proper error message; Comments starting point is standardized

src/IO.f90

@@ -554,7 +554,7 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'invalid selection for debug'
 
 !------------------------------------------------------------------------------------------------
-! errors related to YAML input files
+! errors related to YAML data
     case (701)
       msg = 'Incorrect indent/Null value not allowed'
     case (702)
@@ -565,6 +565,8 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'Space expected after a colon for <key>: <value> pair'
     case (705)
       msg = 'Unsupported feature'
+    case (706)
+      msg = 'Access by incorrect node type'
 
 !-------------------------------------------------------------------------------------------------
 ! errors related to the grid solver

src/YAML_types.f90

@@ -312,7 +312,7 @@ function tNode_asScalar(self) result(scalar)
     class is(tScalar)
       scalar => self
     class default
-      call IO_error(0)
+      call IO_error(706,ext_msg='tNode_asScalar')
   end select
 
 end function tNode_asScalar
@@ -330,7 +330,7 @@ function tNode_asList(self) result(list)
     class is(tList)
       list => self
     class default
-      call IO_error(0)
+      call IO_error(706,ext_msg='tNode_asList')
   end select
 
 end function tNode_asList
@@ -348,7 +348,7 @@ function tNode_asDict(self) result(dict)
     class is(tDict)
       dict => self
     class default
-      call IO_error(0)
+      call IO_error(706,ext_msg='tNode_asDict')
   end select
 
 end function tNode_asDict
@@ -419,7 +419,7 @@ function tNode_get_byIndex(self,i) result(node)
   integer :: j
 
   self_ => self%asList()
-  if(i < 1 .or. i > self_%length) call IO_error(0)
+  if(i < 1 .or. i > self_%length) call IO_error(150,ext_msg='tNode_get_byIndex')
 
   j = 1
   item => self_%first
@@ -642,7 +642,7 @@ function tNode_contains(self,k)  result(exists)
       endif
     enddo
   else
-     call IO_error(0)
+     call IO_error(706,ext_msg='tNode_contains')
   endif
 
 end function tNode_contains

src/grid/DAMASK_grid.f90

@@ -265,7 +265,8 @@ program DAMASK_grid
     reportAndCheck: if (worldrank == 0) then
       write (loadcase_string, '(i0)' ) currentLoadCase
       write(6,'(/,1x,a,i0)') 'load case: ', currentLoadCase
-      if (.not. newLoadCase%followFormerTrajectory) write(6,'(2x,a)') 'drop guessing along trajectory'
+      if (.not. newLoadCase%followFormerTrajectory) &
+        write(6,'(2x,a)') 'drop guessing along trajectory'
       if (newLoadCase%deformation%myType == 'l') then
         do j = 1, 3
           if (any(newLoadCase%deformation%maskLogical(j,1:3) .eqv. .true.) .and. &