data-utils

Utility function for on-compute data processing of generic arrays and maps

Examples

Run the following to get the package

go get github.com/soumitsalman/data-utils

Use the following import

import (    
    // "utils" or whatever alias you want to use
    utils "github.com/soumitsalman/data-utils"
)

Transform[T_input, T_output any](items []T_input, transformer func(item *T_input) T_output) []T_output

This is equivalent to Python map. It can be used to convert an array of T_input to array of T_output or even extract a specific field from a struct.

type Message struct {
    Source string
    Id string
    PrettyName string
    // ... other fields
}

var messages []Message
// ... some instantiation of messages

sources := utils.Transform[Message, string](messages, func(item *Message) string { 
    return item.Source 
})

Filter[T any](items []T, condition func(item *T) bool) []T

This is equivalent to Python filter. It can be used to pick a sub-array based on the condition function.

unknown_source := utils.Filter[Message](engagements, func(item *Message) bool {
	return item.Source == ""
})

Reduce[T any](items []T, reduce func(a, b T) T) T

This is equivalent to Python reduce. It can be used to add or combine an array of type T into one T value.

sum_result := utils.Reduce[int](int, func(a, b int) int { 
    return a + b 
})

Any[T any](list []T, condition func(item *T) bool) bool

Looks through list to see if there is any item that matches the condition. If so it will return true. If there is no such item, it returns false.

utils.Any[Message](existing_cats, func(item *Message) bool 
{ 
    return item.Source == "My Trunk" && item.Id == "pile driver" 
})

IndexAny[T any](list []T, condition func(item *T) bool) int

Similar to Any, it looks through list to see if there is any item that matches the condition. If so it will return the index of the item in the array. If there is no such item, it returns -1.

utils.IndexAny[Message](existing_cats, func(item *Message) bool 
{ 
    return item.Source == "My Trunk" && item.Id == "pile driver" 
})

ForEach[T any](items []T, do func(item *T)) []T

A for-loop wrapper on items array. This can be used to do any function with and on each item in the array. item *T allows passing reference to the item in the array.

sources := make([]string, 0, len(messages))

utils.ForEach[Message](contents, func(item *Message) {
	sources = append(sources, item.Source)
    item.PrettyName = fmt.Sprintf("%s@%s", item.Id, item.Sources)
    // ... do other stuff
})

Other functions in this package

In[T any](item T, list []T, condition func(a, b *T) bool) bool --> Similar to Any except it tries to match item within list using condition function.
Index[T any](item T, list []T, compare func(a, b *T) bool) int --> Similar to IndexAny except it tries to match item within list using compare function.
SafeSlice[T any](array []T, start, noninclusive_end int) []T --> similar to somearray[start:noninclusive_end] but it normalizes the start and noninclusive_end to keep it contained within 0 to len(somearray).
MapToArray[TKey comparable, TValue any](list map[TKey]TValue) ([]TKey, []TValue) --> Returns two arrays: one of the keys and one of the values.
AppendMaps[TKey comparable, TValue any](to_map, from_map map[TKey]TValue) map[TKey]TValue --> Inserts the values from from_map to to_map.
DateToString(time_val float64) string --> Represents a floating point value of time into YYYY-MM-DD` format.
TruncateTextWithEllipsis(text string, max_len int) string --> If text is longer than max_len then it crops the text to max_len and adds .... Or else it returns the text unmodified.

# README