From fd116b676e6a4fbf835004e104761c8a7a936f74 Mon Sep 17 00:00:00 2001
From: Kai Schmidt <kaikaliischmidt@gmail.com>
Date: Wed, 27 Nov 2024 10:22:19 -0800
Subject: [PATCH] fix a bug in pre-evaluation

---
 src/compile/mod.rs      |  6 +++---
 src/compile/modifier.rs | 23 ++++++++++++++---------
 src/compile/pre_eval.rs |  8 ++++----
 tests/macros.ua         |  6 ++++++
 4 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/src/compile/mod.rs b/src/compile/mod.rs
index fbde39577..59ebe4690 100644
--- a/src/compile/mod.rs
+++ b/src/compile/mod.rs
@@ -330,7 +330,7 @@ impl Compiler {
         let input: EcoString = fs::read_to_string(path)
             .map_err(|e| UiuaErrorKind::Load(path.into(), e.into()))?
             .into();
-        // _ = crate::lsp::Spans::from_input(&input);
+        _ = crate::lsp::Spans::from_input(&input);
         self.asm.inputs.files.insert(path.into(), input.clone());
         self.load_impl(&input, InputSrc::File(path.into()))
     }
@@ -661,12 +661,12 @@ code:
                     }
                     // Try to evaluate at comptime
                     // This can be done when:
-                    // - the pre-eval mode is not `Line`
+                    // - the pre-eval mode is greater that `Line`
                     // - there are at least as many push nodes preceding the current line as there are arguments to the line
                     // - the words create no bindings
                     if precomp
                         && error_count_after == error_count_before
-                        && self.pre_eval_mode != PreEvalMode::Line
+                        && self.pre_eval_mode > PreEvalMode::Line
                         && !line_node.is_empty()
                         && binding_count_before == binding_count_after
                         && root_len_before == self.asm.root.len()
diff --git a/src/compile/modifier.rs b/src/compile/modifier.rs
index 21fdc4a7e..1b310da22 100644
--- a/src/compile/modifier.rs
+++ b/src/compile/modifier.rs
@@ -1177,7 +1177,7 @@ impl Compiler {
             })
             .collect();
 
-        let mut code = String::new();
+        let mut code: Option<String> = None;
         (|| -> UiuaResult {
             if let Some(index) = self.node_unbound_index(&mac.root.node) {
                 let name = self.scope.names.iter().find_map(|(name, local)| {
@@ -1225,8 +1225,9 @@ impl Compiler {
                     Ok(strings) => strings,
                     Err(_) => val.representation().lines().map(Into::into).collect(),
                 };
+                let code = code.get_or_insert_with(String::new);
                 for s in strings {
-                    if s.chars().last().is_some_and(|c| !c.is_whitespace()) {
+                    if code.chars().last().is_some_and(|c| !c.is_whitespace()) {
                         code.push(' ');
                     }
                     code.push_str(&s);
@@ -1247,14 +1248,18 @@ impl Compiler {
         .map_err(|e| e.trace_macro(mac_name.clone(), modifier_span.clone()))?;
 
         // Quote
-        self.code_meta
-            .macro_expansions
-            .insert(full_span, (mac_name.clone(), code.clone()));
-        self.suppress_diagnostics(|comp| {
-            comp.temp_scope(mac.names, None, |comp| {
-                comp.quote(&code, mac_name, &modifier_span)
+        if let Some(code) = code {
+            self.code_meta
+                .macro_expansions
+                .insert(full_span, (mac_name.clone(), code.clone()));
+            self.suppress_diagnostics(|comp| {
+                comp.temp_scope(mac.names, None, |comp| {
+                    comp.quote(&code, mac_name, &modifier_span)
+                })
             })
-        })
+        } else {
+            Ok(Node::empty())
+        }
     }
     fn node_unbound_index(&self, node: &Node) -> Option<usize> {
         match node {
diff --git a/src/compile/pre_eval.rs b/src/compile/pre_eval.rs
index 6ae8b5946..a85e92866 100644
--- a/src/compile/pre_eval.rs
+++ b/src/compile/pre_eval.rs
@@ -13,15 +13,15 @@ use super::*;
 pub enum PreEvalMode {
     /// Does not evalute pure constants and expressions at comptime, but still evaluates `comptime`
     Lazy,
-    /// Evaluate as much as possible at compile time, even impure expressions
-    ///
-    /// Recursive functions and certain system functions are not evaluated
-    Lsp,
     /// Pre-evaluate each line, but not multiple lines together
     Line,
     /// The normal mode. Tries to evaluate pure, time-bounded constants and expressions at comptime
     #[default]
     Normal,
+    /// Evaluate as much as possible at compile time, even impure expressions
+    ///
+    /// Recursive functions and certain system functions are not evaluated
+    Lsp,
 }
 
 const MAX_PRE_EVAL_ELEMS: usize = 1000;
diff --git a/tests/macros.ua b/tests/macros.ua
index 863f2973e..3ba96b89e 100644
--- a/tests/macros.ua
+++ b/tests/macros.ua
@@ -81,6 +81,12 @@ M! ←^ ⋅"∘"
 @a @b
 ⍤⤙≍ "b" [⋅M!∘]
 
+Join! ←^ ↯:@⊂↥0-1⋕
+{Join!0 "a" "bc" "def"}
+{Join!1 "a" "bc" "def"}
+{Join!2 "a" "bc" "def"}
+◌◌◌
+
 # Experimental!
 
 # Inline macros