From 3fe5550a3bb1fbca159f4e4e1f4d766f2757ad2e Mon Sep 17 00:00:00 2001
From: Dima Kossovich <koss@null.net>
Date: Mon, 16 Oct 2023 01:31:55 +0300
Subject: [PATCH] add Yeti as a pipe function

---
 example/main.go               | 22 ++++++++++++++++++++++
 internal/internalpipe/pipe.go |  7 -------
 internal/internalpipe/snag.go | 25 +++++++++++++++++++++++++
 internal/internalpipe/yeet.go |  2 +-
 pkg/pipe/interface.go         |  8 ++++++++
 pkg/pipe/yeet.go              | 19 +++----------------
 6 files changed, 59 insertions(+), 24 deletions(-)
 create mode 100644 example/main.go

diff --git a/example/main.go b/example/main.go
new file mode 100644
index 0000000..d855ff6
--- /dev/null
+++ b/example/main.go
@@ -0,0 +1,22 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/koss-null/funcfrog/pkg/pipe"
+)
+
+func main() {
+	p := pipe.Slice([]int{1, 2, 3, 4, 5, 6, 7, 8, 9})
+	y := pipe.NewYeti()
+	res := p.Yeti(y).Map(func(i int) int {
+		if i < 0 {
+			y.Yeet(errors.New("omg the value is negative"))
+		}
+		return 2 * i
+	}).Snag(func(err error) {
+		fmt.Println("Snagging an error: " + err.Error())
+	}).Do()
+	fmt.Println(res)
+}
diff --git a/internal/internalpipe/pipe.go b/internal/internalpipe/pipe.go
index 841dcc3..f6e3dfd 100644
--- a/internal/internalpipe/pipe.go
+++ b/internal/internalpipe/pipe.go
@@ -2,7 +2,6 @@ package internalpipe
 
 import (
 	"math"
-	"unsafe"
 
 	"golang.org/x/exp/constraints"
 )
@@ -62,12 +61,6 @@ func (p Pipe[T]) Count() int {
 	return cnt
 }
 
-// Sang ads error handler to a current Pipe step.
-func (p Pipe[T]) Snag(h ErrHandler) Pipe[T] {
-	p.y.SnagPipe(unsafe.Pointer(p.prevP), h)
-	return p
-}
-
 // limit returns the upper border limit as the pipe evaluation limit.
 func (p *Pipe[T]) limit() int {
 	switch {
diff --git a/internal/internalpipe/snag.go b/internal/internalpipe/snag.go
index e69de29..f82eecb 100644
--- a/internal/internalpipe/snag.go
+++ b/internal/internalpipe/snag.go
@@ -0,0 +1,25 @@
+package internalpipe
+
+import "unsafe"
+
+// Sang ads error handler to a current Pipe step.
+func (p Pipe[T]) Snag(h ErrHandler) Pipe[T] {
+	// todo: think about NPE here
+	p.y.SnagPipe(unsafe.Pointer(p.prevP), h)
+	return p
+}
+
+type YeetSnag interface {
+	// yeet an error
+	Yeet(err error)
+	// snag and handle the error
+	Snag(ErrHandler)
+}
+
+// Yeti adds Yeti error handler to the pipe.
+// If some other handlers were set before, they are handled by the Snag
+func (p Pipe[T]) Yeti(y YeetSnag) Pipe[T] {
+	// todo: save previous y
+	p.y = y.(yeti)
+	return p
+}
diff --git a/internal/internalpipe/yeet.go b/internal/internalpipe/yeet.go
index 5dd30b3..e7a03cd 100644
--- a/internal/internalpipe/yeet.go
+++ b/internal/internalpipe/yeet.go
@@ -5,7 +5,7 @@ import (
 	"unsafe"
 )
 
-type ErrHandler func(err error)
+type ErrHandler func(error)
 
 type Yeti struct {
 	Errs       []error
diff --git a/pkg/pipe/interface.go b/pkg/pipe/interface.go
index 314f31b..fc8f267 100644
--- a/pkg/pipe/interface.go
+++ b/pkg/pipe/interface.go
@@ -1,5 +1,7 @@
 package pipe
 
+import "github.com/koss-null/funcfrog/internal/internalpipe"
+
 // Piper interface contains all methods of a pipe with determened length.
 type Piper[T any] interface {
 	doer[T]
@@ -19,6 +21,7 @@ type Piper[T any] interface {
 	promicer[T]
 	eraser[Piper[any]]
 	snagger[Piper[T]]
+	yeti[Piper[T]]
 }
 
 // PiperNoLen represents methods available to a Pipe type with no length determened.
@@ -36,6 +39,7 @@ type PiperNoLen[T any] interface {
 
 	eraser[PiperNoLen[any]]
 	snagger[PiperNoLen[T]]
+	yeti[PiperNoLen[T]]
 }
 
 type paralleller[T, PiperT any] interface {
@@ -97,3 +101,7 @@ type promicer[T any] interface {
 type snagger[PiperT any] interface {
 	Snag(func(error)) PiperT
 }
+
+type yeti[PiperT any] interface {
+	Yeti(y internalpipe.YeetSnag) PiperT
+}
diff --git a/pkg/pipe/yeet.go b/pkg/pipe/yeet.go
index 7a1a2c6..4f2697c 100644
--- a/pkg/pipe/yeet.go
+++ b/pkg/pipe/yeet.go
@@ -1,8 +1,6 @@
 package pipe
 
 import (
-	"sync"
-
 	"github.com/koss-null/funcfrog/internal/internalpipe"
 )
 
@@ -11,18 +9,7 @@ const (
 	initHandlersAmount = 5
 )
 
-type Yeti interface {
-	// yeet an error
-	Yeet(err error)
-	// snag and handle the error
-	Snag(handler func(err error))
-}
-
-// FIXME
-func Yeet() Yeti {
-	return &internalpipe.Yeti{
-		Errs:     make(map[*any][]error, initErrsAmount),
-		Handlers: make(map[*any][]internalpipe.ErrHandler, initHandlersAmount),
-		Mx:       &sync.Mutex{},
-	}
+// NewYeti creates a brand new Yeti - an object for error handling.
+func NewYeti() internalpipe.YeetSnag {
+	return internalpipe.NewYeti()
 }