[sc-483] Add an option to pass arguments to hvm-lang programs

src/lib.rs

@@ -95,13 +95,18 @@ pub fn create_host(book: Arc<Book>, labels: Arc<Labels>, compile_opts: CompileOp
 pub fn check_book(book: &mut Book) -> Result<(), Info> {
   // TODO: Do the checks without having to do full compilation
   // TODO: Shouldn't the check mode show warnings?
-  compile_book(book, CompileOpts::light())?;
+  compile_book(book, None, CompileOpts::light())?;
   Ok(())
 }
 
-pub fn compile_book(book: &mut Book, opts: CompileOpts) -> Result<CompileResult, Info> {
-  let warns = desugar_book(book, opts)?;
+pub fn compile_book(
+  book: &mut Book,
+  args: Option<Vec<Term>>,
+  opts: CompileOpts,
+) -> Result<CompileResult, Info> {
+  let warns = desugar_book(book, args, opts)?;
   let (nets, labels) = book_to_nets(book);
+
   let mut core_book = nets_to_hvmc(nets)?;
   if opts.pre_reduce {
     pre_reduce_book(&mut core_book, book.hvmc_entrypoint())?;
@@ -112,11 +117,17 @@ pub fn compile_book(book: &mut Book, opts: CompileOpts) -> Result<CompileResult,
   Ok(CompileResult { core_book, labels, warns })
 }
 
-pub fn desugar_book(book: &mut Book, opts: CompileOpts) -> Result<Vec<Warning>, Info> {
+pub fn desugar_book(
+  book: &mut Book,
+  args: Option<Vec<Term>>,
+  opts: CompileOpts,
+) -> Result<Vec<Warning>, Info> {
   let mut ctx = Ctx::new(book);
 
   ctx.check_shared_names();
-  ctx.set_entrypoint();
+  ctx.set_entrypoint(if let Some(args) = &args { args.len() } else { 0 });
+
+  ctx.book.apply_args(args)?;
 
   ctx.book.encode_adts(opts.adt_encoding);
   ctx.book.encode_builtins();
@@ -184,8 +195,9 @@ pub fn run_book(
   run_opts: RunOpts,
   warning_opts: WarningOpts,
   compile_opts: CompileOpts,
+  args: Option<Vec<Term>>,
 ) -> Result<(Term, RunInfo), Info> {
-  let CompileResult { core_book, labels, warns } = compile_book(&mut book, compile_opts)?;
+  let CompileResult { core_book, labels, warns } = compile_book(&mut book, args, compile_opts)?;
 
   // Turn the book into an Arc so that we can use it for logging, debugging, etc.
   // from anywhere else in the program

src/main.rs

@@ -86,6 +86,13 @@ enum Mode {
     )]
     comp_opts: Vec<OptArgs>,
 
+    #[arg(value_parser = |arg: &str| hvml::term::parser::parse_term(arg)
+      .map_err(|e| match e[0].reason() {
+        chumsky::error::RichReason::Many(errs) => format!("{}", &errs[0]),
+        _ => format!("{}", e[0].reason()),
+      }))]
+    arguments: Option<Vec<hvml::term::Term>>,
+
     #[command(flatten)]
     warn_opts: CliWarnOpts,
   },
@@ -192,7 +199,7 @@ fn execute_cli_mode(mut cli: Cli) -> Result<(), Info> {
       }
 
       let mut book = load_book(&path)?;
-      let compiled = compile_book(&mut book, opts)?;
+      let compiled = compile_book(&mut book, None, opts)?;
       println!("{}", compiled.display_with_warns(warning_opts)?);
     }
     Mode::Desugar { path, comp_opts, lazy_mode } => {
@@ -202,7 +209,7 @@ fn execute_cli_mode(mut cli: Cli) -> Result<(), Info> {
       }
       let mut book = load_book(&path)?;
       // TODO: Shouldn't the desugar have `warn_opts` too? maybe WarningOpts::allow_all() by default
-      let _warns = desugar_book(&mut book, opts)?;
+      let _warns = desugar_book(&mut book, None, opts)?;
       println!("{}", book);
     }
     Mode::Run {
@@ -216,6 +223,7 @@ fn execute_cli_mode(mut cli: Cli) -> Result<(), Info> {
       comp_opts,
       warn_opts,
       lazy_mode,
+      arguments,
     } => {
       if debug && lazy_mode {
         return Err("Unsupported configuration, can not use debug mode `-d` with lazy mode `-L`".into());
@@ -235,7 +243,7 @@ fn execute_cli_mode(mut cli: Cli) -> Result<(), Info> {
       let run_opts =
         RunOpts { single_core, debug, linear, lazy_mode, max_memory: max_mem, max_rewrites: max_rwts };
       let (res_term, RunInfo { stats, readback_errors, net, book: _, labels: _ }) =
-        run_book(book, max_mem as usize, run_opts, warning_opts, opts)?;
+        run_book(book, max_mem as usize, run_opts, warning_opts, opts, arguments)?;
 
       let total_rewrites = stats.rewrites.total() as f64;
       let rps = total_rewrites / stats.run_time / 1_000_000.0;

src/term/check/set_entrypoint.rs

@@ -9,7 +9,7 @@ pub enum EntryErr {
   NotFound(Name),
   Multiple(Vec<Name>),
   MultipleRules,
-  Arguments,
+  Arguments(usize, usize),
 }
 
 impl Display for EntryErr {
@@ -23,19 +23,21 @@ impl Display for EntryErr {
         write!(f, "File has '{}', '{}' and '{}' definitions.", fnd[0], fnd[1], fnd[2])
       }
       EntryErr::MultipleRules => write!(f, "Main definition can't have more than one rule."),
-      EntryErr::Arguments => write!(f, "Main definition can't have any arguments."),
+      EntryErr::Arguments(expected, got) => {
+        write!(f, "Main definition expects {expected} arguments, got {got}.")
+      }
     }
   }
 }
 
 impl Ctx<'_> {
-  pub fn set_entrypoint(&mut self) {
+  pub fn set_entrypoint(&mut self, given_arguments: usize) {
     let mut entrypoint = None;
 
     let (custom, main, hvm1_main) = self.book.get_possible_entry_points();
     match (custom, main, hvm1_main) {
       (Some(entry), None, None) | (None, Some(entry), None) | (None, None, Some(entry)) => {
-        match validate_entry_point(entry) {
+        match validate_entry_point(entry, given_arguments) {
           Ok(name) => entrypoint = Some(name),
           Err(err) => self.info.error(err),
         }
@@ -44,7 +46,7 @@ impl Ctx<'_> {
       (Some(a), Some(b), None) | (None, Some(a), Some(b)) | (Some(a), None, Some(b)) => {
         self.info.error(EntryErr::Multiple(vec![a.name.clone(), b.name.clone()]));
 
-        match validate_entry_point(a) {
+        match validate_entry_point(a, given_arguments) {
           Ok(name) => entrypoint = Some(name),
           Err(err) => self.info.error(err),
         }
@@ -53,7 +55,7 @@ impl Ctx<'_> {
       (Some(a), Some(b), Some(c)) => {
         self.info.error(EntryErr::Multiple(vec![a.name.clone(), b.name.clone(), c.name.clone()]));
 
-        match validate_entry_point(a) {
+        match validate_entry_point(a, given_arguments) {
           Ok(name) => entrypoint = Some(name),
           Err(err) => self.info.error(err),
         }
@@ -68,11 +70,11 @@ impl Ctx<'_> {
   }
 }
 
-fn validate_entry_point(entry: &Definition) -> Result<Name, EntryErr> {
+fn validate_entry_point(entry: &Definition, given_arguments: usize) -> Result<Name, EntryErr> {
   if entry.rules.len() > 1 {
     Err(EntryErr::MultipleRules)
-  } else if !entry.rules[0].pats.is_empty() {
-    Err(EntryErr::Arguments)
+  } else if entry.rules[0].pats.len() != given_arguments {
+    Err(EntryErr::Arguments(entry.rules[0].pats.len(), given_arguments))
   } else {
     Ok(entry.name.clone())
   }

src/term/transform/apply_args.rs

@@ -0,0 +1,21 @@
+use crate::term::{Book, Pattern, Term};
+
+impl Book {
+  pub fn apply_args(&mut self, args: Option<Vec<Term>>) -> Result<(), String> {
+    if let Some(main) = &self.entrypoint
+      && let Some(args) = args
+    {
+      let main_def = &mut self.defs[main];
+
+      if !main_def.rules[0].pats.iter().all(|pat| matches!(pat, Pattern::Var(Some(..)))) {
+        return Err("Main definition should contain only var patterns.".into());
+      }
+
+      main_def.convert_match_def_to_term();
+      let main_body = &mut self.defs[main].rule_mut().body;
+
+      *main_body = Term::call(main_body.clone(), args);
+    }
+    Ok(())
+  }
+}

src/term/transform/mod.rs

@@ -1,3 +1,4 @@
+pub mod apply_args;
 pub mod definition_merge;
 pub mod definition_pruning;
 pub mod desugar_implicit_match_binds;