range_type; |
| 51 | + context.set_attr(&range_type, "__new__", context.new_rustfunc(range_new)); |
| 52 | + context.set_attr(&range_type, "__iter__", context.new_rustfunc(range_iter)); |
| 53 | + context.set_attr(&range_type, "__len__", context.new_rustfunc(range_len)); |
| 54 | + context.set_attr( |
| 55 | + &range_type, |
| 56 | + "__getitem__", |
| 57 | + context.new_rustfunc(range_getitem), |
| 58 | + ); |
| 59 | +} |
| 60 | + |
| 61 | +fn range_new(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult { |
| 62 | + arg_check!( |
| 63 | + vm, |
| 64 | + args, |
| 65 | + required = [(cls, None), (first, Some(vm.ctx.int_type()))], |
| 66 | + optional = [ |
| 67 | + (second, Some(vm.ctx.int_type())), |
| 68 | + (step, Some(vm.ctx.int_type())) |
| 69 | + ] |
| 70 | + ); |
| 71 | + |
| 72 | + let start = if let Some(_) = second { |
| 73 | + objint::get_value(first).to_i64().unwrap() |
| 74 | + } else { |
| 75 | + 0i64 |
| 76 | + }; |
| 77 | + |
| 78 | + let end = if let Some(pyint) = second { |
| 79 | + objint::get_value(pyint).to_i64().unwrap() |
| 80 | + } else { |
| 81 | + objint::get_value(first).to_i64().unwrap() |
| 82 | + }; |
| 83 | + |
| 84 | + let step = if let Some(pyint) = step { |
| 85 | + objint::get_value(pyint).to_i64().unwrap() |
| 86 | + } else { |
| 87 | + 1i64 |
| 88 | + }; |
| 89 | + |
| 90 | + if step == 0 { |
| 91 | + Err(vm.new_value_error("range with 0 step size".to_string())) |
| 92 | + } else { |
| 93 | + Ok(PyObject::new( |
| 94 | + PyObjectPayload::Range { |
| 95 | + range: RangeType { start, end, step }, |
| 96 | + }, |
| 97 | + cls.clone(), |
| 98 | + )) |
| 99 | + } |
| 100 | +} |
| 101 | + |
| 102 | +fn range_iter(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult { |
| 103 | + arg_check!(vm, args, required = [(range, Some(vm.ctx.range_type()))]); |
| 104 | + |
| 105 | + Ok(PyObject::new( |
| 106 | + PyObjectPayload::Iterator { |
| 107 | + position: 0, |
| 108 | + iterated_obj: range.clone(), |
| 109 | + }, |
| 110 | + vm.ctx.iter_type(), |
| 111 | + )) |
| 112 | +} |
| 113 | + |
| 114 | +fn range_len(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult { |
| 115 | + arg_check!(vm, args, required = [(zelf, Some(vm.ctx.range_type()))]); |
| 116 | + |
| 117 | + let len = match zelf.borrow().payload { |
| 118 | + PyObjectPayload::Range { ref range } => range.len(), |
| 119 | + _ => unreachable!(), |
| 120 | + }; |
| 121 | + |
| 122 | + Ok(vm.ctx.new_int(len.to_bigint().unwrap())) |
| 123 | +} |
| 124 | + |
| 125 | +fn range_getitem(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult { |
| 126 | + arg_check!( |
| 127 | + vm, |
| 128 | + args, |
| 129 | + required = [(zelf, Some(vm.ctx.range_type())), (subscript, None)] |
| 130 | + ); |
| 131 | + let zrange = if let PyObjectPayload::Range { range } = zelf.borrow().payload { |
| 132 | + range.clone() |
| 133 | + } else { |
| 134 | + unreachable!() |
| 135 | + }; |
| 136 | + |
| 137 | + match subscript.borrow().payload { |
| 138 | + PyObjectPayload::Integer { ref value } => { |
| 139 | + if let Some(int) = zrange.get(value.to_i64().unwrap()) { |
| 140 | + Ok(PyObject::new( |
| 141 | + PyObjectPayload::Integer { |
| 142 | + value: int.to_bigint().unwrap(), |
| 143 | + }, |
| 144 | + vm.ctx.int_type(), |
| 145 | + )) |
| 146 | + } else { |
| 147 | + Err(vm.new_index_error("range object index out of range".to_string())) |
| 148 | + } |
| 149 | + } |
| 150 | + PyObjectPayload::Slice { start, stop, step } => { |
| 151 | + let new_start = if let Some(int) = start { |
| 152 | + if let Some(i) = zrange.get(int.into()) { |
| 153 | + i as i64 |
| 154 | + } else { |
| 155 | + zrange.start |
| 156 | + } |
| 157 | + } else { |
| 158 | + zrange.start |
| 159 | + }; |
| 160 | + |
| 161 | + let new_end = if let Some(int) = stop { |
| 162 | + if let Some(i) = zrange.get(int.into()) { |
| 163 | + i as i64 |
| 164 | + } else { |
| 165 | + zrange.end |
| 166 | + } |
| 167 | + } else { |
| 168 | + zrange.end |
| 169 | + }; |
| 170 | + |
| 171 | + let new_step = if let Some(int) = step { |
| 172 | + (int as i64) * zrange.step |
| 173 | + } else { |
| 174 | + zrange.step |
| 175 | + }; |
| 176 | + |
| 177 | + Ok(PyObject::new( |
| 178 | + PyObjectPayload::Range { |
| 179 | + range: RangeType { |
| 180 | + start: new_start, |
| 181 | + end: new_end, |
| 182 | + step: new_step, |
| 183 | + }, |
| 184 | + }, |
| 185 | + vm.ctx.range_type(), |
| 186 | + )) |
| 187 | + } |
| 188 | + |
| 189 | + _ => Err(vm.new_type_error("range indices must be integer or slice".to_string())), |
| 190 | + } |
| 191 | +} |
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