validate

README

Validate

Package validate contains validation helpers.

struct field tag based validation helpers

Tag	Description/Constraints	Supported Types	Syntax Examples	Notes
min	Value must be greater than or equal to the minimum value specified in the tag.	Numerical, comparable types (e.g., int, float)	min:"10"	Works with numerical and comparable types like integers and floats.
max	Value must be less than or equal to the maximum value specified in the tag.	Numerical, comparable types	max:"25"	Upper-bound check for compatible types (same as min).
range	Value must fall within any of the provided ranges (OR logic between comma-separated values).	String, int/uint/float, rune	range:"..10" range:"a-z,A-Z" range:"5..10"	- Open-ended formats: ..max → ≤ max; min.. → ≥ min. - For strings: Lexical (range:"a..bb") or character ranges (range:"a-z,A-Z"). - Ranges are comma-separated and in OR logic.
char	Every character in the string must fall within specified character ranges (e.g., letters, symbols).	String, rune	char:"a-z,A-Z" char:"0-9"	Supports open-ended ranges like "A-" (characters from A to end of alphabet).
length	Constrain the length of the value (len(value) must match the condition).	string, slice, map, channel	length:"<=10" length:"5..10" length"5" len:"5"	Alias: Use len:"..." for the same effect. Works with types that have a defined len().
enum	Limits valid values to a predefined list of options.	Any type (registered or representable)	enum:"foo bar baz" enum:"foo,bar,baz"	- Uses either enum.Register for registration or direct representation in the tag. - Supports various types when registered.
regexp	Match the value agaist a regular expression.	string, []byte	regexp:"^foo$" rgx:"^foo$" match:"^foo$"	Expects Perl syntax regular expression. Aliases: rgx, match.

Documentation

Overview

Example (RangeInt)

package main

import (
	"context"

	"go.llib.dev/frameless/pkg/validate"
)

func main() {
	type T struct {
		V int `range:"0..100"`
	}

	ctx := context.Background()
	validate.Value(ctx, T{V: 42})  // no error
	validate.Value(ctx, T{V: -1})  // validate.Error
	validate.Value(ctx, T{V: 101}) // validate.Error
}

Example (RangeIntMulti)

package main

import (
	"context"

	"go.llib.dev/frameless/pkg/validate"
)

func main() {
	type T struct {
		Num1 int `range:"0..100"`
		Num2 int `range:"0..25,30..50"`
	}

	ctx := context.Background()
	_ = validate.Value(ctx, T{})
}

Index

• Constants
• func SkipValidate(ctx context.Context) context.Context
• func Struct(ctx context.Context, v any) error
• func StructField(ctx context.Context, field reflect.StructField, value reflect.Value) error
• func Value[T any](ctx context.Context, v T) error
• type Error
  • func (err Error) Error() string
  • func (err Error) Unwrap() error
• type Option
• type Validatable
• type ValidationError
• type Validator
• type X

Examples

• Package (RangeInt)
• Package (RangeIntMulti)

Constants

const ImplementationError errorkit.Error = "ImplementationError"

Functions

func SkipValidate

func SkipValidate(ctx context.Context) context.Context

SkipValidate option indicates that the function is being used inside a Validate(context.Context) error method.

When this option is set, the Validate function call is skipped to prevent an infinite loop caused by a circular Validate call.

Deprecated: no longer needed to use if you migrated to the new Validatable interface signature.

func Struct

func Struct(ctx context.Context, v any) error

func StructField

func StructField(ctx context.Context, field reflect.StructField, value reflect.Value) error

func Value

func Value[T any](ctx context.Context, v T) error

Types

type Error

type Error struct{ Cause error }

Error is a validation error, that represents an incorrect content.

func (Error) Error

func (err Error) Error() string

func (Error) Unwrap

func (err Error) Unwrap() error

type Option

type Option option.Option[config]

type Validatable

type Validatable interface {
	Validate(ctx context.Context) error
}

Validatable is a value that can self-validate.

type ValidationError

type ValidationError = Error

Deprecated: use validate.Error instead

type Validator

type Validator interface {
	Validate() error
}

Validator

Deprecated: use validate.Validatable

type X

type X struct {
	X string `match-posix:"^foo$"`
}