From bb48a09cc7208d8f294cf63b4f8ede56454fc27f Mon Sep 17 00:00:00 2001
From: Mark <mark@betalupi.com>
Date: Sat, 1 Apr 2023 14:20:11 -0700
Subject: [PATCH] Added decimal -> rational parsing

---
 src/parser/mod.rs         | 18 ++++++++++--------
 src/quantity/quantity.rs  | 26 +++++++++++++++++++++++++-
 src/quantity/rationalq.rs |  5 +++++
 3 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 2f09658..8fae8d1 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -73,19 +73,21 @@ impl PreToken {
 	pub fn to_token(self) -> Result<Token, (LineLocation, ParserError)>{
 		match self {
 			PreToken::PreNumber(l, s) => {
-				let n: f64 = match s.parse() {
-					Ok(n) => n,
-					Err(_) => return Err((l, ParserError::BadNumber))
-				};
-				return Ok(Token::Number(Quantity::new_rational_from_f64(n).unwrap()));
+
+				let r = Quantity::new_rational_from_float_string(&s);
+				if r.is_none() {
+					return Err((l, ParserError::BadNumber))
+				}
+				return Ok(Token::Number(r.unwrap()));
 			},
+
 			PreToken::PreWord(l, s) => {
 				return Ok(match &s[..] {
 					// Mathematical constants
 					// 100 digits of each.
-					"π"|"pi" => { Token::Constant(Quantity::float_from_string("3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067"), String::from("π")) },
-					"e" => { Token::Constant(Quantity::float_from_string("2.7182818284590452353602874713526624977572470936999595749669676277240766303535475945713 8217852516642"), String::from("e")) },
-					"phi"|"φ" => { Token::Constant(Quantity::float_from_string("1.618033988749894848204586834365638117720309179805762862135448622705260462818902449707207204189391137"), String::from("φ")) },
+					"π"|"pi" => { Token::Constant(Quantity::new_float_from_string("3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067"), String::from("π")) },
+					"e" => { Token::Constant(Quantity::new_float_from_string("2.7182818284590452353602874713526624977572470936999595749669676277240766303535475945713 8217852516642"), String::from("e")) },
+					"phi"|"φ" => { Token::Constant(Quantity::new_float_from_string("1.618033988749894848204586834365638117720309179805762862135448622705260462818902449707207204189391137"), String::from("φ")) },
 
 					_ => { return Err((l, ParserError::Undefined(s))); }
 				});
diff --git a/src/quantity/quantity.rs b/src/quantity/quantity.rs
index d8d67f3..80d3578 100644
--- a/src/quantity/quantity.rs
+++ b/src/quantity/quantity.rs
@@ -101,7 +101,7 @@ impl Quantity {
 		}
 	}
 
-	pub fn float_from_string(s: &str) -> Quantity {
+	pub fn new_float_from_string(s: &str) -> Quantity {
 		let v = Float::parse(s);
 		return Quantity::Float {
 			v: Float::with_val(FLOAT_PRECISION, v.unwrap())
@@ -115,6 +115,12 @@ impl Quantity {
 		}
 	}
 
+	pub fn new_rational_from_string(s: &str) -> Quantity {
+		return Quantity::Rational {
+			v: RationalQ::from_string(s)
+		}
+	}
+
 	pub fn new_rational_from_f64(f: f64) -> 
 	Option<Quantity> {
 		let r = RationalQ::from_f64(f);
@@ -128,6 +134,24 @@ impl Quantity {
 		}
 	}
 
+	pub fn new_rational_from_float_string(s: &str) -> Option<Quantity> {
+
+		let mut q = s.split(".");
+		let a = q.next().unwrap();
+		let b = q.next();
+		let b = if b.is_some() {b.unwrap()} else {""};
+
+		// Error conditions
+		if {
+			q.next().is_some() || // We should have at most one `.`
+			a.len() == 0 // We need something in the numerator
+		} { return None; }
+
+		return Some(Quantity::new_rational_from_string(
+			&format!("{a}{b}/1{}", "0".repeat(b.len()))
+		));
+	}
+
 	pub fn to_float(&self) -> Float {
 		match self {
 			Quantity::Float { v } => {v.clone()},
diff --git a/src/quantity/rationalq.rs b/src/quantity/rationalq.rs
index e998034..01d789a 100644
--- a/src/quantity/rationalq.rs
+++ b/src/quantity/rationalq.rs
@@ -63,6 +63,11 @@ impl RationalQ {
 		return Some(RationalQ{ val: v.unwrap() });
 	}
 
+	pub fn from_string(s: &str) -> RationalQ {
+		let v = Rational::from_str_radix(s, 10);
+		return RationalQ{ val: v.unwrap() };
+	}
+
 	pub fn to_float(&self) -> Float {
 		Float::with_val(FLOAT_PRECISION, self.val.numer()) /
 		Float::with_val(FLOAT_PRECISION, self.val.denom())