From 9982106fd8923d462a851b60384fb3d2de11d9c7 Mon Sep 17 00:00:00 2001
From: Benjamin DENEUX <benjamin.deneux@proton.me>
Date: Wed, 24 Jul 2024 14:19:02 +0200
Subject: [PATCH] feat: handle MaxVariables error limit exceeded

---
 x/logic/interpreter/interpreter.go | 5 ++++-
 x/logic/interpreter/registry.go    | 5 +++--
 x/logic/prolog/tuple.go            | 2 +-
 x/logic/util/prolog.go             | 8 +++++---
 4 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/x/logic/interpreter/interpreter.go b/x/logic/interpreter/interpreter.go
index 7224c4bb5..cb20e0c73 100644
--- a/x/logic/interpreter/interpreter.go
+++ b/x/logic/interpreter/interpreter.go
@@ -2,13 +2,16 @@ package interpreter
 
 import (
 	goctx "context"
-	"cosmossdk.io/math"
 	"fmt"
 	"io"
 	"io/fs"
 
+	"cosmossdk.io/math"
+
 	"github.com/ichiban/prolog"
 	"github.com/ichiban/prolog/engine"
+
+	"cosmossdk.io/math"
 )
 
 // Option is a function that configures an Interpreter.
diff --git a/x/logic/interpreter/registry.go b/x/logic/interpreter/registry.go
index 45b887470..d019bcf93 100644
--- a/x/logic/interpreter/registry.go
+++ b/x/logic/interpreter/registry.go
@@ -2,12 +2,13 @@ package interpreter
 
 import (
 	"fmt"
-	orderedmap "github.com/wk8/go-ordered-map/v2"
 	"strconv"
 	"strings"
 
+	orderedmap "github.com/wk8/go-ordered-map/v2"
+
 	"github.com/ichiban/prolog"
-	engine "github.com/ichiban/prolog/engine"
+	"github.com/ichiban/prolog/engine"
 
 	"github.com/axone-protocol/axoned/v8/x/logic/predicate"
 )
diff --git a/x/logic/prolog/tuple.go b/x/logic/prolog/tuple.go
index c7d41903f..3fca45744 100644
--- a/x/logic/prolog/tuple.go
+++ b/x/logic/prolog/tuple.go
@@ -4,5 +4,5 @@ import "github.com/ichiban/prolog/engine"
 
 // Tuple is a predicate which unifies the given term with a tuple of the given arity.
 func Tuple(args ...engine.Term) engine.Term {
-	return engine.Atom(0).Apply(args...)
+	return engine.Atom("").Apply(args...)
 }
diff --git a/x/logic/util/prolog.go b/x/logic/util/prolog.go
index 05807bfe7..00ebba2cb 100644
--- a/x/logic/util/prolog.go
+++ b/x/logic/util/prolog.go
@@ -54,16 +54,18 @@ func QueryInterpreter(
 			// error is not part of the look-ahead and should be included in the solutions
 			sdkCtx := sdk.UnwrapSDKContext(ctx)
 
+			var panicErr engine.PanicError
 			switch {
 			case errors.Is(callErr, types.LimitExceeded):
-				return nil, callErr
+				return nil, err
+			case errors.As(callErr, &panicErr) && errors.Is(panicErr.OriginErr, engine.ErrMaxVariables):
+				return nil, errorsmod.Wrapf(types.LimitExceeded, panicErr.OriginErr.Error())
 			case sdkCtx.GasMeter().IsOutOfGas():
 				return nil, errorsmod.Wrapf(
 					types.LimitExceeded, "out of gas: %s <%s> (%d/%d)",
 					types.ModuleName, callErr.Error(), sdkCtx.GasMeter().GasConsumed(), sdkCtx.GasMeter().Limit())
-			default:
-				results = append(results, types.Result{Error: callErr.Error()})
 			}
+			results = append(results, types.Result{Error: callErr.Error()})
 		} else {
 			// error is part of the look-ahead, so let's consider that there's one more solution
 			count = count.Incr()