Fix validator lookup by title.

We want the lookup to yield a result when there's only a single
  validator; and no title is provided. So that users can simply do
  'aiken address' in their project if it's unambiguous. The validator's
  name is only required to disambiguate between multiple validators.

  I also noticed that the order of arguments in with_validator was
  wrong. Somehow.

crates/aiken-lang/src/format.rs

@@ -714,6 +714,7 @@ impl<'comments> Formatter<'comments> {
 
         let document = match expr {
             UntypedExpr::ByteArray { bytes, .. } => self.bytearray(bytes),
+
             UntypedExpr::If {
                 branches,
                 final_else,

crates/aiken-lang/src/uplc.rs

@@ -820,6 +820,7 @@ impl<'a> CodeGenerator<'a> {
                         }
                     };
 
+                    #[allow(clippy::bool_to_int_with_if)]
                     let minus_tail = if has_tail { 1 } else { 0 };
 
                     if current_clause_index as i64 - minus_tail == prev_index {

crates/aiken-project/src/blueprint/mod.rs

@@ -61,8 +61,7 @@ where
         let mut validator = None;
 
         for v in self.validators.iter() {
-            let match_title = title.map(|t| v.title.contains(t)).unwrap_or(false);
+            let match_title = Some(&v.title) == title.or(Some(&v.title));
-
             if match_title {
                 validator = Some(if validator.is_none() {
                     LookupResult::One(v)
@@ -78,8 +77,8 @@ where
     pub fn with_validator<F, A, E>(
         &self,
         title: Option<&String>,
-        when_missing: fn(Vec<String>) -> E,
         when_too_many: fn(Vec<String>) -> E,
+        when_missing: fn(Vec<String>) -> E,
         action: F,
     ) -> Result<A, E>
     where

crates/aiken/src/cmd/blueprint/address.rs

@@ -45,7 +45,7 @@ pub fn exec(
                 validator
                     .as_ref()
                     .map(|v| format!(".{v}"))
-                    .unwrap_or("".to_string())
+                    .unwrap_or_default()
             )
         });
 

crates/aiken/src/cmd/blueprint/apply.rs

@@ -46,7 +46,7 @@ pub fn exec(
                 validator
                     .as_ref()
                     .map(|v| format!(".{v}"))
-                    .unwrap_or("".to_string())
+                    .unwrap_or_default()
             )
         });