improved indexing

Basic/@gds_element/private/get_element_data.c

@@ -129,7 +129,7 @@ static mxArray*
 get_layer(element_t *pe)
 {
  if (pe->kind == GDS_SREF || pe->kind == GDS_AREF)
- mexErrMsgTxt("get_element_data : element as no layer property");
+ return empty_matrix();
  else
  return mxCreateDoubleScalar((double)pe->layer);
 
@@ -143,7 +143,7 @@ static mxArray*
 get_dtype(element_t *pe)
 {
  if (pe->kind == GDS_SREF || pe->kind == GDS_AREF)
- mexErrMsgTxt("get_element_data : element as no [data|text|box|node] type property");
+ return empty_matrix();
  else
  return mxCreateDoubleScalar((double)pe->dtype);
 
@@ -266,7 +266,7 @@ get_sname(element_t *pe)
  if (pe->kind == GDS_SREF || pe->kind == GDS_AREF)
  return mxCreateString(pe->sname);
  else
- mexErrMsgTxt("get_element_data : element as no sname property");
+ return empty_matrix();
 
  return NULL; /* make compiler happy */
 }

Basic/@gds_library/subsref.m

@@ -10,11 +10,16 @@
 
 % Ulf Griesmann, NIST, June 2011
 
- switch ins.type
+ % convert cs-lists --> cell arrays
+ itype = {ins.type};
+ isubs = flatten({ins.subs});
+
+ % first indexing operator
+ switch itype{1}
 
  case '()'
 
- idx = ins.subs{:};
+ idx = isubs{1};
 
  if ischar(idx) && idx == ':'
  gstrs = glib.st(1:end);
@@ -39,5 +44,31 @@
  error('gds_library.subsref : invalid indexing type.');
 
  end
+
+ % pass additional structure indexing to structure subsref method
+ if length(itype) > 1
+ sins.type = itype{2};
+ sins.subs = isubs{2};
+ if iscell(gstrs)
+ gstrs = cellfun(@(x)subsref(x, sins), gstrs, 'Un',0); 
+ else
+ gstrs = subsref(gstrs, sins); 
+ end
+ end
+
+ % flatten a cell array
+ function fca = flatten(ca)
+
+ fca = cell(size(ca));
+
+ for k = 1:length(ca)
+ if iscell(ca{k})
+ ct = ca{k};
+ fca{k} = ct{1};
+ else
+ fca(k) = ca(k);
+ end
+ end 
+ end
 
 end 

Basic/@gds_structure/subsref.m

@@ -12,11 +12,17 @@
 
 % Ulf Griesmann, NIST, June 2011
 
- switch ins.type
+ % convert cs-lists --> cell arrays
+ itype = {ins.type};
+ isubs = flatten({ins.subs});
+
+ % first indexing operator
+ switch itype{1}
 
  case '()'
 
- idx = ins.subs{:};
+ idx = isubs{1};
+
  if ischar(idx) && idx == ':'
  gelp = gstruct.el(1:end);
  elseif length(idx) == 1 
@@ -38,4 +44,30 @@
 
  end
 
+ % pass additional element indexing to element subsref method
+ if length(itype) > 1
+ eins.type = itype{2};
+ eins.subs = isubs{2};
+ if iscell(gelp)
+ gelp = cellfun(@(x)subsref(x, eins), gelp, 'Un',0); 
+ else
+ gelp = subsref(gelp, eins); 
+ end
+ end
+
+ % flatten a cell array
+ function fca = flatten(ca)
+
+ fca = cell(size(ca));
+
+ for k = 1:length(ca)
+ if iscell(ca{k})
+ ct = ca{k};
+ fca{k} = ct{1};
+ else
+ fca(k) = ca(k);
+ end
+ end 
+ end
+
 end 

Basic/gdsii_version.m

@@ -17,7 +17,7 @@
 
  % toolbox version and version date
  tb_version = '136';
- tb_date = '2016-October-24';
+ tb_date = '2016-November-04';
  ltb_ver = [tb_version, ' (', tb_date, ')'];
  if exist('OCTAVE_VERSION')
  interpreter = 'Octave';

ChangeLog

@@ -1,3 +1,12 @@
+2016-November-05
+- version 137
+- return [] in 'get_element_data' if an element does not have a requested 
+ property instead of throwing an error.
+- improved 'subsref' methods for gds_library and gds_structure objects that
+ enable more complex indexing operations. E.g. it is now possible to
+ write S(10).xy to get the xy record of the 10th element in a
+ structure without having to copy the element first.
+
 2016-October-24
 - version 136
 - finally squashed bug in gdsio::now