WriteArray() (type)

Laurence MorganAbout 1 minAPI Reference

`WriteArray()` (type)

Write a data type, one array element at a time

Description

This is a function you would write when programming a Murex data-type.

It's called by builtins to allow them to write data structures one array element at a time.

The purpose of this function is to allow builtins to support sequential writes (where possible) and also create a standard interface for builtins, thus allowing them to be data-type agnostic.

A Collection of Functions

WriteArray() should return a struct that satisfies the following interface{}:

package stdio

// ArrayWriter is a simple interface types can adopt for buffered writes of formatted arrays in structured types (eg JSON)
type ArrayWriter interface {
	Write([]byte) error
	WriteString(string) error
	Close() error
}

Usage

Registering your WriteArray()

// To avoid confusion, this should only happen inside func init()
stdio.RegisterWriteArray(/* your type name */, /* your writeArray func */)

Examples

Example WriteArray() function:

package string

import (
	"github.com/lmorg/murex/lang/stdio"
)

type arrayWriter struct {
	writer stdio.Io
}

func newArrayWriter(writer stdio.Io) (stdio.ArrayWriter, error) {
	w := &arrayWriter{writer: writer}
	return w, nil
}

func (w *arrayWriter) Write(b []byte) error {
	_, err := w.writer.Writeln(b)
	return err
}

func (w *arrayWriter) WriteString(s string) error {
	_, err := w.writer.Writeln([]byte(s))
	return err
}

func (w *arrayWriter) Close() error { return nil }

Detail

Since not all data types will be stream-able (for example json), some types may need to cache the array and then to write it once the array writer has been closed.

package json

import (
	"github.com/lmorg/murex/lang/stdio"
	"github.com/lmorg/murex/utils/json"
)

type arrayWriter struct {
	array  []string
	writer stdio.Io
}

func newArrayWriter(writer stdio.Io) (stdio.ArrayWriter, error) {
	w := &arrayWriter{writer: writer}
	return w, nil
}

func (w *arrayWriter) Write(b []byte) error {
	w.array = append(w.array, string(b))
	return nil
}

func (w *arrayWriter) WriteString(s string) error {
	w.array = append(w.array, s)
	return nil
}

func (w *arrayWriter) Close() error {
	b, err := json.Marshal(w.array, w.writer.IsTTY())
	if err != nil {
		return err
	}

	_, err = w.writer.Write(b)
	return err
}

WriteArray() (type)

# WriteArray() (type)

# Description

# A Collection of Functions

# Usage

# Examples

# Detail

# See Also