Split some expression code into separate functions

This commit is contained in:
Elara 2024-06-06 19:17:20 -07:00
parent c5470a45dd
commit 944663c2b1

93
expr.go
View File

@ -32,47 +32,14 @@ func (t *Template) evalExpr(expr ast.Expr, local map[string]any) (any, error) {
return a.Interface(), nil return a.Interface(), nil
} }
func (t *Template) performOp(a, b reflect.Value, op ast.Operator) (any, error) { func (t *Template) performOp(a, b reflect.Value, op ast.Operator) (result any, err error) {
if op.Value == "in" { if op.Value == "in" {
switch b.Kind() { a, b, err = handleIn(op, a, b)
case reflect.Slice, reflect.Array: if err != nil {
if a.CanConvert(b.Type().Elem()) { return nil, err
a = a.Convert(b.Type().Elem())
} else {
return nil, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
case reflect.Map:
if a.CanConvert(b.Type().Key()) {
a = a.Convert(b.Type().Key())
} else {
return nil, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
case reflect.String:
if a.Kind() != reflect.String {
return nil, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
default:
return nil, ast.PosError(op, "the in operator can only be used on strings, arrays, and slices (got %s and %s)", a.Type(), b.Type())
}
} else if !a.IsValid() && !b.IsValid() {
return true, nil
} else if !a.IsValid() {
return nil, ast.PosError(op, "nil must be on the right side of an expression")
} else if !b.IsValid() {
if op.Value != "==" && op.Value != "!=" {
return nil, ast.PosError(op, "invalid operator for nil value (expected == or !=, got %s)", op.Value)
}
switch a.Kind() {
case reflect.Chan, reflect.Slice, reflect.Map, reflect.Func, reflect.Interface, reflect.Pointer:
if op.Value == "==" {
return a.IsNil(), nil
} else {
return !a.IsNil(), nil
}
default:
return nil, ast.PosError(op, "values of type %s cannot be compared against nil", a.Type())
} }
} else if !a.IsValid() || !b.IsValid() {
return handleNil(op, a, b)
} else if b.CanConvert(a.Type()) { } else if b.CanConvert(a.Type()) {
b = b.Convert(a.Type()) b = b.Convert(a.Type())
} else { } else {
@ -193,3 +160,51 @@ func (t *Template) performOp(a, b reflect.Value, op ast.Operator) (any, error) {
} }
return false, ast.PosError(op, "unknown operator: %q", op.Value) return false, ast.PosError(op, "unknown operator: %q", op.Value)
} }
func handleIn(op ast.Operator, a, b reflect.Value) (c, d reflect.Value, err error) {
switch b.Kind() {
case reflect.Slice, reflect.Array:
if a.CanConvert(b.Type().Elem()) {
a = a.Convert(b.Type().Elem())
} else {
return a, b, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
case reflect.Map:
if a.CanConvert(b.Type().Key()) {
a = a.Convert(b.Type().Key())
} else {
return a, b, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
case reflect.String:
if a.Kind() != reflect.String {
return a, b, ast.PosError(op, "mismatched types in expression (%s and %s)", a.Type(), b.Type())
}
default:
return a, b, ast.PosError(op, "the in operator can only be used on strings, arrays, and slices (got %s and %s)", a.Type(), b.Type())
}
return a, b, nil
}
func handleNil(op ast.Operator, a, b reflect.Value) (any, error) {
if !a.IsValid() && !b.IsValid() {
return true, nil
} else if !a.IsValid() {
return nil, ast.PosError(op, "nil must be on the right side of an expression")
} else if !b.IsValid() {
if op.Value != "==" && op.Value != "!=" {
return nil, ast.PosError(op, "invalid operator for nil value (expected == or !=, got %s)", op.Value)
}
switch a.Kind() {
case reflect.Chan, reflect.Slice, reflect.Map, reflect.Func, reflect.Interface, reflect.Pointer:
if op.Value == "==" {
return a.IsNil(), nil
} else {
return !a.IsNil(), nil
}
default:
return nil, ast.PosError(op, "values of type %s cannot be compared against nil", a.Type())
}
}
return nil, nil
}