fix arbitrary_from ergonomics by removing the implicit reference in the trait signature

simulator/generation/mod.rs

@@ -13,7 +13,7 @@ pub trait Arbitrary {
 }
 
 pub trait ArbitraryFrom<T> {
-    fn arbitrary_from<R: Rng>(rng: &mut R, t: &T) -> Self;
+    fn arbitrary_from<R: Rng>(rng: &mut R, t: T) -> Self;
 }
 
 pub(crate) fn frequency<

simulator/generation/plan.rs

@@ -283,10 +283,8 @@ impl InteractionPlan {
     }
 }
 
-impl InteractionPlan {
-    // todo: This is a hack to get around the fact that `ArbitraryFrom<T>` can't take a mutable
-    // reference of T, so instead write a bespoke function without using the trait system.
-    pub(crate) fn arbitrary_from<R: rand::Rng>(rng: &mut R, env: &mut SimulatorEnv) -> Self {
+impl ArbitraryFrom<&mut SimulatorEnv> for InteractionPlan {
+    fn arbitrary_from<R: rand::Rng>(rng: &mut R, env: &mut SimulatorEnv) -> Self {
         let mut plan = InteractionPlan::new();
 
         let num_interactions = env.opts.max_interactions;
@@ -304,7 +302,7 @@ impl InteractionPlan {
                 plan.plan.len(),
                 num_interactions
             );
-            let interactions = Interactions::arbitrary_from(rng, &(env, plan.stats()));
+            let interactions = Interactions::arbitrary_from(rng, (env, plan.stats()));
             interactions.shadow(env);
 
             plan.plan.push(interactions);
@@ -471,7 +469,7 @@ fn random_fault<R: rand::Rng>(_rng: &mut R, _env: &SimulatorEnv) -> Interactions
 impl ArbitraryFrom<(&SimulatorEnv, InteractionStats)> for Interactions {
     fn arbitrary_from<R: rand::Rng>(
         rng: &mut R,
-        (env, stats): &(&SimulatorEnv, InteractionStats),
+        (env, stats): (&SimulatorEnv, InteractionStats),
     ) -> Self {
         let remaining_read = ((env.opts.max_interactions as f64 * env.opts.read_percent / 100.0)
             - (stats.read_count as f64))
@@ -489,7 +487,7 @@ impl ArbitraryFrom<(&SimulatorEnv, InteractionStats)> for Interactions {
                 (
                     f64::min(remaining_read, remaining_write) + remaining_create,
                     Box::new(|rng: &mut R| {
-                        Interactions::Property(Property::arbitrary_from(rng, &(env, stats)))
+                        Interactions::Property(Property::arbitrary_from(rng, (env, &stats)))
                     }),
                 ),
                 (

simulator/generation/property.rs

@@ -115,10 +115,7 @@ impl Property {
 
                 interactions
             }
-            Property::DoubleCreateFailure {
-                create,
-                queries,
-            } => {
+            Property::DoubleCreateFailure { create, queries } => {
                 let table_name = create.table.name.clone();
 
                 let assumption = Interaction::Assumption(Assertion {
@@ -186,7 +183,11 @@ fn remaining(env: &SimulatorEnv, stats: &InteractionStats) -> Remaining {
     }
 }
 
-fn property_insert_select<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv, remaining: &Remaining) -> Property {
+fn property_insert_select<R: rand::Rng>(
+    rng: &mut R,
+    env: &SimulatorEnv,
+    remaining: &Remaining,
+) -> Property {
     // Get a random table
     let table = pick(&env.tables, rng);
     // Pick a random column
@@ -218,7 +219,7 @@ fn property_insert_select<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv, remaini
     // - [ ] The inserted row will not be updated. (todo: add this constraint once UPDATE is implemented)
     // - [ ] The table `t` will not be renamed, dropped, or altered. (todo: add this constraint once ALTER or DROP is implemented)
     for _ in 0..rng.gen_range(0..3) {
-        let query = Query::arbitrary_from(rng, &(table, remaining));
+        let query = Query::arbitrary_from(rng, (table, remaining));
         match &query {
             Query::Delete(Delete {
                 table: t,
@@ -244,7 +245,7 @@ fn property_insert_select<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv, remaini
     // Select the row
     let select_query = Select {
         table: table.name.clone(),
-        predicate: Predicate::arbitrary_from(rng, &(table, &row)),
+        predicate: Predicate::arbitrary_from(rng, (table, &row)),
     };
 
     Property::InsertSelect {
@@ -254,7 +255,11 @@ fn property_insert_select<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv, remaini
     }
 }
 
-fn property_double_create_failure<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv, remaining: &Remaining) -> Property {
+fn property_double_create_failure<R: rand::Rng>(
+    rng: &mut R,
+    env: &SimulatorEnv,
+    remaining: &Remaining,
+) -> Property {
     // Get a random table
     let table = pick(&env.tables, rng);
     // Create the table
@@ -268,7 +273,7 @@ fn property_double_create_failure<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv,
     // - [x] There will be no errors in the middle interactions.(best effort)
     // - [ ] Table `t` will not be renamed or dropped.(todo: add this constraint once ALTER or DROP is implemented)
     for _ in 0..rng.gen_range(0..3) {
-        let query = Query::arbitrary_from(rng, &(table, remaining));
+        let query = Query::arbitrary_from(rng, (table, remaining));
         match &query {
             Query::Create(Create { table: t }) => {
                 // There will be no errors in the middle interactions.
@@ -288,12 +293,10 @@ fn property_double_create_failure<R: rand::Rng>(rng: &mut R, env: &SimulatorEnv,
     }
 }
 
-
-
 impl ArbitraryFrom<(&SimulatorEnv, &InteractionStats)> for Property {
     fn arbitrary_from<R: rand::Rng>(
         rng: &mut R,
-        (env, stats): &(&SimulatorEnv, &InteractionStats),
+        (env, stats): (&SimulatorEnv, &InteractionStats),
     ) -> Self {
         let remaining_ = remaining(env, stats);
         frequency(

simulator/generation/query.rs

@@ -17,7 +17,7 @@ impl Arbitrary for Create {
     }
 }
 
-impl ArbitraryFrom<Vec<Table>> for Select {
+impl ArbitraryFrom<&Vec<Table>> for Select {
     fn arbitrary_from<R: Rng>(rng: &mut R, tables: &Vec<Table>) -> Self {
         let table = pick(tables, rng);
         Self {
@@ -27,7 +27,7 @@ impl ArbitraryFrom<Vec<Table>> for Select {
     }
 }
 
-impl ArbitraryFrom<Vec<&Table>> for Select {
+impl ArbitraryFrom<&Vec<&Table>> for Select {
     fn arbitrary_from<R: Rng>(rng: &mut R, tables: &Vec<&Table>) -> Self {
         let table = pick(tables, rng);
         Self {
@@ -37,7 +37,7 @@ impl ArbitraryFrom<Vec<&Table>> for Select {
     }
 }
 
-impl ArbitraryFrom<Table> for Insert {
+impl ArbitraryFrom<&Table> for Insert {
     fn arbitrary_from<R: Rng>(rng: &mut R, table: &Table) -> Self {
         let num_rows = rng.gen_range(1..10);
         let values: Vec<Vec<Value>> = (0..num_rows)
@@ -56,7 +56,7 @@ impl ArbitraryFrom<Table> for Insert {
     }
 }
 
-impl ArbitraryFrom<Table> for Delete {
+impl ArbitraryFrom<&Table> for Delete {
     fn arbitrary_from<R: Rng>(rng: &mut R, table: &Table) -> Self {
         Self {
             table: table.name.clone(),
@@ -65,7 +65,7 @@ impl ArbitraryFrom<Table> for Delete {
     }
 }
 
-impl ArbitraryFrom<Table> for Query {
+impl ArbitraryFrom<&Table> for Query {
     fn arbitrary_from<R: Rng>(rng: &mut R, table: &Table) -> Self {
         frequency(
             vec![
@@ -89,7 +89,7 @@ impl ArbitraryFrom<Table> for Query {
 }
 
 impl ArbitraryFrom<(&Table, &Remaining)> for Query {
-    fn arbitrary_from<R: Rng>(rng: &mut R, (table, remaining): &(&Table, &Remaining)) -> Self {
+    fn arbitrary_from<R: Rng>(rng: &mut R, (table, remaining): (&Table, &Remaining)) -> Self {
         frequency(
             vec![
                 (
@@ -98,7 +98,7 @@ impl ArbitraryFrom<(&Table, &Remaining)> for Query {
                 ),
                 (
                     remaining.read,
-                    Box::new(|rng| Self::Select(Select::arbitrary_from(rng, &vec![*table]))),
+                    Box::new(|rng| Self::Select(Select::arbitrary_from(rng, &vec![table]))),
                 ),
                 (
                     remaining.write,
@@ -118,7 +118,7 @@ struct CompoundPredicate(Predicate);
 struct SimplePredicate(Predicate);
 
 impl ArbitraryFrom<(&Table, bool)> for SimplePredicate {
-    fn arbitrary_from<R: Rng>(rng: &mut R, (table, predicate_value): &(&Table, bool)) -> Self {
+    fn arbitrary_from<R: Rng>(rng: &mut R, (table, predicate_value): (&Table, bool)) -> Self {
         // Pick a random column
         let column_index = rng.gen_range(0..table.columns.len());
         let column = &table.columns[column_index];
@@ -182,15 +182,15 @@ impl ArbitraryFrom<(&Table, bool)> for SimplePredicate {
 }
 
 impl ArbitraryFrom<(&Table, bool)> for CompoundPredicate {
-    fn arbitrary_from<R: Rng>(rng: &mut R, (table, predicate_value): &(&Table, bool)) -> Self {
+    fn arbitrary_from<R: Rng>(rng: &mut R, (table, predicate_value): (&Table, bool)) -> Self {
         // Decide if you want to create an AND or an OR
         Self(if rng.gen_bool(0.7) {
             // An AND for true requires each of its children to be true
             // An AND for false requires at least one of its children to be false
-            if *predicate_value {
+            if predicate_value {
                 Predicate::And(
                     (0..rng.gen_range(0..=3))
-                        .map(|_| SimplePredicate::arbitrary_from(rng, &(*table, true)).0)
+                        .map(|_| SimplePredicate::arbitrary_from(rng, (table, true)).0)
                         .collect(),
                 )
             } else {
@@ -209,14 +209,14 @@ impl ArbitraryFrom<(&Table, bool)> for CompoundPredicate {
                 Predicate::And(
                     booleans
                         .iter()
-                        .map(|b| SimplePredicate::arbitrary_from(rng, &(*table, *b)).0)
+                        .map(|b| SimplePredicate::arbitrary_from(rng, (table, *b)).0)
                         .collect(),
                 )
             }
         } else {
             // An OR for true requires at least one of its children to be true
             // An OR for false requires each of its children to be false
-            if *predicate_value {
+            if predicate_value {
                 // Create a vector of random booleans
                 let mut booleans = (0..rng.gen_range(0..=3))
                     .map(|_| rng.gen_bool(0.5))
@@ -230,13 +230,13 @@ impl ArbitraryFrom<(&Table, bool)> for CompoundPredicate {
                 Predicate::Or(
                     booleans
                         .iter()
-                        .map(|b| SimplePredicate::arbitrary_from(rng, &(*table, *b)).0)
+                        .map(|b| SimplePredicate::arbitrary_from(rng, (table, *b)).0)
                         .collect(),
                 )
             } else {
                 Predicate::Or(
                     (0..rng.gen_range(0..=3))
-                        .map(|_| SimplePredicate::arbitrary_from(rng, &(*table, false)).0)
+                        .map(|_| SimplePredicate::arbitrary_from(rng, (table, false)).0)
                         .collect(),
                 )
             }
@@ -244,28 +244,28 @@ impl ArbitraryFrom<(&Table, bool)> for CompoundPredicate {
     }
 }
 
-impl ArbitraryFrom<Table> for Predicate {
+impl ArbitraryFrom<&Table> for Predicate {
     fn arbitrary_from<R: Rng>(rng: &mut R, table: &Table) -> Self {
         let predicate_value = rng.gen_bool(0.5);
-        CompoundPredicate::arbitrary_from(rng, &(table, predicate_value)).0
+        CompoundPredicate::arbitrary_from(rng, (table, predicate_value)).0
     }
 }
 
 impl ArbitraryFrom<(&str, &Value)> for Predicate {
-    fn arbitrary_from<R: Rng>(rng: &mut R, (column_name, value): &(&str, &Value)) -> Self {
+    fn arbitrary_from<R: Rng>(rng: &mut R, (column_name, value): (&str, &Value)) -> Self {
         one_of(
             vec![
                 Box::new(|_| Predicate::Eq(column_name.to_string(), (*value).clone())),
                 Box::new(|rng| {
                     Self::Gt(
                         column_name.to_string(),
-                        GTValue::arbitrary_from(rng, *value).0,
+                        GTValue::arbitrary_from(rng, value).0,
                     )
                 }),
                 Box::new(|rng| {
                     Self::Lt(
                         column_name.to_string(),
-                        LTValue::arbitrary_from(rng, *value).0,
+                        LTValue::arbitrary_from(rng, value).0,
                     )
                 }),
             ],
@@ -275,7 +275,7 @@ impl ArbitraryFrom<(&str, &Value)> for Predicate {
 }
 
 /// Produces a predicate that is true for the provided row in the given table
-fn produce_true_predicate<R: Rng>(rng: &mut R, (t, row): &(&Table, &Vec<Value>)) -> Predicate {
+fn produce_true_predicate<R: Rng>(rng: &mut R, (t, row): (&Table, &Vec<Value>)) -> Predicate {
     // Pick a column
     let column_index = rng.gen_range(0..t.columns.len());
     let column = &t.columns[column_index];
@@ -304,7 +304,7 @@ fn produce_true_predicate<R: Rng>(rng: &mut R, (t, row): &(&Table, &Vec<Value>))
 }
 
 /// Produces a predicate that is false for the provided row in the given table
-fn produce_false_predicate<R: Rng>(rng: &mut R, (t, row): &(&Table, &Vec<Value>)) -> Predicate {
+fn produce_false_predicate<R: Rng>(rng: &mut R, (t, row): (&Table, &Vec<Value>)) -> Predicate {
     // Pick a column
     let column_index = rng.gen_range(0..t.columns.len());
     let column = &t.columns[column_index];
@@ -333,18 +333,18 @@ fn produce_false_predicate<R: Rng>(rng: &mut R, (t, row): &(&Table, &Vec<Value>)
 }
 
 impl ArbitraryFrom<(&Table, &Vec<Value>)> for Predicate {
-    fn arbitrary_from<R: Rng>(rng: &mut R, (t, row): &(&Table, &Vec<Value>)) -> Self {
+    fn arbitrary_from<R: Rng>(rng: &mut R, (t, row): (&Table, &Vec<Value>)) -> Self {
         // We want to produce a predicate that is true for the row
         // We can do this by creating several predicates that
         // are true, some that are false, combiend them in ways that correspond to the creation of a true predicate
 
         // Produce some true and false predicates
         let mut true_predicates = (1..=rng.gen_range(1..=4))
-            .map(|_| produce_true_predicate(rng, &(*t, row)))
+            .map(|_| produce_true_predicate(rng, (t, row)))
             .collect::<Vec<_>>();
 
         let false_predicates = (0..=rng.gen_range(0..=3))
-            .map(|_| produce_false_predicate(rng, &(*t, row)))
+            .map(|_| produce_false_predicate(rng, (t, row)))
             .collect::<Vec<_>>();
 
         // Start building a top level predicate from a true predicate

simulator/generation/table.rs

@@ -45,7 +45,7 @@ impl Arbitrary for ColumnType {
     }
 }
 
-impl ArbitraryFrom<Vec<&Value>> for Value {
+impl ArbitraryFrom<&Vec<&Value>> for Value {
     fn arbitrary_from<R: Rng>(rng: &mut R, values: &Vec<&Self>) -> Self {
         if values.is_empty() {
             return Self::Null;
@@ -55,7 +55,7 @@ impl ArbitraryFrom<Vec<&Value>> for Value {
     }
 }
 
-impl ArbitraryFrom<ColumnType> for Value {
+impl ArbitraryFrom<&ColumnType> for Value {
     fn arbitrary_from<R: Rng>(rng: &mut R, column_type: &ColumnType) -> Self {
         match column_type {
             ColumnType::Integer => Self::Integer(rng.gen_range(i64::MIN..i64::MAX)),
@@ -68,7 +68,7 @@ impl ArbitraryFrom<ColumnType> for Value {
 
 pub(crate) struct LTValue(pub(crate) Value);
 
-impl ArbitraryFrom<Vec<&Value>> for LTValue {
+impl ArbitraryFrom<&Vec<&Value>> for LTValue {
     fn arbitrary_from<R: Rng>(rng: &mut R, values: &Vec<&Value>) -> Self {
         if values.is_empty() {
             return Self(Value::Null);
@@ -79,7 +79,7 @@ impl ArbitraryFrom<Vec<&Value>> for LTValue {
     }
 }
 
-impl ArbitraryFrom<Value> for LTValue {
+impl ArbitraryFrom<&Value> for LTValue {
     fn arbitrary_from<R: Rng>(rng: &mut R, value: &Value) -> Self {
         match value {
             Value::Integer(i) => Self(Value::Integer(rng.gen_range(i64::MIN..*i - 1))),
@@ -128,7 +128,7 @@ impl ArbitraryFrom<Value> for LTValue {
 
 pub(crate) struct GTValue(pub(crate) Value);
 
-impl ArbitraryFrom<Vec<&Value>> for GTValue {
+impl ArbitraryFrom<&Vec<&Value>> for GTValue {
     fn arbitrary_from<R: Rng>(rng: &mut R, values: &Vec<&Value>) -> Self {
         if values.is_empty() {
             return Self(Value::Null);
@@ -139,7 +139,7 @@ impl ArbitraryFrom<Vec<&Value>> for GTValue {
     }
 }
 
-impl ArbitraryFrom<Value> for GTValue {
+impl ArbitraryFrom<&Value> for GTValue {
     fn arbitrary_from<R: Rng>(rng: &mut R, value: &Value) -> Self {
         match value {
             Value::Integer(i) => Self(Value::Integer(rng.gen_range(*i..i64::MAX))),

simulator/main.rs

@@ -2,6 +2,7 @@
 use clap::Parser;
 use core::panic;
 use generation::plan::{InteractionPlan, InteractionPlanState};
+use generation::ArbitraryFrom;
 use limbo_core::Database;
 use rand::prelude::*;
 use rand_chacha::ChaCha8Rng;

simulator/shrink/plan.rs

@@ -1,5 +1,5 @@
 use crate::{
-    generation::plan::{Interaction, InteractionPlan, Interactions},
+    generation::plan::{InteractionPlan, Interactions},
     runner::execution::Execution,
 };
 
@@ -26,13 +26,9 @@ impl InteractionPlan {
         for interaction in plan.plan.iter_mut() {
             if let Interactions::Property(p) = interaction {
                 match p {
-                    crate::generation::property::Property::InsertSelect {
-                        queries,
-                        ..
-                    } |
-                    crate::generation::property::Property::DoubleCreateFailure {
-                        queries,
-                        ..
+                    crate::generation::property::Property::InsertSelect { queries, .. }
+                    | crate::generation::property::Property::DoubleCreateFailure {
+                        queries, ..
                     } => {
                         queries.clear();
                     }