Fix elements being enclosed when not needed

Cargo.toml

@@ -2,7 +2,7 @@
 name = "asciimath-rs"
 description = "AsciiMath parser"
 repository = "https://github.com/trivernis/asciimath-rs"
-version = "0.4.5"
+version = "0.4.6"
 authors = ["trivernis <trivernis@protonmail.com>"]
 edition = "2018"
 readme = "README.md"

src/elements/group.rs

@@ -14,6 +14,7 @@ pub enum Group {
     Norm(Norm),
     Matrix(Matrix),
     Vector(Vector),
+    NonEnclosed(NonEnclosed),
 }
 
 #[derive(Debug, Clone, PartialOrd, PartialEq)]
@@ -70,3 +71,24 @@ pub struct Matrix {
 pub struct Vector {
     pub inner: Vec<Vec<Expression>>,
 }
+
+#[derive(Debug, Clone, PartialOrd, PartialEq)]
+pub struct NonEnclosed {
+    pub inner: Box<Expression>,
+}
+
+impl Group {
+    pub(crate) fn to_non_enclosed(&self) -> Option<Self> {
+        let inner = match self {
+            Group::Parentheses(p) => Some(p.inner.clone()),
+            Group::Braces(b) => Some(b.inner.clone()),
+            Group::Brackets(b) => Some(b.inner.clone()),
+            _ => None,
+        };
+        if let Some(inner) = inner {
+            Some(Group::NonEnclosed(NonEnclosed { inner }))
+        } else {
+            None
+        }
+    }
+}

src/format/mathml.rs

@@ -1,6 +1,7 @@
 use crate::elements::accent::{Color, ExpressionAccent, GenericAccent, OverSet, UnderSet};
 use crate::elements::group::{
-    Abs, Angles, Braces, Brackets, Ceil, Floor, Group, Matrix, Norm, Parentheses, Vector, XGroup,
+    Abs, Angles, Braces, Brackets, Ceil, Floor, Group, Matrix, NonEnclosed, Norm, Parentheses,
+    Vector, XGroup,
 };
 use crate::elements::literal::{Literal, Number, PlainText, Symbol};
 use crate::elements::special::{
@@ -382,6 +383,7 @@ impl ToMathML for Group {
             Group::Ceil(c) => c.to_mathml(),
             Group::Norm(n) => n.to_mathml(),
             Group::Matrix(m) => m.to_mathml(),
+            Group::NonEnclosed(ne) => ne.to_mathml(),
         }
     }
 }
@@ -501,6 +503,12 @@ impl ToMathML for Vector {
     }
 }
 
+impl ToMathML for NonEnclosed {
+    fn to_mathml(&self) -> String {
+        format!("<mrow>{}</mrow>", self.inner.to_mathml())
+    }
+}
+
 impl ToMathML for Special {
     fn to_mathml(&self) -> String {
         match self {

src/parsing/tree_parser.rs

@@ -400,6 +400,11 @@ impl TreeParser {
             self.step();
             self.step();
             if let Some(element) = self.parse_element() {
+                if let Element::Group(g) = &element {
+                    if let Some(ne) = g.to_non_enclosed() {
+                        return Some(Element::Group(ne).boxed());
+                    }
+                }
                 Some(element.boxed())
             } else {
                 None
@@ -414,6 +419,11 @@ impl TreeParser {
             self.step();
             self.step();
             if let Some(element) = self.parse_element() {
+                if let Element::Group(g) = &element {
+                    if let Some(ne) = g.to_non_enclosed() {
+                        return Some(Element::Group(ne).boxed());
+                    }
+                }
                 Some(element.boxed())
             } else {
                 None