Water 5-Flow Control and Boolean-Sequential Flow

Contract
Return type	wob
No input parameters.
Parameter kind	Default value	Type
Other unkeyed arguments	opt with ekind of expression	wob

Water Contract
<method do _other_unkeyed=opt=wob=ekind.expression="_body"/>

do executes all its arguments and all the expressions in the content, and returns the value of the last one.

<do 2 3 4/>

4

<do 2> 3 4 </do>

4

do allows you to put many statements where only one is expected; for example, as the corresponding action of an if condition, or to execute a sequence of instructions that return a single result when generating HTML output.

<if> 3.<is 0/>
      "never happens"
     else 
      <do>
        <echo "3 is not more than zero"/>
        "happens"
      </do>
</if>

"happens"

do with no arguments returns null .