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use parol_runtime::TerminalIndex;
use crate::analysis::compiled_terminal::{EPS, INVALID};
use crate::{CompiledTerminal, MAX_K};
use std::fmt::{Debug, Display, Error, Formatter};
use std::hash::{Hash, Hasher};
const EOI: TerminalIndex = 0;
const NEW_LINE: TerminalIndex = 1;
const WHITESPACE: TerminalIndex = 2;
const LINE_COMMENT: TerminalIndex = 3;
const BLOCK_COMMENT: TerminalIndex = 4;
/// Common functions needed for terminal handling
pub trait TerminalMappings<T> {
/// Create an epsilon representation
fn eps() -> T;
/// Create an end-of-input representation
fn end() -> T;
/// Check for epsilon
fn is_eps(&self) -> bool;
/// Check for end-of-input
fn is_end(&self) -> bool;
/// Check for invalid (i.e. unassigned) terminal
fn is_inv(&self) -> bool;
}
/// When storing MAX_K terminals in 128 bits, the maximum number of bits used per terminal is 12.
const MAX_BITS: u8 = (std::mem::size_of::<u128>() * 8) as u8 / MAX_K as u8;
/// A collection of terminals
///
/// The terminals are stored in a 128 bit integer where each terminal is stored in a fixed number of
/// bits. The number of bits is determined by the number of terminals to store.
/// The maximum number of terminals when storing MAX_K terminals in 128 bits is:
/// 128 / MAX_K = 128 / 10 = 12.8 => 12 bits
/// The maximum number of terminals that can be stored is 2^12 = 4096.
/// The maximum value of the bit count is therefore 12 and can safely be stored in four bits.
/// We store a mask to more easily extract the terminals from the 128 bits unsigned integer.
/// The mask to extract single terminals from the 128 bit unsigned integer is calculated as
/// 2^bits - 1 that is equivalent to the expression !(!0u128 << bits) at runtime.
///
/// Since we use only 120 bits to store the terminals, we have 8 bits left. We use the 8 bits to
/// store the index of the next insertion as well as the bit count used to calculate the mask.
/// Therefore we split the highest 8 bits of the 128 bits unsigned integer as follows:
/// - The higher 4 bits are used to store the number of bits used per terminal
/// - The lower 4 bits are used to store the index of the next insertion
#[derive(Clone, Copy, Default, Hash, Eq, PartialEq)]
pub struct Terminals {
t: u128,
}
impl Terminals {
/// Creates a new item
/// ```
/// use parol::analysis::k_tuple::Terminals;
/// use parol::analysis::compiled_terminal::CompiledTerminal;
/// let t = Terminals::new(1);
/// assert!(t.is_empty());
/// assert_eq!(0, t.len(), "len");
/// assert_eq!(0, t.k_len(5), "k_len");
/// assert_eq!(None, t.get(0));
/// assert_eq!(None, t.get(9));
/// ```
pub fn new(max_terminal_index: usize) -> Self {
// max_terminal_index + 1: we also need to store EPS
let bits = (max_terminal_index + 1).ilog2() as u8 + 1;
if bits > MAX_BITS {
panic!(
"The number of bits required to store {} terminals is {} which is greater than the maximum of {}",
max_terminal_index + 1, bits, MAX_BITS
);
}
let mut this = Self { t: 0 };
this.set_bits(bits);
this
}
/// Creates a new item with epsilon semantic
/// ```
/// use parol::analysis::k_tuple::{Terminals, TerminalMappings};
/// use parol::analysis::compiled_terminal::CompiledTerminal;
/// let t = Terminals::eps(1);
/// assert!(!t.is_empty());
/// assert_eq!(1, t.len(), "len");
/// assert_eq!(1, t.k_len(5), "k_len");
/// assert_eq!(Some(CompiledTerminal::eps()), t.get(0));
/// assert_eq!(None, t.get(1));
/// assert_eq!(None, t.get(9));
/// ```
pub fn eps(max_terminal_index: usize) -> Terminals {
let mut t = Self::new(max_terminal_index);
t.set(0, CompiledTerminal(EPS));
t.set_next_index(1);
t
}
/// Creates a new item with end (EOI) semantic
/// Such a terminal can't be extended, i.e. you can't append more terminals
/// ```
/// use parol::analysis::k_tuple::{Terminals, TerminalMappings};
/// use parol::analysis::compiled_terminal::CompiledTerminal;
/// let t = Terminals::end(1);
/// assert!(!t.is_empty());
/// assert_eq!(1, t.len());
/// assert_eq!(1, t.k_len(5));
/// assert_eq!(Some(CompiledTerminal::end()), t.get(0));
/// assert_eq!(None, t.get(1));
/// assert_eq!(None, t.get(9));
/// ```
pub fn end(max_terminal_index: usize) -> Terminals {
let mut t = Self::new(max_terminal_index);
// t.t = 0; // EOI as u128 & t.mask;
t.set_next_index(1);
t
}
///
/// Creates a new object with maximum k length from another object
///
#[must_use]
pub fn of(k: usize, other: Self) -> Self {
let bits = other.bits();
let mask = other.mask();
let i = other.k_len(k) as u8;
let mut copy_mask = 0u128;
(0..i).for_each(|_| {
copy_mask <<= bits as usize;
copy_mask |= mask;
});
let t = other.t & copy_mask;
let mut t = Self { t };
t.set_bits(bits);
t.set_next_index(i);
t
}
/// Returns the length of the collection
#[inline]
pub fn len(&self) -> usize {
self.next_index() as usize
}
/// Checks if the collection is empty
#[inline]
pub fn is_empty(&self) -> bool {
self.next_index() == 0
}
/// Returns the index of the next insertion
/// The highest 8 bits of t are used to store the index of the next insertion in it's lowest 4
/// bits.
#[inline]
pub fn next_index(&self) -> u8 {
((self.t & 0x0F00_0000_0000_0000_0000_0000_0000_0000) >> 120) as u8
}
/// Sets the index of the next insertion
#[inline]
fn set_next_index(&mut self, i: u8) {
self.t &= 0xF0FF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF;
self.t |= (i as u128) << 120;
}
/// Increments the index of the next insertion
#[inline]
pub fn inc_index(&mut self) {
let i = self.next_index() + 1;
self.t &= 0xF0FF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF;
self.t |= (i as u128) << 120;
}
/// Returns the bits used per terminal
/// The highest 8 bits of t are used to store the number of bits used per terminal in it's highest
/// 4 bits.
/// ```
/// use parol::analysis::k_tuple::Terminals;
/// let t = Terminals::eps(1);
/// assert_eq!(2, t.bits());
/// ```
#[inline]
pub fn bits(&self) -> u8 {
((self.t & 0xF000_0000_0000_0000_0000_0000_0000_0000) >> 124) as u8
}
/// Sets the number of bits used per terminal
#[inline]
pub fn set_bits(&mut self, bits: u8) {
self.t &= 0x0FFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF;
self.t |= (bits as u128) << 124;
debug_assert_ne!(self.bits(), 0, "Bits must not be 0");
}
/// Returns the mask used to extract the terminal at position i
/// The mask is calculated as 2^bits - 1 that is equivalent to the expression !(!0u128 << bits).
#[inline]
pub fn mask(&self) -> u128 {
!(!0u128 << self.bits())
}
#[must_use]
fn last(&self) -> Option<CompiledTerminal> {
if self.is_empty() {
None
} else {
self.get(self.next_index() as usize - 1)
}
}
/// Checks if the collection is k-complete, i.e. no terminals can be added
/// ```
/// use parol::analysis::k_tuple::Terminals;
/// let t = Terminals::end(1);
/// assert!(t.is_k_complete(5));
/// ```
pub fn is_k_complete(&self, k: usize) -> bool {
!self.is_eps() && (self.len() >= k || self.last().map_or(false, |t| t.is_end()))
}
/// Returns the k-length, i.e. the number of symbols that contributes to lookahead sizes
#[must_use]
pub fn k_len(&self, k: usize) -> usize {
std::cmp::min(self.len(), k)
}
/// Clears the collection
pub fn clear(&mut self) {
let bits = self.bits();
self.t = 0;
self.set_bits(bits);
debug_assert_ne!(self.bits(), 0, "Bits must not be 0");
}
/// Concatenates two collections with respect to the rules of k-concatenation
/// ```
/// use parol::analysis::k_tuple::{Terminals, TerminalMappings};
/// use parol::analysis::compiled_terminal::CompiledTerminal;
/// let t1 = Terminals::eps(1);
/// let t2 = Terminals::end(1);
/// let t = t1.k_concat(&t2, 5);
/// assert!(t.is_k_complete(5));
/// assert_eq!(1, t.len());
/// assert_eq!(Some(CompiledTerminal::end()), t.get(0));
/// let t = t2.k_concat(&t1, 5);
/// assert!(t.is_k_complete(5));
/// assert_eq!(1, t.len());
/// assert_eq!(Some(CompiledTerminal::end()), t.get(0));
/// let mut t1 = Terminals::new(6);
/// t1.extend([1, 2, 3].iter().cloned());
/// let mut t2 = Terminals::new(6);
/// t2.extend([4, 5, 6].iter().cloned());
/// let t = t1.k_concat(&t2, 5);
/// assert!(t.is_k_complete(5));
/// assert_eq!(5, t.len());
/// assert_eq!(Some(CompiledTerminal(1)), t.get(0));
/// assert_eq!(Some(CompiledTerminal(2)), t.get(1));
/// assert_eq!(Some(CompiledTerminal(3)), t.get(2));
/// assert_eq!(Some(CompiledTerminal(4)), t.get(3));
/// assert_eq!(Some(CompiledTerminal(5)), t.get(4));
/// assert_eq!(None, t.get(5));
/// ```
pub fn k_concat(mut self, other: &Self, k: usize) -> Self {
debug_assert!(
other.bits() == self.bits(),
"Bits must be the same, self:({:?}) != other:({:?})",
self,
other
);
debug_assert_ne!(self.bits(), 0, "Bits must not be 0");
if other.is_eps() || other.is_empty() {
// w + ε = w
return self;
}
if self.is_eps() {
// ε + w = w
// Remove possible epsilon terminal
self.clear();
}
if self.is_k_complete(k) {
// k: w would be the same as k: (w + x)
return self;
}
let my_k_len = self.k_len(k);
let other_len = other.k_len(k);
let to_take = std::cmp::min(k - my_k_len, other_len);
if to_take == 0 {
// We can't take any more terminals
debug_assert!(
false,
"to_take == 0, self:({:?}), other:({:?})",
self, other
);
return self;
};
let bits = self.bits();
// Mask out the other value with a length of to_take
// Shift the other value to the left by the length of my_k_len
let value =
(other.t & !(!0u128 << (to_take * bits as usize))) << (my_k_len * bits as usize);
// Add the other value to self
self.t |= value;
self.set_next_index((my_k_len + to_take) as u8);
self.set_bits(bits);
self
}
/// Adds a new terminal to self if max size is not reached yet and if last is not EOI
pub fn push(&mut self, t: CompiledTerminal) -> Result<(), String> {
if self.next_index() >= MAX_K as u8 {
return Err("Maximum number of terminals reached".to_owned());
}
if matches!(self.last(), Some(CompiledTerminal(EOI))) {
return Ok(());
}
debug_assert_ne!(t.0, INVALID, "Invalid terminal");
self.set(self.next_index().into(), t);
self.inc_index();
Ok(())
}
/// Checks if self is an Epsilon
#[inline]
pub fn is_eps(&self) -> bool {
if self.next_index() != 1 {
return false;
}
let mask = self.mask();
(self.t & mask) == mask
}
/// Creates an iterator over the terminals
pub fn iter(&self) -> TermIt {
TermIt::new(*self)
}
/// Returns the terminal at position i
pub fn get(&self, i: usize) -> Option<CompiledTerminal> {
if i < self.next_index() as usize {
let mut terminal_index = (self.t >> (i * self.bits() as usize)) & self.mask();
if terminal_index == self.mask() {
// Epsilon is defined as 0xFFFF and stored as a value identical to self.mask, i.e. all
// bits set to 1. We need to convert it back to 0xFFFF.
terminal_index = EPS as u128;
}
Some(CompiledTerminal(terminal_index as TerminalIndex))
} else {
None
}
}
/// Sets the terminal at position i
pub fn set(&mut self, i: usize, t: CompiledTerminal) {
let terminal_mask = self.mask();
debug_assert!(
t.0 <= terminal_mask as TerminalIndex || t.0 == EPS as TerminalIndex,
"Terminal index {} out of range",
t.0
);
debug_assert_ne!(t.0, INVALID, "Invalid terminal");
let bits = self.bits() as usize;
let v = (t.0 as u128 & terminal_mask) << (i * bits);
let mask = !(terminal_mask << (i * bits));
self.t &= mask;
self.t |= v;
}
}
impl Ord for Terminals {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
match self.next_index().cmp(&other.next_index()) {
std::cmp::Ordering::Less => std::cmp::Ordering::Less,
std::cmp::Ordering::Equal => {
<&Self as Into<u128>>::into(self).cmp(&<&Self as Into<u128>>::into(other))
}
std::cmp::Ordering::Greater => std::cmp::Ordering::Greater,
}
}
}
impl PartialOrd for Terminals {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.cmp(other))
}
}
impl Display for Terminals {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
write!(
f,
"[{}(i{})]",
(0..self.next_index())
.map(|i| format!("{}", self.get(i as usize).unwrap()))
.collect::<Vec<String>>()
.join(", "),
self.next_index(),
)
}
}
// Used for comparison in implementation of Ord
impl From<&Terminals> for u128 {
fn from(t: &Terminals) -> Self {
// Mask out the unused bits although it should not be necessary
t.t & !(!0u128 << (t.next_index() * t.bits()) as usize)
}
}
impl Extend<CompiledTerminal> for Terminals {
fn extend<I: IntoIterator<Item = CompiledTerminal>>(&mut self, iter: I) {
for t in iter {
let _ = self.push(t);
}
}
}
impl Extend<TerminalIndex> for Terminals {
fn extend<I: IntoIterator<Item = TerminalIndex>>(&mut self, iter: I) {
for t in iter {
let _ = self.push(CompiledTerminal(t));
}
}
}
impl Debug for Terminals {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(
f,
"0b{:b}, i:{}, bits:0x{:x}, mask:0x{:x}",
self.t,
self.next_index(),
self.bits(),
self.mask()
)
}
}
/// Iterator for Terminals
/// It returns the terminal indices
#[derive(Debug)]
pub struct TermIt {
/// A copy of the Terminals object.
/// During iteration, the member t is shifted to the right by bits and the terminal is extracted
/// by masking the lowest bits.
t: Terminals,
/// The current index
i: usize,
/// The number of bits used per terminal
bits: usize,
/// The mask to extract the terminal
mask: u128,
/// The number of terminals in the collection
len: usize,
}
impl TermIt {
fn new(t: Terminals) -> Self {
Self {
t,
i: 0,
bits: t.bits() as usize,
mask: t.mask(),
len: t.next_index() as usize,
}
}
}
impl Iterator for TermIt {
type Item = TerminalIndex;
fn next(&mut self) -> Option<Self::Item> {
if self.i < self.len {
let t = self.t.t & self.mask;
// Prepare for the next iteration
self.t.t >>= self.bits;
self.i += 1;
if t == self.mask {
// Epsilon is defined as 0xFFFF and stored as a value identical to self.mask, i.e.
// all bits set to 1. We need to convert it back to 0xFFFF.
Some(EPS)
} else {
Some(t as TerminalIndex)
}
} else {
None
}
}
}
/// Terminal string with support for k-completeness
#[derive(Clone, Copy, Hash, Eq, PartialEq, Ord, PartialOrd)]
pub enum TerminalString {
/// Incomplete sequence
Incomplete(Terminals),
/// k-complete sequence
Complete(Terminals),
}
impl TerminalString {
/// Returns the length of the sequence
pub fn len(&self) -> usize {
self.inner().len()
}
/// Checks if the sequence is empty
pub fn is_empty(&self) -> bool {
self.inner().is_empty()
}
/// Checks if the sequence is k-complete
pub fn is_k_complete(&self) -> bool {
match self {
Self::Incomplete(_) => false,
Self::Complete(_) => true,
}
}
/// Checks if the inner sequence is k-complete
pub fn is_complete(&self, k: usize) -> bool {
self.inner().is_k_complete(k)
}
/// Change the state to k-complete
pub fn make_complete(self) -> Self {
if let Self::Incomplete(e) = self {
Self::Complete(e)
} else {
self
}
}
/// Revoke the k-complete state
pub fn make_incomplete(self) -> Self {
if let Self::Complete(e) = self {
Self::Incomplete(e)
} else {
self
}
}
/// Clear the sequences
pub fn clear(self) -> Self {
let mut inner = match self {
Self::Incomplete(t) | Self::Complete(t) => t,
};
inner.clear();
Self::Incomplete(inner)
}
/// Return the inner sequences
pub fn inner(&self) -> &Terminals {
match self {
Self::Incomplete(v) => v,
Self::Complete(v) => v,
}
}
/// Checks if self is an Epsilon
pub fn is_eps(&self) -> bool {
match self {
Self::Incomplete(v) => v.is_eps(),
Self::Complete(_) => false,
}
}
/// Push a new terminal
pub fn push(&mut self, t: CompiledTerminal, k: usize) -> Result<(), String> {
match self {
Self::Incomplete(v) => {
v.push(t)?;
if v.is_k_complete(k) {
*self = Self::Complete(*v);
}
}
Self::Complete(_) => {}
}
Ok(())
}
/// Concat self with another sequence while consuming self
pub fn k_concat(self, other: &Self, k: usize) -> Self {
match self {
Self::Incomplete(v) => {
let terminals = v.k_concat(other.inner(), k);
if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
}
}
Self::Complete(_) => self,
}
}
}
impl Display for TerminalString {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
match self {
Self::Incomplete(v) => write!(f, "Incomplete({})", v),
Self::Complete(v) => write!(f, "Complete ({})", v),
}
}
}
impl Debug for TerminalString {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
match self {
Self::Incomplete(v) => write!(f, "Incomplete({:?})", v),
Self::Complete(v) => write!(f, "Complete ({:?})", v),
}
}
}
/// A builder for KTuple
#[derive(Clone, Default)]
pub struct KTupleBuilder<'a> {
k: Option<usize>,
max_terminal_index: Option<usize>,
k_tuple: Option<&'a KTuple>,
terminal_string: Option<&'a [TerminalIndex]>,
}
impl<'a> KTupleBuilder<'a> {
/// Creates a new builder
pub fn new() -> Self {
Self::default()
}
/// Sets the lookahead size
pub fn k(mut self, k: usize) -> Self {
self.k = Some(k);
self
}
/// Sets the maximum terminal index
pub fn max_terminal_index(mut self, max_terminal_index: usize) -> Self {
self.max_terminal_index = Some(max_terminal_index);
self
}
/// Sets the k-tuple to be used during construction
pub fn k_tuple(mut self, k_tuple: &'a KTuple) -> Self {
self.k_tuple = Some(k_tuple);
self
}
/// Sets the terminal string to be used during construction
pub fn terminal_string(mut self, terminal_string: &'a [TerminalIndex]) -> Self {
self.terminal_string = Some(terminal_string);
self
}
/// Builds a new KTuple
pub fn build(self) -> Result<KTuple, String> {
if self.k.is_none() {
return Err("k is not set".to_owned());
}
if self.max_terminal_index.is_none() {
return Err("max_terminal_index is not set".to_owned());
}
let k = self.k.unwrap_or(0);
let max_terminal_index = self.max_terminal_index.unwrap_or(0);
if let Some(k_tuple) = self.k_tuple {
let mut terminals = Terminals::new(max_terminal_index);
for t in k_tuple.terminals.inner().iter().take(k) {
terminals.push(CompiledTerminal(t))?;
}
let terminals = if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
};
Ok(KTuple {
terminals,
k: std::cmp::min(k, MAX_K),
})
} else if let Some(terminal_string) = self.terminal_string {
let mut terminals = Terminals::new(max_terminal_index);
for t in terminal_string.iter().take(k) {
terminals.push(CompiledTerminal(*t))?;
}
let terminals = if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
};
Ok(KTuple {
terminals,
k: std::cmp::min(k, MAX_K),
})
} else {
Err("k_tuple or terminal_string must be set".to_owned())
}
}
///
/// Creates a new ε object
///
pub fn eps(self) -> Result<KTuple, String> {
if self.k.is_none() {
return Err("k is not set".to_owned());
}
if self.max_terminal_index.is_none() {
return Err("max_terminal_index is not set".to_owned());
}
let terminals =
TerminalString::Incomplete(Terminals::eps(self.max_terminal_index.unwrap()));
Ok(KTuple {
terminals,
k: self.k.unwrap(),
})
}
///
/// Creates a new End object
///
pub fn end(self) -> Result<KTuple, String> {
if self.k.is_none() {
return Err("k is not set".to_owned());
}
if self.max_terminal_index.is_none() {
return Err("max_terminal_index is not set".to_owned());
}
let terminals = TerminalString::Complete(Terminals::end(self.max_terminal_index.unwrap()));
Ok(KTuple {
terminals,
k: self.k.unwrap(),
})
}
}
// ---------------------------------------------------
// Part of the Public API
// *Changes will affect crate's version according to semver*
// ---------------------------------------------------
///
/// Terminal symbol string type
///
#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
pub struct KTuple {
/// The sequence of terminals
terminals: TerminalString,
/// The lookahead size
k: usize,
}
impl KTuple {
/// Used for debugging only
pub fn with_terminal_indices(self, terms: &[TerminalIndex]) -> Self {
let k = self.k;
let mut terminals = match self.terminals {
TerminalString::Incomplete(s) => s,
TerminalString::Complete(s) => s,
};
terms.iter().take(k).enumerate().for_each(|(i, t)| {
terminals.set(i, CompiledTerminal(*t));
terminals.inc_index();
});
let terminals = if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
};
Self { terminals, k }
}
///
/// Creates a new object from a slice of CompiledTerminals
///
pub fn from_slice(others: &[CompiledTerminal], k: usize, max_terminal_index: usize) -> Self {
let mut terminals = Terminals::new(max_terminal_index);
terminals.extend(others.iter().take(k).cloned());
let terminals = if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
};
Self { terminals, k }
}
///
/// Creates a new object from a vector of terminal symbols
///
pub fn of(t: Terminals, k: usize) -> Self {
let terminals = Terminals::of(k, t);
let terminals = if terminals.is_k_complete(k) {
TerminalString::Complete(terminals)
} else {
TerminalString::Incomplete(terminals)
};
Self { terminals, k }
}
/// Adds a new terminal to self while consuming self
pub fn push(&mut self, t: CompiledTerminal) -> Result<(), String> {
self.terminals.push(t, self.k)
}
/// Checks if self is an Epsilon
pub fn is_eps(&self) -> bool {
self.terminals.is_eps()
}
/// Returns the length of the sequence
pub fn len(&self) -> usize {
self.terminals.len()
}
/// Checks if the sequence is empty
pub fn is_empty(&self) -> bool {
self.terminals.is_empty()
}
/// Returns the k-length of the sequence
pub fn k_len(&self, k: usize) -> usize {
self.terminals.inner().k_len(k)
}
/// Checks if the sequence is k-complete
pub fn is_k_complete(&self) -> bool {
self.terminals.is_k_complete()
}
/// Concat self with another sequence while consuming self
pub fn k_concat(self, other: &Self, k: usize) -> Self {
let terminals = self.terminals.k_concat(&other.terminals, k);
let k = terminals.inner().k_len(k);
Self { terminals, k }
}
/// Sets the lookahead size
pub fn set_k(mut self, k: usize) -> Self {
if self.terminals.is_complete(k) {
self.terminals = self.terminals.make_complete();
} else {
self.terminals = self.terminals.make_incomplete();
}
self.k = k;
self
}
/// Conversion to string with the help of the terminals slice
pub fn to_string(&self, terminals: &[String]) -> String {
format!(
"[{}]",
self.terminals
.inner()
.iter()
.map(|t| match t {
EOI => "$".to_owned(),
NEW_LINE => "NewLine".to_owned(),
WHITESPACE => "WhiteSpace".to_owned(),
LINE_COMMENT => "LineComment".to_owned(),
BLOCK_COMMENT => "BlockComment".to_owned(),
EPS => "\u{03B5}".to_owned(),
_ => terminals[t as usize].to_string(),
})
.collect::<Vec<String>>()
.join(", ")
)
}
/// Returns the k value
#[inline]
pub fn k(&self) -> usize {
self.k
}
/// Returns the terminals
#[inline]
pub fn terminals(&self) -> &Terminals {
self.terminals.inner()
}
}
impl Debug for KTuple {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
write!(
f,
"[{:?}(i{})](k{})",
self.terminals,
self.terminals.inner().next_index(),
self.k
)
}
}
impl Display for KTuple {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
write!(
f,
"[{}(i{})](k{})",
self.terminals,
self.terminals.inner().next_index(),
self.k
)
}
}
impl Hash for KTuple {
fn hash<H: Hasher>(&self, state: &mut H) {
let self_inner = self.terminals.inner();
self_inner.t.hash(state)
}
}
impl Extend<CompiledTerminal> for KTuple {
fn extend<I: IntoIterator<Item = CompiledTerminal>>(&mut self, iter: I) {
if !self.terminals.is_k_complete() {
for t in iter.into_iter().take(self.k - self.len()) {
let _ = self.push(t);
}
}
}
}
impl Extend<TerminalIndex> for KTuple {
fn extend<I: IntoIterator<Item = TerminalIndex>>(&mut self, iter: I) {
if !self.terminals.is_k_complete() {
for t in iter.into_iter().take(self.k - self.len()) {
let _ = self.push(CompiledTerminal(t));
}
}
}
}
#[cfg(test)]
mod test {
use parol_runtime::TerminalIndex;
use super::{TerminalString, Terminals};
use crate::{
analysis::k_tuple::{KTupleBuilder, EOI},
CompiledTerminal, KTuple, MAX_K,
};
fn term(terminals: &[TerminalIndex], k: usize, max_terminal_index: usize) -> Terminals {
debug_assert!(k <= MAX_K);
let mut t = Terminals::new(max_terminal_index);
t.extend(terminals.iter().map(|t| CompiledTerminal(*t)));
t
}
#[test]
fn test_terminals_bits() {
let terminals = Terminals::new(6);
assert_eq!(3, terminals.bits());
}
#[test]
fn test_terminals_set_bits() {
let mut terminals = Terminals::new(6);
terminals.set_bits(0b1010);
assert_eq!(0b1010, terminals.bits());
terminals.set_bits(0b1100);
assert_eq!(0b1100, terminals.bits());
}
#[test]
fn test_terminals_mask() {
let terminals = Terminals::new(6);
assert_eq!(terminals.mask(), 0b111);
}
#[test]
fn test_terminals_next_index() {
let mut terminals = Terminals::new(6);
assert_eq!(0, terminals.next_index());
terminals.set_next_index(3);
assert_eq!(3, terminals.next_index());
}
#[test]
fn test_terminals_set_next_index() {
let mut terminals = Terminals::new(6);
assert_eq!(0, terminals.next_index());
terminals.set_next_index(3);
assert_eq!(3, terminals.next_index());
terminals.set_next_index(5);
assert_eq!(5, terminals.next_index());
}
#[test]
fn test_terminals_inc_index() {
let mut terminals = Terminals::new(6);
assert_eq!(0, terminals.next_index());
terminals.inc_index();
assert_eq!(1, terminals.next_index());
terminals.inc_index();
assert_eq!(2, terminals.next_index());
}
#[test]
fn check_terminals_k_concat() {
// let t1 = Terminals::eps(1);
// let t2 = Terminals::end(1);
// let t = t1.k_concat(&t2, 5);
// assert!(t.is_k_complete(5));
// assert_eq!(1, t.len());
// assert_eq!(Some(CompiledTerminal(EOI)), t.get(0));
// let t = t2.k_concat(&t1, 5);
// assert!(t.is_k_complete(5));
// assert_eq!(1, t.len());
// assert_eq!(Some(CompiledTerminal(EOI)), t.get(0));
let mut t1 = Terminals::new(6);
t1.extend([1, 2, 3].iter().cloned());
let mut t2 = Terminals::new(6);
t2.extend([4, 5, 6].iter().cloned());
let t = t1.k_concat(&t2, 5);
assert!(t.is_k_complete(5));
assert_eq!(5, t.len());
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(2)), t.get(1));
assert_eq!(Some(CompiledTerminal(3)), t.get(2));
assert_eq!(Some(CompiledTerminal(4)), t.get(3));
assert_eq!(Some(CompiledTerminal(5)), t.get(4));
assert_eq!(None, t.get(5));
}
#[test]
fn check_with_terminal_indices() {
{
let k_tuple = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.terminal_string(&[1])
.build()
.unwrap();
let t = term(&[1], 1, 1);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: 1,
};
assert_eq!(None, t.get(1));
assert_eq!(None, t.get(MAX_K - 1));
assert_eq!(expected, k_tuple, "[1]");
}
{
let k_tuple = KTupleBuilder::new()
.k(MAX_K)
.max_terminal_index(10)
.terminal_string(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
.build()
.unwrap();
let t = term(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10], MAX_K, 10);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: MAX_K,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(10)), t.get(MAX_K - 1));
assert_eq!(expected, k_tuple, "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]");
}
{
let k_tuple = KTupleBuilder::new()
.k(5)
.max_terminal_index(10)
.terminal_string(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
.build()
.unwrap();
let t = term(&[1, 2, 3, 4, 5], 5, 10);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: 5,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(5)), t.get(4));
assert_eq!(None, t.get(5));
assert_eq!(expected, k_tuple, "[1, 2, 3, 4, 5]");
}
}
#[test]
fn check_from_slice() {
{
let k_tuple = KTuple::from_slice(&[CompiledTerminal(1)], 1, 1);
let t = term(&[1], 1, 1);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: 1,
};
assert_eq!(None, t.get(1));
assert_eq!(None, t.get(MAX_K - 1));
assert_eq!(expected, k_tuple, "[1]");
}
{
let k_tuple = KTuple::from_slice(
&[
CompiledTerminal(1),
CompiledTerminal(2),
CompiledTerminal(3),
CompiledTerminal(4),
CompiledTerminal(5),
CompiledTerminal(6),
CompiledTerminal(7),
CompiledTerminal(8),
CompiledTerminal(9),
CompiledTerminal(10),
],
MAX_K,
10,
);
let t = term(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10], MAX_K, 10);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: MAX_K,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(10)), t.get(MAX_K - 1));
assert_eq!(expected, k_tuple);
}
{
let k_tuple = KTuple::from_slice(
&[
CompiledTerminal(1),
CompiledTerminal(2),
CompiledTerminal(3),
CompiledTerminal(4),
CompiledTerminal(5),
CompiledTerminal(6),
CompiledTerminal(7),
CompiledTerminal(8),
CompiledTerminal(9),
CompiledTerminal(10),
],
5,
10,
);
let t = term(&[1, 2, 3, 4, 5], 5, 10);
let expected = KTuple {
terminals: TerminalString::Complete(t),
k: 5,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(5)), t.get(4));
assert_eq!(None, t.get(5));
assert_eq!(expected, k_tuple, "[1, 2, 3, 4, 5]");
}
}
#[test]
fn check_k_tuple_of() {
{
let k = 1;
let mut t = Terminals::new(1);
t.extend([1]);
let k_tuple = KTuple::of(t, k);
let mut t2 = Terminals::new(1);
t2.extend([1]);
let expected = KTuple {
terminals: TerminalString::Complete(t2),
k,
};
assert_eq!(None, t.get(1));
assert_eq!(None, t.get(MAX_K - 1));
assert_eq!(expected, k_tuple, "[1]");
}
{
let k = MAX_K;
let mut t = Terminals::new(11);
t.extend([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
let k_tuple = KTuple::of(t, k);
assert_eq!(MAX_K, k_tuple.len());
let mut t2 = Terminals::new(11);
t2.extend([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
let expected = KTuple {
terminals: TerminalString::Complete(t2),
k,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(10)), t.get(MAX_K - 1));
assert_eq!(expected, k_tuple, "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]");
}
{
let k = 5;
let mut t = Terminals::new(11);
t.extend([1, 2, 3, 4, 5]);
let k_tuple = KTuple::of(t, k);
let mut t2 = Terminals::new(11);
t2.extend([1, 2, 3, 4, 5]);
let expected = KTuple {
terminals: TerminalString::Complete(t2),
k,
};
assert_eq!(Some(CompiledTerminal(1)), t.get(0));
assert_eq!(Some(CompiledTerminal(5)), t.get(4));
assert_eq!(None, t.get(5));
assert_eq!(expected, k_tuple, "[1, 2, 3, 4, 5]");
}
}
#[test]
fn check_k_concat() {
{
let tuple1 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.eps()
.unwrap();
let tuple2 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.eps()
.unwrap();
let result = tuple1.k_concat(&tuple2, 1);
let expected = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.eps()
.unwrap();
assert_eq!(expected, result, "1: [ε] + [ε] = [ε]");
}
{
let tuple1 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.terminal_string(&[1])
.build()
.unwrap();
let tuple2 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.eps()
.unwrap();
let result = tuple1.k_concat(&tuple2, 1);
let expected = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.terminal_string(&[1])
.build()
.unwrap();
assert_eq!(expected, result, "1: [a] + [ε] = [a]");
}
{
let tuple1 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.eps()
.unwrap();
let tuple2 = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.terminal_string(&[1])
.build()
.unwrap();
let result = tuple1.k_concat(&tuple2, 1);
let expected = KTupleBuilder::new()
.k(1)
.max_terminal_index(1)
.terminal_string(&[1])
.build()
.unwrap();
assert_eq!(expected, result, "1: [ε] + [a] = [a]");
}
{
let tuple1 = KTupleBuilder::new()
.k(2)
.max_terminal_index(2)
.terminal_string(&[1])
.build()
.unwrap();
let tuple2 = KTupleBuilder::new()
.k(2)
.max_terminal_index(2)
.terminal_string(&[2])
.build()
.unwrap();
let result = tuple1.k_concat(&tuple2, 2);
let expected = KTupleBuilder::new()
.k(2)
.max_terminal_index(1)
.terminal_string(&[1, 2])
.build()
.unwrap();
assert_eq!(expected, result, "2: [a] + [b] = [ab]");
}
}
#[test]
fn check_term() {
{
let terminals = Terminals::new(4);
assert_eq!(0, terminals.k_len(0));
assert_eq!(0, terminals.k_len(1));
assert_eq!(0, terminals.k_len(2));
assert!(terminals.is_k_complete(0));
assert!(!terminals.is_k_complete(1));
assert!(!terminals.is_k_complete(2));
assert!(!terminals.is_k_complete(3));
}
{
let terminals = term(&[1], 1, 4);
assert_eq!(0, terminals.k_len(0));
assert_eq!(1, terminals.k_len(1));
assert_eq!(1, terminals.k_len(2));
assert!(terminals.is_k_complete(0));
assert!(terminals.is_k_complete(1));
assert!(!terminals.is_k_complete(2));
assert!(!terminals.is_k_complete(3));
}
{
let terminals = term(&[1, 2], 2, 4);
assert_eq!(0, terminals.k_len(0));
assert_eq!(1, terminals.k_len(1));
assert_eq!(2, terminals.k_len(2));
assert_eq!(2, terminals.k_len(3));
assert!(terminals.is_k_complete(0));
assert!(terminals.is_k_complete(1));
assert!(terminals.is_k_complete(2));
assert!(!terminals.is_k_complete(3));
}
{
let terminals = term(&[1, EOI], 2, 4);
assert_eq!(0, terminals.k_len(0));
assert_eq!(1, terminals.k_len(1));
assert_eq!(2, terminals.k_len(2));
assert_eq!(2, terminals.k_len(3));
assert!(terminals.is_k_complete(0));
assert!(terminals.is_k_complete(1));
assert!(terminals.is_k_complete(2));
assert!(terminals.is_k_complete(3));
}
{
let terminals = term(
&[
1, EOI, 1, // This constellation is actually illegal!
],
3,
1,
);
assert_eq!(0, terminals.k_len(0));
assert_eq!(1, terminals.k_len(1));
assert_eq!(2, terminals.k_len(2));
assert_eq!(2, terminals.k_len(3));
assert!(terminals.is_k_complete(0));
assert!(terminals.is_k_complete(1));
assert!(terminals.is_k_complete(2));
assert!(terminals.is_k_complete(3));
let terminals2 = term(&[3], 1, 1);
let result = terminals.k_concat(&terminals2, 3);
let expected = term(&[1, EOI, 1], 3, 1);
assert_eq!(expected, result);
}
}
#[test]
fn test_iteration_of_terminals() {
let terminals = term(&[1, 2, 3, 4, 5], 5, 5);
let mut iter = terminals.iter();
assert_eq!(Some(1), iter.next());
assert_eq!(Some(2), iter.next());
assert_eq!(Some(3), iter.next());
assert_eq!(Some(4), iter.next());
assert_eq!(Some(5), iter.next());
assert_eq!(None, iter.next());
}
}