Contract

Part of Entiqon / Database

🧩 Overview

The contract package defines small, reusable behavioral contracts (interfaces)
that core tokens (Field, Table, Join, Condition, etc.) and builders implement
to enable polymorphic behavior without tight coupling between packages.

Contracts are intentionally minimalistic, composable, and auditable.
They focus on clear identity, safe mutation, and consistent rendering across tokens,
while leaving implementation details to each package.

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Available Contracts (strict order)

Contract	Purpose	Methods
Identifiable	Raw input and normalized expression identity (alias-free).	Input() string Expr() string
Aliasable	Alias surface for tokens.	Alias() string IsAliased() bool
BaseToken	Core identity for tokens, including alias.	Input() string Expr() string Alias() string IsAliased() bool
Clonable	Semantic cloning for safe mutation.	Clone() T
Debuggable	Developer-facing diagnostic output.	Debug() string
Errorable	Error state inspection and propagation.	IsErrored() bool Error() error SetError(err error) T
Rawable	Generic SQL fragments, dialect-agnostic.	Raw() string IsRaw() bool
Renderable	Canonical, dialect-aware SQL output.	Render() string
Stringable	Human-facing audit/log output.	String() string
Validable	Structural validation.	IsValid() bool

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Examples

See example_test.go for runnable examples of all contracts:

t := table.New("users", "u")

var k contract.Kindable[myKind] = &myToken{}
k.SetKind(Custom)
fmt.Println("Kind=", k.Kind()) // classification

var id contract.Identifiable = t
fmt.Println(id.Input(), id.Expr()) // identity only

var al contract.Aliasable = t
fmt.Println(al.Alias(), al.IsAliased()) // alias surface

var bt contract.BaseToken = t
fmt.Println(bt.Input(), bt.Expr(), bt.Alias(), bt.IsAliased())
// Output: users users u true

var c contract.Clonable[*table.Table] = t
fmt.Println(c.Clone()) // safe copy

var d contract.Debuggable = t
fmt.Println(d.Debug()) // developer diagnostic

var e contract.Errorable[*table.Table] = t
fmt.Println(e.IsErrored(), e.Error()) // error state

var w contract.Rawable = t
fmt.Println(w.Raw()) // generic SQL

var r contract.Renderable = t
fmt.Println(r.Render()) // dialect-aware SQL

var s contract.Stringable = t
fmt.Println(s.String()) // audit/log

var v contract.Validable = t
fmt.Println(v.IsValid()) // structural validation

Note:
- Use Kindable for classification enums (e.g., condition.Type, identifier.Type).
- Use Identifiable when aliasing must be excluded (e.g., in Condition tokens).

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📄 License

MIT — © Entiqon Project