diff --git a/dsl/src/dsl.rs b/dsl/src/dsl.rs
index ce30384..e7463ae 100644
--- a/dsl/src/dsl.rs
+++ b/dsl/src/dsl.rs
@@ -57,16 +57,16 @@ pub const fn no_trailing_non_space (
     }))
 }
 pub const fn peek (src: &str) -> DslPerhaps<&str> {
-    Ok(Some(if let Ok(Some(expr)) = expr_peek(src) { expr } else
-            if let Ok(Some(word)) = word_peek(src) { word } else
+    Ok(Some(if let Ok(Some(expr))  = expr_peek(src)  { expr  } else
+            if let Ok(Some(word))  = word_peek(src)  { word  } else
             if let Ok(Some(num))  = num_peek(src)  { num  } else
             if let Ok(Some(text)) = text_peek(src) { text } else
             if let Err(e) = no_trailing_non_space(src, 0, Some("peek")) { return Err(e) }
             else { return Ok(None) }))
 }
 pub const fn seek (src: &str) -> DslPerhaps<(usize, usize)> {
-    Ok(Some(if let Ok(Some(expr)) = expr_seek(src) { expr } else
-            if let Ok(Some(word)) = word_seek(src) { word } else
+    Ok(Some(if let Ok(Some(expr))  = expr_seek(src)  { expr  } else
+            if let Ok(Some(word))  = word_seek(src)  { word  } else
             if let Ok(Some(num))  = num_seek(src)  { num  } else
             if let Ok(Some(text)) = text_seek(src) { text } else
             if let Err(e) = no_trailing_non_space(src, 0, Some("seek")) { return Err(e) }
@@ -242,6 +242,29 @@ dsl_type!(DslText {
     }
 });
 
+pub const fn is_key_start (c: char) -> bool { matches!(c, '/'|('a'..='z')) }
+pub const fn is_key_char (c: char) -> bool { is_key_start(c) || matches!(c, '0'..='9'|'-') }
+pub const fn is_key_end (c: char) -> bool { !is_key_char(c) }
+dsl_type!(DslKey {
+    fn key (&self) -> DslPerhaps<&str> { ok_flat(self.src()?.map(key_peek_only)) }
+} {
+    pub const fn key_peek      [generated];
+    pub const fn key_peek_only [generated];
+    pub const fn key_seek      [generated];
+    pub const fn key_seek_start (src) {
+        for_each!((i, c) in char_indices(src) =>
+            if is_key_start(c) { return Ok(Some(i)) } else
+            if !is_space(c)    { return Err(Unexpected(c, Some(i), None)) });
+        Ok(None)
+    }
+    pub const fn key_seek_length (src) {
+        for_each!((i, c) in char_indices(src) =>
+            if is_key_end(c)   { return Ok(Some(i)) } else
+            if !is_key_char(c) { return Err(Unexpected(c, Some(i), None)) });
+        Ok(Some(src.len()))
+    }
+});
+
 dsl_type!(DslNum {
     fn num (&self) -> DslPerhaps<&str> {ok_flat(self.src()?.map(num_peek_only))}
 } {
diff --git a/dsl/src/dsl_ns.rs b/dsl/src/dsl_ns.rs
index b2776aa..7f91c46 100644
--- a/dsl/src/dsl_ns.rs
+++ b/dsl/src/dsl_ns.rs
@@ -10,18 +10,18 @@ use crate::*;
     // Special form for numeric types
     (num |$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
         impl<'t> DslNs<'t, $Type> for $State {
-            const WORDS: DslNsMap<'t, fn (&'t $State)->Perhaps<$Type>> =
+            const SYMS: DslNsMap<'t, fn (&'t $State)->Perhaps<$Type>> =
                 DslNsMap::new(&[$(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
-            const EXPRS: DslNsMap<'t, fn (&'t $State, &str)->Perhaps<$Type>> =
+            const EXPS: DslNsMap<'t, fn (&'t $State, &str)->Perhaps<$Type>> =
                 DslNsMap::new(&[$(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
             fn from <D: Dsl> (&'t self, dsl: D) -> Perhaps<$Type> {
                 if let Ok(Some(src)) = dsl.src() {
-                    if let Ok(num) = to_number(src) {
-                        Ok(Some(num as $Type))
+                    if let Ok(Some(num)) = src.num() {
+                        Ok(Some(to_number(num)? as $Type))
                     } else if let Ok(Some(src)) = src.word() {
                         self.from_word(src)
                     } else {
-                        self.from_expr(src)
+                        self.from_exp(src)
                     }
                 } else {
                     Ok(None)
@@ -36,9 +36,9 @@ use crate::*;
     // Regular form for single type
     (|$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
         impl<'t> DslNs<'t, $Type> for $State {
-            const WORDS: DslNsMap<'t, fn (&'t $State)->Perhaps<$Type>> =
+            const SYMS: DslNsMap<'t, fn (&'t $State)->Perhaps<$Type>> =
                 DslNsMap::new(&[$(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
-            const EXPRS: DslNsMap<'t, fn (&'t $State, &str)->Perhaps<$Type>> =
+            const EXPS: DslNsMap<'t, fn (&'t $State, &str)->Perhaps<$Type>> =
                 DslNsMap::new(&[$(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
         }
     };
@@ -54,16 +54,15 @@ use crate::*;
     }) => { ($head, |$state, tail: &str|{
         $(
             let head = tail.head()?.unwrap_or_default();
-            let tail = tail.tail()?.unwrap_or_default();
             let $arg: $ty = if let Some(arg) = $state.from(&head)? {
                 arg
             } else {
-                return Err(format!("{}: missing argument: {} ({}); got: {tail}",
-                    $head,
-                    stringify!($arg),
-                    stringify!($Type),
+                return Err(format!("{}: missing argument: {}",
+                    stringify!($head),
+                    stringify!($arg)
                 ).into())
             };
+            let tail = tail.tail()?.unwrap_or_default();
         )*
         Ok(Some($body))
     }) };
@@ -85,7 +84,7 @@ pub trait DslNs<'t, T: 't>: 't {
             if let Ok(Some(src)) = src.word() {
                 self.from_word(src)
             } else {
-                self.from_expr(src)
+                self.from_exp(src)
             }
         } else {
             Ok(None)
@@ -94,25 +93,26 @@ pub trait DslNs<'t, T: 't>: 't {
     /// Resolve a symbol if known.
     fn from_word <D: Dsl> (&'t self, dsl: D) -> Perhaps<T> {
         if let Some(dsl) = dsl.word()? {
-            for (word, get) in Self::WORDS.0 { if dsl == *word { return get(self) } }
+            for (word, get) in Self::SYMS.0 { if dsl == *word { return get(self) } }
         }
         return Ok(None)
     }
     /// Resolve an expression if known.
-    fn from_expr <D: Dsl> (&'t self, dsl: D) -> Perhaps<T> {
+    fn from_exp <D: Dsl> (&'t self, dsl: D) -> Perhaps<T> {
         if let Some(head) = dsl.expr().head()? {
-            for (key, value) in Self::EXPRS.0.iter() {
+            for (key, value) in Self::EXPS.0.iter() {
                 if head == *key {
                     return value(self, dsl.expr().tail()?.unwrap_or(""))
                 }
             }
         }
+        panic!("{dsl:?}");
         return Ok(None)
     }
     /// Known symbols.
-    const WORDS: DslNsMap<'t, fn (&'t Self)->Perhaps<T>> = DslNsMap::new(&[]);
+    const SYMS: DslNsMap<'t, fn (&'t Self)->Perhaps<T>> = DslNsMap::new(&[]);
     /// Known expressions.
-    const EXPRS: DslNsMap<'t, fn (&'t Self, &str)->Perhaps<T>> = DslNsMap::new(&[]);
+    const EXPS: DslNsMap<'t, fn (&'t Self, &str)->Perhaps<T>> = DslNsMap::new(&[]);
 }
 /// Namespace mapping.
 #[derive(Debug)]
diff --git a/proc/src/proc_expose.rs b/proc/src/proc_expose.rs
index bb6794b..fa2707c 100644
--- a/proc/src/proc_expose.rs
+++ b/proc/src/proc_expose.rs
@@ -87,7 +87,7 @@ impl ExposeImpl {
                 /// Generated by [tengri_proc::expose].
                 impl ::tengri::dsl::FromDsl<#state> for #t {
                     fn from_dsl (state: &#state, dsl: &impl Dsl) -> Perhaps<Self> {
-                        match dsl.word()? {
+                        match dsl.key()? {
                             Some("true")  => Ok(Some(true)),
                             Some("false") => Ok(Some(false)),
                             _ => match dsl.word()? { #(#variants)* _ => Ok(None) }