Documentation
¶
Overview ¶
Package compare provides generic comparison utilities for structural equality testing.
This package offers a set of helper functions that eliminate boilerplate code when implementing Equal() methods on structs. It handles common patterns like nil checking, pointer comparisons, slice comparisons, and map comparisons.
Key Features ¶
- Generic functions that work with any type
- Nil-safe pointer comparisons
- Slice comparisons with custom equality functions
- Map comparisons with value equality
- Reduces boilerplate code by 60-80%
Usage Examples ¶
Replace repetitive nil checks:
// Before (6 lines):
if x == nil && other == nil {
return true
}
if x == nil || other == nil {
return false
}
// After (2 lines):
if eq, done := compare.NilCheck(x, other); !done {
return eq
}
Compare pointer fields:
// Before (12 lines for 2 fields):
if (t.Field1 != nil) != (other.Field1 != nil) {
return false
}
if t.Field1 != nil && *t.Field1 != *other.Field1 {
return false
}
// ... repeat for Field2
// After (2 lines):
return compare.Pointers(t.Field1, other.Field1) &&
compare.Pointers(t.Field2, other.Field2)
Compare slices with element equality:
// Before (8 lines):
if len(a.Items) != len(other.Items) {
return false
}
for i := range a.Items {
if !a.Items[i].Equal(&other.Items[i]) {
return false
}
}
return true
// After (3 lines):
return compare.Slices(a.Items, other.Items, func(x, y Item) bool {
return x.Equal(&y)
})
Index ¶
- func Maps[K comparable, V comparable](a, b map[K]V) bool
- func MapsWithEqual[K comparable, V any](a, b map[K]V, equalFunc func(V, V) bool) bool
- func NilCheck[T any](a, b *T) (equal bool, needsMoreChecks bool)
- func Pointers[T comparable](a, b *T) bool
- func PointersWithEqual[T any](a, b *T, equalFunc func(*T, *T) bool) bool
- func Slices[T any](a, b []T, equalFunc func(T, T) bool) bool
- func SlicesUnordered[T any](a, b []T, equalFunc func(T, T) bool) bool
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Maps ¶
func Maps[K comparable, V comparable](a, b map[K]V) bool
Maps compares two maps for equality. Returns true if both maps have the same keys and all corresponding values are equal.
Example:
func (t *TableInfo) Equal(other *TableInfo) bool {
return compare.Maps(t.Settings, other.Settings)
}
func MapsWithEqual ¶
func MapsWithEqual[K comparable, V any](a, b map[K]V, equalFunc func(V, V) bool) bool
MapsWithEqual compares two maps using a custom equality function for values. Returns true if both maps have the same keys and all corresponding values are equal according to the equality function.
Example:
func (d *Dictionary) Equal(other *Dictionary) bool {
return compare.MapsWithEqual(d.Columns, other.Columns,
func(a, b *Column) bool { return a.Equal(b) })
}
func NilCheck ¶
NilCheck performs a nil check on two pointers and returns whether they are equal and whether more comparison checks are needed.
Returns (equal, needsMoreChecks) where:
- equal: true if both are nil, false if only one is nil
- needsMoreChecks: true if both pointers are non-nil and further comparison is needed
Example:
func (e *Expression) Equal(other *Expression) bool {
if eq, needsMoreChecks := compare.NilCheck(e, other); !needsMoreChecks {
return eq
}
// Continue with field comparisons...
}
func Pointers ¶
func Pointers[T comparable](a, b *T) bool
Pointers compares two pointer values for equality. Returns true if both are nil, or both are non-nil with equal values.
Example:
func (t *TypeParameter) Equal(other *TypeParameter) bool {
return compare.Pointers(t.Number, other.Number) &&
compare.Pointers(t.String, other.String)
}
func PointersWithEqual ¶
PointersWithEqual compares two pointers using a custom equality function. Returns true if both are nil, or both are non-nil and the equality function returns true.
Example:
func (t *TableEngine) Equal(other *TableEngine) bool {
return compare.PointersWithEqual(t.Engine, other.Engine,
func(a, b *EngineSpec) bool { return a.Equal(b) })
}
func Slices ¶
Slices compares two slices for equality using an equality function for elements. Returns true if both slices have the same length and all corresponding elements are equal.
Example:
func (t *Tuple) Equal(other *Tuple) bool {
return compare.Slices(t.Elements, other.Elements,
func(a, b TupleElement) bool { return a.Equal(&b) })
}
func SlicesUnordered ¶
SlicesUnordered compares two slices for equality regardless of order. Returns true if both slices contain the same elements (by the equality function).
Example:
func (s *Settings) Equal(other *Settings) bool {
return compare.SlicesUnordered(s.Items, other.Items,
func(a, b Setting) bool { return a.Name == b.Name && a.Value == b.Value })
}
Types ¶
This section is empty.
Source Files