Better node display

src/tree/display.rs

@@ -1,12 +1,117 @@
-use crate::Node;
+use crate::{Node, Operator};
 use std::fmt::{Display, Error, Formatter};
 
+fn write_binary(f: &mut Formatter, node: &Node, op: &str) -> Result<(), Error> {
+    write!(
+        f,
+        "({} {} {})",
+        node.children.get(0).ok_or(Error)?,
+        op,
+        node.children.get(1).ok_or(Error)?
+    )
+}
+
+fn write_unary(f: &mut Formatter, node: &Node, op: &str) -> Result<(), Error> {
+    write!(f, "{}{}", op, node.children.get(0).ok_or(Error)?,)
+}
+
+fn write_sequence(f: &mut Formatter, node: &Node, sep: &str) -> Result<(), Error> {
+    write!(f, "(")?;
+    for (i, c) in node.children.iter().enumerate() {
+        write!(f, "{}", c)?;
+        if i + 1 < node.children.len() {
+            write!(f, "{} ", sep)?;
+        }
+    }
+    write!(f, ")")
+}
+
 impl Display for Node {
     fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
-        self.operator.fmt(f)?;
-        for child in self.children() {
-            write!(f, " {}", child)?;
+        match &self.operator {
+            Operator::RootNode => {
+                for (i, c) in self.children.iter().enumerate() {
+                    write!(f, "{}", c)?;
+                    if i + 1 < self.children.len() {
+                        write!(f, " ")?;
+                    }
+                }
+                Ok(())
+            },
+            Operator::Add => write_binary(f, self, "+"),
+            Operator::Sub => write_binary(f, self, "-"),
+            Operator::Neg => write_unary(f, self, "-"),
+            Operator::Mul => write_binary(f, self, "*"),
+            Operator::Div => write_binary(f, self, "/"),
+            Operator::Mod => write_binary(f, self, "%"),
+            Operator::Exp => write_binary(f, self, "^"),
+            Operator::Eq => write_binary(f, self, "=="),
+            Operator::Neq => write_binary(f, self, "!="),
+            Operator::Gt => write_binary(f, self, ">"),
+            Operator::Lt => write_binary(f, self, "<"),
+            Operator::Geq => write_binary(f, self, ">="),
+            Operator::Leq => write_binary(f, self, "<="),
+            Operator::And => write_binary(f, self, "&&"),
+            Operator::Or => write_binary(f, self, "||"),
+            Operator::Not => write_unary(f, self, "!"),
+            Operator::Assign => write_binary(f, self, "="),
+            Operator::AddAssign => write_binary(f, self, "+="),
+            Operator::SubAssign => write_binary(f, self, "-="),
+            Operator::MulAssign => write_binary(f, self, "*="),
+            Operator::DivAssign => write_binary(f, self, "/="),
+            Operator::ModAssign => write_binary(f, self, "%="),
+            Operator::ExpAssign => write_binary(f, self, "^="),
+            Operator::AndAssign => write_binary(f, self, "&&="),
+            Operator::OrAssign => write_binary(f, self, "||="),
+            Operator::Tuple => write_sequence(f, self, ","),
+            Operator::Chain => write_sequence(f, self, ";"),
+            Operator::Const { value } => write!(f, "{}", value),
+            Operator::VariableIdentifierWrite { identifier } => {
+                write!(f, "{}", identifier)
+            },
+            Operator::VariableIdentifierRead { identifier } => {
+                write!(f, "{}", identifier)
+            },
+            Operator::FunctionIdentifier { identifier } => {
+                write!(f, "{} ", identifier)?;
+                for (i, c) in self.children.iter().enumerate() {
+                    write!(f, "{}", c)?;
+                    if i + 1 < self.children.len() {
+                        write!(f, " ")?;
+                    }
+                }
+                Ok(())
+            },
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::build_operator_tree;
+    #[test]
+    fn test_display() {
+        let pairs = [
+            ("", ""),
+            ("0", "0"),
+            ("0.1", "0.1"),
+            ("f (1, 2)", "f (1, 2)"),
+            ("()", ""),
+            ("a; b", "(a; b)"),
+            ("a = b", "(a = b)"),
+            ("5 + 3", "(5 + 3)"),
+            ("5 + 3 * 2", "(5 + (3 * 2))"),
+            ("f (g 4)", "f g 4"),
+            ("f (g 4; 5)", "f (g 4; 5)"),
+        ];
+        for (i, o) in pairs.iter() {
+            assert_eq!(
+                &&format!(
+                    "{}",
+                    build_operator_tree(i).expect("Could not build operator tree")
+                ),
+                o
+            );
         }
-        Ok(())
     }
 }

src/value/display.rs

@@ -6,7 +6,13 @@ impl Display for Value {
     fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
         match self {
             Value::String(string) => write!(f, "\"{}\"", string),
-            Value::Float(float) => write!(f, "{}", float),
+            Value::Float(float) => {
+                if let Some(precision) = f.precision() {
+                    write!(f, "{1:.*}", precision, float)
+                } else {
+                    write!(f, "{}", float)
+                }
+            },
             Value::Int(int) => write!(f, "{}", int),
             Value::Boolean(boolean) => write!(f, "{}", boolean),
             Value::Tuple(tuple) => {