java - Is there any way to use BiConsumers as simply as Consumers? -

this theorical question no concrete application.

i have following method not touch. (if possible @ all) used biconsumer.

void dosmallthing(a a, b b) {   // , b. }  void dobigthing(list<a> as, b b) {   // do? } 

how can iterate on as while keeping b constant , use this::dosmallthing in dobigthing?

of course following doesn't work.

void dobigthing(list<a> as, b b) {   as.stream()   .foreach(this::dosmallthing); } 

the following works nice , use everyday.

void dobigthing(list<a> as, b b) {   as.stream()   .foreach(a -> dosmallthing(a, b)); } 

the following works well, bit more tricky.

consumer<a> dosmallthingwithfixedb(b b) {   return (a) -> dosmallthing(a, b); }  void dobigthing(list<a> as, b b) {   as.stream()   .foreach(dosmallthingwithfixedb(b)) } 

but of solutions don't simplicity of consumer case. there simple exists biconsumer?

you want "bind" function argument. unfortunately there's no built-in mechanism in java 8 (except binding object instance methods this::). may generalize dosmallthingwithfixedb method this:

public class bind {     public static <a, b> consumer<a> bindlast(biconsumer<a, b> fn, b b) {         return -> fn.accept(a, b);     }      public static <a, b> consumer<b> bindfirst(biconsumer<a, b> fn, a) {         return b -> fn.accept(a, b);     } } 

and use:

void dobigthing(list<a> as, b b) {   as.stream()     .foreach(bind.bindlast(this::dosmallthing, b)); } 

probably there's third-party library contains such methods. using explicit lambda seems ok me. should not try express method references.