add a few tests for monomials and polynomials ops

src/bin/flat.rs

@@ -7,9 +7,20 @@ fn main() {
         + (3 * ((var!("x", 1, 9) ^ 5) * (var!("x", 1, 2) ^ 5) * (var!("x", 2, 5) ^ 1)));
 
     let x = var!("x");
-    let y = var!("y");
+    let y = var!("x\u{0304}");
+    let z = var!("z");
     let other = -3 * ((&x ^ 2) * (&y ^ 4));
 
+    let mono = (&x^2)*(&y^4);
+
+    let inside = (&x^2)*(&y^2)*(&z^1);
+
+    if mono.contains(&inside){
+        println!("{inside}\u{2286}{mono}");
+    }else{
+        println!("{inside}\u{2284}{mono}");
+    }
+
     println!("{poly}");
 
     let z = poly - other;

src/fmt.rs

@@ -0,0 +1,34 @@
+
+pub fn num_to_subscript(s:String)->String{
+    s.chars().map(|c| match c{
+        '0'=>'\u{2080}',
+        '1'=>'\u{2081}',
+        '2'=>'\u{2082}',
+        '3'=>'\u{2083}',
+        '4'=>'\u{2084}',
+        '5'=>'\u{2085}',
+        '6'=>'\u{2086}',
+        '7'=>'\u{2087}',
+        '8'=>'\u{2088}',
+        '9'=>'\u{2089}',
+        _=>c
+    }).collect()
+}
+
+pub fn num_to_superscript(s:String)->String{
+    s.chars().map(|c| match c{
+        '0'=>'\u{2070}',
+        '1'=>'\u{20B9}',
+        '2'=>'\u{00B2}',
+        '3'=>'\u{00B3}',
+        '4'=>'\u{2074}',
+        '5'=>'\u{2075}',
+        '6'=>'\u{2076}',
+        '7'=>'\u{2077}',
+        '8'=>'\u{2078}',
+        '9'=>'\u{2079}',
+        _=>c
+    }).collect()
+}
+
+

src/lib.rs

@@ -1 +1,2 @@
 pub mod poly;
+pub mod fmt;

src/poly/flat.rs

@@ -1,12 +1,13 @@
 use itertools::Itertools;
 use std::fmt::{self, Display};
 
-use std::ops::{Add, Sub, BitXor, Mul};
+use std::ops::{Add, BitXor, Mul, Sub};
 
 use super::var::{StaticVar, Var};
+use crate::fmt::num_to_superscript;
 use std::collections::HashMap;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Poly<V: Var> {
     mono: HashMap<Mono<V>, i32>,
 }
@@ -57,6 +58,33 @@ pub struct Mono<V: Var> {
     pub term: Vec<(V, u32)>,
 }
 
+impl<V: Var> Mono<V> {
+    pub fn contains(&self, other: &Mono<V>) -> bool {
+        let mut self_it = self.term.iter().peekable();
+        let mut other_it = other.term.iter().peekable();
+
+        while let Some((o_term, o_exp)) = other_it.peek() {
+            if let Some((s_term, s_exp)) = self_it.peek() {
+                if s_term < o_term {
+                    self_it.next();
+                    continue;
+                } else if s_term > o_term {
+                    return false;
+                } else if o_exp <= s_exp {
+                    self_it.next();
+                    other_it.next();
+                } else {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        }
+
+        true
+    }
+}
+
 impl<V: Var, T: IntoIterator> From<T> for Mono<V>
 where
     Mono<V>: FromIterator<<T as IntoIterator>::Item>,
@@ -75,11 +103,9 @@ impl<V: Var, U: Into<V>> FromIterator<(U, u32)> for Mono<V> {
         term.sort();
 
         // Check duplicate variables
-        assert!(
-            (term[..])
+        assert!((term[..])
             .windows(2)
-                .all(|window| window[0].0 != window[1].0)
-        );
+            .all(|window| window[0].0 != window[1].0));
 
         Mono { term }
     }
@@ -94,7 +120,7 @@ impl<V: Var> Display for Mono<V> {
                 .iter()
                 .map(|(t, p)| match p {
                     1 => format!("{t}"),
-                    _ => format!("{t}^{p}"),
+                    _ => format!("{t}{}", num_to_superscript(p.to_string())),
                 })
                 .join("")
         )
@@ -194,3 +220,107 @@ impl<V: Var> Sub for Poly<V> {
         self
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_mono_contains() {
+        let a: Mono<StaticVar> = [("x", 2), ("y", 1)].into();
+
+        // Lower exponent of same variable is contained
+        assert!(a.contains(&Mono::from([("x", 1)])));
+
+        // Higher exponent of same variable is not contained
+        assert!(!a.contains(&Mono::from([("x", 3)])));
+
+        // Identical monomial is contained
+        assert!(a.contains(&Mono::from([("x", 2), ("y", 1)])));
+
+        // Variable absent from self is not contained
+        assert!(!a.contains(&Mono::from([("x", 2), ("z", 1)])));
+
+        // Subset of variables with lower exponents is contained
+        assert!(a.contains(&Mono::from([("x", 1), ("y", 1)])));
+
+        // Single variable with exact exponent is contained
+        assert!(a.contains(&Mono::from([("x", 2)])));
+
+        // Insufficient exponent in self means not contained
+        assert!(!Mono::<StaticVar>::from([("x", 1)]).contains(&Mono::from([("x", 2)])));
+
+        // Missing variable in self means not contained
+        assert!(!Mono::<StaticVar>::from([("x", 1), ("y", 1)]).contains(&Mono::from([("x", 2)])));
+        assert!(!Mono::<StaticVar>::from([("x", 1)]).contains(&Mono::from([("x", 1), ("y", 1)])));
+    }
+
+    #[test]
+    fn test_mono_mul() {
+        // Same variable: exponents add
+        let a: Mono<StaticVar> = [("x", 2)].into();
+        let b: Mono<StaticVar> = [("x", 3)].into();
+        assert_eq!(a * b, Mono::from([("x", 5)]));
+
+        // Disjoint variables: both appear in result
+        let a: Mono<StaticVar> = [("x", 2)].into();
+        let b: Mono<StaticVar> = [("y", 3)].into();
+        assert_eq!(a * b, Mono::from([("x", 2), ("y", 3)]));
+
+        // Mixed: shared and disjoint variables
+        let a: Mono<StaticVar> = [("x", 1), ("y", 2)].into();
+        let b: Mono<StaticVar> = [("y", 1), ("z", 3)].into();
+        assert_eq!(a * b, Mono::from([("x", 1), ("y", 3), ("z", 3)]));
+
+        // Commutativity
+        let a: Mono<StaticVar> = [("x", 2), ("z", 1)].into();
+        let b: Mono<StaticVar> = [("y", 3)].into();
+        assert_eq!(a.clone() * b.clone(), b * a);
+
+        // Multiply by constant monomial (empty term vec = 1)
+        let a: Mono<StaticVar> = [("x", 4)].into();
+        let one: Mono<StaticVar> = Mono { term: vec![] };
+        assert_eq!(a.clone() * one, a);
+    }
+
+    #[test]
+    fn test_poly_add() {
+        // Distinct monomials are collected as separate terms
+        let a: Poly<StaticVar> = [(1, [("x", 2)]), (2, [("y", 1)])].into();
+        let b: Poly<StaticVar> = [(3, [("z", 1)])].into();
+        let expected: Poly<StaticVar> = [(1, [("x", 2)]), (2, [("y", 1)]), (3, [("z", 1)])].into();
+        assert_eq!(a + b, expected);
+
+        // Coefficients of matching monomials are summed
+        let a: Poly<StaticVar> = [(2, [("x", 1)])].into();
+        let b: Poly<StaticVar> = [(3, [("x", 1)])].into();
+        let expected: Poly<StaticVar> = [(5, [("x", 1)])].into();
+        assert_eq!(a + b, expected);
+
+        // Terms that cancel sum to zero are dropped
+        let a: Poly<StaticVar> = [(1, [("x", 1)])].into();
+        let b: Poly<StaticVar> = [(-1, [("x", 1)])].into();
+        let expected: Poly<StaticVar> = Poly::default();
+        assert_eq!(a + b, expected);
+    }
+
+    #[test]
+    fn test_poly_sub() {
+        // Distinct monomials are collected as separate terms with negated rhs coefficients
+        let a: Poly<StaticVar> = [(3, [("x", 2)])].into();
+        let b: Poly<StaticVar> = [(1, [("y", 1)])].into();
+        let expected: Poly<StaticVar> = [(3, [("x", 2)]), (-1, [("y", 1)])].into();
+        assert_eq!(a - b, expected);
+
+        // Coefficients of matching monomials are subtracted
+        let a: Poly<StaticVar> = [(5, [("x", 1)])].into();
+        let b: Poly<StaticVar> = [(3, [("x", 1)])].into();
+        let expected: Poly<StaticVar> = [(2, [("x", 1)])].into();
+        assert_eq!(a - b, expected);
+
+        // Subtracting equal polynomials yields zero
+        let a: Poly<StaticVar> = [(4, [("x", 2)]), (1, [("y", 1)])].into();
+        let b: Poly<StaticVar> = [(4, [("x", 2)]), (1, [("y", 1)])].into();
+        assert_eq!(a - b, Poly::default());
+    }
+}

src/poly/var.rs

@@ -2,6 +2,8 @@ use itertools::Itertools;
 use std::fmt::{self, Debug, Display, Formatter};
 use std::hash::Hash;
 
+use crate::fmt::num_to_subscript;
+
 #[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct StaticVar {
     name: &'static str,
@@ -15,7 +17,7 @@ impl Display for StaticVar {
         let num_indices = self.indices.len();
         match num_indices {
             0 => write!(fmt, "{}", self.name),
-            _ => write!(fmt, "{}_{{{}}}", self.name, self.indices.iter().join(",")),
+            _ => write!(fmt, "{}{}", self.name, self.indices.iter().map(|x| num_to_subscript(x.to_string())).join(",")),
         }
     }
 }