Generate effectful hosted functions

crates/compiler/can/src/task_module.rs → crates/compiler/can/src/effect_module.rs

@@ -33,7 +33,7 @@ pub fn build_host_exposed_def(
 
  let def_body = {
  match typ.shallow_structural_dealias() {
- Type::Function(args, _, _, _) => {
+ Type::Function(args, _, _, fx) if **fx == Type::Pure => {
  for i in 0..args.len() {
  let name = format!("closure_arg_{ident}_{i}");
 
@@ -107,6 +107,45 @@ pub fn build_host_exposed_def(
  loc_body: Box::new(Loc::at_zero(body)),
  })
  }
+ Type::Function(args, _, _, fx) if **fx == Type::Effectful => {
+ for i in 0..args.len() {
+ let name = format!("{ident}_arg_{i}");
+
+ let arg_symbol = {
+ let ident = name.clone().into();
+ scope.introduce(ident, Region::zero()).unwrap()
+ };
+
+ let arg_var = var_store.fresh();
+
+ arguments.push((
+ arg_var,
+ AnnotatedMark::new(var_store),
+ Loc::at_zero(Pattern::Identifier(arg_symbol)),
+ ));
+
+ linked_symbol_arguments.push((arg_var, Expr::Var(arg_symbol, arg_var)));
+ }
+
+ let foreign_symbol_name = format!("roc_fx_{ident}");
+ let foreign_call = Expr::ForeignCall {
+ foreign_symbol: foreign_symbol_name.into(),
+ args: linked_symbol_arguments,
+ ret_var: var_store.fresh(),
+ };
+
+ Expr::Closure(ClosureData {
+ function_type: var_store.fresh(),
+ closure_type: var_store.fresh(),
+ return_type: var_store.fresh(),
+ fx_type: var_store.fresh(),
+ name: symbol,
+ captured_symbols: std::vec::Vec::new(),
+ recursive: Recursive::NotRecursive,
+ arguments,
+ loc_body: Box::new(Loc::at_zero(foreign_call)),
+ })
+ }
  _ => {
  // not a function
 

crates/compiler/can/src/lib.rs

@@ -14,6 +14,7 @@ pub mod copy;
 pub mod def;
 mod derive;
 pub mod desugar;
+pub mod effect_module;
 pub mod env;
 pub mod exhaustive;
 pub mod expected;
@@ -25,7 +26,6 @@ pub mod procedure;
 pub mod scope;
 pub mod string;
 pub mod suffixed;
-pub mod task_module;
 pub mod traverse;
 
 pub use derive::DERIVED_REGION;

crates/compiler/can/src/module.rs

@@ -527,7 +527,7 @@ pub fn canonicalize_module_defs<'a>(
  aliases: Default::default(),
  };
 
- let hosted_def = crate::task_module::build_host_exposed_def(
+ let hosted_def = crate::effect_module::build_host_exposed_def(
  &mut scope, *symbol, &ident, var_store, annotation,
  );
 
@@ -580,7 +580,7 @@ pub fn canonicalize_module_defs<'a>(
  aliases: Default::default(),
  };
 
- let hosted_def = crate::task_module::build_host_exposed_def(
+ let hosted_def = crate::effect_module::build_host_exposed_def(
  &mut scope, *symbol, &ident, var_store, annotation,
  );
 

examples/cli/effects-platform/Effect.roc

@@ -0,0 +1,7 @@
+hosted Effect
+ exposes [putLine, getLine]
+ imports []
+
+putLine : Str => {}
+
+getLine : {} => Str

examples/cli/effects-platform/host.zig

@@ -12,9 +12,6 @@ const Allocator = mem.Allocator;
 
 extern fn roc__mainForHost_1_exposed_generic([*]u8) void;
 extern fn roc__mainForHost_1_exposed_size() i64;
-extern fn roc__mainForHost_0_caller(*const u8, [*]u8, [*]u8) void;
-extern fn roc__mainForHost_0_size() i64;
-extern fn roc__mainForHost_0_result_size() i64;
 
 const Align = 2 * @alignOf(usize);
 extern fn malloc(size: usize) callconv(.C) ?*align(Align) anyopaque;
@@ -127,8 +124,6 @@ pub export fn main() u8 {
 
  roc__mainForHost_1_exposed_generic(output);
 
- call_the_closure(output);
-
  const nanos = timer.read();
  const seconds = (@as(f64, @floatFromInt(nanos)) / 1_000_000_000.0);
 
@@ -141,35 +136,6 @@ fn to_seconds(tms: std.os.timespec) f64 {
  return @as(f64, @floatFromInt(tms.tv_sec)) + (@as(f64, @floatFromInt(tms.tv_nsec)) / 1_000_000_000.0);
 }
 
-fn call_the_closure(closure_data_pointer: [*]u8) void {
- const allocator = std.heap.page_allocator;
-
- const size = roc__mainForHost_0_result_size();
-
- if (size == 0) {
- // the function call returns an empty record
- // allocating 0 bytes causes issues because the allocator will return a NULL pointer
- // So it's special-cased
- const flags: u8 = 0;
- var result: [1]u8 = .{0};
- roc__mainForHost_0_caller(&flags, closure_data_pointer, &result);
-
- return;
- }
-
- const raw_output = allocator.alignedAlloc(u8, @alignOf(u64), @as(usize, @intCast(size))) catch unreachable;
- var output = @as([*]u8, @ptrCast(raw_output));
-
- defer {
- allocator.free(raw_output);
- }
-
- const flags: u8 = 0;
- roc__mainForHost_0_caller(&flags, closure_data_pointer, output);
-
- return;
-}
-
 pub export fn roc_fx_getLine() str.RocStr {
  return roc_fx_getLine_help() catch return str.RocStr.empty();
 }

examples/cli/effects-platform/main.roc

@@ -1,9 +1,9 @@
 platform "effects"
- requires {} { main : Task {} [] }
+ requires {} { main : {} => {} }
  exposes []
  packages {}
  imports []
  provides [mainForHost]
 
-mainForHost : Task {} []
-mainForHost = main
+mainForHost : {} => {}
+mainForHost = \{} -> main {}

examples/cli/effects.roc

@@ -1,11 +1,9 @@
 app [main] { pf: platform "effects-platform/main.roc" }
 
-import pf.PlatformTasks
+import pf.Effect
 
-main : Task {} []
-main =
- line = PlatformTasks.getLine!
- PlatformTasks.putLine! "You entered: $(line)"
- PlatformTasks.putLine! "It is known"
-
- Task.ok {}
+main : {} => {}
+main = \{} ->
+ line = Effect.getLine {}
+ _ = Effect.putLine "You entered: $(line)"
+ Effect.putLine "It is known"