wip: fix dsl
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🪞👃🪞 2025-07-16 00:10:03 +03:00
parent ca4c558eab
commit e72225f83c
11 changed files with 421 additions and 574 deletions

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@ -7,6 +7,7 @@ edition = { workspace = true }
[dependencies]
tengri_core = { path = "../core" }
konst = { workspace = true }
const_panic = { workspace = true }
itertools = { workspace = true }
thiserror = { workspace = true }

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@ -1,38 +0,0 @@
//! The abstract syntax tree (AST) can be produced from the CST
//! by cloning source slices into owned ([Arc]) string slices.
use crate::*;
#[derive(Debug, Clone, Default, PartialEq)]
pub struct Ast(pub Arc<VecDeque<DslVal<Arc<str>, Ast>>>);
impl Dsl for Ast {
type Str = Arc<str>;
type Exp = Ast;
fn nth (&self, index: usize) -> Option<DslVal<Self::Str, Self::Exp>> {
self.0.get(index).cloned()
}
}
impl<'s> From<Cst<'s>> for Ast {
fn from (cst: Cst<'s>) -> Self {
Self(VecDeque::from([dsl_val(cst.val())]).into())
}
}
impl<'s> From<CstIter<'s>> for Ast {
fn from (cst: CstIter<'s>) -> Self {
Self(cst.map(|x|x.value.into()).collect::<VecDeque<_>>().into())
}
}
impl<'s> From<CstVal<'s>> for Ast {
fn from (cst: CstVal<'s>) -> Self {
Self(VecDeque::from([dsl_val(cst.val())]).into())
}
}
impl<'s> From<DslVal<&'s str, CstIter<'s>>> for DslVal<Arc<str>, Ast> {
fn from (cst: DslVal<&'s str, CstIter<'s>>) -> Self {
dsl_val(cst)
}
}

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@ -1,312 +0,0 @@
//! The concrete syntax tree (CST) implements zero-copy
//! parsing of the DSL from a string reference. CST items
//! preserve info about their location in the source.
use crate::*;
/// CST stores strings as source references and expressions as [CstIter] instances.
#[derive(Debug, Clone, Default, PartialEq)]
pub struct Cst<'s>(pub CstIter<'s>);
impl<'s> Dsl for Cst<'s> {
type Str = &'s str;
type Exp = CstIter<'s>;
fn nth (&self, index: usize) -> Option<DslVal<Self::Str, Self::Exp>> {
self.0.nth(index)
}
}
/// Parsed substring with range and value.
#[derive(Debug, Copy, Clone, Default, PartialEq)]
pub struct CstVal<'s> {
/// Meaning of token.
pub value: DslVal<&'s str, CstIter<'s>>,
/// Reference to source text.
pub source: &'s str,
/// Index of 1st character of token.
pub start: usize,
/// Length of token.
pub length: usize,
}
impl<'s> Dsl for CstVal<'s> {
type Str = &'s str;
type Exp = CstIter<'s>;
fn nth (&self, index: usize) -> Option<DslVal<Self::Str, Self::Exp>> {
todo!()
}
}
impl<'s> CstVal<'s> {
pub const fn new (
source: &'s str,
start: usize,
length: usize,
value: DslVal<&'s str, CstIter<'s>>
) -> Self {
Self { source, start, length, value }
}
pub const fn end (&self) -> usize {
self.start.saturating_add(self.length)
}
pub const fn slice (&'s self) -> &'s str {
self.slice_source(self.source)
}
pub const fn slice_source <'range> (&'s self, source: &'range str) -> &'range str {
str_range(source, self.start, self.end())
}
pub const fn slice_source_exp <'range> (&'s self, source: &'range str) -> &'range str {
str_range(source, self.start.saturating_add(1), self.end())
}
pub const fn with_value (self, value: DslVal<&'s str, CstIter<'s>>) -> Self {
Self { value, ..self }
}
pub const fn value (&self) -> DslVal<&'s str, CstIter<'s>> {
self.value
}
pub const fn error (self, error: DslErr) -> Self {
Self { value: DslVal::Err(error), ..self }
}
pub const fn grow (self) -> Self {
Self { length: self.length.saturating_add(1), ..self }
}
pub const fn grow_num (self, m: usize, c: char) -> Self {
match to_digit(c) {
Result::Ok(n) => Self { value: DslVal::Num(10*m+n), ..self.grow() },
Result::Err(e) => Self { value: DslVal::Err(e), ..self.grow() },
}
}
pub const fn grow_key (self) -> Self {
let token = self.grow();
token.with_value(DslVal::Key(token.slice_source(self.source)))
}
pub const fn grow_sym (self) -> Self {
let token = self.grow();
token.with_value(DslVal::Sym(token.slice_source(self.source)))
}
pub const fn grow_str (self) -> Self {
let token = self.grow();
token.with_value(DslVal::Str(token.slice_source(self.source)))
}
pub const fn grow_exp (self) -> Self {
let token = self.grow();
if let DslVal::Exp(depth, _) = token.value() {
token.with_value(DslVal::Exp(depth, CstIter::new(token.slice_source_exp(self.source))))
} else {
unreachable!()
}
}
pub const fn grow_in (self) -> Self {
let token = self.grow_exp();
if let DslVal::Exp(depth, source) = token.value() {
token.with_value(DslVal::Exp(depth.saturating_add(1), source))
} else {
unreachable!()
}
}
pub const fn grow_out (self) -> Self {
let token = self.grow_exp();
if let DslVal::Exp(depth, source) = token.value() {
if depth > 0 {
token.with_value(DslVal::Exp(depth - 1, source))
} else {
return self.error(Unexpected(')'))
}
} else {
unreachable!()
}
}
}
/// Provides a native [Iterator] API over [CstConstIter],
/// emitting [Cst] items.
///
/// [Cst::next] returns just the [Cst] and mutates `self`,
/// instead of returning an updated version of the struct as [CstConstIter::next] does.
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub struct CstIter<'s>(pub CstConstIter<'s>);
impl<'s> Dsl for CstIter<'s> {
type Str = &'s str;
type Exp = Self;
fn nth (&self, index: usize) -> Option<DslVal<Self::Str, Self::Exp>> {
self.0.nth(index).map(|x|dsl_val(x))
}
}
impl<'s> CstIter<'s> {
pub const fn new (source: &'s str) -> Self {
Self(CstConstIter::new(source))
}
pub const fn peek (&self) -> Option<CstVal<'s>> {
self.0.peek()
}
}
impl<'s> Iterator for CstIter<'s> {
type Item = CstVal<'s>;
fn next (&mut self) -> Option<CstVal<'s>> {
self.0.next().map(|(item, rest)|{
self.0 = rest;
item
})
}
}
impl<'s> Into<Vec<CstVal<'s>>> for CstIter<'s> {
fn into (self) -> Vec<CstVal<'s>> {
self.collect()
}
}
impl<'s> Into<Vec<Ast>> for CstIter<'s> {
fn into (self) -> Vec<Ast> {
self.map(Into::into).collect()
}
}
/// Owns a reference to the source text.
/// [CstConstIter::next] emits subsequent pairs of:
/// * a [Cst] and
/// * the source text remaining
/// * [ ] TODO: maybe [CstConstIter::next] should wrap the remaining source in `Self` ?
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub struct CstConstIter<'s>(pub &'s str);
impl<'s> Dsl for CstConstIter<'s> {
type Str = &'s str;
type Exp = Self;
fn nth (&self, mut index: usize) -> Option<DslVal<Self::Str, Self::Exp>> {
use DslVal::*;
let mut iter = self.clone();
for i in 0..index {
iter = iter.next()?.1
}
iter.next().map(|(x, _)|dsl_val(x.value))
}
}
impl<'s> CstConstIter<'s> {
pub const fn new (source: &'s str) -> Self {
Self(source)
}
pub const fn chomp (&self, index: usize) -> Self {
Self(split_at(self.0, index).1)
}
pub const fn next (mut self) -> Option<(CstVal<'s>, Self)> {
Self::next_mut(&mut self)
}
pub const fn peek (&self) -> Option<CstVal<'s>> {
peek_src(self.0)
}
pub const fn next_mut (&mut self) -> Option<(CstVal<'s>, Self)> {
match self.peek() {
Some(token) => Some((token, self.chomp(token.end()))),
None => None
}
}
}
impl<'s> From<CstConstIter<'s>> for CstIter<'s> {
fn from (iter: CstConstIter<'s>) -> Self {
Self(iter)
}
}
impl<'s> From<CstIter<'s>> for CstConstIter<'s> {
fn from (iter: CstIter<'s>) -> Self {
iter.0
}
}
/// Implement the const iterator pattern.
macro_rules! const_iter {
($(<$l:lifetime>)?|$self:ident: $Struct:ty| => $Item:ty => $expr:expr) => {
impl$(<$l>)? Iterator for $Struct {
type Item = $Item;
fn next (&mut $self) -> Option<$Item> { $expr }
}
impl$(<$l>)? ConstIntoIter for $Struct {
type Kind = IsIteratorKind;
type Item = $Item;
type IntoIter = Self;
}
}
}
const_iter!(<'s>|self: CstConstIter<'s>|
=> CstVal<'s>
=> self.next_mut().map(|(result, _)|result));
/// Static iteration helper used by [cst].
macro_rules! iterate {
($expr:expr => $arg: pat => $body:expr) => {
let mut iter = $expr;
while let Some(($arg, next)) = iter.next() {
$body;
iter = next;
}
}
}
pub const fn peek_src <'s> (source: &'s str) -> Option<CstVal<'s>> {
use DslVal::*;
let mut token: CstVal<'s> = CstVal::new(source, 0, 0, Nil);
iterate!(char_indices(source) => (start, c) => token = match token.value() {
Err(_) => return Some(token),
Nil => match c {
' '|'\n'|'\r'|'\t' =>
token.grow(),
'(' =>
CstVal::new(source, start, 1, Exp(1, CstIter::new(str_range(source, start, start + 1)))),
'"' =>
CstVal::new(source, start, 1, Str(str_range(source, start, start + 1))),
':'|'@' =>
CstVal::new(source, start, 1, Sym(str_range(source, start, start + 1))),
'/'|'a'..='z' =>
CstVal::new(source, start, 1, Key(str_range(source, start, start + 1))),
'0'..='9' =>
CstVal::new(source, start, 1, match to_digit(c) {
Ok(c) => DslVal::Num(c),
Result::Err(e) => DslVal::Err(e)
}),
_ => token.error(Unexpected(c))
},
Str(_) => match c {
'"' => return Some(token),
_ => token.grow_str(),
},
Num(n) => match c {
'0'..='9' => token.grow_num(n, c),
' '|'\n'|'\r'|'\t'|')' => return Some(token),
_ => token.error(Unexpected(c))
},
Sym(_) => match c {
'a'..='z'|'A'..='Z'|'0'..='9'|'-' => token.grow_sym(),
' '|'\n'|'\r'|'\t'|')' => return Some(token),
_ => token.error(Unexpected(c))
},
Key(_) => match c {
'a'..='z'|'0'..='9'|'-'|'/' => token.grow_key(),
' '|'\n'|'\r'|'\t'|')' => return Some(token),
_ => token.error(Unexpected(c))
},
Exp(depth, _) => match depth {
0 => return Some(token.grow_exp()),
_ => match c {
')' => token.grow_out(),
'(' => token.grow_in(),
_ => token.grow_exp(),
}
},
});
match token.value() {
Nil => None,
_ => Some(token),
}
}
pub const fn to_number (digits: &str) -> DslResult<usize> {
let mut value = 0;
iterate!(char_indices(digits) => (_, c) => match to_digit(c) {
Ok(digit) => value = 10 * value + digit,
Result::Err(e) => return Result::Err(e)
});
Ok(value)
}
pub const fn to_digit (c: char) -> DslResult<usize> {
Ok(match c {
'0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4,
'5' => 5, '6' => 6, '7' => 7, '8' => 8, '9' => 9,
_ => return Result::Err(Unexpected(c))
})
}

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@ -1,178 +0,0 @@
use crate::*;
use std::error::Error;
/// Standard result type for DSL-specific operations.
pub type DslResult<T> = Result<T, DslErr>;
/// DSL-specific error codes.
#[derive(Error, Debug, Copy, Clone, PartialEq)] pub enum DslErr {
#[error("parse failed: not implemented")]
Unimplemented,
#[error("parse failed: empty")]
Empty,
#[error("parse failed: incomplete")]
Incomplete,
#[error("parse failed: unexpected character '{0}'")]
Unexpected(char),
#[error("parse failed: error #{0}")]
Code(u8),
}
/// Enumeration of possible DSL tokens.
/// Generic over string and expression storage.
///
/// * [ ] FIXME: Value may be [Err] which may shadow [Result::Err]
/// * [DslVal::Exp] wraps an expression depth and a [CstIter]
/// with the remaining part of the expression.
/// * expression depth other that 0 mean unclosed parenthesis.
/// * closing and unopened parenthesis panics during reading.
/// * [ ] TODO: signed depth might be interesting
/// * [DslVal::Sym] and [DslVal::Key] are stringish literals
/// with slightly different parsing rules.
/// * [DslVal::Num] is an unsigned integer literal.
#[derive(Clone, Debug, PartialEq, Default)]
pub enum DslVal<Str, Exp> {
#[default]
Nil,
Err(DslErr),
Num(usize),
Sym(Str),
Key(Str),
Str(Str),
Exp(usize, Exp),
}
pub fn dsl_val <A: Into<X>, B: Into<Y>, X, Y> (val: DslVal<A, B>) -> DslVal<X, Y> {
use DslVal::*;
match val {
Nil => Nil,
Err(e) => Err(e),
Num(u) => Num(u),
Sym(s) => Sym(s.into()),
Key(s) => Key(s.into()),
Str(s) => Str(s.into()),
Exp(d, x) => Exp(d, x.into()),
}
}
pub trait Dsl: Debug {
type Str: PartialEq + Clone + Default + Debug + AsRef<str>;
type Exp: PartialEq + Clone + Default + Debug + Dsl;
fn nth (&self, index: usize) -> Option<DslVal<Self::Str, Self::Exp>>;
fn val (&self) -> DslVal<Self::Str, Self::Exp> {
self.nth(0).unwrap_or(DslVal::Nil)
}
// exp-only nth here?
}
impl<
Str: PartialEq + Clone + Default + Debug + AsRef<str>,
Exp: PartialEq + Clone + Default + Debug + Dsl,
> Dsl for DslVal<Str, Exp> {
type Str = Str;
type Exp = Exp;
fn val (&self) -> DslVal<Str, Exp> {
self.clone()
}
fn nth (&self, _index: usize) -> Option<DslVal<Str, Exp>> {
todo!()
}
}
/// May construct self from state and DSL.
pub trait DslFrom<State>: Sized {
fn try_dsl_from (state: &State, value: &impl Dsl) -> Perhaps<Self>;
fn dsl_from (
state: &State, value: &impl Dsl, error: impl Fn()->Box<dyn Error>
) -> Usually<Self> {
match Self::try_dsl_from(state, value)? {
Some(value) => Ok(value),
_ => Err(error())
}
}
}
/// May construct another from self and DSL.
pub trait DslInto<Item> {
fn try_dsl_into (&self, dsl: &impl Dsl) -> Perhaps<Item>;
fn dsl_into (
&self, value: &impl Dsl, error: impl Fn()->Box<dyn Error>
) -> Usually<Item> {
match Self::try_dsl_into(self, value)? {
Some(value) => Ok(value),
_ => Err(error())
}
}
}
impl<Str, Exp> DslVal<Str, Exp> {
pub fn is_nil (&self) -> bool {
matches!(self, Self::Nil)
}
pub fn as_err (&self) -> Option<&DslErr> {
if let Self::Err(e) = self { Some(e) } else { None }
}
pub fn as_num (&self) -> Option<usize> {
if let Self::Num(n) = self { Some(*n) } else { None }
}
pub fn as_exp (&self) -> Option<&Exp> {
if let Self::Exp(_, x) = self { Some(x) } else { None }
}
pub fn exp_depth (&self) -> Option<usize> {
todo!()
}
pub fn exp_head (&self) -> Option<&Self> {
todo!()
} // TODO
pub fn exp_tail (&self) -> Option<&Exp> {
todo!()
} // TODO
pub fn peek (&self) -> Option<Self> {
todo!()
}
pub fn next (&mut self) -> Option<Self> {
todo!()
}
pub fn rest (self) -> Vec<Self> {
todo!()
}
}
impl<Str: Copy, Exp: Copy> Copy for DslVal<Str, Exp> {}
impl<Str: AsRef<str>, Exp> DslVal<Str, Exp> {
pub fn as_sym (&self) -> Option<&str> {
if let Self::Sym(s) = self { Some(s.as_ref()) } else { None }
}
pub fn as_key (&self) -> Option<&str> {
if let Self::Key(k) = self { Some(k.as_ref()) } else { None }
}
pub fn as_str (&self) -> Option<&str> {
if let Self::Str(s) = self { Some(s.as_ref()) } else { None }
}
pub fn exp_match <T, F> (&self, namespace: &str, cb: F) -> Perhaps<T>
where F: Fn(&str, &Exp)-> Perhaps<T> {
if let Some(Self::Key(key)) = self.exp_head()
&& key.as_ref().starts_with(namespace)
&& let Some(tail) = self.exp_tail() {
cb(key.as_ref().split_at(namespace.len()).1, tail)
} else {
Ok(None)
}
}
}
macro_rules! from_str {
($Struct:ty |$source:ident| $expr:expr) => {
impl<'s> From<&'s str> for $Struct {
fn from ($source: &'s str) -> Self {
$expr
}
}
}
}
from_str!(Ast|source|Self::from(CstIter::from(source)));
from_str!(Cst<'s>|source|Self(CstIter(CstConstIter(source))));
from_str!(CstIter<'s>|source|Self(CstConstIter(source)));
from_str!(CstConstIter<'s>|source|Self::new(source));

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@ -1,17 +1,376 @@
#![feature(adt_const_params)]
#![feature(type_alias_impl_trait)]
#![feature(impl_trait_in_fn_trait_return)]
#![feature(const_precise_live_drops)]
extern crate const_panic;
use const_panic::{concat_panic, PanicFmt};
pub(crate) use ::tengri_core::*;
pub(crate) use std::error::Error;
pub(crate) use std::fmt::Debug;
pub(crate) use std::sync::Arc;
pub(crate) use std::collections::VecDeque;
pub(crate) use konst::iter::{ConstIntoIter, IsIteratorKind};
pub(crate) use konst::string::{split_at, str_range, char_indices};
pub(crate) use thiserror::Error;
pub(crate) use self::DslErr::*;
mod dsl; pub use self::dsl::*;
mod ast; pub use self::ast::*;
mod cst; pub use self::cst::*;
pub(crate) use self::DslError::*;
#[cfg(test)] mod test;
pub type DslUsually<T> = Result<T, DslError>;
pub type DslPerhaps<T> = Result<Option<T>, DslError>;
/// Pronounced dizzle.
pub trait Dsl: Clone + Debug {
/// The string representation for a dizzle.
type Str: DslStr;
/// The expression representation for a dizzle.
type Exp: DslExp;
/// Return a token iterator for this dizzle.
fn dsl (&self) -> DslUsually<&Val<Self>>;
}
/// Enumeration of values representable by a DSL [Token]s.
/// Generic over string and expression storage.
#[derive(Clone, Debug, PartialEq, Default)]
pub enum Val<D: Dsl> {
#[default]
Nil,
/// Unsigned integer literal
Num(usize),
/// Tokens that start with `:`
Sym(D::Str),
/// Tokens that don't start with `:`
Key(D::Str),
/// Quoted string literals
Str(D::Str),
/// Expressions.
Exp(
/// Expression depth checksum. Must be 0, otherwise you have an unclosed delimiter.
usize,
/// Expression content.
D::Exp
),
Error(DslError),
}
impl<Str: Copy, Exp: Copy, D: Dsl<Str=Str,Exp=Exp>> Copy for Val<D> {}
impl<D: Dsl> Val<D> {
pub fn convert <T: Dsl> (&self) -> Val<T> where
B::Str: for<'a> From<&'a D::Str>,
B::Exp: for<'a> From<&'a D::Exp>
{
match self { Val::Nil => Val::Nil,
Val::Num(u) => Val::Num(*u),
Val::Sym(s) => Val::Sym(s.into()),
Val::Key(s) => Val::Key(s.into()),
Val::Str(s) => Val::Str(s.into()),
Val::Exp(d, x) => Val::Exp(*d, x.into()),
Val::Error(e) => Val::Error(*e) } }
pub fn is_nil (&self) -> bool { matches!(self, Self::Nil) }
pub fn as_error (&self) -> Option<&DslError> { if let Self::Error(e) = self { Some(e) } else { None } }
pub fn as_num (&self) -> Option<usize> {match self{Self::Num(n)=>Some(*n),_=>None}}
pub fn as_sym (&self) -> Option<&str> {match self{Self::Sym(s )=>Some(s.as_ref()),_=>None}}
pub fn as_key (&self) -> Option<&str> {match self{Self::Key(k )=>Some(k.as_ref()),_=>None}}
pub fn as_str (&self) -> Option<&str> {match self{Self::Str(s )=>Some(s.as_ref()),_=>None}}
pub fn as_exp (&self) -> Option<&D::Exp> {match self{Self::Exp(_, x)=>Some(x),_=>None}}
pub fn exp_depth (&self) -> Option<usize> { todo!() }
pub fn exp_head_tail (&self) -> (Option<&Self>, Option<&D::Exp>) { (self.exp_head(), self.exp_tail()) }
pub fn exp_head (&self) -> Option<&Self> { todo!() } // TODO
pub fn exp_tail (&self) -> Option<&D::Exp> { todo!() }
pub fn peek (&self) -> Option<Self> { todo!() }
pub fn next (&mut self) -> Option<Self> { todo!() }
pub fn rest (self) -> Vec<Self> { todo!() }
//pub fn exp_match <T, F> (&self, namespace: &str, cb: F) -> DslPerhaps<T>
//where F: Fn(&str, &Exp)-> DslPerhaps<T> {
//if let Some(Self::Key(key)) = self.exp_head()
//&& key.as_ref().starts_with(namespace)
//&& let Some(tail) = self.exp_tail() {
//cb(key.as_ref().split_at(namespace.len()).1, tail)
//} else {
//Ok(None)
//}
//}
}
/// The string representation for a [Dsl] implementation.
/// [Cst] uses `&'s str`. [Ast] uses `Arc<str>`.
pub trait DslStr: PartialEq + Clone + Default + Debug + AsRef<str> + std::ops::Deref<Target = str> {}
impl<T: PartialEq + Clone + Default + Debug + AsRef<str> + std::ops::Deref<Target = str>> DslStr for T {}
/// The expression representation for a [Dsl] implementation.
/// [Cst] uses [CstIter]. [Ast] uses [VecDeque].
pub trait DslExp: PartialEq + Clone + Default + Debug {}
impl <T: PartialEq + Clone + Default + Debug> DslExp for T {}
/// The abstract syntax tree (AST) can be produced from the CST
/// by cloning source slices into owned ([Arc]) string slices.
#[derive(Debug, Clone, Default, PartialEq)]
pub struct Ast(Token<Ast>);
impl Dsl for Ast {
type Str = Arc<str>;
type Exp = VecDeque<Arc<Token<Ast>>>;
fn dsl (&self) -> DslUsually<&Val<Self>> {
Ok(self.0.value())
}
}
/// The concrete syntax tree (CST) implements zero-copy
/// parsing of the DSL from a string reference. CST items
/// preserve info about their location in the source.
/// CST stores strings as source references and expressions as [CstIter] instances.
#[derive(Debug, Clone, Default, PartialEq)]
pub struct Cst<'s>(Token<Cst<'s>>);
impl<'s> Dsl for Cst<'s> {
type Str = &'s str;
type Exp = CstConstIter<'s>;
fn dsl (&self) -> DslUsually<&Val<Self>> {
Ok(self.0.value())
}
}
/// `State` + [Dsl] -> `Self`.
pub trait FromDsl<State>: Sized {
fn try_from_dsl (state: &State, dsl: &impl Dsl) -> Perhaps<Self>;
fn from_dsl (state: &State, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<Self> {
match Self::try_from_dsl(state, dsl)? { Some(dsl) => Ok(dsl), _ => Err(err()) } } }
/// `self` + `Options` -> [Dsl]
pub trait IntoDsl { /*TODO*/ }
/// `self` + [Dsl] -> `Item`
pub trait DslInto<Item> {
fn try_dsl_into (&self, dsl: &impl Dsl) -> Perhaps<Item>;
fn dsl_into (&self, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<Item> {
match Self::try_dsl_into(self, dsl)? { Some(dsl) => Ok(dsl), _ => Err(err()) } } }
/// `self` + `Item` -> [Dsl]
pub trait DslFrom { /*TODO*/ }
/// Standard result type for DSL-specific operations.
pub type DslResult<T> = Result<T, DslError>;
/// DSL-specific error codes.
#[derive(Error, Debug, Copy, Clone, PartialEq, PanicFmt)] pub enum DslError {
#[error("parse failed: not implemented")]
Unimplemented,
#[error("parse failed: empty")]
Empty,
#[error("parse failed: incomplete")]
Incomplete,
#[error("parse failed: unexpected character '{0}'")]
Unexpected(char),
#[error("parse failed: error #{0}")]
Code(u8),
#[error("end reached")]
End
}
/// Provides native [Iterator] API over [CstConstIter], emitting [Cst] items.
///
/// [Cst::next] returns just the [Cst] and mutates `self`,
/// instead of returning an updated version of the struct as [CstConstIter::next] does.
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub struct CstIter<'s>(CstConstIter<'s>);
impl<'s> CstIter<'s> {
pub const fn new (source: &'s str) -> Self { Self(CstConstIter::new(source)) }
}
impl<'s> Iterator for CstIter<'s> {
type Item = Token<Cst<'s>>;
fn next (&mut self) -> Option<Self::Item> {
match self.0.advance() {
Ok(Some((item, rest))) => { self.0 = rest; item.into() },
Ok(None) => None,
Err(e) => panic!("{e:?}")
}
}
}
/// Holds a reference to the source text.
/// [CstConstIter::next] emits subsequent pairs of:
/// * a [Cst] and
/// * the source text remaining
/// * [ ] TODO: maybe [CstConstIter::next] should wrap the remaining source in `Self` ?
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub struct CstConstIter<'s>(pub &'s str);
impl<'s> From <&'s str> for CstConstIter<'s> {
fn from (src: &'s str) -> Self { Self(src) }
}
impl<'s> Iterator for CstConstIter<'s> {
type Item = Token<Cst<'s>>;
fn next (&mut self) -> Option<Token<Cst<'s>>> { self.advance().unwrap().map(|x|x.0) }
}
impl<'s> ConstIntoIter for CstConstIter<'s> {
type Kind = IsIteratorKind;
type Item = Cst<'s>;
type IntoIter = Self;
}
impl<'s> CstConstIter<'s> {
pub const fn new (source: &'s str) -> Self { Self(source) }
pub const fn chomp (&self, index: usize) -> Self { Self(split_at(self.0, index).1) }
pub const fn peek (&self) -> DslPerhaps<Token<Cst<'s>>> { Token::peek(self.0) }
//pub const fn next (mut self) -> Option<(Token<Cst<'s>>, Self)> {
//Self::advance(&mut self).unwrap() }
pub const fn advance (&mut self) -> DslPerhaps<(Token<Cst<'s>>, Self)> {
match self.peek() {
Ok(Some(token)) => {
let end = self.chomp(token.span.end());
Ok(Some((token.copy(), end)))
},
Ok(None) => Ok(None),
Err(e) => Err(e)
}
}
}
#[derive(Debug, Copy, Clone, Default, PartialEq)]
pub struct Span<D: Dsl> {
/// Reference to source text.
pub source: D::Str,
/// Index of 1st character of span.
pub start: usize,
/// Length of span.
pub length: usize,
}
impl<'s, D: Dsl> Span<D> {
pub const fn end (&self) -> usize { self.start.saturating_add(self.length) }
}
impl<'s, D: Dsl<Str=&'s str>> Span<D> {
pub const fn slice (&self) -> &'s str {
str_range(self.source, self.start, self.end()) }
pub const fn slice_exp (&self) -> &'s str {
str_range(self.source, self.start.saturating_add(1), self.end()) }
pub const fn grow (&mut self) -> DslUsually<&mut Self> {
if self.length + self.start >= self.source.len() { return Err(End) }
self.length = self.length.saturating_add(1);
Ok(self) }
}
/// Parsed substring with range and value.
#[derive(Debug, Clone, Default, PartialEq)]
pub struct Token<D: Dsl> {
/// Source span of token.
span: Span<D>,
/// Meaning of token.
value: Val<D>,
}
impl<D: Dsl> Token<D> {
pub const fn value (&self) -> &Val<D> { &self.value }
pub const fn span (&self) -> &Span<D> { &self.span }
pub const fn err (&self) -> Option<DslError> {
if let Val::Error(e) = self.value { Some(e) } else { None } }
pub const fn new (source: D::Str, start: usize, length: usize, value: Val<D>) -> Self {
Self { value, span: Span { source, start, length } } }
pub const fn copy (&self) -> Self where D::Str: Copy, D::Exp: Copy {
Self { span: Span { ..self.span }, value: self.value } }
}
const fn or_panic <T> (result: DslUsually<T>) -> T {
match result { Ok(t) => t, Err(e) => const_panic::concat_panic!(e) }
}
impl<'s, D: Dsl<Str = &'s str>> Token<D> {
pub const fn peek (src: D::Str) -> DslPerhaps<Self> where D::Exp: From<&'s str> {
use Val::*;
let mut t = Self::new(src, 0, 0, Nil);
let mut iter = char_indices(src);
while let Some(((i, c), next)) = iter.next() {
t = match (t.value(), c) {
(Error(_), _) =>
return Ok(Some(t)),
(Nil, ' '|'\n'|'\r'|'\t') =>
*or_panic(t.grow()),
(Nil, '(') =>
Self::new(src, i, 1, Exp(1, D::Exp::from(str_range(src, i, i + 1)))),
(Nil, '"') =>
Self::new(src, i, 1, Str(str_range(src, i, i + 1))),
(Nil, ':'|'@') =>
Self::new(src, i, 1, Sym(str_range(src, i, i + 1))),
(Nil, '/'|'a'..='z') =>
Self::new(src, i, 1, Key(str_range(src, i, i + 1))),
(Nil, '0'..='9') =>
Self::new(src, i, 1, match to_digit(c) { Ok(c) => Num(c), Err(e) => Error(e) }),
(Nil, _) =>
{ t.value = Val::Error(Unexpected(c)); t },
(Str(_), '"') =>
return Ok(Some(t)),
(Str(_), _) =>
{ or_panic(t.grow()); t.value = Str(t.span.slice()); t },
(Num(m), ' '|'\n'|'\r'|'\t'|')') =>
return Ok(Some(t)),
(Num(m), _) => match to_digit(c) {
Ok(n) => { t.grow()?; t.value = Num(10*m+n); t },
Err(e) => { t.grow()?; t.value = Error(e); t } },
(Sym(_), ' '|'\n'|'\r'|'\t'|')') =>
return Ok(Some(t)),
(Sym(_), 'a'..='z'|'A'..='Z'|'0'..='9'|'-') => {
t.grow()?; t.value = Sym(t.span.slice()); t },
(Sym(_), _) =>
{ t.value = Error(Unexpected(c)); t },
(Key(_), ' '|'\n'|'\r'|'\t'|')') =>
return Ok(Some(t)),
(Key(_), 'a'..='z'|'0'..='9'|'-'|'/') =>
{ t.grow()?; t.value = Key(t.span.slice()); t },
(Key(_), _ ) =>
{ t.value = Error(Unexpected(c)); t },
(Exp(0, _), _) =>
{ t.grow()?; t.value = Exp(0, D::Exp::from(t.span.slice_exp())); return Ok(Some(t)) },
(Exp(d, _), ')') =>
{ t.grow()?; t.value = Exp(d-1, D::Exp::from(t.span.slice_exp())); t },
(Exp(d, _), '(') =>
{ t.grow()?; t.value = Exp(d+1, D::Exp::from(t.span.slice_exp())); t },
(Exp(d, _), _ ) =>
{ t.grow()?; t.value = Exp(*d, D::Exp::from(t.span.slice_exp())); t },
};
iter = next;
}
Ok(match t.value() {
Nil => None,
_ => Some(t)
})
}
pub const fn grow (&mut self) -> DslUsually<&mut Self> { self.span.grow()?; Ok(self) }
pub const fn grow_exp (&mut self, d: isize) -> &mut Self where D::Exp: From<&'s str> {
if let Val::Exp(depth, _) = self.value() {
self.value = Val::Exp((*depth as isize + d) as usize, D::Exp::from(self.span.slice_exp()));
self
} else {
unreachable!()
}
}
}
pub const fn to_digit (c: char) -> DslResult<usize> {
Ok(match c {
'0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4,
'5' => 5, '6' => 6, '7' => 7, '8' => 8, '9' => 9,
_ => return Result::Err(Unexpected(c)) }) }
macro_rules! iterate(($expr:expr => $arg: pat => $body:expr) => {
let mut iter = $expr; while let Some(($arg, next)) = iter.next() { $body; iter = next; } });
pub const fn to_number (digits: &str) -> DslResult<usize> {
let mut value = 0;
iterate!(char_indices(digits) => (_, c) => match to_digit(c) {
Ok(digit) => value = 10 * value + digit,
Result::Err(e) => return Result::Err(e) });
Ok(value) }
/// Implement type conversions.
macro_rules! from(($($Struct:ty { $(
$(<$($l:lifetime),* $($T:ident$(:$U:ident)?),*>)? ($source:ident: $From:ty) $expr:expr
);+ $(;)? })*) => { $(
$(impl $(<$($l),* $($T$(:$U)?),*>)? From<$From> for $Struct {
fn from ($source: $From) -> Self { $expr }
})+
)* });
//from! {
////Vec<Token<'s>> { <'s> (val: CstIter<'s>) val.collect(); }
//CstConstIter<'s> {
//<'s> (src: &'s str) Self(src);
//<'s> (iter: CstIter<'s>) iter.0; }
//CstIter<'s> {
//<'s> (src: &'s str) Self(CstConstIter(src));
//<'s> (iter: CstConstIter<'s>) Self(iter); }
//Cst<'s> { <'s> (src: &'s str) Self(CstIter(CstConstIter(src))); }
//Vec<Ast> { <'s> (val: CstIter<'s>) val.map(Into::into).collect(); }
//Token<Cst<'s>> { <'s> (token: Token<Cst<'s>>) Self { value: token.value.into(), span: token.span.into() } }
//Ast {
//<'s> (src: &'s str) Ast::from(CstIter(CstConstIter(src)));
//<'s> (cst: Cst<'s>) Ast(VecDeque::from([dsl_val(cst.val())]).into());
//<'s> (iter: CstIter<'s>) Ast(iter.map(|x|x.value.into()).collect::<VecDeque<_>>().into());
//<D: Dsl> (token: Token<D>) Ast(VecDeque::from([dsl_val(token.val())]).into()); }
//}

View file

@ -12,10 +12,10 @@ use proptest::prelude::*;
}
#[test] fn test_num () {
let _digit = to_digit('0');
let _digit = to_digit('x');
let _number = to_number(&"123");
let _number = to_number(&"12asdf3");
let _digit = Token::to_digit('0');
let _digit = Token::to_digit('x');
let _number = Token::to_number(&"123");
let _number = Token::to_number(&"12asdf3");
}
//proptest! {
//#[test] fn proptest_source_iter (
@ -48,15 +48,15 @@ use proptest::prelude::*;
//}
#[test] fn test_token () -> Result<(), Box<dyn std::error::Error>> {
use crate::DslVal::*;
use crate::Val::*;
let source = ":f00";
let mut token = CstVal::new(source, 0, 1, Sym(":"));
let mut token = CstToken::new(source, 0, 1, Sym(":"));
token = token.grow_sym();
assert_eq!(token, CstVal::new(source, 0, 2, Sym(":f")));
assert_eq!(token, CstToken::new(source, 0, 2, Sym(":f")));
token = token.grow_sym();
assert_eq!(token, CstVal::new(source, 0, 3, Sym(":f0")));
assert_eq!(token, CstToken::new(source, 0, 3, Sym(":f0")));
token = token.grow_sym();
assert_eq!(token, CstVal::new(source, 0, 4, Sym(":f00")));
assert_eq!(token, CstToken::new(source, 0, 4, Sym(":f00")));
assert_eq!(None, CstIter::new("").next());
assert_eq!(None, CstIter::new(" \n \r \t ").next());