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Merge branch '52_remove_automatic_function_argument_decomposition'

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This commit is contained in:
Sebastian Schmidt 2019-05-04 13:53:47 +02:00
commit 6f533ca925
9 changed files with 264 additions and 119 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(Box::new(|_| Ok(42.into()) ))
/// }.unwrap();
///
/// assert_eq!(eval_with_context("x + f()", &ctx), Ok(50.into()));

8
src/error/mod.rs
View File

@ -353,6 +353,14 @@ pub fn expect_boolean(actual: &Value) -> EvalexprResult<bool> {
}
}
/// Returns `Ok(&[Value])` if the given value is a `Value::Tuple`, or `Err(Error::ExpectedTuple)` otherwise.
pub fn expect_tuple(actual: &Value) -> EvalexprResult<&TupleType> {
match actual {
Value::Tuple(tuple) => Ok(tuple),
_ => Err(EvalexprError::expected_tuple(actual.clone())),
}
}
impl std::error::Error for EvalexprError {}
/// Standard result type used by this crate.

38
src/function/builtin.rs
View File

@ -10,8 +10,8 @@ use Value;
pub fn builtin_function(identifier: &str) -> Option<Function> {
match identifier {
"min" => Some(Function::new(
None,
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
let mut min_int = IntType::max_value();
let mut min_float = 1.0f64 / 0.0f64;
debug_assert!(min_float.is_infinite());
@ -34,8 +34,8 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
}),
)),
"max" => Some(Function::new(
None,
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
let mut max_int = IntType::min_value();
let mut max_float = -1.0f64 / 0.0f64;
debug_assert!(max_float.is_infinite());
@ -59,9 +59,8 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
)),
"len" => Some(Function::new(
Some(1),
Box::new(|arguments| {
let subject = expect_string(&arguments[0])?;
Box::new(|argument| {
let subject = expect_string(argument)?;
Ok(Value::from(subject.len() as i64))
}),
)),
@ -69,8 +68,9 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
// string functions
#[cfg(feature = "regex_support")]
"str::regex_matches" => Some(Function::new(
Some(2),
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
let subject = expect_string(&arguments[0])?;
let re_str = expect_string(&arguments[1])?;
match Regex::new(re_str) {
@ -84,8 +84,9 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
)),
#[cfg(feature = "regex_support")]
"str::regex_replace" => Some(Function::new(
Some(3),
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
let subject = expect_string(&arguments[0])?;
let re_str = expect_string(&arguments[1])?;
let repl = expect_string(&arguments[2])?;
@ -99,23 +100,20 @@ pub fn builtin_function(identifier: &str) -> Option<Function> {
}),
)),
"str::to_lowercase" => Some(Function::new(
Some(1),
Box::new(|arguments| {
let subject = expect_string(&arguments[0])?;
Box::new(|argument| {
let subject = expect_string(argument)?;
Ok(Value::from(subject.to_lowercase()))
}),
)),
"str::to_uppercase" => Some(Function::new(
Some(1),
Box::new(|arguments| {
let subject = expect_string(&arguments[0])?;
Box::new(|argument| {
let subject = expect_string(argument)?;
Ok(Value::from(subject.to_uppercase()))
}),
)),
"str::trim" => Some(Function::new(
Some(1),
Box::new(|arguments| {
let subject = expect_string(&arguments[0])?;
Box::new(|argument| {
let subject = expect_string(argument)?;
Ok(Value::from(subject.trim()))
}),
)),

29
src/function/mod.rs
View File

@ -1,6 +1,6 @@
use std::fmt;
use error::{self, EvalexprResult};
use error::{EvalexprResult};
use value::Value;
pub(crate) mod builtin;
@ -14,39 +14,29 @@ pub(crate) mod builtin;
/// use evalexpr::*;
///
/// let mut context = HashMapContext::new();
/// context.set_function("id".into(), Function::new(Some(1), Box::new(|arguments| {
/// Ok(arguments[0].clone())
/// context.set_function("id".into(), Function::new(Box::new(|argument| {
/// Ok(argument.clone())
/// }))).unwrap(); // Do proper error handling here
/// assert_eq!(eval_with_context("id(4)", &context), Ok(Value::from(4)));
/// ```
pub struct Function {
argument_amount: Option<usize>,
function: Box<Fn(&[Value]) -> EvalexprResult<Value>>,
function: Box<Fn(&Value) -> EvalexprResult<Value>>,
}
impl Function {
/// Creates a user-defined function.
///
/// The `argument_amount` is the amount of arguments this function takes.
/// It is verified before the actual function is executed, assuming it is not `None`.
///
/// The `function` is a boxed function that takes a slice of values and returns a `EvalexprResult<Value, Error>`.
/// The `function` is a boxed function that takes a `Value` and returns a `EvalexprResult<Value, Error>`.
pub fn new(
argument_amount: Option<usize>,
function: Box<Fn(&[Value]) -> EvalexprResult<Value>>,
function: Box<Fn(&Value) -> EvalexprResult<Value>>,
) -> Self {
Self {
argument_amount,
function,
}
}
pub(crate) fn call(&self, arguments: &[Value]) -> EvalexprResult<Value> {
if let Some(argument_amount) = self.argument_amount {
error::expect_function_argument_amount(arguments.len(), argument_amount)?;
}
(self.function)(arguments)
pub(crate) fn call(&self, argument: &Value) -> EvalexprResult<Value> {
(self.function)(argument)
}
}
@ -54,8 +44,7 @@ impl fmt::Debug for Function {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(
f,
"Function {{ argument_amount: {:?}, function: [...] }}",
self.argument_amount
"Function {{ [...] }}"
)
}
}

15
src/lib.rs
View File

@ -49,21 +49,22 @@
//!
//! ```rust
//! use evalexpr::*;
//! use evalexpr::error::expect_number;
//! use evalexpr::error::{expect_number, expect_tuple};
//!
//! let context = context_map! {
//! "five" => 5,
//! "twelve" => 12,
//! "f" => Function::new(Some(1) /* argument amount */, Box::new(|arguments| {
//! if let Value::Int(int) = arguments[0] {
//! "f" => Function::new(Box::new(|argument| {
//! if let Value::Int(int) = argument {
//! Ok(Value::Int(int / 2))
//! } else if let Value::Float(float) = arguments[0] {
//! } else if let Value::Float(float) = argument {
//! Ok(Value::Float(float / 2.0))
//! } else {
//! Err(EvalexprError::expected_number(arguments[0].clone()))
//! Err(EvalexprError::expected_number(argument.clone()))
//! }
//! })),
//! "avg" => Function::new(Some(2) /* argument amount */, Box::new(|arguments| {
//! "avg" => Function::new(Box::new(|argument| {
//! let arguments = expect_tuple(argument)?;
//! expect_number(&arguments[0])?;
//! expect_number(&arguments[1])?;
//!
@ -343,7 +344,7 @@
//! Ok(free) => assert_eq!(free.eval_with_context(&context), Ok(Value::from(25))),
//! Err(error) => {
//! () // Handle error
//! },
//! }
//! }
//! # }
//! ```

58
src/operator/mod.rs
View File

@ -4,7 +4,7 @@ use crate::{context::Context, error::*, value::Value};
mod display;
#[derive(Debug)]
#[derive(Debug, PartialEq)]
pub enum Operator {
RootNode,
@ -91,23 +91,34 @@ 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
pub(crate) fn is_sequence(&self) -> bool {
use crate::operator::Operator::*;
match self {
Tuple | Chain => true,
_ => false,
}
}
/// True if this operator is a leaf, meaning it accepts no arguments.
// Make this a const fn once #57563 is resolved
pub(crate) fn is_leaf(&self) -> bool {
self.max_argument_amount() == 0
self.max_argument_amount() == Some(0)
}
/// Returns the maximum amount of arguments required by this operator.
// Make this a const fn once #57563 is resolved
pub(crate) fn max_argument_amount(&self) -> usize {
pub(crate) fn max_argument_amount(&self) -> Option<usize> {
use crate::operator::Operator::*;
match self {
Add | Sub | Mul | Div | Mod | Exp | Eq | Neq | Gt | Lt | Geq | Leq | And | Or
| Tuple | Assign | Chain => 2,
Not | Neg | RootNode => 1,
Const { value: _ } => 0,
VariableIdentifier { identifier: _ } => 0,
FunctionIdentifier { identifier: _ } => 1,
| Assign => Some(2),
Tuple | Chain => None,
Not | Neg | RootNode => Some(1),
Const { value: _ } => Some(0),
VariableIdentifier { identifier: _ } => Some(0),
FunctionIdentifier { identifier: _ } => Some(1),
}
}
@ -410,27 +421,7 @@ impl Operator {
}
},
Tuple => {
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] {
tuple.extend(tuple2.iter().cloned());
} else {
tuple.push(arguments[1].clone());
}
Ok(Value::from(tuple))
} else {
if let Value::Tuple(tuple) = &arguments[1] {
let mut tuple = tuple.clone();
tuple.insert(0, arguments[0].clone());
Ok(Value::from(tuple))
} else {
Ok(Value::from(vec![
arguments[0].clone(),
arguments[1].clone(),
]))
}
}
Ok(Value::Tuple(arguments.into()))
},
Assign => Err(EvalexprError::ContextNotManipulable),
Chain => {
@ -438,7 +429,7 @@ 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)?;
@ -456,12 +447,7 @@ impl Operator {
},
FunctionIdentifier { identifier } => {
expect_operator_argument_amount(arguments.len(), 1)?;
let arguments = if let Value::Tuple(arguments) = &arguments[0] {
arguments
} else {
arguments
};
let arguments = &arguments[0];
if let Some(function) = context.get_function(&identifier) {
function.call(arguments)

135
src/tree/mod.rs
View File

@ -11,6 +11,7 @@ use crate::{
operator::*,
value::Value,
};
use std::mem;
mod display;
mod iter;
@ -32,10 +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 {
@ -362,10 +363,11 @@ impl Node {
}
fn has_enough_children(&self) -> bool {
self.children().len() == self.operator().max_argument_amount()
Some(self.children().len()) == self.operator().max_argument_amount()
}
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())
@ -379,11 +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 {
// println!("Rotating");
if node.operator().is_leaf() {
return Err(EvalexprError::AppendedToLeafNode);
}
@ -396,6 +400,7 @@ impl Node {
Ok(())
}
} else {
// println!("Inserting as specified");
self.children.push(node);
Ok(())
}
@ -405,8 +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();
@ -438,14 +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()
}
},
@ -470,9 +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() {
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);
}
@ -481,9 +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)

6
src/value/mod.rs
View File

@ -194,6 +194,12 @@ impl From<Value> for EvalexprResult<Value> {
}
}
impl From<()> for Value {
fn from(_: ()) -> Self {
Value::Empty
}
}
#[cfg(test)]
mod tests {
use value::{TupleType, Value};

90
tests/integration.rs
View File

@ -138,14 +138,13 @@ fn test_functions() {
.set_function(
"sub2".to_string(),
Function::new(
Some(1),
Box::new(|arguments| {
if let Value::Int(int) = arguments[0] {
Box::new(|argument| {
if let Value::Int(int) = argument {
Ok(Value::Int(int - 2))
} else if let Value::Float(float) = arguments[0] {
} else if let Value::Float(float) = argument {
Ok(Value::Float(float - 2.0))
} else {
Err(EvalexprError::expected_number(arguments[0].clone()))
Err(EvalexprError::expected_number(argument.clone()))
}
}),
),
@ -172,14 +171,13 @@ fn test_n_ary_functions() {
.set_function(
"sub2".into(),
Function::new(
Some(1),
Box::new(|arguments| {
if let Value::Int(int) = arguments[0] {
Box::new(|argument| {
if let Value::Int(int) = argument {
Ok(Value::Int(int - 2))
} else if let Value::Float(float) = arguments[0] {
} else if let Value::Float(float) = argument {
Ok(Value::Float(float - 2.0))
} else {
Err(EvalexprError::expected_number(arguments[0].clone()))
Err(EvalexprError::expected_number(argument.clone()))
}
}),
),
@ -189,8 +187,8 @@ fn test_n_ary_functions() {
.set_function(
"avg".into(),
Function::new(
Some(2),
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
expect_number(&arguments[0])?;
expect_number(&arguments[1])?;
@ -209,8 +207,8 @@ fn test_n_ary_functions() {
.set_function(
"muladd".into(),
Function::new(
Some(3),
Box::new(|arguments| {
Box::new(|argument| {
let arguments = expect_tuple(argument)?;
expect_number(&arguments[0])?;
expect_number(&arguments[1])?;
expect_number(&arguments[2])?;
@ -233,16 +231,11 @@ fn test_n_ary_functions() {
.set_function(
"count".into(),
Function::new(
None,
Box::new(|arguments| {
if arguments.len() == 1 {
if arguments[0] == Value::Empty {
Ok(Value::Int(0))
} else {
Ok(Value::Int(1))
}
} else {
Ok(Value::Int(arguments.len() as IntType))
match arguments {
Value::Tuple(tuple) => Ok(Value::from(tuple.len() as IntType)),
Value::Empty => Ok(Value::from(0)),
_ => Ok(Value::from(1)),
}
}),
),
@ -251,6 +244,7 @@ fn test_n_ary_functions() {
context
.set_value("five".to_string(), Value::Int(5))
.unwrap();
context.set_function("function_four".into(), Function::new(Box::new(|_| {Ok(Value::Int(4))}))).unwrap();
assert_eq!(eval_with_context("avg(7, 5)", &context), Ok(Value::Int(6)));
assert_eq!(
@ -270,11 +264,13 @@ fn test_n_ary_functions() {
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(3)));
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)));
}
#[test]
@ -605,3 +601,51 @@ 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)])
);
}