Fix them rounding errors!

asklyphe-frontend/src/math.rs

@@ -1,5 +1,15 @@
 use tracing::{debug, error};
 use once_cell::sync::Lazy;
+use astro_float::{BigFloat, Sign, RoundingMode, Consts};
+use std::str::FromStr;
+use std::sync::{Arc, Mutex};
+use std::mem;
+
+pub const PRECISION: usize = 2048;
+static CONST_CACHE: Lazy<Arc<Mutex<Consts>>> = Lazy::new(|| Arc::new(Mutex::new(Consts::new().expect("Unable to allocate memory for Conts cache"))));
+// static PI: Lazy<BigFloat> = Lazy::new(|| BigFloat::from_str("3.141592653589793238462643383279").unwrap());
+// static E: Lazy<BigFloat> = Lazy::new(|| BigFloat::from_str("2.718281828459045235360287471352").unwrap());
+
 
 #[derive(Debug)]
 pub struct Calculation {
@@ -10,21 +20,22 @@ pub struct Calculation {
 pub fn calculate(query: &str) -> Option<Calculation> {
 	debug!("Got query {}", query);
 	let mut parser = Parser::new(Lexer::new(query));
-	let tree = parser.parse()?;
+	let mut tree = parser.parse()?;
 	let res = tree.eval();
+	let res_float = f64::from_str(&format!("{}", res)).unwrap();
 
 	debug!("Calculation: {}", query);
 	debug!("Tree: {:?}", tree);
-	debug!("Result: {}", res);
-	Some(Calculation {equation: query.to_string(), result: res.to_string()})
+	debug!("Result: {:?}", res_float);
+	Some(Calculation {equation: query.to_string(), result: res_float.to_string()})
 }
 
-// TODO: put into own crate with dependency astro-float = "0.9.2" so I can use more than f64
-#[derive(Debug, Copy, Clone, PartialEq)]
+// TODO: put into own crate with dependency astro-float = "0.9.2" so I can use more than BigFloat
+#[derive(Debug, Clone, PartialEq)]
 enum Token {
 	Op(Op),
 	Atom(Atom),
-/*	Number(f64),
+/*	Number(BigFloat),
 	Func(Func),*/
 }
 
@@ -64,67 +75,93 @@ impl Op {
 		}
 	}
 
-	fn apply_to(&self, args: &Vec<Expr>) -> f64 {
+	fn apply_to(&self, args: &mut Vec<Expr>) -> BigFloat {
 		match args.len() {
 			1 => match self {
-				Op::Subtract => Some(0.0 - args[0].eval()),
-				Op::Add => Some(args[0].eval().abs()),
-				Op::Func(f) => match f {
-					Func::Sine => Some(args[0].eval().sin()),
-					Func::Cosine => Some(args[0].eval().cos()),
-					Func::Tangent => Some(args[0].eval().tan()),
-					Func::ArcSine => Some(args[0].eval().asin()),
-					Func::ArcCosine => Some(args[0].eval().acos()),
-					Func::ArcTangent => Some(args[0].eval().atan()),
-					Func::Log2 => Some(args[0].eval().log2()),
-					Func::Log10 => Some(args[0].eval().log10()),
-					Func::LogN => Some(args[0].eval().ln()),
-					Func::Square => Some(args[0].eval().powf(2.0)),
-					Func::SquareRoot => Some(args[0].eval().sqrt()),
-					Func::Abs => Some(args[0].eval().abs()),
-					Func::Log => None,
-					// _ => todo!("{:?}", self)
+				Op::Subtract => {
+					let mut res = args[0].eval();
+					res.set_sign(Sign::Neg);
+					res
+				},
+				Op::Add => {
+					let mut res = args[0].eval();
+					res.set_sign(Sign::Pos);
+					res
 				}
-				_ => None,
+				Op::Func(f) => match f {
+					Func::Sine => args[0].eval().sin(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::Cosine => args[0].eval().cos(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::Tangent => args[0].eval().tan(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::ArcSine => args[0].eval().asin(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::ArcCosine => args[0].eval().acos(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::ArcTangent => args[0].eval().atan(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::Log2 => args[0].eval().log2(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::Log10 => args[0].eval().log10(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::LogN => args[0].eval().ln(PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::Square => args[0].eval().pow(&BigFloat::from_f64(2.0, PRECISION), PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+					Func::SquareRoot => args[0].eval().sqrt(PRECISION, RoundingMode::None),
+					Func::Abs => args[0].eval().abs(),
+					_ => {
+						error!("Got 1 params for func {:?} which expects 2 (should not be possible)", self);
+						astro_float::NAN
+					},
+				},
+				_ => {
+					error!("Got 1 params for {:?} which expects 2 (should not be possible)", self);
+					astro_float::NAN
+				},
 			}
 			2 => match self {
-				Op::LParen => Some(args[0].eval()),
-				Op::RParen => Some(args[0].eval()),
-				Op::Add => Some(args[0].eval() + args[1].eval()),
-				Op::Subtract => Some(args[0].eval() - args[1].eval()),
-				Op::Multiply => Some(args[0].eval() * args[1].eval()),
-				Op::Divide => Some(args[0].eval() / args[1].eval()),
-				Op::Exponent => Some(args[0].eval().powf(args[1].eval())),
-				Op::Func(Func::Log) => Some(args[0].eval().log(args[1].eval())),
-				_ => None,
+				Op::LParen => args[0].eval(),
+				Op::RParen => args[0].eval(),
+				Op::Add => args[0].eval().add(&mut args[1].eval(), PRECISION, RoundingMode::None),
+				Op::Subtract => args[0].eval().sub(&mut args[1].eval(), PRECISION, RoundingMode::None),
+				Op::Multiply => args[0].eval().mul(&mut args[1].eval(), PRECISION, RoundingMode::None),
+				Op::Divide => args[0].eval().div(&mut args[1].eval(), PRECISION, RoundingMode::None),
+				Op::Exponent => args[0].eval().pow(&mut args[1].eval(), PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+				Op::Func(Func::Log) => args[0].eval().log(&mut args[1].eval(), PRECISION, RoundingMode::None, &mut CONST_CACHE.lock().unwrap()),
+				_ => {
+					error!("Got 2 params for {:?} which only expects 1 (should not be possible)", self);
+					astro_float::NAN
+				},
 			}
-			_ => None,
-		}.unwrap_or_else(|| {
-			error!("ERROR when evaluating maths expression, got invalid number of args ({}) for {:?}", args.len(), self);
-			// None
-			f64::NAN
-		})
+			_ => {
+				error!("Unexpected number of params ({}) for {:?} (should not be possible)", args.len(), self);
+				astro_float::NAN
+			},
+		}
 	}
 }
 
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 enum Atom {
-	Number(f64), // TODO: use the high precision floats library instead
+	Number(BigFloat),
 	Const(Const),
 }
 
-impl Atom {
-	fn get_val(&self) -> f64 {
+/*impl Atom {
+	fn get_val(&self) -> BigFloat {
 		match self {
 			Atom::Number(val) => *val,
 			Atom::Const(c) => match c {
-				Const::Pi => 3.141592653589793238462643383279,
-				Const::E => 2.718281828459045235360287471352,
-				Const::Inf => f64::INFINITY,
-				Const::Nan => f64::NAN,
+				Const::Pi => CONST_CACHE.lock().unwrap().pi(PRECISION, RoundingMode::None),
+				Const::E => CONST_CACHE.lock().unwrap().e(PRECISION, RoundingMode::None),
+				Const::Inf => astro_float::INF_POS,
+				Const::Nan => astro_float::NAN,
 			}
 		}
 	}
+}*/
+
+impl Const {
+	fn get_val(&self) -> BigFloat {
+		match self {
+			Const::Pi => CONST_CACHE.lock().unwrap().pi(PRECISION, RoundingMode::None),
+			Const::E => CONST_CACHE.lock().unwrap().e(PRECISION, RoundingMode::None),
+			Const::Inf => astro_float::INF_POS,
+			Const::Nan => astro_float::NAN,
+		}
+	}
 }
 
 #[derive(Debug, Copy, Clone, PartialEq)]
@@ -270,13 +307,14 @@ impl Lexer<'_> {
 	}
 
 	fn next(&mut self) -> Result<Token, ParseErr> {
-		let val = self.next_tok;
-		self.next_tok = self._next();
+		let res = self._next();
+		let val = mem::replace(&mut self.next_tok, res);
+		// self.next_tok = self._next();
 		val
 	}
 
-	fn peek(&mut self) -> Result<Token, ParseErr> {
-		self.next_tok
+	fn peek(&mut self) -> &Result<Token, ParseErr> {
+		&self.next_tok
 	}
 
 	// TODO: replace with iterator so I can do parser.parse(lexer.iter()) and parse does lex_iter.next() & such
@@ -348,14 +386,14 @@ impl Parser<'_> {
 			debug!("loop start");
 			let op: Op = match self.lex.peek() {
 				Err(ParseErr::Eof) => break,
-				Err(e) => { debug!("In expr got err {:?}", e); Err(e) },
+				Err(e) => { debug!("In expr got err {:?}", e); Err(*e) },
 				Ok(tok) => match tok {
 					Token::Op(op) => match op {
 						Op::RParen => {
 							debug!("got RParen");
 							break;
 						},
-						_ => Ok(op),
+						_ => Ok(*op),
 					}
 					v => { debug!("Got unexpected token {:?}", v); Err(ParseErr::Invalid) },
 				}
@@ -378,15 +416,31 @@ impl Parser<'_> {
 
 #[derive(Debug)]
 enum Expr {
+	Evaluated,
 	Atom(Atom),
 	Node(Op, Vec<Expr>),
 }
 
 impl Expr {
-	fn eval(&self) -> f64 {
-		let res = match (self) {
-			Expr::Atom(at) => at.get_val(),
-			Expr::Node(op, exprs) => op.apply_to(exprs),
+	fn eval(&mut self) -> BigFloat {
+		let res = match self {
+			Expr::Atom(_) => {
+				let v = mem::replace(self, Expr::Evaluated);
+				if let Expr::Atom(at) = v {
+					match at {
+						Atom::Number(n) => n,
+						Atom::Const(c) => c.get_val(),
+					}
+				} else {
+					unreachable!();
+				}
+				// at.get_val()
+			}
+			Expr::Node(op, exprs) => {
+				*self = Expr::Atom(Atom::Number(op.apply_to(exprs)));
+				self.eval()
+			}
+			Expr::Evaluated => unreachable!("Tried to evaluate an already evaluated node"),
 		};
 		// debug!("{:?} evaluated to {}", self, res);
 		res