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Fixed aggregation operator

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Manage sequence operators, which currently are `Chain` and `Token` on the stack without ever inserting unfinished sequence operator nodes into another node.

Relates to #44
This commit is contained in:
Sebastian Schmidt 2019-04-22 19:08:55 +02:00
parent 2e929ae0fe
commit 6f77471354
5 changed files with 185 additions and 33 deletions
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2
src/context/mod.rs
View File

@ -103,7 +103,7 @@ impl Context for HashMapContext {
///
/// let ctx = evalexpr::context_map! {
/// "x" => 8,
/// "f" => Function::new(None, Box::new(|_| Ok(42.into()) ))
/// "f" => Function::new(None, Box::new(|_| Ok(42.into()) ))
/// }.unwrap();
///
/// assert_eq!(eval_with_context("x + f()", &ctx), Ok(50.into()));

19
src/operator/mod.rs
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@ -4,7 +4,7 @@ use crate::{context::Context, error::*, value::Value};
mod display;
#[derive(Debug)]
#[derive(Debug, PartialEq)]
pub enum Operator {
RootNode,
@ -93,9 +93,10 @@ impl Operator {
/// 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 {
pub(crate) fn is_sequence(&self) -> bool {
use crate::operator::Operator::*;
match self {
Operator::Tuple => true,
Tuple | Chain => true,
_ => false,
}
}
@ -112,8 +113,8 @@ impl Operator {
use crate::operator::Operator::*;
match self {
Add | Sub | Mul | Div | Mod | Exp | Eq | Neq | Gt | Lt | Geq | Leq | And | Or
| Assign | Chain => Some(2),
Tuple => None,
| Assign => Some(2),
Tuple | Chain => None,
Not | Neg | RootNode => Some(1),
Const { value: _ } => Some(0),
VariableIdentifier { identifier: _ } => Some(0),
@ -420,7 +421,9 @@ impl Operator {
}
}
Tuple => {
expect_operator_argument_amount(arguments.len(), 2)?;
Ok(Value::Tuple(arguments.into()))
/*expect_operator_argument_amount(arguments.len(), 2)?;
if let Value::Tuple(tuple) = &arguments[0] {
let mut tuple = tuple.clone();
if let Value::Tuple(tuple2) = &arguments[1] {
@ -440,7 +443,7 @@ impl Operator {
arguments[1].clone(),
]))
}
}
}*/
}
Assign => Err(EvalexprError::ContextNotManipulable),
Chain => {
@ -448,7 +451,7 @@ impl Operator {
return Err(EvalexprError::wrong_operator_argument_amount(0, 1));
}
Ok(arguments.get(1).cloned().unwrap_or(Value::Empty))
Ok(arguments.last().cloned().unwrap_or(Value::Empty))
}
Const { value } => {
expect_operator_argument_amount(arguments.len(), 0)?;

140
src/tree/mod.rs
View File

@ -11,8 +11,7 @@ use crate::{
operator::*,
value::Value,
};
use std::error::Error;
use std::any::Any;
use std::mem;
mod display;
mod iter;
@ -34,10 +33,10 @@ mod iter;
/// assert_eq!(node.eval_with_context(&context), Ok(Value::from(3)));
/// ```
///
#[derive(Debug)]
#[derive(Debug, PartialEq)]
pub struct Node {
children: Vec<Node>,
operator: Operator,
children: Vec<Node>,
}
impl Node {
@ -368,6 +367,7 @@ impl Node {
}
fn insert_back_prioritized(&mut self, node: Node, is_root_node: bool) -> EvalexprResult<()> {
println!("Inserting {:?} into {:?}", node.operator, self.operator());
if self.operator().precedence() < node.operator().precedence() || is_root_node
// Right-to-left chaining
|| (self.operator().precedence() == node.operator().precedence() && !self.operator().is_left_to_right() && !node.operator().is_left_to_right())
@ -381,14 +381,13 @@ impl Node {
|| (self.children.last().unwrap().operator().precedence()
== node.operator().precedence() && !self.children.last().unwrap().operator().is_left_to_right() && !node.operator().is_left_to_right())
{
println!("Recursing into {:?}", self.children.last().unwrap().operator());
self.children
.last_mut()
.unwrap()
.insert_back_prioritized(node, false)
} else if self.children.last().unwrap().operator().type_id() == node.operator().type_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 {
println!("Rotating");
if node.operator().is_leaf() {
return Err(EvalexprError::AppendedToLeafNode);
}
@ -401,6 +400,7 @@ impl Node {
Ok(())
}
} else {
println!("Inserting as specified");
self.children.push(node);
Ok(())
}
@ -410,8 +410,63 @@ impl Node {
}
}
fn collapse_root_stack_to(root_stack: &mut Vec<Node>, mut root: Node, collapse_goal: &Node) -> EvalexprResult<Node> {
loop {
if let Some(mut potential_higher_root) = root_stack.pop() {
// TODO I'm not sure about this >, as I have no example for different sequence operators with the same precedence
if potential_higher_root.operator().precedence() > collapse_goal.operator().precedence() {
potential_higher_root.children.push(root);
root = potential_higher_root;
} else {
root_stack.push(potential_higher_root);
break;
}
} else {
// This is the only way the topmost root node could have been removed
return Err(EvalexprError::UnmatchedRBrace);
}
}
Ok(root)
}
fn collapse_all_sequences(root_stack: &mut Vec<Node>) -> EvalexprResult<()> {
println!("Collapsing all sequences");
println!("Initial root stack is: {:?}", root_stack);
let mut root = if let Some(root) = root_stack.pop() {
root
} else {
return Err(EvalexprError::UnmatchedRBrace);
};
loop {
println!("Root is: {:?}", root);
if root.operator() == &Operator::RootNode {
root_stack.push(root);
break;
}
if let Some(mut potential_higher_root) = root_stack.pop() {
if root.operator().is_sequence() {
potential_higher_root.children.push(root);
root = potential_higher_root;
} else {
root_stack.push(potential_higher_root);
root_stack.push(root);
break;
}
} else {
// This is the only way the topmost root node could have been removed
return Err(EvalexprError::UnmatchedRBrace);
}
}
println!("Root stack after collapsing all sequences is: {:?}", root_stack);
Ok(())
}
pub(crate) fn tokens_to_operator_tree(tokens: Vec<Token>) -> EvalexprResult<Node> {
let mut root = vec![Node::root_node()];
let mut root_stack = vec![Node::root_node()];
let mut last_token_is_rightsided_value = false;
let mut token_iter = tokens.iter().peekable();
@ -443,14 +498,15 @@ pub(crate) fn tokens_to_operator_tree(tokens: Vec<Token>) -> EvalexprResult<Node
Token::Not => Some(Node::new(Operator::Not)),
Token::LBrace => {
root.push(Node::root_node());
root_stack.push(Node::root_node());
None
}
Token::RBrace => {
if root.len() < 2 {
if root_stack.len() <= 1 {
return Err(EvalexprError::UnmatchedRBrace);
} else {
root.pop()
collapse_all_sequences(&mut root_stack)?;
root_stack.pop()
}
}
@ -475,9 +531,58 @@ pub(crate) fn tokens_to_operator_tree(tokens: Vec<Token>) -> EvalexprResult<Node
Token::String(string) => Some(Node::new(Operator::value(Value::String(string)))),
};
if let Some(node) = node {
if let Some(root) = root.last_mut() {
root.insert_back_prioritized(node, true)?;
if let Some(mut node) = node {
// Need to pop and then repush here, because Rust 1.33.0 cannot release the mutable borrow of root_stack before the end of this complete if-statement
if let Some(mut root) = root_stack.pop() {
if node.operator().is_sequence() {
println!("Found a sequence operator");
println!("Stack before sequence operation: {:?}, {:?}", root_stack, root);
// If root.operator() and node.operator() are of the same variant, ...
if mem::discriminant(root.operator()) == mem::discriminant(node.operator()) {
// ... we create a new root node for the next expression in the sequence
root.children.push(Node::root_node());
root_stack.push(root);
} else if root.operator() == &Operator::RootNode {
// If the current root is an actual root node, we start a new sequence
node.children.push(root);
node.children.push(Node::root_node());
root_stack.push(Node::root_node());
root_stack.push(node);
} else {
// Otherwise, we combine the sequences based on their precedences
// TODO I'm not sure about this <, as I have no example for different sequence operators with the same precedence
if root.operator().precedence() < node.operator().precedence() {
// If the new sequence has a higher precedence, it is part of the last element of the current root sequence
if let Some(last_root_child) = root.children.pop() {
node.children.push(last_root_child);
node.children.push(Node::root_node());
root_stack.push(root);
root_stack.push(node);
} else {
// Once a sequence has been pushed on top of the stack, it also gets a child
unreachable!()
}
} else {
// If the new sequence doesn't have a higher precedence, then all sequences with a higher precedence are collapsed below this one
root = collapse_root_stack_to(&mut root_stack, root, &node)?;
node.children.push(root);
root_stack.push(node);
}
}
println!("Stack after sequence operation: {:?}", root_stack);
} else if root.operator().is_sequence() {
if let Some(mut last_root_child) = root.children.pop() {
last_root_child.insert_back_prioritized(node, true)?;
root.children.push(last_root_child);
root_stack.push(root);
} else {
// Once a sequence has been pushed on top of the stack, it also gets a child
unreachable!()
}
} else {
root.insert_back_prioritized(node, true)?;
root_stack.push(root);
}
} else {
return Err(EvalexprError::UnmatchedRBrace);
}
@ -486,9 +591,12 @@ pub(crate) fn tokens_to_operator_tree(tokens: Vec<Token>) -> EvalexprResult<Node
last_token_is_rightsided_value = token.is_rightsided_value();
}
if root.len() > 1 {
// In the end, all sequences are implicitly terminated
collapse_all_sequences(&mut root_stack)?;
if root_stack.len() > 1 {
Err(EvalexprError::UnmatchedLBrace)
} else if let Some(root) = root.pop() {
} else if let Some(root) = root_stack.pop() {
Ok(root)
} else {
Err(EvalexprError::UnmatchedRBrace)

4
src/value/mod.rs
View File

@ -195,7 +195,9 @@ impl From<Value> for EvalexprResult<Value> {
}
impl From<()> for Value {
fn from(_: ()) -> Self { Value::Empty }
fn from(_: ()) -> Self {
Value::Empty
}
}
#[cfg(test)]

53
tests/integration.rs
View File

@ -251,6 +251,7 @@ fn test_n_ary_functions() {
context
.set_value("five".to_string(), Value::Int(5))
.unwrap();
context.set_function("function_four".into(), Function::new(Some(0), Box::new(|_| {Ok(Value::Int(4))}))).unwrap();
assert_eq!(eval_with_context("avg(7, 5)", &context), Ok(Value::Int(6)));
assert_eq!(
@ -265,16 +266,20 @@ fn test_n_ary_functions() {
eval_with_context("sub2 avg(3, 6)", &context),
Ok(Value::Int(2))
);
dbg!(build_operator_tree("muladd(3, 6, -4)").unwrap());
assert_eq!(
eval_with_context("muladd(3, 6, -4)", &context),
Ok(Value::Int(14))
);
assert_eq!(eval_with_context("count()", &context), Ok(Value::Int(0)));
assert_eq!(eval_with_context("count((1, 2, 3))", &context), Ok(Value::Int(1)));
assert_eq!(
eval_with_context("count(3, 5.5, 2)", &context),
Ok(Value::Int(3))
);
assert_eq!(eval_with_context("count 5", &context), Ok(Value::Int(1)));
assert_eq!(eval_with_context("function_four()", &context), Ok(Value::Int(4)));
assert_eq!(eval_with_context("function_four(())", &context), Err(EvalexprError::WrongFunctionArgumentAmount{expected: 0, actual: 1}));
}
#[test]
@ -610,12 +615,46 @@ fn test_serde() {
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("(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)]));
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)])
);
}