fix add & buffered pipe

Author: Dean Karn

cmd/ksql/main.go

@@ -1,11 +1,12 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/go-playground/ksql"
+	"github.com/go-playground/pkg/v5/bytes"
 )
 
 func main() {
@@ -25,21 +26,35 @@ func main() {
 	var input []byte
 
 	if isPipe {
-		input, err = ioutil.ReadAll(os.Stdin)
+		w := bufio.NewWriter(os.Stdout)
+		scanner := bufio.NewScanner(os.Stdin)
+		scanner.Buffer(make([]byte, 0, 200*bytesext.KiB), 5*bytesext.MiB)
+		for scanner.Scan() {
+			result, err := ex.Calculate(scanner.Bytes())
+			if err != nil {
+				fmt.Fprintln(os.Stderr, "reading standard input:", err)
+				return
+			}
+			if _, err = fmt.Fprintln(w, result); err != nil {
+				fmt.Fprintln(os.Stderr, "writing standard output:", err)
+				return
+			}
+		}
+		if err := scanner.Err(); err != nil {
+			fmt.Fprintln(os.Stderr, "reading standard input:", err)
+		}
+		if err = w.Flush(); err != nil {
+			fmt.Fprintln(os.Stderr, "writing standard output:", err)
+		}
+	} else {
+		input = []byte(args[1])
+		result, err := ex.Calculate(input)
 		if err != nil {
 			usage()
 			return
 		}
-	} else {
-		input = []byte(args[1])
-	}
-
-	result, err := ex.Calculate(input)
-	if err != nil {
-		usage()
-		return
+		fmt.Println(result)
 	}
-	fmt.Println(result)
 }
 
 func usage() {

go.mod

@@ -9,6 +9,7 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/go-playground/pkg/v5 v5.5.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-playground/pkg/v5 v5.5.0 h1:I+2yXV/GSH4MB/s2RXIlRnWZZdSgttS+MnAH4yRt8sE=
+github.com/go-playground/pkg/v5 v5.5.0/go.mod h1:TvZ2nNtNh6VfoNteY9ApA2BXt1ZwJliFZ4hzPAwLS9Y=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

parser.go

@@ -390,6 +390,17 @@ func (a add) Calculate(src []byte) (any, error) {
 	}
 
 	if reflect.TypeOf(left) != reflect.TypeOf(right) {
+		if left != nil && right == nil {
+			switch left.(type) {
+			case string, float64:
+				return left, nil
+			}
+		} else if right != nil && left == nil {
+			switch right.(type) {
+			case string, float64:
+				return right, nil
+			}
+		}
 		return nil, ErrUnsupportedTypeComparison{s: fmt.Sprintf("%s + %s", left, right)}
 	}