dsl: compact

dsl/src/dsl.rs

@@ -0,0 +1,324 @@
+use crate::*;
+use thiserror::Error;
+
+pub type ParseResult<T> = Result<T, ParseError>;
+
+#[derive(Error, Debug, Copy, Clone, PartialEq)] pub enum ParseError {
+    #[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),
+}
+
+pub trait TryFromDsl<'state, T>: Sized {
+    fn try_from_expr <'source: 'state> (
+        _state: &'state T, _iter: TokenIter<'source>
+    ) -> Option<Self> {
+        None
+    }
+    fn try_from_atom <'source: 'state> (
+        state: &'state T, value: Value<'source>
+    ) -> Option<Self> {
+        if let Exp(0, iter) = value {
+            return Self::try_from_expr(state, iter.clone())
+        }
+        None
+    }
+}
+
+pub trait TryIntoDsl<T>: Sized {
+    fn try_into_atom (&self) -> Option<Value>;
+}
+
+/// Map EDN tokens to parameters of a given type for a given context
+pub trait Context<'state, U>: Sized {
+    fn get <'source> (&'state self, _iter: &mut TokenIter<'source>) -> Option<U> {
+        None
+    }
+}
+
+impl<'state, T: Context<'state, U>, U> Context<'state, U> for &T {
+    fn get <'source> (&'state self, iter: &mut TokenIter<'source>) -> Option<U> {
+        (*self).get(iter)
+    }
+}
+
+impl<'state, T: Context<'state, U>, U> Context<'state, U> for Option<T> {
+    fn get <'source> (&'state self, iter: &mut TokenIter<'source>) -> Option<U> {
+        self.as_ref().map(|s|s.get(iter)).flatten()
+    }
+}
+
+/// Implement the const iterator pattern.
+#[macro_export] 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;
+        }
+    }
+}
+
+/// Provides a native [Iterator] API over the [ConstIntoIter] [SourceIter]
+/// [TokenIter::next] returns just the [Token] and mutates `self`,
+/// instead of returning an updated version of the struct as [SourceIter::next] does.
+#[derive(Copy, Clone, Debug, Default, PartialEq)]
+pub struct TokenIter<'a>(
+    pub SourceIter<'a>
+);
+
+impl<'a> TokenIter<'a> {
+    pub const fn new (source: &'a str) -> Self {
+        Self(SourceIter::new(source))
+    }
+    pub const fn peek (&self) -> Option<Token<'a>> {
+        self.0.peek()
+    }
+}
+
+impl<'a> Iterator for TokenIter<'a> {
+    type Item = Token<'a>;
+    fn next (&mut self) -> Option<Token<'a>> {
+        self.0.next().map(|(item, rest)|{self.0 = rest; item})
+    }
+}
+
+impl<'a> From<&'a str> for TokenIter<'a> {
+    fn from (source: &'a str) -> Self{
+        Self(SourceIter(source))
+    }
+}
+
+impl<'a> From<SourceIter<'a>> for TokenIter<'a> {
+    fn from (source: SourceIter<'a>) -> Self{
+        Self(source)
+    }
+}
+
+/// Owns a reference to the source text.
+/// [SourceIter::next] emits subsequent pairs of:
+///   * a [Token] and
+///   * the source text remaining
+///     * [ ] TODO: maybe [SourceIter::next] should wrap the remaining source in `Self` ?
+#[derive(Copy, Clone, Debug, Default, PartialEq)]
+pub struct SourceIter<'a>(pub &'a str);
+
+const_iter!(<'a>|self: SourceIter<'a>| => Token<'a> => self.next_mut().map(|(result, _)|result));
+
+impl<'a> From<&'a str> for SourceIter<'a> {
+    fn from (source: &'a str) -> Self{
+        Self::new(source)
+    }
+}
+
+impl<'a> SourceIter<'a> {
+    pub const fn new (source: &'a 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<(Token<'a>, Self)> {
+        Self::next_mut(&mut self)
+    }
+    pub const fn peek (&self) -> Option<Token<'a>> {
+        peek_src(self.0)
+    }
+    pub const fn next_mut (&mut self) -> Option<(Token<'a>, Self)> {
+        match self.peek() {
+            Some(token) => Some((token, self.chomp(token.end()))),
+            None => None
+        }
+    }
+}
+/// Static iteration helper.
+#[macro_export] 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 <'a> (source: &'a str) -> Option<Token<'a>> {
+    let mut token: Token<'a> = Token::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(),
+            '(' =>
+                Token::new(source, start, 1, Exp(1, TokenIter::new(str_range(source, start, start + 1)))),
+            '"' =>
+                Token::new(source, start, 1, Str(str_range(source, start, start + 1))),
+            ':'|'@' =>
+                Token::new(source, start, 1, Sym(str_range(source, start, start + 1))),
+            '/'|'a'..='z' =>
+                Token::new(source, start, 1, Key(str_range(source, start, start + 1))),
+            '0'..='9' =>
+                Token::new(source, start, 1, match to_digit(c) {
+                    Ok(c) => Value::Num(c),
+                    Result::Err(e) => Value::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) -> Result<usize, ParseError> {
+    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) -> Result<usize, ParseError> {
+    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))
+    })
+}
+
+#[derive(Debug, Copy, Clone, Default, PartialEq)] pub struct Token<'source> {
+    pub source: &'source str,
+    pub start:  usize,
+    pub length: usize,
+    pub value:  Value<'source>,
+}
+
+#[derive(Debug, Copy, Clone, Default, PartialEq)] pub enum Value<'source> {
+    #[default] Nil,
+    Err(ParseError),
+    Num(usize),
+    Sym(&'source str),
+    Key(&'source str),
+    Str(&'source str),
+    Exp(usize, TokenIter<'source>),
+}
+
+impl<'source> Token<'source> {
+    pub const fn new (source: &'source str, start: usize, length: usize, value: Value<'source>) -> Self {
+        Self { source, start, length, value }
+    }
+    pub const fn end (&self) -> usize {
+        self.start.saturating_add(self.length)
+    }
+    pub const fn slice (&'source self) -> &'source str {
+        self.slice_source(self.source)
+        //str_range(self.source, self.start, self.end())
+    }
+    pub const fn slice_source <'range> (&'source self, source: &'range str) -> &'range str {
+        str_range(source, self.start, self.end())
+    }
+    pub const fn slice_source_exp <'range> (&'source self, source: &'range str) -> &'range str {
+        str_range(source, self.start.saturating_add(1), self.end())
+    }
+    pub const fn value (&self) -> Value {
+        self.value
+    }
+    pub const fn error (self, error: ParseError) -> Self {
+        Self { value: Value::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) {
+            Ok(n) => Self { value: Num(10*m+n), ..self.grow() },
+            Result::Err(e) => Self { value: Err(e), ..self.grow() },
+        }
+    }
+    pub const fn grow_key (self) -> Self {
+        let mut token = self.grow();
+        token.value = Key(token.slice_source(self.source));
+        token
+    }
+    pub const fn grow_sym (self) -> Self {
+        let mut token = self.grow();
+        token.value = Sym(token.slice_source(self.source));
+        token
+    }
+    pub const fn grow_str (self) -> Self {
+        let mut token = self.grow();
+        token.value = Str(token.slice_source(self.source));
+        token
+    }
+    pub const fn grow_exp (self) -> Self {
+        let mut token = self.grow();
+        if let Exp(depth, _) = token.value {
+            token.value = Exp(depth, TokenIter::new(token.slice_source_exp(self.source)));
+        } else {
+            unreachable!()
+        }
+        token
+    }
+    pub const fn grow_in (self) -> Self {
+        let mut token = self.grow_exp();
+        if let Value::Exp(depth, source) = token.value {
+            token.value = Value::Exp(depth.saturating_add(1), source)
+        } else {
+            unreachable!()
+        }
+        token
+    }
+    pub const fn grow_out (self) -> Self {
+        let mut token = self.grow_exp();
+        if let Value::Exp(depth, source) = token.value {
+            if depth > 0 {
+                token.value = Value::Exp(depth - 1, source)
+            } else {
+                return self.error(Unexpected(')'))
+            }
+        } else {
+            unreachable!()
+        }
+        token
+    }
+}

dsl/src/dsl_context.rs

@@ -1,40 +0,0 @@
-use crate::*;
-
-pub trait TryFromDsl<'state, T>: Sized {
-    fn try_from_expr <'source: 'state> (
-        _state: &'state T, _iter: TokenIter<'source>
-    ) -> Option<Self> {
-        None
-    }
-    fn try_from_atom <'source: 'state> (
-        state: &'state T, value: Value<'source>
-    ) -> Option<Self> {
-        if let Exp(0, iter) = value {
-            return Self::try_from_expr(state, iter.clone())
-        }
-        None
-    }
-}
-
-pub trait TryIntoDsl<T>: Sized {
-    fn try_into_atom (&self) -> Option<Value>;
-}
-
-/// Map EDN tokens to parameters of a given type for a given context
-pub trait Context<'state, U>: Sized {
-    fn get <'source> (&'state self, _iter: &mut TokenIter<'source>) -> Option<U> {
-        None
-    }
-}
-
-impl<'state, T: Context<'state, U>, U> Context<'state, U> for &T {
-    fn get <'source> (&'state self, iter: &mut TokenIter<'source>) -> Option<U> {
-        (*self).get(iter)
-    }
-}
-
-impl<'state, T: Context<'state, U>, U> Context<'state, U> for Option<T> {
-    fn get <'source> (&'state self, iter: &mut TokenIter<'source>) -> Option<U> {
-        self.as_ref().map(|s|s.get(iter)).flatten()
-    }
-}

dsl/src/dsl_error.rs

@@ -1,15 +0,0 @@
-use crate::*;
-use thiserror::Error;
-pub type ParseResult<T> = Result<T, ParseError>;
-#[derive(Error, Debug, Copy, Clone, PartialEq)] pub enum ParseError {
-    #[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),
-}

dsl/src/dsl_iter.rs

@@ -1,157 +0,0 @@
-//! The token iterator [TokenIter] allows you to get the
-//! general-purpose syntactic [Token]s represented by the source text.
-//!
-//! Both iterators are `peek`able:
-//!
-//! ```
-//! let src = include_str!("../test.edn");
-//! let mut view = tengri_dsl::TokenIter::new(src);
-//! assert_eq!(view.0.0, src);
-//! assert_eq!(view.peek(), view.0.peek())
-//! ```
-use crate::*;
-
-/// Provides a native [Iterator] API over the [ConstIntoIter] [SourceIter]
-/// [TokenIter::next] returns just the [Token] and mutates `self`,
-/// instead of returning an updated version of the struct as [SourceIter::next] does.
-#[derive(Copy, Clone, Debug, Default, PartialEq)] pub struct TokenIter<'a>(
-    pub SourceIter<'a>
-);
-
-impl<'a> TokenIter<'a> {
-    pub const fn new (source: &'a str) -> Self {
-        Self(SourceIter::new(source))
-    }
-    pub const fn peek (&self) -> Option<Token<'a>> {
-        self.0.peek()
-    }
-}
-
-impl<'a> Iterator for TokenIter<'a> {
-    type Item = Token<'a>;
-    fn next (&mut self) -> Option<Token<'a>> {
-        self.0.next().map(|(item, rest)|{self.0 = rest; item})
-    }
-}
-
-impl<'a> From<&'a str> for TokenIter<'a> {
-    fn from (source: &'a str) -> Self{
-        Self(SourceIter(source))
-    }
-}
-
-impl<'a> From<SourceIter<'a>> for TokenIter<'a> {
-    fn from (source: SourceIter<'a>) -> Self{
-        Self(source)
-    }
-}
-
-/// Owns a reference to the source text.
-/// [SourceIter::next] emits subsequent pairs of:
-///   * a [Token] and
-///   * the source text remaining
-///     * [ ] TODO: maybe [SourceIter::next] should wrap the remaining source in `Self` ?
-#[derive(Copy, Clone, Debug, Default, PartialEq)]
-pub struct SourceIter<'a>(pub &'a str);
-
-const_iter!(<'a>|self: SourceIter<'a>| => Token<'a> => self.next_mut().map(|(result, _)|result));
-
-impl<'a> From<&'a str> for SourceIter<'a> {
-    fn from (source: &'a str) -> Self{
-        Self::new(source)
-    }
-}
-
-impl<'a> SourceIter<'a> {
-    pub const fn new (source: &'a 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<(Token<'a>, Self)> {
-        Self::next_mut(&mut self)
-    }
-    pub const fn peek (&self) -> Option<Token<'a>> {
-        peek_src(self.0)
-    }
-    pub const fn next_mut (&mut self) -> Option<(Token<'a>, Self)> {
-        match self.peek() {
-            Some(token) => Some((token, self.chomp(token.end()))),
-            None => None
-        }
-    }
-}
-
-pub const fn peek_src <'a> (source: &'a str) -> Option<Token<'a>> {
-    let mut token: Token<'a> = Token::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(),
-            '(' =>
-                Token::new(source, start, 1, Exp(1, TokenIter::new(str_range(source, start, start + 1)))),
-            '"' =>
-                Token::new(source, start, 1, Str(str_range(source, start, start + 1))),
-            ':'|'@' =>
-                Token::new(source, start, 1, Sym(str_range(source, start, start + 1))),
-            '/'|'a'..='z' =>
-                Token::new(source, start, 1, Key(str_range(source, start, start + 1))),
-            '0'..='9' =>
-                Token::new(source, start, 1, match to_digit(c) {
-                    Ok(c) => Value::Num(c),
-                    Result::Err(e) => Value::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) -> Result<usize, ParseError> {
-    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) -> Result<usize, ParseError> {
-    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))
-    })
-}

dsl/src/dsl_macros.rs

@@ -1,46 +0,0 @@
-/// Static iteration helper.
-#[macro_export] macro_rules! iterate {
-    ($expr:expr => $arg: pat => $body:expr) => {
-        let mut iter = $expr;
-        while let Some(($arg, next)) = iter.next() {
-            $body;
-            iter = next;
-        }
-    }
-}
-
-/// Implement the const iterator pattern.
-#[macro_export] macro_rules! const_iter {
-    ($(<$l:lifetime>)?|$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 = $Item;
-            type IntoIter = Self;
-        }
-    }
-}
-
-#[macro_export] macro_rules! get_value {
-    ($state:expr => $token:expr) => {
-        if let Some(value) = $state.get(&$token.value) {
-            value
-        } else {
-            panic!("no value corresponding to {:?}", &$token.value);
-        }
-    }
-}
-
-#[macro_export] macro_rules! get_content {
-    ($state:expr => $token:expr) => {
-        if let Some(content) = $state.get_content(&$token.value) {
-            content
-        } else {
-            panic!("no content corresponding to {:?}", &$token.value);
-        }
-    }
-}
-

dsl/src/dsl_token.rs

@@ -1,120 +0,0 @@
-//! [Token]s are parsed substrings with an associated [Value].
-//!
-//! * [ ] FIXME: Value may be [Err] which may shadow [Result::Err]
-//! * [Value::Exp] wraps an expression depth and a [SourceIter]
-//!   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
-//! * [Value::Sym] and [Value::Key] are stringish literals
-//!   with slightly different parsing rules.
-//! * [Value::Num] is an unsigned integer literal.
-//!```
-//! use tengri_dsl::{*, Value::*};
-//! let source = include_str!("../test.edn");
-//! let mut view = TokenIter::new(source);
-//! assert_eq!(view.peek(), Some(Token {
-//!     source,
-//!     start: 0,
-//!     length: source.len(),
-//!     value: Exp(0, TokenIter::new(&source[1..]))
-//! }));
-//!```
-use crate::*;
-
-#[derive(Debug, Copy, Clone, Default, PartialEq)] pub struct Token<'source> {
-    pub source: &'source str,
-    pub start:  usize, 
-    pub length: usize,
-    pub value:  Value<'source>,
-}
-
-#[derive(Debug, Copy, Clone, Default, PartialEq)] pub enum Value<'source> {
-    #[default] Nil,
-    Err(ParseError),
-    Num(usize),
-    Sym(&'source str),
-    Key(&'source str),
-    Str(&'source str),
-    Exp(usize, TokenIter<'source>),
-}
-
-impl<'source> Token<'source> {
-    pub const fn new (source: &'source str, start: usize, length: usize, value: Value<'source>) -> Self {
-        Self { source, start, length, value }
-    }
-    pub const fn end (&self) -> usize {
-        self.start.saturating_add(self.length)
-    }
-    pub const fn slice (&'source self) -> &'source str {
-        self.slice_source(self.source)
-        //str_range(self.source, self.start, self.end())
-    }
-    pub const fn slice_source <'range> (&'source self, source: &'range str) -> &'range str {
-        str_range(source, self.start, self.end())
-    }
-    pub const fn slice_source_exp <'range> (&'source self, source: &'range str) -> &'range str {
-        str_range(source, self.start.saturating_add(1), self.end())
-    }
-    pub const fn value (&self) -> Value {
-        self.value
-    }
-    pub const fn error (self, error: ParseError) -> Self {
-        Self { value: Value::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) {
-            Ok(n) => Self { value: Num(10*m+n), ..self.grow() },
-            Result::Err(e) => Self { value: Err(e), ..self.grow() },
-        } 
-    }
-    pub const fn grow_key (self) -> Self {
-        let mut token = self.grow();
-        token.value = Key(token.slice_source(self.source));
-        token
-    }
-    pub const fn grow_sym (self) -> Self {
-        let mut token = self.grow();
-        token.value = Sym(token.slice_source(self.source));
-        token
-    }
-    pub const fn grow_str (self) -> Self {
-        let mut token = self.grow();
-        token.value = Str(token.slice_source(self.source));
-        token
-    }
-    pub const fn grow_exp (self) -> Self {
-        let mut token = self.grow();
-        if let Exp(depth, _) = token.value {
-            token.value = Exp(depth, TokenIter::new(token.slice_source_exp(self.source)));
-        } else {
-            unreachable!()
-        }
-        token
-    }
-    pub const fn grow_in (self) -> Self {
-        let mut token = self.grow_exp();
-        if let Value::Exp(depth, source) = token.value {
-            token.value = Value::Exp(depth.saturating_add(1), source)
-        } else {
-            unreachable!()
-        }
-        token
-    }
-    pub const fn grow_out (self) -> Self {
-        let mut token = self.grow_exp();
-        if let Value::Exp(depth, source) = token.value {
-            if depth > 0 {
-                token.value = Value::Exp(depth - 1, source)
-            } else {
-                return self.error(Unexpected(')'))
-            }
-        } else {
-            unreachable!()
-        }
-        token
-    }
-}

dsl/src/lib.rs

@@ -1,3 +1,36 @@
+//! [Token]s are parsed substrings with an associated [Value].
+//!
+//! * [ ] FIXME: Value may be [Err] which may shadow [Result::Err]
+//! * [Value::Exp] wraps an expression depth and a [SourceIter]
+//!   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
+//! * [Value::Sym] and [Value::Key] are stringish literals
+//!   with slightly different parsing rules.
+//! * [Value::Num] is an unsigned integer literal.
+//!```
+//! use tengri_dsl::{*, Value::*};
+//! let source = include_str!("../test.edn");
+//! let mut view = TokenIter::new(source);
+//! assert_eq!(view.peek(), Some(Token {
+//!     source,
+//!     start: 0,
+//!     length: source.len(),
+//!     value: Exp(0, TokenIter::new(&source[1..]))
+//! }));
+//!```
+//! The token iterator [TokenIter] allows you to get the
+//! general-purpose syntactic [Token]s represented by the source text.
+//!
+//! Both iterators are `peek`able:
+//!
+//! ```
+//! let src = include_str!("../test.edn");
+//! let mut view = tengri_dsl::TokenIter::new(src);
+//! assert_eq!(view.0.0, src);
+//! assert_eq!(view.peek(), view.0.peek())
+//! ```
 #![feature(adt_const_params)]
 #![feature(type_alias_impl_trait)]
 #![feature(impl_trait_in_fn_trait_return)]
@@ -8,11 +41,7 @@ pub(crate) use konst::iter::{ConstIntoIter, IsIteratorKind};
 pub(crate) use konst::string::{split_at, str_range, char_indices};
 pub(crate) use std::fmt::Debug;
 
-mod dsl_error;   pub use self::dsl_error::*;
-mod dsl_token;   pub use self::dsl_token::*;
-mod dsl_iter;    pub use self::dsl_iter::*;
-mod dsl_context; pub use self::dsl_context::*;
-mod dsl_macros;
+mod dsl; pub use self::dsl::*;
 
 #[cfg(test)] mod test_token_iter {
     use crate::*;