surrealdb_sql/
constant.rs

1use crate::ctx::Context;
2use crate::dbs::{Options, Transaction};
3use crate::doc::CursorDoc;
4use crate::err::Error;
5use crate::value::Value;
6use crate::Datetime;
7use chrono::TimeZone;
8use chrono::Utc;
9use derive::Store;
10use revision::revisioned;
11use serde::{Deserialize, Serialize};
12use std::fmt;
13
14pub(crate) const TOKEN: &str = "$surrealdb::private::crate::Constant";
15
16#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Serialize, Deserialize, Store, Hash)]
17#[serde(rename = "$surrealdb::private::crate::Constant")]
18#[revisioned(revision = 1)]
19pub enum Constant {
20	MathE,
21	MathFrac1Pi,
22	MathFrac1Sqrt2,
23	MathFrac2Pi,
24	MathFrac2SqrtPi,
25	MathFracPi2,
26	MathFracPi3,
27	MathFracPi4,
28	MathFracPi6,
29	MathFracPi8,
30	MathInf,
31	MathLn10,
32	MathLn2,
33	MathLog102,
34	MathLog10E,
35	MathLog210,
36	MathLog2E,
37	MathPi,
38	MathSqrt2,
39	MathTau,
40	TimeEpoch,
41	// Add new variants here
42}
43
44/// A type of constant that may be converted to a value or JSON.
45pub(crate) enum ConstantValue {
46	Float(f64),
47	Datetime(Datetime),
48}
49
50impl Constant {
51	pub(crate) fn value(&self) -> ConstantValue {
52		use std::f64::consts as f64c;
53		match self {
54			Self::MathE => ConstantValue::Float(f64c::E),
55			Self::MathFrac1Pi => ConstantValue::Float(f64c::FRAC_1_PI),
56			Self::MathFrac1Sqrt2 => ConstantValue::Float(f64c::FRAC_1_SQRT_2),
57			Self::MathFrac2Pi => ConstantValue::Float(f64c::FRAC_2_PI),
58			Self::MathFrac2SqrtPi => ConstantValue::Float(f64c::FRAC_2_SQRT_PI),
59			Self::MathFracPi2 => ConstantValue::Float(f64c::FRAC_PI_2),
60			Self::MathFracPi3 => ConstantValue::Float(f64c::FRAC_PI_3),
61			Self::MathFracPi4 => ConstantValue::Float(f64c::FRAC_PI_4),
62			Self::MathFracPi6 => ConstantValue::Float(f64c::FRAC_PI_6),
63			Self::MathFracPi8 => ConstantValue::Float(f64c::FRAC_PI_8),
64			Self::MathInf => ConstantValue::Float(f64::INFINITY),
65			Self::MathLn10 => ConstantValue::Float(f64c::LN_10),
66			Self::MathLn2 => ConstantValue::Float(f64c::LN_2),
67			Self::MathLog102 => ConstantValue::Float(f64c::LOG10_2),
68			Self::MathLog10E => ConstantValue::Float(f64c::LOG10_E),
69			Self::MathLog210 => ConstantValue::Float(f64c::LOG2_10),
70			Self::MathLog2E => ConstantValue::Float(f64c::LOG2_E),
71			Self::MathPi => ConstantValue::Float(f64c::PI),
72			Self::MathSqrt2 => ConstantValue::Float(f64c::SQRT_2),
73			Self::MathTau => ConstantValue::Float(f64c::TAU),
74			Self::TimeEpoch => ConstantValue::Datetime(Datetime(Utc.timestamp_nanos(0))),
75		}
76	}
77	/// Process this type returning a computed simple Value
78	pub(crate) async fn compute(
79		&self,
80		_ctx: &Context<'_>,
81		_opt: &Options,
82		_txn: &Transaction,
83		_doc: Option<&CursorDoc<'_>>,
84	) -> Result<Value, Error> {
85		Ok(match self.value() {
86			ConstantValue::Datetime(d) => d.into(),
87			ConstantValue::Float(f) => f.into(),
88		})
89	}
90}
91
92impl fmt::Display for Constant {
93	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
94		f.write_str(match self {
95			Self::MathE => "math::E",
96			Self::MathFrac1Pi => "math::FRAC_1_PI",
97			Self::MathFrac1Sqrt2 => "math::FRAC_1_SQRT_2",
98			Self::MathFrac2Pi => "math::FRAC_2_PI",
99			Self::MathFrac2SqrtPi => "math::FRAC_2_SQRT_PI",
100			Self::MathFracPi2 => "math::FRAC_PI_2",
101			Self::MathFracPi3 => "math::FRAC_PI_3",
102			Self::MathFracPi4 => "math::FRAC_PI_4",
103			Self::MathFracPi6 => "math::FRAC_PI_6",
104			Self::MathFracPi8 => "math::FRAC_PI_8",
105			Self::MathInf => "math::INF",
106			Self::MathLn10 => "math::LN_10",
107			Self::MathLn2 => "math::LN_2",
108			Self::MathLog102 => "math::LOG10_2",
109			Self::MathLog10E => "math::LOG10_E",
110			Self::MathLog210 => "math::LOG2_10",
111			Self::MathLog2E => "math::LOG2_E",
112			Self::MathPi => "math::PI",
113			Self::MathSqrt2 => "math::SQRT_2",
114			Self::MathTau => "math::TAU",
115			Self::TimeEpoch => "time::EPOCH",
116		})
117	}
118}
surrealdb_sql/constant.rs

surrealdb_sql/
constant.rs
