From f22dc3aa000438bdb2c38f4b7acf70d0903f5960 Mon Sep 17 00:00:00 2001
From: Andrew Poelstra <apoelstra@wpsoftware.net>
Date: Sun, 3 Mar 2024 02:28:03 +0000
Subject: [PATCH] miniscript: use new TRUE/FALSE constants throughout the
 codebase

This eliminates a bunch of error paths, which is nice.
---
 src/interpreter/inner.rs  |  8 ++------
 src/miniscript/astelem.rs | 23 ++++-------------------
 src/policy/compiler.rs    | 27 +++------------------------
 3 files changed, 9 insertions(+), 49 deletions(-)

diff --git a/src/interpreter/inner.rs b/src/interpreter/inner.rs
index cb9fbfc35..9fc3d11b5 100644
--- a/src/interpreter/inner.rs
+++ b/src/interpreter/inner.rs
@@ -46,12 +46,8 @@ fn script_from_stack_elem<Ctx: ScriptContext>(
             Miniscript::parse_with_ext(bitcoin::Script::from_bytes(sl), &ExtParams::allow_all())
                 .map_err(Error::from)
         }
-        stack::Element::Satisfied => {
-            Miniscript::from_ast(crate::Terminal::True).map_err(Error::from)
-        }
-        stack::Element::Dissatisfied => {
-            Miniscript::from_ast(crate::Terminal::False).map_err(Error::from)
-        }
+        stack::Element::Satisfied => Ok(Miniscript::TRUE),
+        stack::Element::Dissatisfied => Ok(Miniscript::FALSE),
     }
 }
 
diff --git a/src/miniscript/astelem.rs b/src/miniscript/astelem.rs
index e3dd0edf0..2b7417a34 100644
--- a/src/miniscript/astelem.rs
+++ b/src/miniscript/astelem.rs
@@ -331,7 +331,7 @@ impl<Pk: crate::FromStrKey, Ctx: ScriptContext> crate::expression::FromTree for
             ("and_n", 2) => Ok(Terminal::AndOr(
                 expression::FromTree::from_tree(&top.args[0])?,
                 expression::FromTree::from_tree(&top.args[1])?,
-                Arc::new(Miniscript::from_ast(Terminal::False)?),
+                Arc::new(Miniscript::FALSE),
             )),
             ("andor", 3) => Ok(Terminal::AndOr(
                 expression::FromTree::from_tree(&top.args[0])?,
@@ -400,24 +400,9 @@ impl<Pk: crate::FromStrKey, Ctx: ScriptContext> crate::expression::FromTree for
                 'v' => unwrapped = Terminal::Verify(Arc::new(ms)),
                 'j' => unwrapped = Terminal::NonZero(Arc::new(ms)),
                 'n' => unwrapped = Terminal::ZeroNotEqual(Arc::new(ms)),
-                't' => {
-                    unwrapped = Terminal::AndV(
-                        Arc::new(ms),
-                        Arc::new(Miniscript::from_ast(Terminal::True)?),
-                    )
-                }
-                'u' => {
-                    unwrapped = Terminal::OrI(
-                        Arc::new(ms),
-                        Arc::new(Miniscript::from_ast(Terminal::False)?),
-                    )
-                }
-                'l' => {
-                    unwrapped = Terminal::OrI(
-                        Arc::new(Miniscript::from_ast(Terminal::False)?),
-                        Arc::new(ms),
-                    )
-                }
+                't' => unwrapped = Terminal::AndV(Arc::new(ms), Arc::new(Miniscript::TRUE)),
+                'u' => unwrapped = Terminal::OrI(Arc::new(ms), Arc::new(Miniscript::FALSE)),
+                'l' => unwrapped = Terminal::OrI(Arc::new(Miniscript::FALSE), Arc::new(ms)),
                 x => return Err(Error::UnknownWrapper(x)),
             }
         }
diff --git a/src/policy/compiler.rs b/src/policy/compiler.rs
index 5a0b88809..1b1ced6e7 100644
--- a/src/policy/compiler.rs
+++ b/src/policy/compiler.rs
@@ -704,27 +704,13 @@ fn all_casts<Pk: MiniscriptKey, Ctx: ScriptContext>() -> [Cast<Pk, Ctx>; 10] {
         },
         Cast {
             ext_data: types::ExtData::cast_likely,
-            node: |ms| {
-                Terminal::OrI(
-                    Arc::new(
-                        Miniscript::from_ast(Terminal::False).expect("False Miniscript creation"),
-                    ),
-                    ms,
-                )
-            },
+            node: |ms| Terminal::OrI(Arc::new(Miniscript::FALSE), ms),
             ast_type: types::Type::cast_likely,
             comp_ext_data: CompilerExtData::cast_likely,
         },
         Cast {
             ext_data: types::ExtData::cast_unlikely,
-            node: |ms| {
-                Terminal::OrI(
-                    ms,
-                    Arc::new(
-                        Miniscript::from_ast(Terminal::False).expect("False Miniscript creation"),
-                    ),
-                )
-            },
+            node: |ms| Terminal::OrI(ms, Arc::new(Miniscript::FALSE)),
             ast_type: types::Type::cast_unlikely,
             comp_ext_data: CompilerExtData::cast_unlikely,
         },
@@ -742,14 +728,7 @@ fn all_casts<Pk: MiniscriptKey, Ctx: ScriptContext>() -> [Cast<Pk, Ctx>; 10] {
         },
         Cast {
             ext_data: types::ExtData::cast_true,
-            node: |ms| {
-                Terminal::AndV(
-                    ms,
-                    Arc::new(
-                        Miniscript::from_ast(Terminal::True).expect("True Miniscript creation"),
-                    ),
-                )
-            },
+            node: |ms| Terminal::AndV(ms, Arc::new(Miniscript::TRUE)),
             ast_type: types::Type::cast_true,
             comp_ext_data: CompilerExtData::cast_true,
         },