Add flattening of operator chains when building operator tree

Relates to #44

src/operator/mod.rs

@@ -7,6 +7,10 @@ use crate::{context::Context, error::*, value::Value};
 mod display;
 
 pub trait Operator: Debug + Display {
+    /// A numeric id to compare operator types.
+    // Make this a const fn once #57563 is resolved
+    fn id(&self) -> i32;
+
     /// Returns the precedence of the operator.
     /// A high precedence means that the operator has priority to be deeper in the tree.
     // Make this a const fn once #57563 is resolved
@@ -20,6 +24,12 @@ pub trait Operator: Debug + Display {
         true
     }
 
+    /// Returns true if chains of this operator should be flattened into one operator with many arguments.
+    // Make this a const fn once #57563 is resolved
+    fn is_flatten_chains(&self) -> bool {
+        false
+    }
+
     /// True if this operator is a leaf, meaning it accepts no arguments.
     // Make this a const fn once #57563 is resolved
     fn is_leaf(&self) -> bool {
@@ -123,6 +133,10 @@ impl FunctionIdentifier {
 }
 
 impl Operator for RootNode {
+    fn id(&self) -> i32 {
+        1
+    }
+
     fn precedence(&self) -> i32 {
         200
     }
@@ -141,6 +155,10 @@ impl Operator for RootNode {
 }
 
 impl Operator for Add {
+    fn id(&self) -> i32 {
+        2
+    }
+
     fn precedence(&self) -> i32 {
         95
     }
@@ -178,6 +196,10 @@ impl Operator for Add {
 }
 
 impl Operator for Sub {
+    fn id(&self) -> i32 {
+        3
+    }
+
     fn precedence(&self) -> i32 {
         95
     }
@@ -210,6 +232,10 @@ impl Operator for Sub {
 }
 
 impl Operator for Neg {
+    fn id(&self) -> i32 {
+        4
+    }
+
     fn precedence(&self) -> i32 {
         110
     }
@@ -236,6 +262,10 @@ impl Operator for Neg {
 }
 
 impl Operator for Mul {
+    fn id(&self) -> i32 {
+        5
+    }
+
     fn precedence(&self) -> i32 {
         100
     }
@@ -268,6 +298,10 @@ impl Operator for Mul {
 }
 
 impl Operator for Div {
+    fn id(&self) -> i32 {
+        6
+    }
+
     fn precedence(&self) -> i32 {
         100
     }
@@ -300,6 +334,10 @@ impl Operator for Div {
 }
 
 impl Operator for Mod {
+    fn id(&self) -> i32 {
+        7
+    }
+
     fn precedence(&self) -> i32 {
         100
     }
@@ -332,6 +370,10 @@ impl Operator for Mod {
 }
 
 impl Operator for Exp {
+    fn id(&self) -> i32 {
+        8
+    }
+
     fn precedence(&self) -> i32 {
         120
     }
@@ -355,6 +397,10 @@ impl Operator for Exp {
 }
 
 impl Operator for Eq {
+    fn id(&self) -> i32 {
+        9
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -375,6 +421,10 @@ impl Operator for Eq {
 }
 
 impl Operator for Neq {
+    fn id(&self) -> i32 {
+        10
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -395,6 +445,10 @@ impl Operator for Neq {
 }
 
 impl Operator for Gt {
+    fn id(&self) -> i32 {
+        11
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -431,6 +485,10 @@ impl Operator for Gt {
 }
 
 impl Operator for Lt {
+    fn id(&self) -> i32 {
+        12
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -467,6 +525,10 @@ impl Operator for Lt {
 }
 
 impl Operator for Geq {
+    fn id(&self) -> i32 {
+        13
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -503,6 +565,10 @@ impl Operator for Geq {
 }
 
 impl Operator for Leq {
+    fn id(&self) -> i32 {
+        14
+    }
+
     fn precedence(&self) -> i32 {
         80
     }
@@ -539,6 +605,10 @@ impl Operator for Leq {
 }
 
 impl Operator for And {
+    fn id(&self) -> i32 {
+        15
+    }
+
     fn precedence(&self) -> i32 {
         75
     }
@@ -561,6 +631,10 @@ impl Operator for And {
 }
 
 impl Operator for Or {
+    fn id(&self) -> i32 {
+        16
+    }
+
     fn precedence(&self) -> i32 {
         70
     }
@@ -583,6 +657,10 @@ impl Operator for Or {
 }
 
 impl Operator for Not {
+    fn id(&self) -> i32 {
+        17
+    }
+
     fn precedence(&self) -> i32 {
         110
     }
@@ -604,17 +682,26 @@ impl Operator for Not {
 }
 
 impl Operator for Tuple {
+    fn id(&self) -> i32 {
+        18
+    }
+
     fn precedence(&self) -> i32 {
         40
     }
 
     fn max_argument_amount(&self) -> Option<usize> {
-        Some(2)
+        None
     }
 
     fn eval(&self, arguments: &[Value], _context: &Context) -> EvalexprResult<Value> {
-        expect_operator_argument_amount(arguments.len(), 2)?;
+        if arguments.len() < 2 {
-        if let Value::Tuple(tuple) = &arguments[0] {
+            return Err(EvalexprError::wrong_operator_argument_amount(arguments.len(), 2));
+        }
+
+        Ok(Value::Tuple(arguments.iter().cloned().collect()))
+
+        /*if let Value::Tuple(tuple) = &arguments[0] {
             let mut tuple = tuple.clone();
             if let Value::Tuple(tuple2) = &arguments[1] {
                 tuple.extend(tuple2.iter().cloned());
@@ -633,11 +720,15 @@ impl Operator for Tuple {
                     arguments[1].clone(),
                 ]))
             }
-        }
+        }*/
     }
 }
 
 impl Operator for Assign {
+    fn id(&self) -> i32 {
+        19
+    }
+
     fn precedence(&self) -> i32 {
         50
     }
@@ -664,10 +755,18 @@ impl Operator for Assign {
 }
 
 impl Operator for Chain {
+    fn id(&self) -> i32 {
+        20
+    }
+
     fn precedence(&self) -> i32 {
         0
     }
 
+    fn is_flatten_chains(&self) -> bool {
+        true
+    }
+
     fn max_argument_amount(&self) -> Option<usize> {
         Some(2)
     }
@@ -682,6 +781,10 @@ impl Operator for Chain {
 }
 
 impl Operator for Const {
+    fn id(&self) -> i32 {
+        21
+    }
+
     fn precedence(&self) -> i32 {
         200
     }
@@ -698,6 +801,10 @@ impl Operator for Const {
 }
 
 impl Operator for VariableIdentifier {
+    fn id(&self) -> i32 {
+        22
+    }
+
     fn precedence(&self) -> i32 {
         200
     }
@@ -722,6 +829,10 @@ impl Operator for VariableIdentifier {
 }
 
 impl Operator for FunctionIdentifier {
+    fn id(&self) -> i32 {
+        23
+    }
+
     fn precedence(&self) -> i32 {
         190
     }

src/tree/mod.rs

@@ -337,6 +337,9 @@ impl Node {
                         .last_mut()
                         .unwrap()
                         .insert_back_prioritized(node, false)
+                } else if self.children.last().unwrap().operator().id() == node.operator().id() && node.operator().is_flatten_chains() && !self.children.last().unwrap().has_enough_children() {
+                    // The operators will be chained together, and the next value will be added to this nodes last child.
+                    Ok(())
                 } else {
                     if node.operator().is_leaf() {
                         return Err(EvalexprError::AppendedToLeafNode);

src/value/mod.rs

@@ -194,6 +194,10 @@ impl From<Value> for EvalexprResult<Value> {
     }
 }
 
+impl From<()> for Value {
+    fn from(_: ()) -> Self { Value::Empty }
+}
+
 #[cfg(test)]
 mod tests {
     use value::{TupleType, Value};

tests/integration.rs

@@ -614,3 +614,17 @@ fn test_serde() {
         assert_eq!(manual_tree.eval(), serde_tree.eval());
     }
 }
+
+#[test]
+fn test_tuple_definitions() {
+    assert_eq!(eval_empty("()"), Ok(()));
+    assert_eq!(eval_int("(3)"), Ok(3));
+    assert_eq!(eval_tuple("(3, 4)"), Ok(vec![Value::from(3), Value::from(4)]));
+    assert_eq!(eval_tuple("2, (5, 6)"), Ok(vec![Value::from(2), Value::from(vec![Value::from(5), Value::from(6)])]));
+    assert_eq!(eval_tuple("1, 2"), Ok(vec![Value::from(1), Value::from(2)]));
+    assert_eq!(eval_tuple("1, 2, 3, 4"), Ok(vec![Value::from(1), Value::from(2), Value::from(3), Value::from(4)]));
+    assert_eq!(eval_tuple("(1, 2, 3), 5, 6, (true, false, 0)"), Ok(vec![Value::from(vec![Value::from(1), Value::from(2), Value::from(3)]), Value::from(5), Value::from(6), Value::from(vec![Value::from(true), Value::from(false), Value::from(0)])]));
+    assert_eq!(eval_tuple("1, (2)"), Ok(vec![Value::from(1), Value::from(2)]));
+    assert_eq!(eval_tuple("1, ()"), Ok(vec![Value::from(1), Value::from(())]));
+    assert_eq!(eval_tuple("1, ((2))"), Ok(vec![Value::from(1), Value::from(2)]));
+}