Skip to main content

Small Utilities

This page documents lightweight utility packages that provide common helper functions.

ptr — Pointer Helpers​

Generic utility functions for safe pointer operations.

ptr.Of — Value to Pointer​

Returns a pointer to the value, or nil if the value is zero:

import "github.com/coldsmirk/vef-framework-go/ptr"

p := ptr.Of("hello")   // *string → "hello"
p = ptr.Of("")          // *string → nil (zero value)
p = ptr.Of(42)          // *int → 42
p = ptr.Of(0)           // *int → nil

ptr.Value — Pointer to Value​

Dereferences a pointer with optional fallbacks:

s := ptr.Value(p)                   // Dereference, or zero if nil
s = ptr.Value(p, fallback1, fallback2) // Try each fallback in order

ptr.ValueOrElse — Lazy Fallback​

Dereferences with a lazy fallback function:

s := ptr.ValueOrElse(p, func() string {
    return computeDefault()
})

ptr.Zero — Zero Value​

Returns the zero value of any type:

z := ptr.Zero[string]()  // ""
z := ptr.Zero[int]()     // 0

ptr.Equal — Pointer Equality​

Compares two pointers by value:

ptr.Equal(a, b)  // Both nil → true, one nil → false, else compare values

ptr.Coalesce — First Non-Nil​

Returns the first non-nil pointer from a list:

result := ptr.Coalesce(p1, p2, p3)  // First non-nil, or nil

Practical Usage​

The ptr package is commonly used in:

  • Search structs: Optional filter fields use *bool, *string, etc.
  • Model fields: Nullable database columns use pointer types
  • Params structs: Optional update fields
type UserSearch struct {
    api.P
    IsActive *bool   `json:"isActive" search:"eq,column=is_active"`
    DeptID   *string `json:"deptId" search:"eq,column=department_id"`
}

// Setting optional search filters
search := UserSearch{
    IsActive: ptr.Of(true),
    DeptID:   ptr.Of("dept-123"),
}