diff --git a/src/config.rs b/src/config.rs
index 28c5a66..b3f687e 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -10,6 +10,8 @@ use std::{
     str::FromStr,
 };
 
+// https://michael-f-bryan.github.io/static-analyser-in-rust/book/codemap.html
+
 type VarName = String;
 type AttrValue = String;
 type AttrName = String;
@@ -24,48 +26,6 @@ impl FromExpr for Expr {
     }
 }
 
-#[derive(Debug, Eq, PartialEq)]
-pub enum DefType {
-    Widget,
-}
-
-impl FromStr for DefType {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s {
-            "defwidget" => Ok(DefType::Widget),
-            _ => Err(()),
-        }
-    }
-}
-
-#[derive(Debug, Eq, PartialEq)]
-pub struct Definitional<C, A> {
-    def_type: DefType,
-    name: String,
-    attrs: HashMap<AttrName, A>,
-    children: Vec<C>,
-    span: Span,
-}
-
-impl<C: FromExpr, A: FromExpr> FromExpr for Definitional<C, A> {
-    fn from_expr(e: Expr) -> AstResult<Self> {
-        let span = e.span();
-        spanned!(e.span(), {
-            let list = e.as_list()?;
-            let mut iter = ExprIterator::new(list.into_iter());
-            let (span, def_type) = iter.next_symbol()?;
-            let def_type = def_type.parse().map_err(|_| AstError::InvalidDefinition(Some(span)))?;
-
-            let (_, name) = iter.next_symbol()?;
-            let attrs = iter.key_values()?;
-            let children = iter.map(|x| C::from_expr(x)).collect::<AstResult<Vec<_>>>()?;
-            Definitional { span, def_type, name, attrs, children }
-        })
-    }
-}
-
 #[derive(Debug, Eq, PartialEq)]
 pub struct Element<C, A> {
     name: String,
@@ -80,8 +40,8 @@ impl<C: FromExpr, A: FromExpr> FromExpr for Element<C, A> {
         spanned!(e.span(), {
             let list = e.as_list()?;
             let mut iter = ExprIterator::new(list.into_iter());
-            let (_, name) = iter.next_symbol()?;
-            let attrs = iter.key_values()?;
+            let (_, name) = iter.expect_symbol()?;
+            let attrs = iter.expect_key_values()?;
             let children = iter.map(C::from_expr).collect::<AstResult<Vec<_>>>()?;
             Element { span, name, attrs, children }
         })
@@ -101,9 +61,6 @@ mod test {
             insta::assert_debug_snapshot!(
                 Element::<Expr, Expr>::from_expr(parser.parse("(box :bar 12 :baz \"hi\" foo (bar))").unwrap()).unwrap()
             );
-            insta::assert_debug_snapshot!(
-                Definitional::<Expr, Expr>::from_expr(parser.parse("(defwidget box (child) (child2))").unwrap()).unwrap()
-            );
         });
     }
 }
diff --git a/src/expr.rs b/src/expr.rs
index 099b5e2..97a0b92 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -15,7 +15,7 @@ impl std::fmt::Display for Span {
 
 impl std::fmt::Debug for Span {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self)
+        write!(f, "{}..{}", self.0, self.1)
     }
 }
 
@@ -36,7 +36,7 @@ impl Display for ExprType {
     }
 }
 
-#[derive(Debug, PartialEq, Eq, Clone)]
+#[derive(PartialEq, Eq, Clone)]
 pub enum Expr {
     List(Span, Vec<Expr>),
     Table(Span, Vec<(Expr, Expr)>),
@@ -48,22 +48,29 @@ pub enum Expr {
 }
 
 macro_rules! as_func {
-    ($exprtype:expr, $name:ident < $t:ty > = $p:pat => $value:expr) => {
+    ($exprtype:expr, $name:ident $nameref:ident < $t:ty > = $p:pat => $value:expr) => {
         pub fn $name(self) -> Result<$t, AstError> {
             match self {
                 $p => Ok($value),
                 x => Err(AstError::WrongExprType(Some(x.span()), $exprtype, x.expr_type())),
             }
         }
+
+        pub fn $nameref(&self) -> Result<&$t, AstError> {
+            match self {
+                $p => Ok($value),
+                x => Err(AstError::WrongExprType(Some(x.span()), $exprtype, x.expr_type())),
+            }
+        }
     };
 }
 
 impl Expr {
-    as_func!(ExprType::Str, as_str<String> = Expr::Str(_, x) => x);
+    as_func!(ExprType::Str, as_str as_str_ref<String> = Expr::Str(_, x) => x);
 
-    as_func!(ExprType::Symbol, as_symbol<String> = Expr::Symbol(_, x) => x);
+    as_func!(ExprType::Symbol, as_symbol as_symbol_ref<String> = Expr::Symbol(_, x) => x);
 
-    as_func!(ExprType::List, as_list<Vec<Expr>> = Expr::List(_, x) => x);
+    as_func!(ExprType::List, as_list as_list_ref<Vec<Expr>> = Expr::List(_, x) => x);
 
     pub fn expr_type(&self) -> ExprType {
         match self {
@@ -88,6 +95,13 @@ impl Expr {
             Expr::Comment(span) => *span,
         }
     }
+
+    pub fn first_list_elem(&self) -> Option<&Expr> {
+        match self {
+            Expr::List(_, list) => list.first(),
+            _ => None,
+        }
+    }
 }
 
 impl std::fmt::Display for Expr {
@@ -104,6 +118,20 @@ impl std::fmt::Display for Expr {
         }
     }
 }
+impl std::fmt::Debug for Expr {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use Expr::*;
+        match self {
+            Number(span, x) => write!(f, "Number<{}>({})", span, x),
+            List(span, x) => f.debug_tuple(&format!("List<{}>", span)).field(x).finish(),
+            Table(span, x) => f.debug_tuple(&format!("Table<{}>", span)).field(x).finish(),
+            Keyword(span, x) => write!(f, "Number<{}>({})", span, x),
+            Symbol(span, x) => write!(f, "Symbol<{}>({})", span, x),
+            Str(span, x) => write!(f, "Str<{}>({})", span, x),
+            Comment(span) => write!(f, "Comment<{}>", span),
+        }
+    }
+}
 
 pub struct ExprIterator<I: Iterator<Item = Expr>> {
     iter: itertools::PutBack<I>,
@@ -128,15 +156,19 @@ macro_rules! return_or_put_back {
 }
 
 impl<I: Iterator<Item = Expr>> ExprIterator<I> {
-    return_or_put_back!(next_symbol, ExprType::Symbol, (Span, String) = Expr::Symbol(span, x) => (span, x));
+    return_or_put_back!(expect_symbol, ExprType::Symbol, (Span, String) = Expr::Symbol(span, x) => (span, x));
 
-    return_or_put_back!(next_string, ExprType::Str, (Span, String) = Expr::Str(span, x) => (span, x));
+    return_or_put_back!(expect_string, ExprType::Str, (Span, String) = Expr::Str(span, x) => (span, x));
+
+    return_or_put_back!(expect_number, ExprType::Number, (Span, i32) = Expr::Number(span, x) => (span, x));
+
+    return_or_put_back!(expect_list, ExprType::List, (Span, Vec<Expr>) = Expr::List(span, x) => (span, x));
 
     pub fn new(iter: I) -> Self {
         ExprIterator { iter: itertools::put_back(iter) }
     }
 
-    pub fn key_values<T: FromExpr>(&mut self) -> AstResult<HashMap<String, T>> {
+    pub fn expect_key_values<T: FromExpr>(&mut self) -> AstResult<HashMap<String, T>> {
         parse_key_values(&mut self.iter)
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index d4a6f66..5135ce4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -41,6 +41,7 @@ fn test() {
         r#"{:key value 12 "hi" (test) (1 2 3)}"#,
         r#"; test"#,
         r#"(f arg ; test
-        arg2)"#
+        arg2)"#,
+        "\"h\\\"i\""
     );
 }
diff --git a/src/snapshots/eww_config__config__test__test-2.snap b/src/snapshots/eww_config__config__test__test-2.snap
index 39b709c..991e320 100644
--- a/src/snapshots/eww_config__config__test__test-2.snap
+++ b/src/snapshots/eww_config__config__test__test-2.snap
@@ -8,22 +8,14 @@ Definitional {
     name: "box",
     attrs: {},
     children: [
-        List(
-            15..22,
+        List<15..22>(
             [
-                Symbol(
-                    16..21,
-                    "child",
-                ),
+                Symbol<16..21>(child),
             ],
         ),
-        List(
-            23..31,
+        List<23..31>(
             [
-                Symbol(
-                    24..30,
-                    "child2",
-                ),
+                Symbol<24..30>(child2),
             ],
         ),
     ],
diff --git a/src/snapshots/eww_config__config__test__test.snap b/src/snapshots/eww_config__config__test__test.snap
index b58093b..2a5ccaa 100644
--- a/src/snapshots/eww_config__config__test__test.snap
+++ b/src/snapshots/eww_config__config__test__test.snap
@@ -6,27 +6,14 @@ expression: "Element::<Expr,\n          Expr>::from_expr(parser.parse(\"(box :ba
 Element {
     name: "box",
     attrs: {
-        ":bar": Number(
-            10..12,
-            12,
-        ),
-        ":baz": Str(
-            18..22,
-            "hi",
-        ),
+        ":baz": Str<18..22>(hi),
+        ":bar": Number<10..12>(12),
     },
     children: [
-        Symbol(
-            23..26,
-            "foo",
-        ),
-        List(
-            27..32,
+        Symbol<23..26>(foo),
+        List<27..32>(
             [
-                Symbol(
-                    28..31,
-                    "bar",
-                ),
+                Symbol<28..31>(bar),
             ],
         ),
     ],
diff --git a/src/snapshots/eww_config__test-10.snap b/src/snapshots/eww_config__test-10.snap
index 2d0f6c5..50bf3b4 100644
--- a/src/snapshots/eww_config__test-10.snap
+++ b/src/snapshots/eww_config__test-10.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(r#\"(test \"h\\\"i\")\"#)"
 
 ---
 Ok(
-    List(
-        0..13,
+    List<0..13>(
         [
-            Symbol(
-                1..5,
-                "test",
-            ),
-            Str(
-                6..12,
-                "h\\\"i",
-            ),
+            Symbol<1..5>(test),
+            Str<6..12>(h\"i),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-11.snap b/src/snapshots/eww_config__test-11.snap
index ae042cc..8437f61 100644
--- a/src/snapshots/eww_config__test-11.snap
+++ b/src/snapshots/eww_config__test-11.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(r#\"(test \" hi \")\"#)"
 
 ---
 Ok(
-    List(
-        0..13,
+    List<0..13>(
         [
-            Symbol(
-                1..5,
-                "test",
-            ),
-            Str(
-                6..12,
-                " hi ",
-            ),
+            Symbol<1..5>(test),
+            Str<6..12>( hi ),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-12.snap b/src/snapshots/eww_config__test-12.snap
index 96fcd40..1f7e872 100644
--- a/src/snapshots/eww_config__test-12.snap
+++ b/src/snapshots/eww_config__test-12.snap
@@ -1,42 +1,21 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(+ (1 2 (* 2 5)))\")"
 
 ---
 Ok(
-    List(
-        0..17,
+    List<0..17>(
         [
-            Symbol(
-                1..2,
-                "+",
-            ),
-            List(
-                3..16,
+            Symbol<1..2>(+),
+            List<3..16>(
                 [
-                    Number(
-                        4..5,
-                        1,
-                    ),
-                    Number(
-                        6..7,
-                        2,
-                    ),
-                    List(
-                        8..15,
+                    Number<4..5>(1),
+                    Number<6..7>(2),
+                    List<8..15>(
                         [
-                            Symbol(
-                                9..10,
-                                "*",
-                            ),
-                            Number(
-                                11..12,
-                                2,
-                            ),
-                            Number(
-                                13..14,
-                                5,
-                            ),
+                            Symbol<9..10>(*),
+                            Number<11..12>(2),
+                            Number<13..14>(5),
                         ],
                     ),
                 ],
diff --git a/src/snapshots/eww_config__test-13.snap b/src/snapshots/eww_config__test-13.snap
index aeed887..9b51e53 100644
--- a/src/snapshots/eww_config__test-13.snap
+++ b/src/snapshots/eww_config__test-13.snap
@@ -1,57 +1,30 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(r#\"{:key value 12 \"hi\" (test) (1 2 3)}\"#)"
 
 ---
 Ok(
-    Table(
-        0..35,
+    Table<0..35>(
         [
             (
-                Keyword(
-                    1..5,
-                    ":key",
-                ),
-                Symbol(
-                    6..11,
-                    "value",
-                ),
+                Number<1..5>(:key),
+                Symbol<6..11>(value),
             ),
             (
-                Number(
-                    12..14,
-                    12,
-                ),
-                Str(
-                    15..19,
-                    "hi",
-                ),
+                Number<12..14>(12),
+                Str<15..19>(hi),
             ),
             (
-                List(
-                    20..26,
+                List<20..26>(
                     [
-                        Symbol(
-                            21..25,
-                            "test",
-                        ),
+                        Symbol<21..25>(test),
                     ],
                 ),
-                List(
-                    27..34,
+                List<27..34>(
                     [
-                        Number(
-                            28..29,
-                            1,
-                        ),
-                        Number(
-                            30..31,
-                            2,
-                        ),
-                        Number(
-                            32..33,
-                            3,
-                        ),
+                        Number<28..29>(1),
+                        Number<30..31>(2),
+                        Number<32..33>(3),
                     ],
                 ),
             ),
diff --git a/src/snapshots/eww_config__test-14.snap b/src/snapshots/eww_config__test-14.snap
index 5b8d869..3abe4ce 100644
--- a/src/snapshots/eww_config__test-14.snap
+++ b/src/snapshots/eww_config__test-14.snap
@@ -1,10 +1,8 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(r#\"; test\"#)"
 
 ---
 Ok(
-    Comment(
-        0..6,
-    ),
+    Comment<0..6>,
 )
diff --git a/src/snapshots/eww_config__test-15.snap b/src/snapshots/eww_config__test-15.snap
index b2943ca..c2f54ba 100644
--- a/src/snapshots/eww_config__test-15.snap
+++ b/src/snapshots/eww_config__test-15.snap
@@ -4,24 +4,12 @@ expression: "p.parse(r#\"(f arg ; test\n        arg2)\"#)"
 
 ---
 Ok(
-    List(
-        0..27,
+    List<0..27>(
         [
-            Symbol(
-                1..2,
-                "f",
-            ),
-            Symbol(
-                3..6,
-                "arg",
-            ),
-            Comment(
-                7..13,
-            ),
-            Symbol(
-                22..26,
-                "arg2",
-            ),
+            Symbol<1..2>(f),
+            Symbol<3..6>(arg),
+            Comment<7..13>,
+            Symbol<22..26>(arg2),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-16.snap b/src/snapshots/eww_config__test-16.snap
new file mode 100644
index 0000000..021fcd1
--- /dev/null
+++ b/src/snapshots/eww_config__test-16.snap
@@ -0,0 +1,8 @@
+---
+source: src/lib.rs
+expression: "p.parse(\"\\\"h\\\\\\\"i\\\"\")"
+
+---
+Ok(
+    Str<0..6>(h\"i),
+)
diff --git a/src/snapshots/eww_config__test-2.snap b/src/snapshots/eww_config__test-2.snap
index f16a309..dd84a41 100644
--- a/src/snapshots/eww_config__test-2.snap
+++ b/src/snapshots/eww_config__test-2.snap
@@ -1,16 +1,12 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(12)\")"
 
 ---
 Ok(
-    List(
-        0..4,
+    List<0..4>(
         [
-            Number(
-                1..3,
-                12,
-            ),
+            Number<1..3>(12),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-3.snap b/src/snapshots/eww_config__test-3.snap
index 99b52c6..5f7b32c 100644
--- a/src/snapshots/eww_config__test-3.snap
+++ b/src/snapshots/eww_config__test-3.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(1 2)\")"
 
 ---
 Ok(
-    List(
-        0..5,
+    List<0..5>(
         [
-            Number(
-                1..2,
-                1,
-            ),
-            Number(
-                3..4,
-                2,
-            ),
+            Number<1..2>(1),
+            Number<3..4>(2),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-4.snap b/src/snapshots/eww_config__test-4.snap
index 6ecf27d..8ce142b 100644
--- a/src/snapshots/eww_config__test-4.snap
+++ b/src/snapshots/eww_config__test-4.snap
@@ -1,24 +1,14 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(1 :foo 1)\")"
 
 ---
 Ok(
-    List(
-        0..10,
+    List<0..10>(
         [
-            Number(
-                1..2,
-                1,
-            ),
-            Keyword(
-                3..7,
-                ":foo",
-            ),
-            Number(
-                8..9,
-                1,
-            ),
+            Number<1..2>(1),
+            Number<3..7>(:foo),
+            Number<8..9>(1),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-5.snap b/src/snapshots/eww_config__test-5.snap
index ff6efe3..9db3361 100644
--- a/src/snapshots/eww_config__test-5.snap
+++ b/src/snapshots/eww_config__test-5.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(:foo 1)\")"
 
 ---
 Ok(
-    List(
-        0..8,
+    List<0..8>(
         [
-            Keyword(
-                1..5,
-                ":foo",
-            ),
-            Number(
-                6..7,
-                1,
-            ),
+            Number<1..5>(:foo),
+            Number<6..7>(1),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-6.snap b/src/snapshots/eww_config__test-6.snap
index 919dd49..f368f33 100644
--- a/src/snapshots/eww_config__test-6.snap
+++ b/src/snapshots/eww_config__test-6.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(:foo->: 1)\")"
 
 ---
 Ok(
-    List(
-        0..11,
+    List<0..11>(
         [
-            Keyword(
-                1..8,
-                ":foo->:",
-            ),
-            Number(
-                9..10,
-                1,
-            ),
+            Number<1..8>(:foo->:),
+            Number<9..10>(1),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-7.snap b/src/snapshots/eww_config__test-7.snap
index 0c038c5..eb63df2 100644
--- a/src/snapshots/eww_config__test-7.snap
+++ b/src/snapshots/eww_config__test-7.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(foo 1)\")"
 
 ---
 Ok(
-    List(
-        0..7,
+    List<0..7>(
         [
-            Symbol(
-                1..4,
-                "foo",
-            ),
-            Number(
-                5..6,
-                1,
-            ),
+            Symbol<1..4>(foo),
+            Number<5..6>(1),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-8.snap b/src/snapshots/eww_config__test-8.snap
index eec1f65..ee21f3e 100644
--- a/src/snapshots/eww_config__test-8.snap
+++ b/src/snapshots/eww_config__test-8.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"(lol😄 1)\")"
 
 ---
 Ok(
-    List(
-        0..11,
+    List<0..11>(
         [
-            Symbol(
-                1..8,
-                "lol😄",
-            ),
-            Number(
-                9..10,
-                1,
-            ),
+            Symbol<1..8>(lol😄),
+            Number<9..10>(1),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test-9.snap b/src/snapshots/eww_config__test-9.snap
index ce6c9db..edc1cb8 100644
--- a/src/snapshots/eww_config__test-9.snap
+++ b/src/snapshots/eww_config__test-9.snap
@@ -1,20 +1,13 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(r#\"(test \"hi\")\"#)"
 
 ---
 Ok(
-    List(
-        0..11,
+    List<0..11>(
         [
-            Symbol(
-                1..5,
-                "test",
-            ),
-            Str(
-                6..10,
-                "hi",
-            ),
+            Symbol<1..5>(test),
+            Str<6..10>(hi),
         ],
     ),
 )
diff --git a/src/snapshots/eww_config__test.snap b/src/snapshots/eww_config__test.snap
index 2547c26..8c42a6b 100644
--- a/src/snapshots/eww_config__test.snap
+++ b/src/snapshots/eww_config__test.snap
@@ -1,11 +1,8 @@
 ---
-source: src/main.rs
+source: src/lib.rs
 expression: "p.parse(\"1\")"
 
 ---
 Ok(
-    Number(
-        0..1,
-        1,
-    ),
+    Number<0..1>(1),
 )