Add support for AssemblyFor (#94)

* Add support for AssemblyIf

* Print assembly cases blocks

* Add support for AssemblyFor

Author: Franco Victorio

src/printer.js

@@ -489,7 +489,7 @@ function genericPrint(path, options, print) {
       return concat([
         '{',
         indent(hardline),
-        indent(join(line, path.map(print, 'operations'))),
+        indent(printPreservingEmptyLines(path, 'operations', options, print)),
         hardline,
         '}'
       ]);
@@ -545,6 +545,15 @@ function genericPrint(path, options, print) {
         ' ',
         path.call(print, 'body')
       ]);
+    case 'AssemblyFor': {
+      return join(' ', [
+        'for',
+        path.call(print, 'pre'),
+        path.call(print, 'condition'),
+        path.call(print, 'post'),
+        path.call(print, 'body')
+      ]);
+    }
     case 'FunctionTypeName': {
       const returns = returnTypes => {
         if (returnTypes.length > 0) {

tests/Assembly/Assembly.sol

@@ -19,4 +19,10 @@ contract Assembly {
             }
         }
   }
+
+  function forAssembly() {
+    assembly {
+for { let i := 0 } lt(i, x) { i := add(i, 1) } { y := mul(2, y) }
+        }
+  }
 }

tests/Assembly/__snapshots__/jsfmt.spec.js.snap

@@ -22,6 +22,12 @@ contract Assembly {
             }
         }
   }
+
+  function forAssembly() {
+    assembly {
+for { let i := 0 } lt(i, x) { i := add(i, 1) } { y := mul(2, y) }
+        }
+  }
 }
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 contract Assembly {
@@ -44,6 +50,18 @@ contract Assembly {
         }
     }
   }
+
+  function forAssembly() {
+    assembly {
+      for {
+        let i := 0
+      } lt(i, x) {
+        i := add(i, 1)
+      } {
+        y := mul(2, y)
+      }
+    }
+  }
 }
 
 `;