[sc-538] Remove simplify_main_ref and simplify_ref_to_ref passes

docs/compiler-options.md

@@ -5,12 +5,10 @@
 | `-Oall`        | Disabled | Enables all compiler passes |
 | `-Ono-all`     | Disabled | Disables all compiler passes |
 | `-Oeta` `-Ono-eta` | Disabled | [eta-reduction](#eta-reduction) |
-| `-Oref-to-ref` `-Ono-ref-to-ref` | Disabled | [ref-to-ref](#ref-to-ref) |
 | `-Oprune` `-Ono-prune` | Disabled | [definition-pruning](#definition-pruning) |
 | `-Opre-reduce` `-Ono-pre-reduce` | Disabled | [pre-reduce](#pre-reduce) |
 | `-Olinearize-matches` `-Olinearize-matches-extra` `-Ono-linearize-matches` | Extra  | [linearize-matches](#linearize-matches) |
 | `-Ofloat_combinators` `-Ono-float_combinators` | Enabled  | [float-combinators](#float-combinators) |
-| `-Osimplify-main` `-Ono-simplify-main` | Disabled | [simplify-main](#simplify-main) |
 | `-Omerge` `-Ono-merge` | Disabled | [definition-merging](#definition-merging) |
 | `-Oinline` `-Ono-inline` | Disabled | [inline](#inline) |
 | `-e` `--entrypoint` | `Main \| main` | [entrypoint](#entrypoint) |
@@ -34,34 +32,6 @@ id_id = id
 id_id = λz (id z)
 ```
 
-## Ref-to-ref
-
-If enabled, When a function that is simply directly calling another function, substitutes all occurrences of that function to the one being called.
-
-Example:
-```rs
-// program
-Foo = λ* 0
-
-Bar = Foo
-
-Main = (Bar *)
-
-// -Oref-to-ref
-Foo = λ* 0
-
-Bar = Foo
-
-Main = (Foo *) // Call `Bar` is resolved to a call to `Foo`.
-
-// -Ono-ref-to-ref
-(Foo) = λ* 0
-
-(Bar) = Foo
-
-(Main) = (Bar *)
-```
-
 ## Definition-pruning
 
 If enabled, removes all unused definitions.
@@ -137,7 +107,7 @@ main = (bar)
 
 ## linearize-matches
 
-Linearizes the variables between match cases, transforming them into combinators when possible.  
+Linearizes the variables between match cases, transforming them into combinators when possible.
 When the `linearize-matches` option is used, linearizes only vars that are used in more than one arm.
 
 Example:
@@ -179,25 +149,6 @@ fold = λinit λf λxs (xs λh λt (fold (f init h) f t) init)
 // Here we need to extract `λh λt (fold (f init h) f t)` to not expand `fold` infinitely, but it will not be extracted because of the free variable `init`.
 ```
 
-## Simplify-main
-
-If enabled, when directly calling another function, substitute the ref with a copy of its body.
-
-Example:
-```rs
-// program
-id = λx x
-main = id
-
-// -Osimplify-main
-@id = (a a)
-main = (a a)
-
-// -Ono-simplify-main
-@id = (a a)
-@main = @id
-```
-
 # Inline
 
 If enabled, inlines terms that compiles to 0 or 1 inet nodes at lambda level, before pre reduction.

src/lib.rs

@@ -2,7 +2,7 @@
 #![feature(let_chains)]
 
 use builtins::create_host;
-use diagnostics::{DiagnosticOrigin, Diagnostics, DiagnosticsConfig, Severity};
+use diagnostics::{DiagnosticOrigin, Diagnostics, DiagnosticsConfig, Severity, ERR_INDENT_SIZE};
 use hvmc::{
   ast::Net,
   dispatch_dyn_net,
@@ -49,6 +49,9 @@ pub fn compile_book(
   if opts.eta {
     core_book.values_mut().for_each(Net::eta_reduce);
   }
+  if opts.inline {
+    core_book.inline().map_err(|e| format!("Inline:\n{:ERR_INDENT_SIZE$}{e}", ""))?;
+  }
   if opts.pre_reduce {
     core_book.pre_reduce(&|x| x == book.hvmc_entrypoint(), None, 100_000);
   }
@@ -110,18 +113,9 @@ pub fn desugar_book(
   if opts.float_combinators {
     ctx.book.float_combinators();
   }
-  if opts.ref_to_ref {
-    ctx.simplify_ref_to_ref()?;
-  }
-  if opts.simplify_main {
-    ctx.book.simplify_main_ref();
-  }
 
   ctx.prune(opts.prune, opts.adt_encoding);
 
-  if opts.inline {
-    ctx.book.inline();
-  }
   if opts.merge {
     ctx.book.merge_definitions();
   }
@@ -319,9 +313,6 @@ pub struct CompileOpts {
   /// Enables [term::transform::eta_reduction].
   pub eta: bool,
 
-  /// Enables [term::transform::simplify_ref_to_ref].
-  pub ref_to_ref: bool,
-
   /// Enables [term::transform::definition_pruning] and [hvmc_net::prune].
   pub prune: bool,
 
@@ -334,9 +325,6 @@ pub struct CompileOpts {
   /// Enables [term::transform::float_combinators].
   pub float_combinators: bool,
 
-  /// Enables [term::transform::simplify_main_ref].
-  pub simplify_main: bool,
-
   /// Enables [term::transform::definition_merge]
   pub merge: bool,
 
@@ -349,11 +337,9 @@ impl CompileOpts {
   pub fn heavy() -> Self {
     Self {
       eta: true,
-      ref_to_ref: true,
       prune: true,
       pre_reduce: true,
       float_combinators: true,
-      simplify_main: true,
       merge: true,
       inline: true,
       adt_encoding: Default::default(),

src/main.rs

@@ -154,17 +154,13 @@ pub enum OptArgs {
   NoEta,
   Prune,
   NoPrune,
-  RefToRef,
-  NoRefToRef,
   PreReduce,
   NoPreReduce,
   LinearizeMatches,
   LinearizeMatchesExtra,
   NoLinearizeMatches,
   FloatCombinators,
   NoFloatCombinators,
-  SimplifyMain,
-  NoSimplifyMain,
   Merge,
   NoMerge,
   Inline,
@@ -185,14 +181,10 @@ impl OptArgs {
         NoEta => opts.eta = false,
         Prune => opts.prune = true,
         NoPrune => opts.prune = false,
-        RefToRef => opts.ref_to_ref = true,
-        NoRefToRef => opts.ref_to_ref = false,
         PreReduce => opts.pre_reduce = true,
         NoPreReduce => opts.pre_reduce = false,
         FloatCombinators => opts.float_combinators = true,
         NoFloatCombinators => opts.float_combinators = false,
-        SimplifyMain => opts.simplify_main = true,
-        NoSimplifyMain => opts.simplify_main = false,
         Merge => opts.merge = true,
         NoMerge => opts.merge = false,
         Inline => opts.inline = true,

src/term/mod.rs

@@ -7,7 +7,11 @@ use crate::{
 use indexmap::{IndexMap, IndexSet};
 use interner::global::GlobalString;
 use itertools::Itertools;
-use std::{borrow::Cow, collections::HashMap, ops::Deref};
+use std::{
+  borrow::Cow,
+  collections::{BTreeMap, HashMap},
+  ops::Deref,
+};
 
 pub mod builtins;
 pub mod check;
@@ -701,6 +705,28 @@ impl Term {
     })
   }
 
+  /// Returns whether any substitution happened within the term or not
+  pub fn subst_ref_to_ref(term: &mut Term, ref_map: &BTreeMap<Name, Name>) -> bool {
+    Term::recursive_call(move || match term {
+      Term::Ref { nam: def_name } => {
+        if let Some(target_name) = ref_map.get(def_name) {
+          *def_name = target_name.clone();
+          true
+        } else {
+          false
+        }
+      }
+
+      _ => {
+        let mut subst = false;
+        for child in term.children_mut() {
+          subst |= Term::subst_ref_to_ref(child, ref_map);
+        }
+        subst
+      }
+    })
+  }
+
   /// Collects all the free variables that a term has
   /// and the number of times each var is used
   pub fn free_vars(&self) -> HashMap<Name, u64> {

src/term/transform/definition_merge.rs

@@ -1,4 +1,3 @@
-use super::simplify_ref_to_ref::subst_ref_to_ref;
 use crate::term::{Book, Definition, Name, Rule, Term};
 use indexmap::{IndexMap, IndexSet};
 use itertools::Itertools;
@@ -72,7 +71,7 @@ impl Book {
     let mut updated_defs = Vec::new();
 
     for def in self.defs.values_mut() {
-      if subst_ref_to_ref(&mut def.rule_mut().body, name_map) {
+      if Term::subst_ref_to_ref(&mut def.rule_mut().body, name_map) {
         updated_defs.push(def.name.clone());
       }
     }

src/term/transform/mod.rs

@@ -8,12 +8,9 @@ pub mod encode_match_terms;
 pub mod fix_match_defs;
 pub mod fix_match_terms;
 pub mod float_combinators;
-pub mod inline;
 pub mod linearize_matches;
 pub mod linearize_vars;
 pub mod resolve_refs;
 pub mod resugar_adts;
 pub mod resugar_builtins;
-pub mod simplify_main_ref;
-pub mod simplify_ref_to_ref;
 pub mod unique_names;