Merge pull request #3368 from onflow/sainati/casting-move-precedence

Decrease move operator precedence relative to cast operators
onflow · May 31, 2024 · 499c877 · 499c877
2 parents 30a0604 + bd88a14
commit 499c877
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Showing 3 changed files with 195 additions and 1 deletion.
diff --git a/runtime/parser/expression.go b/runtime/parser/expression.go
@@ -43,6 +43,7 @@ const (
 	exprLeftBindingPowerBitwiseShift
 	exprLeftBindingPowerAddition
 	exprLeftBindingPowerMultiplication
+	exprLeftBindingPowerMove
 	exprLeftBindingPowerCasting
 	exprLeftBindingPowerUnaryPrefix
 	exprLeftBindingPowerUnaryPostfix
@@ -484,7 +485,7 @@ func init() {
 
 	defineExpr(unaryExpr{
 		tokenType:    lexer.TokenLeftArrow,
-		bindingPower: exprLeftBindingPowerUnaryPrefix,
+		bindingPower: exprLeftBindingPowerMove,
 		operation:    ast.OperationMove,
 	})
 

diff --git a/runtime/parser/expression_test.go b/runtime/parser/expression_test.go
@@ -504,6 +504,111 @@ func TestParseAdvancedExpression(t *testing.T) {
 		)
 	})
 
+	t.Run("move operator, force casted", func(t *testing.T) {
+
+		t.Parallel()
+
+		result, errs := testParseExpression("<-x as! @T")
+		require.Empty(t, errs)
+
+		utils.AssertEqualWithDiff(t,
+			&ast.UnaryExpression{
+				Operation: ast.OperationMove,
+				Expression: &ast.CastingExpression{
+					Expression: &ast.IdentifierExpression{
+						Identifier: ast.Identifier{
+							Identifier: "x",
+							Pos:        ast.Position{Line: 1, Column: 2, Offset: 2},
+						},
+					},
+					TypeAnnotation: &ast.TypeAnnotation{
+						Type: &ast.NominalType{
+							Identifier: ast.Identifier{
+								Identifier: "T",
+								Pos:        ast.Position{Line: 1, Column: 9, Offset: 9},
+							},
+						},
+						StartPos:   ast.Position{Line: 1, Column: 8, Offset: 8},
+						IsResource: true,
+					},
+					Operation: ast.OperationForceCast,
+				},
+				StartPos: ast.Position{Line: 1, Column: 0, Offset: 0},
+			},
+			result,
+		)
+	})
+
+	t.Run("move operator, failable casted", func(t *testing.T) {
+
+		t.Parallel()
+
+		result, errs := testParseExpression("<-x as? @T")
+		require.Empty(t, errs)
+
+		utils.AssertEqualWithDiff(t,
+			&ast.UnaryExpression{
+				Operation: ast.OperationMove,
+				Expression: &ast.CastingExpression{
+					Expression: &ast.IdentifierExpression{
+						Identifier: ast.Identifier{
+							Identifier: "x",
+							Pos:        ast.Position{Line: 1, Column: 2, Offset: 2},
+						},
+					},
+					TypeAnnotation: &ast.TypeAnnotation{
+						Type: &ast.NominalType{
+							Identifier: ast.Identifier{
+								Identifier: "T",
+								Pos:        ast.Position{Line: 1, Column: 9, Offset: 9},
+							},
+						},
+						StartPos:   ast.Position{Line: 1, Column: 8, Offset: 8},
+						IsResource: true,
+					},
+					Operation: ast.OperationFailableCast,
+				},
+				StartPos: ast.Position{Line: 1, Column: 0, Offset: 0},
+			},
+			result,
+		)
+	})
+
+	t.Run("move operator, casted", func(t *testing.T) {
+
+		t.Parallel()
+
+		result, errs := testParseExpression("<-x as @T")
+		require.Empty(t, errs)
+
+		utils.AssertEqualWithDiff(t,
+			&ast.UnaryExpression{
+				Operation: ast.OperationMove,
+				Expression: &ast.CastingExpression{
+					Expression: &ast.IdentifierExpression{
+						Identifier: ast.Identifier{
+							Identifier: "x",
+							Pos:        ast.Position{Line: 1, Column: 2, Offset: 2},
+						},
+					},
+					TypeAnnotation: &ast.TypeAnnotation{
+						Type: &ast.NominalType{
+							Identifier: ast.Identifier{
+								Identifier: "T",
+								Pos:        ast.Position{Line: 1, Column: 8, Offset: 8},
+							},
+						},
+						StartPos:   ast.Position{Line: 1, Column: 7, Offset: 7},
+						IsResource: true,
+					},
+					Operation: ast.OperationCast,
+				},
+				StartPos: ast.Position{Line: 1, Column: 0, Offset: 0},
+			},
+			result,
+		)
+	})
+
 }
 
 func TestParseArrayExpression(t *testing.T) {

diff --git a/runtime/tests/checker/move_test.go b/runtime/tests/checker/move_test.go
@@ -64,3 +64,91 @@ func TestCheckInvalidMoves(t *testing.T) {
 		require.ErrorAs(t, errors[1], &invalidMoveError)
 	})
 }
+
+func TestCheckCastedMove(t *testing.T) {
+
+	t.Parallel()
+
+	t.Run("force", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := ParseAndCheck(t, `
+			resource R {}
+
+			fun foo(): @R {
+				let r: @AnyResource <- create R()
+				return <-r as! @R
+			}
+		`)
+
+		require.NoError(t, err)
+	})
+
+	t.Run("static", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := ParseAndCheck(t, `
+			resource R {}
+
+			fun foo(): @AnyResource {
+				let r <- create R()
+				return <-r as @AnyResource
+			}
+		`)
+
+		require.NoError(t, err)
+	})
+
+	t.Run("parenthesized", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := ParseAndCheck(t, `
+			resource R {}
+
+			fun foo(): @R {
+				let r: @AnyResource <- create R()
+				return <-(r as! @R)
+			}
+		`)
+
+		require.NoError(t, err)
+	})
+
+	t.Run("function call", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := ParseAndCheck(t, `
+			resource R {}
+
+			fun bar(_ r: @R) {
+				destroy r
+			}
+
+			fun foo() {
+				let r: @AnyResource <- create R()
+				bar(<-r as! @R)
+			}
+		`)
+
+		require.NoError(t, err)
+	})
+
+	t.Run("function call, parenthesized", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := ParseAndCheck(t, `
+			resource R {}
+
+			fun bar(_ r: @R) {
+				destroy r
+			}
+
+			fun foo() {
+				let r: @AnyResource <- create R()
+				bar(<-(r as! @R))
+			}
+		`)
+
+		require.NoError(t, err)
+	})
+}