Fix parsing of function

Cargo.toml

@@ -2,7 +2,7 @@
 name = "asciimath-rs"
 description = "AsciiMath parser"
 repository = "https://github.com/trivernis/asciimath-rs"
-version = "0.5.1"
+version = "0.5.2"
 authors = ["trivernis <trivernis@protonmail.com>"]
 edition = "2018"
 readme = "README.md"

src/lib.rs

@@ -311,22 +311,26 @@ mod tests {
     #[test]
     fn it_parses_vectors() {
         assert_eq!(
-            parse("((1), (2))".to_string()),
+            parse("((1), (2)) - f".to_string()),
             Expression {
-                children: vec![Element::Group(Group::Vector(Vector {
-                    inner: vec![
-                        vec![Expression {
-                            children: vec![Element::Literal(Literal::Number(Number {
-                                number: "1".to_string()
-                            }))]
-                        }],
-                        vec![Expression {
-                            children: vec![Element::Literal(Literal::Number(Number {
-                                number: "2".to_string()
-                            }))]
-                        }]
-                    ]
-                }))]
+                children: vec![
+                    Element::Group(Group::Vector(Vector {
+                        inner: vec![
+                            vec![Expression {
+                                children: vec![Element::Literal(Literal::Number(Number {
+                                    number: "1".to_string()
+                                }))]
+                            }],
+                            vec![Expression {
+                                children: vec![Element::Literal(Literal::Number(Number {
+                                    number: "2".to_string()
+                                }))]
+                            }]
+                        ]
+                    })),
+                    Element::Literal(Literal::Operation(Operation::Minus)),
+                    Element::Literal(Literal::Function(Function::F))
+                ]
             }
         );
         assert_eq!(

src/parsing/tree_parser.rs

@@ -101,6 +101,7 @@ impl TreeParser {
             Token::Logical(l) => Some(Element::Literal(Literal::Logical(l.clone()))),
             Token::Relation(r) => Some(Element::Literal(Literal::Relation(r.clone()))),
             Token::Greek(g) => Some(Element::Literal(Literal::Greek(g.clone()))),
+            Token::Function(f) => Some(Element::Literal(Literal::Function(f.clone()))),
             Token::Text(t) => {
                 if let Some(literal) = self.parse_text(t) {
                     Some(Element::Literal(literal))