okane_core/report/eval/
single_amount.rs

1use std::{
2    fmt::Display,
3    ops::{Mul, Neg},
4};
5
6use rust_decimal::Decimal;
7
8use crate::report::{commodity::Commodity, ReportContext};
9
10use super::error::EvalError;
11
12/// Amount with only one commodity.
13#[derive(Debug, PartialEq, Eq, Clone, Copy)]
14pub struct SingleAmount<'ctx> {
15    pub(crate) value: Decimal,
16    pub(crate) commodity: Commodity<'ctx>,
17}
18
19impl Neg for SingleAmount<'_> {
20    type Output = Self;
21
22    fn neg(self) -> Self::Output {
23        SingleAmount {
24            value: -self.value,
25            commodity: self.commodity,
26        }
27    }
28}
29
30impl Mul<Decimal> for SingleAmount<'_> {
31    type Output = Self;
32
33    fn mul(self, rhs: Decimal) -> Self::Output {
34        Self {
35            value: self.value * rhs,
36            commodity: self.commodity,
37        }
38    }
39}
40
41impl<'ctx> SingleAmount<'ctx> {
42    /// Constructs an instance with single commodity.
43    #[inline]
44    pub fn from_value(value: Decimal, commodity: Commodity<'ctx>) -> Self {
45        Self { value, commodity }
46    }
47
48    /// Adds the amount with keeping commodity single.
49    pub fn check_add(self, rhs: Self) -> Result<Self, EvalError> {
50        if self.commodity != rhs.commodity {
51            Err(EvalError::UnmatchingCommodities(
52                self.commodity.into(),
53                rhs.commodity.into(),
54            ))
55        } else {
56            Ok(Self {
57                value: self
58                    .value
59                    .checked_add(rhs.value)
60                    .ok_or(EvalError::NumberOverflow)?,
61                commodity: self.commodity,
62            })
63        }
64    }
65
66    /// Subtracts the amount with keeping the commodity single.
67    pub fn check_sub(self, rhs: Self) -> Result<Self, EvalError> {
68        self.check_add(-rhs)
69    }
70
71    /// Divides by given Decimal.
72    pub fn check_div(self, rhs: Decimal) -> Result<Self, EvalError> {
73        if rhs.is_zero() {
74            return Err(EvalError::DivideByZero);
75        }
76        Ok(Self {
77            value: self
78                .value
79                .checked_div(rhs)
80                .ok_or(EvalError::NumberOverflow)?,
81            commodity: self.commodity,
82        })
83    }
84
85    /// Returns an absolute value of the current value.
86    pub fn abs(self) -> Self {
87        Self {
88            value: self.value.abs(),
89            commodity: self.commodity,
90        }
91    }
92
93    /// Rounds the Amount with the given context provided precision.
94    pub fn round(self, ctx: &ReportContext) -> Self {
95        match ctx.commodities.get_decimal_point(self.commodity) {
96            None => self,
97            Some(dp) => Self {
98                value: self.value.round_dp_with_strategy(
99                    dp,
100                    rust_decimal::RoundingStrategy::MidpointNearestEven,
101                ),
102                commodity: self.commodity,
103            },
104        }
105    }
106
107    /// Returns a new instance with having the same sign with given SingleAmount.
108    pub(crate) fn with_sign_of(mut self, sign: Self) -> Self {
109        self.value.set_sign_positive(sign.value.is_sign_positive());
110        self
111    }
112}
113
114impl Display for SingleAmount<'_> {
115    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
116        write!(f, "{} {}", self.value, self.commodity.as_str())
117    }
118}
119
120#[cfg(test)]
121mod tests {
122    use super::*;
123
124    use bumpalo::Bump;
125    use pretty_assertions::assert_eq;
126    use rust_decimal_macros::dec;
127
128    use crate::{report::ReportContext, syntax::pretty_decimal::PrettyDecimal};
129
130    #[test]
131    fn neg_returns_negative_value() {
132        let arena = Bump::new();
133        let mut ctx = ReportContext::new(&arena);
134
135        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
136
137        assert_eq!(
138            SingleAmount::from_value(dec!(-5), jpy),
139            -SingleAmount::from_value(dec!(5), jpy)
140        );
141    }
142
143    #[test]
144    fn check_add_fails_different_commodity() {
145        let arena = Bump::new();
146        let mut ctx = ReportContext::new(&arena);
147
148        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
149        let chf = ctx.commodities.insert_canonical("CHF").unwrap();
150
151        assert_eq!(
152            Err(EvalError::UnmatchingCommodities(jpy.into(), chf.into())),
153            SingleAmount::from_value(dec!(10), jpy)
154                .check_add(SingleAmount::from_value(dec!(20), chf))
155        );
156    }
157
158    #[test]
159    fn check_add_succeeds() {
160        let arena = Bump::new();
161        let mut ctx = ReportContext::new(&arena);
162
163        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
164
165        assert_eq!(
166            SingleAmount::from_value(dec!(-10), jpy),
167            SingleAmount::from_value(dec!(10), jpy)
168                .check_add(SingleAmount::from_value(dec!(-20), jpy))
169                .unwrap()
170        );
171    }
172
173    #[test]
174    fn check_sub_fails_different_commodity() {
175        let arena = Bump::new();
176        let mut ctx = ReportContext::new(&arena);
177
178        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
179        let chf = ctx.commodities.insert_canonical("CHF").unwrap();
180
181        assert_eq!(
182            Err(EvalError::UnmatchingCommodities(jpy.into(), chf.into())),
183            SingleAmount::from_value(dec!(10), jpy)
184                .check_sub(SingleAmount::from_value(dec!(0), chf))
185        );
186    }
187
188    #[test]
189    fn check_sub_succeeds() {
190        let arena = Bump::new();
191        let mut ctx = ReportContext::new(&arena);
192
193        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
194
195        assert_eq!(
196            SingleAmount::from_value(dec!(5), jpy),
197            SingleAmount::from_value(dec!(10), jpy)
198                .check_sub(SingleAmount::from_value(dec!(5), jpy))
199                .unwrap()
200        );
201    }
202
203    #[test]
204    fn single_amount_to_string() {
205        let arena = Bump::new();
206        let mut ctx = ReportContext::new(&arena);
207
208        let usd = ctx.commodities.insert_canonical("USD").unwrap();
209
210        assert_eq!(
211            "1.20 USD".to_string(),
212            SingleAmount::from_value(dec!(1.20), usd).to_string()
213        );
214    }
215
216    #[test]
217    fn single_amount_round() {
218        let arena = Bump::new();
219        let mut ctx = ReportContext::new(&arena);
220        let jpy = ctx.commodities.ensure("JPY");
221        let eur = ctx.commodities.ensure("EUR");
222        let chf = ctx.commodities.ensure("CHF");
223
224        ctx.commodities
225            .set_format(jpy, PrettyDecimal::comma3dot(dec!(12345)));
226        ctx.commodities
227            .set_format(eur, PrettyDecimal::plain(dec!(123.45)));
228        ctx.commodities
229            .set_format(chf, PrettyDecimal::comma3dot(dec!(123.450)));
230
231        // as-is
232        assert_eq!(
233            SingleAmount::from_value(dec!(812), jpy),
234            SingleAmount::from_value(dec!(812), jpy).round(&ctx),
235        );
236        assert_eq!(
237            SingleAmount::from_value(dec!(-100.00), eur),
238            SingleAmount::from_value(dec!(-100.0), eur).round(&ctx),
239        );
240        assert_eq!(
241            SingleAmount::from_value(dec!(6.660), chf),
242            SingleAmount::from_value(dec!(6.66), chf).round(&ctx),
243        );
244
245        assert_eq!(
246            SingleAmount::from_value(dec!(812), jpy),
247            SingleAmount::from_value(dec!(812.5), jpy).round(&ctx),
248        );
249        assert_eq!(
250            SingleAmount::from_value(dec!(-100.02), eur),
251            SingleAmount::from_value(dec!(-100.015), eur).round(&ctx),
252        );
253        assert_eq!(
254            SingleAmount::from_value(dec!(6.666), chf),
255            SingleAmount::from_value(dec!(6.6665), chf).round(&ctx),
256        );
257    }
258
259    #[test]
260    fn with_sign_negative() {
261        let arena = Bump::new();
262        let mut ctx = ReportContext::new(&arena);
263
264        let jpy = ctx.commodities.insert_canonical("JPY").unwrap();
265        let eur = ctx.commodities.insert_canonical("EUR").unwrap();
266
267        let positive = SingleAmount::from_value(dec!(1000), jpy);
268        assert_eq!(
269            SingleAmount::from_value(dec!(15), eur),
270            SingleAmount::from_value(dec!(15), eur).with_sign_of(positive)
271        );
272        assert_eq!(
273            SingleAmount::from_value(dec!(0), eur),
274            SingleAmount::from_value(dec!(0), eur).with_sign_of(positive)
275        );
276        assert_eq!(
277            SingleAmount::from_value(dec!(15), eur),
278            SingleAmount::from_value(dec!(-15), eur).with_sign_of(positive)
279        );
280
281        let negative = SingleAmount::from_value(dec!(-1000), jpy);
282        assert_eq!(
283            SingleAmount::from_value(dec!(-15), eur),
284            SingleAmount::from_value(dec!(15), eur).with_sign_of(negative)
285        );
286        assert_eq!(
287            SingleAmount::from_value(dec!(0), eur),
288            SingleAmount::from_value(dec!(0), eur).with_sign_of(negative)
289        );
290        assert_eq!(
291            SingleAmount::from_value(dec!(-15), eur),
292            SingleAmount::from_value(dec!(-15), eur).with_sign_of(negative)
293        );
294    }
295}
okane_core/report/eval/single_amount.rs

okane_core/report/eval/
single_amount.rs
