feat: Support printing more types

compiler/noirc_frontend/src/hir_def/types.rs

@@ -64,7 +64,7 @@
     TypeVariable(TypeVariable, TypeVariableKind),
 
     /// `impl Trait` when used in a type position.
     /// These are only matched based on the TraitId. The trait name paramer is only
     /// used for displaying error messages using the name of the trait.
     TraitAsType(TraitId, /*name:*/ Rc<String>, /*generics:*/ Vec<Type>),
 
@@ -1408,7 +1408,7 @@
             Type::MutableReference(element) => Type::MutableReference(Box::new(
                 element.substitute_helper(type_bindings, substitute_bound_typevars),
             )),
 
             Type::FieldElement
             | Type::Integer(_, _)
             | Type::Bool
@@ -1423,7 +1423,7 @@
     /// True if the given TypeVariableId is free anywhere within self
     fn occurs(&self, target_id: TypeVariableId) -> bool {
         match self {
             Type::Array(len, elem) => len.occurs(target_id) || elem.occurs(target_id),
             Type::String(len) => len.occurs(target_id),
             Type::FmtString(len, fields) => {
                 let len_occurs = len.occurs(target_id);
@@ -1583,7 +1583,7 @@
         match value {
             Type::FieldElement => PrintableType::Field,
             Type::Array(size, typ) => {
-                let length = size.evaluate_to_u64().expect("Cannot print variable sized arrays");
+                let length = size.evaluate_to_u64();
                 let typ = typ.as_ref();
                 PrintableType::Array { length, typ: Box::new(typ.into()) }
             }
@@ -1604,21 +1604,25 @@
             }
             Type::FmtString(_, _) => unreachable!("format strings cannot be printed"),
             Type::Error => unreachable!(),
-            Type::Unit => unreachable!(),
+            Type::Unit => PrintableType::Unit,
             Type::Constant(_) => unreachable!(),
             Type::Struct(def, ref args) => {
                 let struct_type = def.borrow();
                 let fields = struct_type.get_fields(args);
                 let fields = vecmap(fields, |(name, typ)| (name, typ.into()));
                 PrintableType::Struct { fields, name: struct_type.name.to_string() }
             }
-            Type::TraitAsType(..) => unreachable!(),
-            Type::Tuple(_) => todo!("printing tuple types is not yet implemented"),
+            Type::TraitAsType(_, _, _) => unreachable!(),
+            Type::Tuple(types) => PrintableType::Tuple { types: vecmap(types, |typ| typ.into()) },
             Type::TypeVariable(_, _) => unreachable!(),
             Type::NamedGeneric(..) => unreachable!(),
             Type::Forall(..) => unreachable!(),
-            Type::Function(_, _, _) => unreachable!(),
-            Type::MutableReference(_) => unreachable!("cannot print &mut"),
+            Type::Function(_, _, env) => {
+                PrintableType::Function { env: Box::new(env.as_ref().into()) }
+            }
+            Type::MutableReference(typ) => {
+                PrintableType::MutableReference { typ: Box::new(typ.as_ref().into()) }
+            }
             Type::NotConstant => unreachable!(),
         }
     }

compiler/noirc_frontend/src/monomorphization/mod.rs

@@ -1029,11 +1029,16 @@ impl<'interner> Monomorphizer<'interner> {
     }
 
     fn append_printable_type_info_inner(typ: &Type, arguments: &mut Vec<ast::Expression>) {
+        // Disallow printing slices and mutable references for consistency,
+        // since they cannot be passed from ACIR into Brillig
         if let HirType::Array(size, _) = typ {
             if let HirType::NotConstant = **size {
                 unreachable!("println does not support slices. Convert the slice to an array before passing it to println");
             }
+        } else if matches!(typ, HirType::MutableReference(_)) {
+            unreachable!("println does not support mutable references.");
         }
+
         let printable_type: PrintableType = typ.into();
         let abi_as_string = serde_json::to_string(&printable_type)
             .expect("ICE: expected PrintableType to serialize");

compiler/noirc_printable_type/src/lib.rs

@@ -11,10 +11,13 @@
 pub enum PrintableType {
     Field,
     Array {
-        length: u64,
+        length: Option<u64>,
         #[serde(rename = "type")]
         typ: Box<PrintableType>,
     },
+    Tuple {
+        types: Vec<PrintableType>,
+    },
     SignedInteger {
         width: u32,
     },
@@ -29,23 +32,13 @@
     String {
         length: u64,
     },
-}
-
-impl PrintableType {
-    /// Returns the number of field elements required to represent the type once encoded.
-    fn field_count(&self) -> u32 {
-        match self {
-            Self::Field
-            | Self::SignedInteger { .. }
-            | Self::UnsignedInteger { .. }
-            | Self::Boolean => 1,
-            Self::Array { length, typ } => typ.field_count() * (*length as u32),
-            Self::Struct { fields, .. } => {
-                fields.iter().fold(0, |acc, (_, field_type)| acc + field_type.field_count())
-            }
-            Self::String { length } => *length as u32,
-        }
-    }
+    Function {
+        env: Box<PrintableType>,
+    },
+    MutableReference {
+        typ: Box<PrintableType>,
+    },
+    Unit,
 }
 
 /// This is what all formats eventually transform into
@@ -114,43 +107,26 @@
 fn convert_fmt_string_inputs(
     foreign_call_inputs: &[ForeignCallParam],
 ) -> Result<PrintableValueDisplay, ForeignCallError> {
-    let (message, input_and_printable_values) =
+    let (message, input_and_printable_types) =
         foreign_call_inputs.split_first().ok_or(ForeignCallError::MissingForeignCallInputs)?;
 
     let message_as_fields = vecmap(message.values(), |value| value.to_field());
     let message_as_string = decode_string_value(&message_as_fields);
 
-    let (num_values, input_and_printable_values) = input_and_printable_values
+    let (num_values, input_and_printable_types) = input_and_printable_types
         .split_first()
         .ok_or(ForeignCallError::MissingForeignCallInputs)?;
 
     let mut output = Vec::new();
     let num_values = num_values.unwrap_value().to_field().to_u128() as usize;
 
-    for (i, printable_value) in input_and_printable_values
+    let types_start_at = input_and_printable_types.len() - num_values;
+    let mut input_iter = input_and_printable_types[0..types_start_at]
         .iter()
-        .skip(input_and_printable_values.len() - num_values)
-        .enumerate()
-    {
-        let printable_type = fetch_printable_type(printable_value)?;
-        let type_size = printable_type.field_count() as usize;
-        let value = match printable_type {
-            PrintableType::Array { .. } | PrintableType::String { .. } => {
-                // Arrays and strings are represented in a single value vector rather than multiple separate input values
-                let mut input_values_as_fields = input_and_printable_values[i]
-                    .values()
-                    .into_iter()
-                    .map(|value| value.to_field());
-                decode_value(&mut input_values_as_fields, &printable_type)
-            }
-            _ => {
-                // We must use a flat map here as each value in a struct will be in a separate input value
-                let mut input_values_as_fields = input_and_printable_values[i..(i + type_size)]
-                    .iter()
-                    .flat_map(|param| vecmap(param.values(), |value| value.to_field()));
-                decode_value(&mut input_values_as_fields, &printable_type)
-            }
-        };
+        .flat_map(|param| vecmap(param.values(), |value| value.to_field()));
+    for printable_type in input_and_printable_types.iter().skip(types_start_at) {
+        let printable_type = fetch_printable_type(printable_type)?;
+        let value = decode_value(&mut input_iter, &printable_type);
 
         output.push((value, printable_type));
     }
@@ -196,6 +172,12 @@
                 output.push_str("false");
             }
         }
+        (PrintableValue::Field(_), PrintableType::Function { .. }) => {
+            output.push_str("<<function>>");
+        }
+        (_, PrintableType::MutableReference { .. }) => {
+            output.push_str("<<mutable ref>>");
+        }
         (PrintableValue::Vec(vector), PrintableType::Array { typ, .. }) => {
             output.push('[');
             let mut values = vector.iter().peekable();
@@ -233,6 +215,22 @@
             output.push_str(" }");
         }
 
+        (PrintableValue::Vec(values), PrintableType::Tuple { types }) => {
+            output.push('(');
+            let mut elems = values.iter().zip(types).peekable();
+            while let Some((value, typ)) = elems.next() {
+                output.push_str(
+                    &PrintableValueDisplay::Plain(value.clone(), typ.clone()).to_string(),
+                );
+                if elems.peek().is_some() {
+                    output.push_str(", ");
+                }
+            }
+            output.push(')');
+        }
+
+        (_, PrintableType::Unit) => output.push_str("()"),
+
         _ => return None,
     };
 
@@ -308,7 +306,19 @@
 
             PrintableValue::Field(field_element)
         }
-        PrintableType::Array { length, typ } => {
+        PrintableType::Array { length: None, typ } => {
+            let length = field_iterator
+                .next()
+                .expect("not enough data to decode variable array length")
+                .to_u128() as usize;
+            let mut array_elements = Vec::with_capacity(length);
+            for _ in 0..length {
+                array_elements.push(decode_value(field_iterator, typ));
+            }
+
+            PrintableValue::Vec(array_elements)
+        }
+        PrintableType::Array { length: Some(length), typ } => {
             let length = *length as usize;
             let mut array_elements = Vec::with_capacity(length);
             for _ in 0..length {
@@ -317,6 +327,9 @@
 
             PrintableValue::Vec(array_elements)
         }
+        PrintableType::Tuple { types } => {
+            PrintableValue::Vec(vecmap(types, |typ| decode_value(field_iterator, typ)))
+        }
         PrintableType::String { length } => {
             let field_elements: Vec<FieldElement> = field_iterator.take(*length as usize).collect();
 
@@ -333,6 +346,18 @@
 
             PrintableValue::Struct(struct_map)
         }
+        PrintableType::Function { env } => {
+            let field_element = field_iterator.next().unwrap();
+            let func_ref = PrintableValue::Field(field_element);
+            // we want to consume the fields from the environment, but for now they are not actually printed
+            decode_value(field_iterator, env);
+            func_ref
+        }
+        PrintableType::MutableReference { typ } => {
+            // we decode the reference, but it's not really used for printing
+            decode_value(field_iterator, typ)
+        }
+        PrintableType::Unit => PrintableValue::Field(FieldElement::zero()),
     }
 }
 

test_programs/execution_success/debug_logs/src/main.nr

@@ -39,7 +39,26 @@ fn main(x: Field, y: pub Field) {
     let struct_string = if x != 5 { f"{foo}" } else { f"{bar}" };
     std::println(struct_string);
 
+    let one_tuple = (1, 2, 3);
+    let another_tuple = (4, 5, 6);
+    std::println(f"one_tuple: {one_tuple}, another_tuple: {another_tuple}");
+    std::println(one_tuple);
+
+    let tuples_nested = (one_tuple, another_tuple);
+    std::println(f"tuples_nested: {tuples_nested}");
+    std::println(tuples_nested);
+
     regression_2906();
+
+    let free_lambda = |x| x + 1;
+    let sentinel: u32 = 8888;
+    std::println(f"free_lambda: {free_lambda}, sentinel: {sentinel}");
+    std::println(free_lambda);
+
+    let one = 1;
+    let closured_lambda = |x| x + one;
+    std::println(f"closured_lambda: {closured_lambda}, sentinel: {sentinel}");
+    std::println(closured_lambda);
 }
 
 fn string_identity(string: fmtstr<14, (Field, Field)>) -> fmtstr<14, (Field, Field)> {
@@ -79,3 +98,4 @@ fn regression_2906() {
 
     dep::std::println(f"array_five_vals: {array_five_vals}, label_five_vals: {label_five_vals}");
 }
+