dsl: actually test it

and decide how exprs gon work once and for all

dsl/src/dsl.rs

@@ -8,7 +8,8 @@ use const_panic::PanicFmt;
 use std::fmt::Debug;
 pub(crate) use std::error::Error;
 pub(crate) use std::sync::Arc;
-pub(crate) use konst::string::{str_range, char_indices};
+pub(crate) use konst::iter::for_each;
+pub(crate) use konst::string::{str_from, str_range, char_indices};
 pub(crate) use thiserror::Error;
 pub(crate) use ::tengri_core::*;
 pub(crate) use self::DslError::*;
@@ -16,69 +17,94 @@ mod dsl_conv; pub use self::dsl_conv::*;
 mod dsl_parse;
 pub(crate) use self::dsl_parse::*;
 pub mod parse { pub use crate::dsl_parse::*; }
-
-#[cfg(test)]
-mod dsl_test;
+#[cfg(test)] mod dsl_test;
 
 flex_trait!(Dsl: Debug + Send + Sync + Sized {
-    fn src (&self) -> &str {
+    fn src (&self) -> DslPerhaps<&str> {
         unreachable!("Dsl::src default impl")
     }
 });
 impl Dsl for Arc<str> {
-    fn src (&self) -> &str { self.as_ref() }
+    fn src (&self) -> DslPerhaps<&str> {
+        Ok(Some(self.as_ref()))
+    }
 }
 impl<'s> Dsl for &'s str {
-    fn src (&self) -> &str { self.as_ref() }
+    fn src (&self) -> DslPerhaps<&str> {
+        Ok(Some(self.as_ref()))
+    }
 }
 impl<D: Dsl> Dsl for Option<D> {
-    fn src (&self) -> &str { if let Some(dsl) = self { dsl.src() } else { "" } }
+    fn src (&self) -> DslPerhaps<&str> {
+        Ok(if let Some(dsl) = self { dsl.src()? } else { None })
+    }
+}
+impl<D: Dsl> Dsl for Result<D, DslError> {
+    fn src (&self) -> DslPerhaps<&str> {
+        match self {
+            Ok(dsl) => Ok(dsl.src()?),
+            Err(e)  => Err(*e)
+        }
+    }
 }
 
 impl<D: Dsl> DslExp for D {}
 pub trait DslExp: Dsl {
     fn exp (&self) -> DslPerhaps<&str> {
-        Ok(exp_peek(self.src())?)
+        Ok(self.src()?
+            .map(exp_peek)
+            .transpose()?
+            .flatten())
     }
     fn head (&self) -> DslPerhaps<&str> {
-        let start = 1;
-        let src   = self.src();
-        let src   = &src[start.min(src.len().saturating_sub(1))..];
-        peek(src)
+        Ok(self.src()?
+            .map(peek) //|src|Ok(if src.len() > 0 { return peek(&src)) } else { None }))
+            .transpose()?
+            .flatten())
     }
     fn tail (&self) -> DslPerhaps<&str> {
-        let start = 1;
-        let src   = self.src();
-        let src   = &src[start.min(src.len().saturating_sub(1))..];
-        Ok(if let Some((head_start, head_len)) = seek(src)? {
-            let start = 1 + head_start + head_len;
-            let src   = self.src();
-            let src   = &src[start.min(src.len().saturating_sub(1))..];
-            peek(src)?
-        } else {
-            None
-        })
+        Ok(self.src()?
+            .map(|src|Ok(if let Some(next) = self.head()? {
+                let src = &src[src.len().min(1 + next.len() + 1)..];
+                if src.len() > 2 {
+                    return peek(&src)
+                } else {
+                    None
+                }
+            } else {
+                None
+            }))
+            .transpose()?
+            .flatten())
     }
 }
 
 impl<D: Dsl> DslSym for D {}
 pub trait DslSym: Dsl {
-    fn sym (&self) -> DslPerhaps<&str> { crate::parse::sym_peek(self.src()) }
+    fn sym (&self) -> DslPerhaps<&str> {
+        Ok(self.src()?.map(crate::parse::sym_peek).transpose()?.flatten())
+    }
 }
 
 impl<D: Dsl> DslKey for D {}
 pub trait DslKey: Dsl {
-    fn key (&self) -> DslPerhaps<&str> { crate::parse::key_peek(self.src()) }
+    fn key (&self) -> DslPerhaps<&str> {
+        Ok(self.src()?.map(crate::parse::key_peek).transpose()?.flatten())
+    }
 }
 
 impl<D: Dsl> DslText for D {}
 pub trait DslText: Dsl {
-    fn text (&self) -> DslPerhaps<&str> { crate::parse::text_peek(self.src()) }
+    fn text (&self) -> DslPerhaps<&str> {
+        Ok(self.src()?.map(crate::parse::text_peek).transpose()?.flatten())
+    }
 }
 
 impl<D: Dsl> DslNum for D {}
 pub trait DslNum: Dsl {
-    fn num (&self) -> DslPerhaps<&str> { crate::parse::num_peek(self.src()) }
+    fn num (&self) -> DslPerhaps<&str> {
+        Ok(self.src()?.map(crate::parse::num_peek).transpose()?.flatten())
+    }
 }
 
 /// DSL-specific result type.
@@ -97,3 +123,22 @@ pub enum DslError {
     #[error("parse failed: error #{0}")] Code(u8),
     #[error("end reached")] End
 }
+
+#[macro_export] macro_rules! dsl_for_each (($dsl:expr => |$next:ident|$body:expr)=>{
+    let mut dsl:   Arc<str>         = $dsl.src().into();
+    let mut $next: Option<Arc<str>> = dsl.next()?.map(Into::into);
+    let mut rest:  Option<Arc<str>> = dsl.rest()?.map(Into::into);
+    loop {
+        if let Some($next) = $next {
+            $body;
+        } else {
+            break
+        }
+        if let Some(next) = rest {
+            $next = next.next()?.map(Into::into);
+            rest  = next.rest()?.map(Into::into);
+        } else {
+            break
+        }
+    }
+});

dsl/src/dsl_parse.rs

@@ -1,32 +1,33 @@
 use crate::*;
 
-macro_rules! iter_chars(($source:expr => |$i:ident, $c:ident|$val:expr)=>{
-    while let Some((($i, $c), next)) = char_indices($source).next() {
-        $source = next.as_str(); $val } });
-
 macro_rules! def_peek_seek(($peek:ident, $seek:ident, $seek_start:ident, $seek_length:ident)=>{
     /// Find a slice corrensponding to a syntax token.
     pub const fn $peek (source: &str) -> DslPerhaps<&str> {
         match $seek(source) {
             Ok(Some((start, length))) => Ok(Some(str_range(source, start, start + length))),
             Ok(None) => Ok(None),
-            Err(e) => Err(e) } }
+            Err(e) => Err(e)
+        }
+    }
     /// Find a start and length corresponding to a syntax token.
     pub const fn $seek (source: &str) -> DslPerhaps<(usize, usize)> {
         match $seek_start(source) {
-            Ok(Some(start)) => match $seek_length(str_range(source, start, source.len() - start)) {
+            Ok(Some(start)) => match $seek_length(str_from(source, start)) {
                 Ok(Some(length)) => Ok(Some((start, length))),
                 Ok(None) => Ok(None),
                 Err(e) => Err(e),
             },
             Ok(None) => Ok(None),
-            Err(e) => Err(e) } } });
+            Err(e) => Err(e)
+        }
+    }
+});
 
 def_peek_seek!(exp_peek, exp_seek, exp_seek_start, exp_seek_length);
-pub const fn is_exp_start (c: char) -> bool { matches!(c, '(') }
-pub const fn is_exp_end (c: char) -> bool { matches!(c, ')') }
+pub const fn is_exp_start (c: char) -> bool { c == '(' }
+pub const fn is_exp_end (c: char) -> bool { c == ')' }
 pub const fn exp_seek_start (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_exp_start(c) {
+    for_each!((i, c) in char_indices(source) => if is_exp_start(c) {
         return Ok(Some(i))
     } else if !is_whitespace(c) {
         return Err(Unexpected(c))
@@ -35,18 +36,18 @@ pub const fn exp_seek_start (mut source: &str) -> DslPerhaps<usize> {
 }
 pub const fn exp_seek_length (mut source: &str) -> DslPerhaps<usize> {
     let mut depth = 0;
-    iter_chars!(source => |i, c| if is_exp_start(c) {
+    for_each!((i, c) in char_indices(source) => if is_exp_start(c) {
         depth += 1;
     } else if is_exp_end(c) {
         if depth == 0 {
             return Err(Unexpected(c))
         } else if depth == 1 {
-            return Ok(Some(i))
+            return Ok(Some(i + 1))
         } else {
             depth -= 1;
         }
     });
-    Ok(None)
+    Err(Incomplete)
 }
 
 def_peek_seek!(sym_peek,  sym_seek,  sym_seek_start,  sym_seek_length);
@@ -54,7 +55,7 @@ pub const fn is_sym_start (c: char) -> bool { matches!(c, ':'|'@') }
 pub const fn is_sym_char (c: char) -> bool { matches!(c, 'a'..='z'|'A'..='Z'|'0'..='9'|'-') }
 pub const fn is_sym_end (c: char) -> bool { matches!(c, ' '|'\n'|'\r'|'\t'|')') }
 pub const fn sym_seek_start (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_sym_start(c) {
+    for_each!((i, c) in char_indices(source) => if is_sym_start(c) {
         return Ok(Some(i))
     } else if !is_whitespace(c) {
         return Err(Unexpected(c))
@@ -62,20 +63,20 @@ pub const fn sym_seek_start (mut source: &str) -> DslPerhaps<usize> {
     Ok(None)
 }
 pub const fn sym_seek_length (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_sym_end(c) {
+    for_each!((i, c) in char_indices(source) => if is_sym_end(c) {
         return Ok(Some(i))
     } else if !is_sym_char(c) {
         return Err(Unexpected(c))
     });
-    Ok(None)
+    Ok(Some(source.len()))
 }
 
 def_peek_seek!(key_peek,  key_seek,  key_seek_start,  key_seek_length);
-pub const fn is_key_start (c: char) -> bool { matches!(c, '/'|'a'..='z') }
+pub const fn is_key_start (c: char) -> bool { matches!(c, '/'|('a'..='z')) }
 pub const fn is_key_char (c: char) -> bool { matches!(c, 'a'..='z'|'0'..='9'|'-'|'/') }
 pub const fn is_key_end (c: char) -> bool { matches!(c, ' '|'\n'|'\r'|'\t'|')') }
 pub const fn key_seek_start (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_key_start(c) {
+    for_each!((i, c) in char_indices(source) => if is_key_start(c) {
         return Ok(Some(i))
     } else if !is_whitespace(c) {
         return Err(Unexpected(c))
@@ -83,19 +84,19 @@ pub const fn key_seek_start (mut source: &str) -> DslPerhaps<usize> {
     Ok(None)
 }
 pub const fn key_seek_length (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_key_end(c) {
+    for_each!((i, c) in char_indices(source) => if is_key_end(c) {
         return Ok(Some(i))
     } else if !is_key_char(c) {
         return Err(Unexpected(c))
     });
-    Ok(None)
+    Ok(Some(source.len()))
 }
 
 def_peek_seek!(text_peek, text_seek, text_seek_start, text_seek_length);
 pub const fn is_text_start (c: char) -> bool { matches!(c, '"') }
 pub const fn is_text_end (c: char) -> bool { matches!(c, '"') }
 pub const fn text_seek_start (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_text_start(c) {
+    for_each!((i, c) in char_indices(source) => if is_text_start(c) {
         return Ok(Some(i))
     } else if !is_whitespace(c) {
         return Err(Unexpected(c))
@@ -103,13 +104,13 @@ pub const fn text_seek_start (mut source: &str) -> DslPerhaps<usize> {
     Ok(None)
 }
 pub const fn text_seek_length (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_text_end(c) { return Ok(Some(i)) });
+    for_each!((i, c) in char_indices(source) => if is_text_end(c) { return Ok(Some(i)) });
     Ok(None)
 }
 
 def_peek_seek!(num_peek,  num_seek,  num_seek_start,  num_seek_length);
 pub const fn num_seek_start (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_digit(c) {
+    for_each!((i, c) in char_indices(source) => if is_digit(c) {
         return Ok(Some(i));
     } else if !is_whitespace(c) {
         return Err(Unexpected(c))
@@ -117,7 +118,7 @@ pub const fn num_seek_start (mut source: &str) -> DslPerhaps<usize> {
     Ok(None)
 }
 pub const fn num_seek_length (mut source: &str) -> DslPerhaps<usize> {
-    iter_chars!(source => |i, c| if is_num_end(c) {
+    for_each!((i, c) in char_indices(source) => if is_num_end(c) {
         return Ok(Some(i))
     } else if !is_digit(c) {
         return Err(Unexpected(c))
@@ -154,7 +155,7 @@ pub const fn peek (mut src: &str) -> DslPerhaps<&str> {
         _ if let Ok(Some(num))  = num_peek(src) => num,
         _ if let Ok(Some(text)) = text_peek(src) => text,
         _ => {
-            iter_chars!(src => |_i, c| if !is_whitespace(c) {
+            for_each!((i, c) in char_indices(src) => if !is_whitespace(c) {
                 return Err(Unexpected(c))
             });
             return Ok(None)
@@ -170,7 +171,7 @@ pub const fn seek (mut src: &str) -> DslPerhaps<(usize, usize)> {
         _ if let Ok(Some(num))  = num_seek(src) => num,
         _ if let Ok(Some(text)) = text_seek(src) => text,
         _ => {
-            iter_chars!(src => |_i, c| if !is_whitespace(c) {
+            for_each!((i, c) in char_indices(src) => if !is_whitespace(c) {
                 return Err(Unexpected(c))
             });
             return Ok(None)

dsl/src/dsl_test.rs

@@ -0,0 +1,52 @@
+use crate::*;
+#[test] fn test_exp () -> Result<(), DslError> {
+    assert_eq!(is_whitespace(' '), true);
+
+    assert_eq!(is_key_start(' '),              false);
+    assert_eq!(is_key_start('f'),              true);
+    assert_eq!(key_seek_start("foo"),          Ok(Some(0)));
+    assert_eq!(key_seek_start("foo "),         Ok(Some(0)));
+    assert_eq!(key_seek_start(" foo "),        Ok(Some(1)));
+    assert_eq!(key_seek_length(&" foo "[1..]), Ok(Some(3)));
+    assert_eq!(key_seek("foo"),                Ok(Some((0, 3))));
+    assert_eq!(key_peek("foo"),                Ok(Some("foo")));
+    assert_eq!(key_seek("foo "),               Ok(Some((0, 3))));
+    assert_eq!(key_peek("foo "),               Ok(Some("foo")));
+    assert_eq!(key_seek(" foo "),              Ok(Some((1, 3))));
+    assert_eq!(key_peek(" foo "),              Ok(Some("foo")));
+
+    assert_eq!("foo".key(),   Ok(Some("foo")));
+    assert_eq!(" foo".key(),  Ok(Some("foo")));
+    assert_eq!(" foo ".key(), Ok(Some("foo")));
+
+    assert_eq!(" foo ".head(),        Ok(Some("foo")));
+    assert_eq!(" foo ".head().head(), Ok(None));
+    assert_eq!(" foo ".head().tail(), Ok(None));
+    assert_eq!(" foo ".tail(),        Ok(None));
+    assert_eq!(" foo ".tail().head(), Ok(None));
+    assert_eq!(" foo ".tail().tail(), Ok(None));
+
+    assert_eq!(" foo bar ".head(),        Ok(Some("foo")));
+    assert_eq!(" foo bar ".head().head(), Ok(None));
+    assert_eq!(" foo bar ".head().tail(), Ok(None));
+    assert_eq!(" foo bar ".tail(),        Ok(Some("bar")));
+    assert_eq!(" foo bar ".tail().head(), Ok(None));
+    assert_eq!(" foo bar ".tail().tail(), Ok(None));
+
+    assert_eq!(" (foo) ".head(),               Ok(Some("(foo)")));
+    assert_eq!(" (foo) ".head().head(),        Ok(Some("foo")));
+    assert_eq!(" (foo) ".head().head().head(), Ok(None));
+    assert_eq!(" (foo) ".tail(),               Ok(None));
+
+    assert_eq!(" (foo) (bar) ".head(),               Ok(Some("(foo)")));
+    assert_eq!(" (foo) (bar) ".head().head(),        Ok(Some("foo")));
+    assert_eq!(" (foo) (bar) ".head().head().head(), Ok(None));
+    assert_eq!(" (foo) (bar) ".tail(),               Ok(None));
+
+    assert_eq!(" (foo bar baz) ".head(),               Ok(Some("(foo bar baz)")));
+    assert_eq!(" (foo bar baz) ".head().head(),        Ok(Some("foo")));
+    assert_eq!(" (foo bar baz) ".head().tail(),        Ok(Some("bar baz")));
+    assert_eq!(" (foo bar baz) ".head().tail().head(), Ok(Some("bar")));
+    assert_eq!(" (foo bar baz) ".head().tail().tail(), Ok(Some("baz")));
+    Ok(())
+}