4 files changed, 41 insertions, 14 deletions
diff --git a/src/parse/regex/dfa.rs b/src/parse/regex/dfa.rs
index 243176d..0a5c78d 100644
--- a/src/parse/regex/dfa.rs
+++ b/src/parse/regex/dfa.rs
@@ -34,7 +34,7 @@ impl fmt::Debug for DFA {
                 write!(f, "{chr:?} to {to}, ")?;
             }
 
-            write!(f, "default to {}", s.default_trans)?;
+            write!(f, "dfl to {}", s.default_trans)?;
             if s.accept {
                 write!(f, ", accept")?;
             }
@@ -58,14 +58,18 @@ impl DFA {
         }
         self.states[state].accept
     }
+
+    pub fn simplify(&mut self) {
+        for state in self.states.iter_mut() {
+            state.trans.retain(|_, to| *to != state.default_trans);
+        }
+    }
 }
 
 impl From<ENFA> for DFA {
     fn from(mut nfa: ENFA) -> Self {
         nfa.remove_unreachable();
 
-        println!("{nfa:?}");
-
         let mut multi_states = nfa.all_multi_states();
         multi_states.insert(nfa.void_multi_state());
         let mut len = 0;
@@ -97,9 +101,11 @@ impl From<ENFA> for DFA {
             }
         }
 
-        Self {
+        let mut this = Self {
             start: multi_to_dfa[&nfa.start_multi_state()],
             states,
-        }
+        };
+        this.simplify();
+        this
     }
 }
diff --git a/src/parse/regex/mod.rs b/src/parse/regex/mod.rs
index 2f7c223..b8dd8ba 100644
--- a/src/parse/regex/mod.rs
+++ b/src/parse/regex/mod.rs
@@ -3,8 +3,8 @@ use crate::parse::OtherHighlights;
 use super::{Parse, ParseError, Result};
 
 mod byte_range;
-mod dfa;
-mod enfa;
+pub mod dfa;
+pub mod enfa;
 
 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
 pub enum LookDirection {
diff --git a/src/run/builtin.rs b/src/run/builtin.rs
index fd4cbed..87a0be0 100644
--- a/src/run/builtin.rs
+++ b/src/run/builtin.rs
@@ -1039,7 +1039,9 @@ impl Builtin for pish_theme {
 
 #[cfg(debug_assertions)]
 mod dbg {
-    use super::*;
+    use crate::parse::regex::{dfa::DFA, enfa::ENFA};
+
+use super::*;
 
     #[derive(Copy, Clone)]
     pub struct debug;
@@ -1121,13 +1123,17 @@ mod dbg {
                 },
             };
 
-            match regex.try_compile() {
-                Ok(compiled) => writeln!(stdout, "{compiled:?}")?,
-                Err(e) => {
-                    writeln!(stdout, "compilation error: {e:?}")?;
+            let nfa = match ENFA::try_from(regex) {
+                Ok(nfa) => nfa,
+                Err(err) => {
+                    writeln!(stdout, "nfa error: {err:?}")?;
                     return Err(Error::Exit(2));
-                },
-            }
+                }
+            };
+            writeln!(stdout, "{nfa:?}")?;
+
+            let dfa = DFA::from(nfa);
+            writeln!(stdout, "{dfa:?}")?;
 
             Ok(())
         }
diff --git a/test-cases/case2_lookahead/script.sh b/test-cases/case2_lookahead/script.sh
index a77eb85..891441b 100644
--- a/test-cases/case2_lookahead/script.sh
+++ b/test-cases/case2_lookahead/script.sh
@@ -48,3 +48,18 @@ match x2 xfoobar_some_more_stuff yes
 match x2 x___bar no
 match x2 xfoo___ no
 match x2 xfoo    no
+
+fun x3 {
+    case $1 {
+        x(?!(a|b)).* { echo yes }
+        .* { echo no }
+    }
+}
+match x3 x yes
+match x3 xa no
+match x3 xb no
+match x3 xax no
+match x3 xbx no
+match x3 xxa yes
+match x3 xxb yes
+match x3 xfoobar yes