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lib.rs
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lib.rs
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//! A command matching engine
//!
//! This library matches a list of input parameters such as:
//! `["example", "input", "123"]`
//! to a handler that is able to handle these inputs.
//!
//! The handlers are registered using the `Spec` (specification) format:
//! ```
//! use cmdmat::{Decider, Decision, Spec, SVec};
//!
//! type Accept = i32;
//! type Deny = String;
//! type Context = i32;
//!
//! fn handler(_ctx: &mut Context, _args: &[Accept]) -> Result<String, String> {
//! Ok("".into())
//! }
//!
//! fn accept_integer(input: &[&str], out: &mut SVec<Accept>) -> Decision<Deny> {
//! if input.len() != 1 {
//! return Decision::Deny("Require exactly 1 input".into());
//! }
//! if let Ok(num) = input[0].parse::<Accept>() {
//! out.push(num);
//! Decision::Accept(1)
//! } else {
//! Decision::Deny("Unable to get number".into())
//! }
//! }
//!
//! const DEC: Decider<Accept, Deny> = Decider {
//! description: "<i32>",
//! decider: accept_integer,
//! };
//!
//! const SPEC: Spec<Accept, Deny, Context> = (&[("example", None), ("input", Some(&DEC))], handler);
//!
//! ```
//!
//! In the above the `SPEC` variable defines a path to get to the `handler`, requiring first
//! `"example"` with no validator `None`, then followed by `"input"` which takes a single
//! integer.
//!
//! If the validator `accept_integer` fails, then the command lookup will also fail.
//!
//! The `Spec`s will be collected inside a `Mapping`, where lookup will happen among a tree of
//! merged `Spec`s.
//!
//! The reason we have a separate literal string and validator is to make it easy and unambiguous
//! to find the next node in the search tree. If we only used validators (which can be completely
//! arbitrary), then we can not sort a tree to make searching `O(log n)`. These fixed literal
//! search points also give us a good way to debug commands if they happen to not match anything.
//!
//! Here is an example with actual lookup where we call a handler:
//! (Unfortunately, a bit of setup is required.)
//!
//! ```
//! use cmdmat::{Decider, Decision, Mapping, Spec, SVec};
//!
//! // The accept type is the type enum containing accepted tokens, parsed into useful formats
//! // the list of accepted input is at last passed to the finalizer
//! #[derive(Debug)]
//! enum Accept {
//! I32(i32),
//! }
//!
//! // Deny is the type returned by a decider when it denies an input (the input is invalid)
//! type Deny = String;
//!
//! // The context is the type on which "finalizers" (the actual command handler) will run
//! type Context = i32;
//!
//! // This is a `spec` (command specification)
//! const SPEC: Spec<Accept, Deny, Context> = (&[("my-command-name", Some(&DEC))], print_hello);
//!
//! fn print_hello(_ctx: &mut Context, args: &[Accept]) -> Result<String, String> {
//! println!("Hello world!");
//! assert_eq!(1, args.len());
//! println!("The args I got: {:?}", args);
//! Ok("".into())
//! }
//!
//! // This decider accepts only a single number
//! fn decider_function(input: &[&str], out: &mut SVec<Accept>) -> Decision<Deny> {
//! if input.is_empty() {
//! return Decision::Deny("No argument provided".into());
//! }
//! let num = input[0].parse::<i32>();
//! if let Ok(num) = num {
//! out.push(Accept::I32(num));
//! Decision::Accept(1)
//! } else {
//! Decision::Deny("Number is not a valid i32".into())
//! }
//! }
//!
//! const DEC: Decider<Accept, Deny> = Decider {
//! description: "<i32>",
//! decider: decider_function,
//! };
//!
//! let mut mapping = Mapping::default();
//! mapping.register(SPEC).unwrap();
//!
//! let handler = mapping.lookup(&["my-command-name", "123"]);
//!
//! match handler {
//! Ok((func, buf)) => {
//! let mut ctx = 0i32;
//! func(&mut ctx, &buf); // prints hello world
//! }
//! Err(look_err) => {
//! println!("{:?}", look_err);
//! assert!(false);
//! }
//! }
//! ```
//!
//! This library also allows partial lookups and iterating over the direct descendants in order
//! to make autocomplete easy to implement for terminal interfaces.
//! ```
//! use cmdmat::{Decider, Decision, Mapping, MappingEntry, Spec, SVec};
//!
//! #[derive(Debug)]
//! enum Accept {
//! I32(i32),
//! }
//! type Deny = String;
//! type Context = i32;
//!
//! const SPEC: Spec<Accept, Deny, Context> =
//! (&[("my-command-name", Some(&DEC)), ("something", None)], print_hello);
//!
//! fn print_hello(_ctx: &mut Context, args: &[Accept]) -> Result<String, String> {
//! Ok("".into())
//! }
//!
//! fn decider_function(input: &[&str], out: &mut SVec<Accept>) -> Decision<Deny> {
//! if input.is_empty() {
//! return Decision::Deny("No argument provided".into());
//! }
//! let num = input[0].parse::<i32>();
//! if let Ok(num) = num {
//! out.push(Accept::I32(num));
//! Decision::Accept(1)
//! } else {
//! Decision::Deny("Number is not a valid i32".into())
//! }
//! }
//!
//! const DEC: Decider<Accept, Deny> = Decider {
//! description: "<i32>",
//! decider: decider_function,
//! };
//!
//! let mut mapping = Mapping::default();
//! mapping.register(SPEC).unwrap();
//!
//! // When a decider is "next-up", we get its description
//! // We can't know in advance what the decider will consume because it is arbitrary code,
//! // so we will have to trust its description to be valuable.
//! let decider_desc = mapping.partial_lookup(&["my-command-name"]).unwrap().right().unwrap();
//! assert_eq!("<i32>", decider_desc);
//!
//! // In this case the decider succeeded during the partial lookup, so the next step in the
//! // tree is the "something" node.
//! let mapping = mapping.partial_lookup(&["my-command-name", "123"]).unwrap().left().unwrap();
//! let MappingEntry { literal, decider, finalizer, submap } = mapping.get_direct_keys().next().unwrap();
//! assert_eq!("something", literal);
//! assert!(decider.is_none());
//! assert!(finalizer.is_some());
//! ```
#![deny(
missing_docs,
trivial_casts,
trivial_numeric_casts,
unsafe_code,
unused_import_braces,
unused_qualifications
)]
#![feature(test, try_trait_v2)]
extern crate test;
use smallvec::SmallVec;
use std::{
collections::HashMap,
convert::Infallible,
ops::{ControlFlow, FromResidual, Try},
};
// ---
/// A specific-sized small vector
pub type SVec<A> = SmallVec<[A; 8]>;
/// The command specification format
pub type Spec<'b, 'a, A, D, C> = (
&'b [(&'static str, Option<&'a Decider<A, D>>)],
Finalizer<A, C>,
);
/// A finalizer is the function that runs to handle the entirety of the command after it has been
/// verified by the deciders.
pub type Finalizer<A, C> = fn(&mut C, &[A]) -> Result<String, String>;
/// Finalizer with associated vector of arguments
pub type FinWithArgs<'o, A, C> = (Finalizer<A, C>, SVec<A>);
/// Either a mapping or a descriptor of a mapping
pub type MapOrDesc<'a, 'b, A, D, C> = Either<&'b Mapping<'a, A, D, C>, &'a str>;
// ---
/// Either sum type
pub enum Either<L, R> {
/// Left variant
Left(L),
/// Right variant
Right(R),
}
impl<L, R> Either<L, R> {
/// Convert [Either] into [Option].
pub fn left(self) -> Option<L> {
match self {
Either::Left(left) => Some(left),
Either::Right(_) => None,
}
}
/// Convert [Either] into [Option].
pub fn right(self) -> Option<R> {
match self {
Either::Left(_) => None,
Either::Right(right) => Some(right),
}
}
}
// ---
/// A decision contains information about token consumption by the decider
///
/// If the decider has accepted the tokens, it will return an `Accept(usize)`, if it failed to
/// parse interpret the tokens, it will return a deny value.
#[derive(Debug, PartialEq)]
pub enum Decision<D> {
/// Accept any number of inputs
Accept(usize),
/// Deny the input
Deny(D),
}
impl<R> FromResidual<Result<Infallible, R>> for Decision<R> {
fn from_residual(residual: Result<Infallible, R>) -> Self {
Decision::Deny(residual.err().unwrap())
}
}
impl<D> FromResidual<D> for Decision<D> {
fn from_residual(residual: D) -> Self {
Decision::Deny(residual)
}
}
impl<D> Try for Decision<D> {
type Output = usize;
type Residual = D;
fn from_output(output: Self::Output) -> Self {
Decision::Accept(output)
}
fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
match self {
Decision::Accept(value) => ControlFlow::Continue(value),
Decision::Deny(value) => ControlFlow::Break(value),
}
}
}
/// A decider is a function taking in a sequence of tokens and an output array
///
/// It puts tokens into the output array according to interal logic and returns how many elements
/// it has consumed. If it could not process the input tokens it will return a `Deny`, containing
/// the reason for denying.
pub struct Decider<A, D> {
/// The description of the decider. Used in help and error messages.
pub description: &'static str,
/// Decider function, takes a list of inputs and writes it to the list of outputs, returns a
/// decision that informs the machinery how to continue, by either telling it to consume N
/// items or to deny the input.
pub decider: fn(&[&str], &mut SVec<A>) -> Decision<D>,
}
/// Errors we can get by registering specs.
#[derive(Debug, PartialEq)]
pub enum RegError {
/// Decider for this node already exists
DeciderAlreadyExists,
/// Finalizer for this node already exists
FinalizerAlreadyExists,
}
/// Errors happening during lookup of a command.
#[derive(Debug, PartialEq)]
pub enum LookError<D> {
/// Decider consumed more than available input
DeciderAdvancedTooFar,
/// Decider denies the input
DeciderDenied(String, D),
/// A finalizer does not exist for this entry
FinalizerDoesNotExist,
/// The mapping element does not exist
UnknownMapping(String),
}
/// An entry in the mapping table
pub struct MappingEntry<'a, A, D, C> {
/// The literal this mapping entry is matched against
pub literal: &'a str,
/// The decider function for miscellaneous arguments
pub decider: Option<&'a Decider<A, D>>,
/// The finalizer function for this mapping
pub finalizer: Option<Finalizer<A, C>>,
/// Submap containing all other literal-mapping pairs
pub submap: &'a HashMap<&'a str, Mapping<'a, A, D, C>>,
}
// ---
/// Node in the matching tree
///
/// A `Mapping` is used to interface with `cmdmat`. Each node defines a point in a command tree,
/// containing subcommands, deciders for argument parsing, and a finalizer if this mapping can be
/// run.
pub struct Mapping<'a, A, D, C> {
map: HashMap<&'a str, Mapping<'a, A, D, C>>,
decider: Option<&'a Decider<A, D>>,
finalizer: Option<Finalizer<A, C>>,
}
impl<'a, A, D, C> Default for Mapping<'a, A, D, C> {
fn default() -> Self {
Mapping {
map: HashMap::new(),
decider: None,
finalizer: None,
}
}
}
impl<'a, A, D, C> Mapping<'a, A, D, C> {
/// Register many command specs at once, see [Mapping::register] for more detail
pub fn register_many<'b>(&mut self, spec: &[Spec<'b, 'a, A, D, C>]) -> Result<(), RegError> {
for subspec in spec {
self.register(subspec.clone())?;
}
Ok(())
}
/// Register a single command specification into the tree
///
/// The specification will be merged with existing command specifications, and may not
/// overwrite commands with new deciders or finalizers. The overriding decider must be `None`
/// to avoid an error.
pub fn register<'b>(&mut self, spec: Spec<'b, 'a, A, D, C>) -> Result<(), RegError> {
if spec.0.is_empty() {
if self.finalizer.is_some() {
return Err(RegError::FinalizerAlreadyExists);
}
self.finalizer = Some(spec.1);
return Ok(());
}
let key = spec.0[0].0;
let decider = spec.0[0].1;
if let Some(ref mut entry) = self.map.get_mut(key) {
if decider.is_some() {
return Err(RegError::DeciderAlreadyExists);
}
entry.register((&spec.0[1..], spec.1))?;
} else {
let mut mapping = Mapping::<A, D, C> {
map: HashMap::new(),
decider,
finalizer: None,
};
mapping.register((&spec.0[1..], spec.1))?;
self.map.insert(key, mapping);
}
Ok(())
}
/// Looks up a command and runs deciders to collect all arguments
pub fn lookup(&self, input: &[&str]) -> Result<FinWithArgs<A, C>, LookError<D>> {
let mut output = SVec::<A>::new();
match self.lookup_internal(input, &mut output) {
Ok((finalizer, _advance)) => Ok((finalizer, output)),
Err(err) => Err(err),
}
}
/// Looks up a command and runs deciders to collect all arguments
fn lookup_internal(
&self,
input: &[&str],
output: &mut SVec<A>,
) -> Result<(Finalizer<A, C>, usize), LookError<D>> {
if input.is_empty() {
if let Some(finalizer) = self.finalizer {
return Ok((finalizer, 0));
} else {
return Err(LookError::FinalizerDoesNotExist);
}
}
if let Some(handler) = self.map.get(&input[0]) {
let mut advance_output = 0;
if let Some(ref decider) = handler.decider {
match (decider.decider)(&input[1..], output) {
Decision::Accept(byte_count) => {
advance_output = byte_count;
}
Decision::Deny(res) => {
return Err(LookError::DeciderDenied(decider.description.into(), res));
}
}
}
if input.len() > advance_output {
let res = handler.lookup_internal(&input[1 + advance_output..], output);
if let Ok(mut res) = res {
res.1 += advance_output;
return Ok(res);
} else {
return res;
}
} else {
return Err(LookError::DeciderAdvancedTooFar);
}
}
Err(LookError::UnknownMapping(input[0].to_string()))
}
/// Iterator over the current `Mapping` keys: containing subcommands
pub fn get_direct_keys(&self) -> impl Iterator<Item = MappingEntry<'_, A, D, C>> {
self.map.iter().map(|(k, v)| MappingEntry {
literal: *k,
decider: v.decider,
finalizer: v.finalizer,
submap: &v.map,
})
}
/// Acquire any intermediate mapping, discards parsed inputs
pub fn partial_lookup<'b>(
&'b self,
input: &'b [&str],
) -> Result<MapOrDesc<'a, 'b, A, D, C>, LookError<D>> {
let mut output = SVec::<A>::new();
self.partial_lookup_internal(input, &mut output)
}
/// Perform a partial lookup, useful for autocompletion
///
/// Due to the node structure of `Mapping`, this function returns either a `Mapping` or a
/// `&str` describing the active decider.
fn partial_lookup_internal<'b>(
&'b self,
input: &'b [&str],
output: &mut SVec<A>,
) -> Result<MapOrDesc<'a, 'b, A, D, C>, LookError<D>> {
if input.is_empty() {
return Ok(Either::Left(self));
}
if let Some(handler) = self.map.get(&input[0]) {
let mut advance_output = 0;
if let Some(ref decider) = handler.decider {
if input.len() == 1 {
return Ok(Either::Right(decider.description));
}
match (decider.decider)(&input[1..], output) {
Decision::Accept(res) => {
advance_output = res;
}
Decision::Deny(res) => {
return Err(LookError::DeciderDenied(decider.description.into(), res));
}
}
}
if input.len() > advance_output {
return handler.partial_lookup_internal(&input[1 + advance_output..], output);
} else {
return Err(LookError::DeciderAdvancedTooFar);
}
}
Err(LookError::UnknownMapping(input[0].to_string()))
}
/// Get the decider associated with this node
pub fn decider(&self) -> &Option<&'a Decider<A, D>> {
&self.decider
}
/// Get the finalizer associated with this node
pub fn finalizer(&self) -> &Option<Finalizer<A, C>> {
&self.finalizer
}
/// Iterator looping over all submappings
pub fn iter(&self) -> impl Iterator<Item = (&&'a str, &Mapping<'a, A, D, C>)> {
self.map.iter()
}
}
// ---
#[cfg(test)]
mod tests {
use super::*;
use test::{black_box, Bencher};
// ---
type Accept = bool;
type Context = u32;
fn add_one(ctx: &mut Context, _: &[Accept]) -> Result<String, String> {
*ctx += 1;
Ok("".into())
}
// ---
#[test]
fn single_mapping() {
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping.register((&[("add-one", None)], add_one)).unwrap();
let handler = mapping.lookup(&["add-one"]).unwrap();
assert_eq!(0, handler.1.len());
let mut ctx = 123;
handler.0(&mut ctx, &handler.1).unwrap();
assert_eq!(124, ctx);
}
#[test]
fn mapping_does_not_exist() {
let mapping: Mapping<Accept, (), Context> = Mapping::default();
if let Err(err) = mapping.lookup(&["add-one"]) {
assert_eq!(LookError::UnknownMapping("add-one".into()), err);
} else {
assert!(false);
}
}
#[test]
fn overlapping_decider_fails() {
fn decide(_: &[&str], _: &mut SVec<Accept>) -> Decision<()> {
Decision::Deny(())
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping.register((&[("add-one", None)], add_one)).unwrap();
assert_eq!(
Err(RegError::DeciderAlreadyExists),
mapping.register((&[("add-one", Some(&DECIDE))], add_one))
);
}
#[test]
fn sequences_decider_fails() {
fn decide(_: &[&str], _: &mut SVec<Accept>) -> Decision<()> {
Decision::Deny(())
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((&[("add-one", Some(&DECIDE))], add_one))
.unwrap();
if let Err(err) = mapping.register((&[("add-one", None)], add_one)) {
assert_eq!(RegError::FinalizerAlreadyExists, err);
} else {
assert!(false);
}
}
#[test]
fn decider_of_one() {
fn decide(_: &[&str], out: &mut SVec<Accept>) -> Decision<()> {
out.push(true);
Decision::Accept(1)
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((&[("add-one", Some(&DECIDE))], add_one))
.unwrap();
let out = mapping.lookup(&["add-one", "123"]).unwrap();
assert_eq!(1, out.1.len());
assert_eq!(true, out.1[0]);
}
#[test]
fn decider_of_two_overrun() {
fn decide(_: &[&str], out: &mut SVec<Accept>) -> Decision<()> {
out.push(true);
out.push(true);
Decision::Accept(2)
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((&[("add-one", Some(&DECIDE))], add_one))
.unwrap();
if let Err(err) = mapping.lookup(&["add-one", "123"]) {
assert_eq!(LookError::DeciderAdvancedTooFar, err);
} else {
assert!(false);
}
}
#[test]
fn decider_of_two() {
fn decide(_: &[&str], out: &mut SVec<Accept>) -> Decision<()> {
out.push(true);
out.push(false);
Decision::Accept(2)
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((&[("add-one", Some(&DECIDE))], add_one))
.unwrap();
let output = mapping.lookup(&["add-one", "123", "456"]).unwrap().1;
assert_eq!(2, output.len());
assert_eq!(true, output[0]);
assert_eq!(false, output[1]);
}
#[test]
fn decider_of_two_short_output() {
fn decide(_: &[&str], _: &mut SVec<Accept>) -> Decision<()> {
Decision::Accept(2)
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "",
decider: decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((&[("add-one", Some(&DECIDE))], add_one))
.unwrap();
let output = mapping.lookup(&["add-one", "123", "456"]).unwrap();
assert_eq!(0, output.1.len());
}
#[test]
fn decider_of_many() {
fn decide(input: &[&str], out: &mut SVec<i32>) -> Decision<()> {
for i in input.iter() {
let number = i.parse::<i32>();
if let Ok(number) = number {
out.push(number);
} else {
return Decision::Deny(());
}
}
Decision::Accept(input.len())
}
const DECIDE: Decider<i32, ()> = Decider {
description: "",
decider: decide,
};
fn do_sum(ctx: &mut u32, out: &[i32]) -> Result<String, String> {
for i in out {
*ctx += *i as u32;
}
Ok("".into())
}
let mut mapping: Mapping<i32, (), Context> = Mapping::default();
mapping
.register((&[("sum", Some(&DECIDE))], do_sum))
.unwrap();
let handler = mapping.lookup(&["sum", "123", "456", "789"]).unwrap();
assert_eq!(3, handler.1.len());
let mut ctx = 0;
handler.0(&mut ctx, &handler.1).unwrap();
assert_eq!(1368, ctx);
}
#[test]
fn nested() {
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((
&[("lorem", None), ("ipsum", None), ("dolor", None)],
add_one,
))
.unwrap();
mapping.lookup(&["lorem", "ipsum", "dolor"]).unwrap();
if let Err(err) = mapping.lookup(&["lorem", "ipsum", "dolor", "exceed"]) {
assert_eq!(LookError::UnknownMapping("exceed".into()), err);
} else {
assert!(false);
}
if let Err(err) = mapping.lookup(&["lorem", "ipsum"]) {
assert_eq!(LookError::FinalizerDoesNotExist, err);
} else {
assert!(false);
}
}
#[test]
fn finalizer_at_multiple_levels() {
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((
&[("lorem", None), ("ipsum", None), ("dolor", None)],
add_one,
))
.unwrap();
mapping
.register((&[("lorem", None), ("ipsum", None)], add_one))
.unwrap();
mapping.lookup(&["lorem", "ipsum", "dolor"]).unwrap();
if let Err(err) = mapping.lookup(&["lorem", "ipsum", "dolor", "exceed"]) {
assert_eq!(LookError::UnknownMapping("exceed".into()), err);
} else {
assert!(false);
}
mapping.lookup(&["lorem", "ipsum"]).unwrap();
}
#[test]
fn partial_lookup() {
fn decide(_: &[&str], _: &mut SVec<Accept>) -> Decision<()> {
Decision::Accept(0)
}
const DECIDE: Decider<Accept, ()> = Decider {
description: "Do nothing",
decider: decide,
};
fn consume_decide(input: &[&str], _: &mut SVec<Accept>) -> Decision<()> {
if input.is_empty() {
Decision::Deny(())
} else {
Decision::Accept(1)
}
}
const CONSUME_DECIDE: Decider<Accept, ()> = Decider {
description: "Consume a single element, regardless of what it is",
decider: consume_decide,
};
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((
&[("lorem", None), ("ipsum", None), ("dolor", None)],
add_one,
))
.unwrap();
mapping
.register((&[("lorem", None), ("ipsum", None)], add_one))
.unwrap();
mapping
.register((&[("mirana", None), ("ipsum", Some(&DECIDE))], add_one))
.unwrap();
mapping
.register((
&[("consume", Some(&CONSUME_DECIDE)), ("dummy", None)],
add_one,
))
.unwrap();
let part = mapping
.partial_lookup(&["lorem", "ipsum"])
.unwrap()
.left()
.unwrap();
let key = part.get_direct_keys().next().unwrap();
assert_eq!("dolor", key.literal);
assert!(key.decider.is_none());
assert!(key.finalizer.is_some());
let part = mapping.partial_lookup(&["lorem"]).unwrap().left().unwrap();
let key = part.get_direct_keys().next().unwrap();
assert_eq!("ipsum", key.literal);
assert!(key.decider.is_none());
assert!(key.finalizer.is_some());
let part = mapping.partial_lookup(&["mirana"]).unwrap().left().unwrap();
let key = part.get_direct_keys().next().unwrap();
assert_eq!("ipsum", key.literal);
assert!(key.decider.is_some());
assert_eq!("Do nothing", key.decider.unwrap().description);
assert!(key.finalizer.is_some());
let part = mapping
.partial_lookup(&["consume", "123"])
.unwrap()
.left()
.unwrap();
let key = part.get_direct_keys().next().unwrap();
assert_eq!("dummy", key.literal);
assert!(key.decider.is_none());
assert!(key.finalizer.is_some());
let part = mapping
.partial_lookup(&["consume"])
.unwrap()
.right()
.unwrap();
assert_eq!("Consume a single element, regardless of what it is", part);
}
// ---
#[quickcheck_macros::quickcheck]
fn default_contains_no_elements(strings: Vec<String>) -> bool {
type Accept = ();
type Deny = ();
type Context = ();
let strings_ref = strings.iter().map(|s| &s[..]).collect::<Vec<_>>();
let mapping: Mapping<Accept, Deny, Context> = Mapping::default();
match mapping.lookup(&strings_ref[..]) {
Err(LookError::UnknownMapping(string)) => string == strings[0],
Err(LookError::FinalizerDoesNotExist) => strings.is_empty(),
_ => false,
}
}
// ---
#[bench]
fn lookup_speed(b: &mut Bencher) {
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((
&[("lorem", None), ("ipsum", None), ("dolor", None)],
add_one,
))
.unwrap();
b.iter(|| {
black_box(mapping.lookup(black_box(&["lorem", "ipsum", "dolor"]))).unwrap();
});
}
#[bench]
fn partial_lookup_speed(b: &mut Bencher) {
let mut mapping: Mapping<Accept, (), Context> = Mapping::default();
mapping
.register((
&[("lorem", None), ("ipsum", None), ("dolor", None)],
add_one,
))
.unwrap();
b.iter(|| {
mapping.partial_lookup(black_box(&["lorem"])).unwrap();
});
}
}