Added collection.sh

README.md

@@ -32,6 +32,8 @@ Bash library which provides utility functions and helpers for functional program
 - [Check](#check)
   - [check::command_exists()](#checkcommand_exists)
   - [check::is_sudo()](#checkis_sudo)
+- [Collection](#collection)
+  - [test_func()](#test_func)
 - [Date](#date)
   - [date::now()](#datenow)
   - [date::epoc()](#dateepoc)
@@ -476,6 +478,57 @@ check::is_sudo
 - **0**:  If the script is executed with root privilege.
 - **1**:  If the script is not executed with root privilege
 
+## Collection
+
+(Experimental) Functions to iterates over a list of elements, yielding each in turn to an iteratee function.
+
+### test_func()
+
+Iterates over elements of collection and invokes iteratee for each element.
+Input to the function can here a pipe output, here-string or file
+
+#### Example
+
+```bash
+test_func(){
+### collection::each()
+
+   printf "print value: %s\n" "$1"
+   return 0
+ }
+arr1=("a b" "c d" "a" "d")
+printf "%s\n" "${arr1[@]}" | collection::each "test_func"
+collection::each "test_func"  < <(printf "%s\n" "${arr1[@]}") #alternative approach
+#output
+ print value: a b
+ print value: c d
+ print value: a
+ print value: d
+```
+
+#### Example
+
+```bash
+# If other function from this library is already used to process the array.
+# Then following method could be used to pass the array to the function.
+out=("$(array::dedupe "${arr1[@]}")")
+collection::each "test_func"  <<< "${out[@]}"
+```
+
+#### Arguments
+
+- **$1** (string): Iteratee function.
+
+#### Exit codes
+
+- **0**:  If successful.
+- **2**: Function missing arguments.
+- other exitcode returned by iteratee
+
+#### Output on stdout
+
+- Output of iteratee function.
+
 ## Date
 
 Functions for manipulating dates.

bash_utility.sh

@@ -9,3 +9,4 @@ source src/date.sh
 source src/interaction.sh
 source src/check.sh
 source src/format.sh
+source src/collection.sh

src/collection.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# @file Collection
+# @brief (Experimental) Functions to iterates over a list of elements, yielding each in turn to an iteratee function.
+
+# @description Iterates over elements of collection and invokes iteratee for each element.
+# Input to the function can here a pipe output, here-string or file
+# @example
+#   test_func(){
+#      printf "print value: %s\n" "$1"
+#      return 0
+#    }
+#   arr1=("a b" "c d" "a" "d")
+#   printf "%s\n" "${arr1[@]}" | collection::each "test_func"
+#   collection::each "test_func"  < <(printf "%s\n" "${arr1[@]}") #alternative approach
+#   #output
+#    print value: a b
+#    print value: c d
+#    print value: a
+#    print value: d
+#
+# @example
+#   # If other function from this library is already used to process the array.
+#   # Then following method could be used to pass the array to the function.
+#   out=("$(array::dedupe "${arr1[@]}")")
+#   collection::each "test_func"  <<< "${out[@]}"
+#
+# @arg $1 string Iteratee function.
+#
+# @exitcode 0  If successful.
+# @exitcode 2 Function missing arguments.
+# @exitcode other exitcode returned by iteratee
+#
+# @stdout Output of iteratee function.
+collection::each() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare IFS=$'\n'
+    while read -r it; do
+        if [[ "$@" == *"$"* ]]; then
+            eval "$@"
+        else
+            eval "$@" "'${it}'"
+        fi
+        declare -i ret="$?"
+
+        if [[ $ret -ne 0 ]]; then
+            return $ret
+        fi
+
+    done
+}