Documentation
¶
Overview ¶
Package reflect provides functional programming utilities for working with Go's reflect.Value type. It offers higher-order functions like Map, Reduce, and ReduceWithIndex that operate on reflective values representing slices or arrays.
These utilities are particularly useful when working with dynamic types or when implementing generic algorithms that need to operate on collections discovered at runtime.
Index ¶
- func Map[A any](f func(R.Value) A) func(R.Value) []A
- func MapWithIndex[A any](f func(int, R.Value) A) func(R.Value) []A
- func MonadMapWithIndex[A any](val R.Value, f func(int, R.Value) A) []A
- func MonadReduceWithIndex[A any](val R.Value, f func(int, A, R.Value) A, initial A) A
- func Reduce[A any](f func(A, R.Value) A, initial A) func(R.Value) A
- func ReduceWithIndex[A any](f func(int, A, R.Value) A, initial A) func(R.Value) A
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Map ¶
Map transforms each element of a reflect.Value (representing a slice or array) using the provided function, returning a new slice containing the transformed values.
This is a curried function that first takes the transformation function, then returns a function that accepts the reflect.Value to map over.
Parameters:
- f: A transformation function that takes a reflect.Value and returns a value of type A
Returns:
- A function that takes a reflect.Value and returns a slice of transformed values
Example:
// Extract integers from a reflected slice and double them
doubleInts := Map(func(v reflect.Value) int {
return int(v.Int()) * 2
})
result := doubleInts(reflect.ValueOf([]int{1, 2, 3}))
// result = []int{2, 4, 6}
func MapWithIndex ¶ added in v2.1.11
MapWithIndex transforms each element of a reflect.Value (representing a slice or array) using the provided function that receives both the index and the element, returning a new slice containing the transformed values.
This is a curried function that first takes the transformation function, then returns a function that accepts the reflect.Value to map over.
Parameters:
- f: A transformation function that takes (index int, element reflect.Value) and returns a value of type A
Returns:
- A function that takes a reflect.Value and returns a slice of transformed values
Example:
// Create indexed labels from a reflected slice
indexedLabels := MapWithIndex(func(i int, v reflect.Value) string {
return fmt.Sprintf("[%d]: %d", i, int(v.Int()))
})
result := indexedLabels(reflect.ValueOf([]int{10, 20, 30}))
// result = []string{"[0]: 10", "[1]: 20", "[2]: 30"}
func MonadMapWithIndex ¶ added in v2.1.11
MonadMapWithIndex is the non-curried version of MapWithIndex. It transforms each element of a reflect.Value (representing a slice, array, or string) using the provided function that receives both the index and the element, returning a new slice containing the transformed values.
Unlike MapWithIndex which is curried, this function takes both the reflect.Value and the transformation function as parameters in a single call. This is useful when you need to pass the function directly without partial application.
Parameters:
- val: The reflect.Value to map over (must be a slice, array, or string)
- f: A transformation function that takes (index int, element reflect.Value) and returns a value of type A
Returns:
- A slice of transformed values, or an empty slice if val is not iterable
Example:
// Transform a reflected slice with index awareness
input := reflect.ValueOf([]int{10, 20, 30})
result := MonadMapWithIndex(input, func(i int, v reflect.Value) string {
return fmt.Sprintf("[%d]=%d", i, int(v.Int()))
})
// result = []string{"[0]=10", "[1]=20", "[2]=30"}
func MonadReduceWithIndex ¶ added in v2.1.11
func Reduce ¶
Reduce applies a reducer function to each element of a reflect.Value (representing a slice or array), accumulating a result value. Unlike ReduceWithIndex, the reducer function does not receive the index.
This is a curried function that first takes the reducer function and initial value, then returns a function that accepts the reflect.Value to reduce.
Parameters:
- f: A reducer function that takes (accumulator A, element reflect.Value) and returns the new accumulator
- initial: The initial value for the accumulation
Returns:
- A function that takes a reflect.Value and returns the final accumulated value
Example:
// Sum all integers in a reflected slice
sum := Reduce(func(acc int, v reflect.Value) int {
return acc + int(v.Int())
}, 0)
result := sum(reflect.ValueOf([]int{10, 20, 30}))
// result = 60
func ReduceWithIndex ¶
ReduceWithIndex applies a reducer function to each element of a reflect.Value (representing a slice or array), accumulating a result value. The reducer function receives the current index, the accumulated value, and the current element as a reflect.Value.
This is a curried function that first takes the reducer function and initial value, then returns a function that accepts the reflect.Value to reduce.
Parameters:
- f: A reducer function that takes (index int, accumulator A, element reflect.Value) and returns the new accumulator
- initial: The initial value for the accumulation
Returns:
- A function that takes a reflect.Value and returns the final accumulated value
Example:
// Sum all integers in a reflected slice with their indices
sumWithIndex := ReduceWithIndex(func(i int, acc int, v reflect.Value) int {
return acc + i + int(v.Int())
}, 0)
result := sumWithIndex(reflect.ValueOf([]int{10, 20, 30}))
// result = 0 + (0+10) + (1+20) + (2+30) = 63
Types ¶
This section is empty.
Source Files