Less mixin guard with parameters

// Settings - these need moving to the variables.less file I think
@icon-font-line-height: 1;
@icon-font-size-base: @font-size-base;
// Defaults used by the icon mixins
@icon-font-default-icon: "\f245";
@icon-font-default-color: inherit;
@icon-font-default-margin: (@grid-gutter-width/2);
@icon-font-default-icon: @shopping-cart;
@grid-gutter-width: 12px;
@font-size-base: 14px;
@shopping-cart: "\f07a";
@up: "\f077";
@position: before;
@color: red;
//@loop: false;

.create-loop-icon (@loop: false, @content: @icon-font-default-icon, @color: green) when not (@loop = true) {
    &:@{position} {
     content: @content;
     color: @color;
  }
}

.create-loop-icon (@loop: false, @content: @icon-font-default-icon, @color: orange) when (@loop = true) {
    &:@{position} {
     background: purple;
     content: @content;
     color: @color;
  }
}

.test-class {
  .create-loop-icon(@loop:true, @content: "test", @color: blue);
}

.test-class2 {
  .create-loop-icon(@color: green, @content: "");
}