function goto(pointer,file)
% GOTO Go to a Specific Line or Label in current m File
%
% Usage:
%
% goto(pointer,file)
% return
%
% All goto() commands need to be followed by a 'return', always!
%
% The function's first input, pointer, can either be an integer value
% representing a line in the current code to go to, or a string
% indicating the pointer 'label' in which to go to. Alternatively,
% pointer can be a vector array of line numbers to jump to
% consecutively, or a cell array consisting of label strings. Setting
% pointer to NaN jumps to a random line in the code and setting it to
% inf jumps to the end of the code.
%
% The second input, file, specifies the file name of the code in which
% the jump is headed to. If it is not specified, then it will take the
% default value of the file name of the file that launched the goto()
% command (i.e. the current m file).
%
% If the linenumber approach is used, goto() could direct to a command,
% an if/for/while statement, inside a loop or an if, or anywhere inside
% the current m file.
%
% If the pointer string approach is used, then the code finds out on
% which line in the current code the selected pointer label string lies
% in, and this line number is then used in the goto() algorithm. This
% approach makes it easier to use goto(), since adding additional
% lines of code in between goto()'s changes the line numbers throughout
% the desired m file. To reduce confuction, the labels in the m file
% need to be of the following syntax:
%
% % LABEL labelstring
%
% Twenty four Example files are accompanied with this file. The first
% 15 examples use the line number input approach, while examples 16-18
% address the pointer string approach. Examples 19-24 demonstrate
% goto's ability to handle numeric vector or string cell inputs.
% Check the usage of this goto() inside them in order to understand how
% to implement goto() in your own routines.
%
% Example 1:
%
% 1- % this is a while loop using goto()
% 2-
% 3- a = 5;
% 4- a = a - 1;
% 5- disp(a)
% 6- if a > 0
% 7- goto(4)
% 8- return
% 9- end
%
%
% Example 15:
%
% while true
% for h = 1:1e9
% for k = 1:1e9
% if 1 == 1
% if round(sum(double('life'))/10) == 42
% goto(16)
% return
% end
% end
% pause(1)
% end
% end
% end
%
% 16- msgbox('It worked!')
%
%
% Example 18:
%
% a = 0;
%
% % LABEL Start
%
% a = a + 1;
% disp(a)
%
% if a < 10
% goto('Start')
% return
% else
% goto('End')
% return
% end
%
% % LABEL End
%
%
%
% Example 22:
%
% 1- a = 0;
% 2-
% 3- goto([6,6,6,6,6,6,9])
% 4- return
% 5-
% 6- a = a + 1;
% 7- goto('End')
% 8- return
% 9- msgbox(num2str(a))
% 10-
% 11- % LABEL End
%
%
%
% Example 23:
%
% labels = {'add';'init1';'add';'add';'show'};
%
% goto(labels)
% return
%
% % LABEL init1
% a = 0;
% goto('End')
% return
%
% % LABEL add
% a = a + 1;
% goto('End')
% return
%
% % LABEL init2
% a = 0;
% goto('End')
% return
%
% % LABEL show
% msgbox(num2str(a))
%
% % LABEL End
%
%
% Example 24:
%
% a = 10;
% goto('show','Example23')
% return
%
%
%
% Tested on MATLAB R2007b (7.5). Author is not responsible for any
% problems caused by this function.
%
% Husam Aldahiyat, numandina@gmail.com, Jordan, 2010
%
if ~exist('pointer','var')
error('Please provide goto() with an input')
end
if exist('file','var')
name = file;
else
h = dbstack;
name = h(end).name;
end
fid = fopen([name,'.m']);
CC = textscan(fid,'%s','delimiter','\n','whitespace','');
funz = strtrim(CC{1});
funz = cellfun(@(x)[x,repmat(' ',1,10)],funz,'uniform',0);
if ~ischar(pointer) && numel(pointer) > 1
if iscell(pointer)
for c = 1:length(pointer)
evalin('caller',['goto(''',pointer{c},''')'])
end
else
for c = 1:length(pointer)
evalin('caller',['goto(',num2str(pointer(c)),')'])
end
end
return
end
if ischar(pointer)
label_lines = find(~cellfun(@isempty,...
(cellfun(@(x)strfind(x,'% LABEL '),funz,'un',0))));
indx = cellfun(@(x)strcmp(strtrim(x),pointer),...
cellfun(@(x)x(9:end),funz(label_lines),'un',0));
if sum(indx) > 1
error('Ambiguous Label Name')
end
pointer = label_lines(indx);
end
if isnan(pointer)
pointer = ceil(length(funz));
end
if isinf(pointer)
return
end
while true
if pointer > length(funz)
break
end
if (strcmp(funz{pointer}(1:6),'return')...
&& length(funz{pointer})==6)...
|| strcmp(funz{pointer}(1:7),'return ')
return
end
if strcmp(funz{pointer}(1:5),'else ')
while ~((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
pointer = pointer + 1;
end
pointer = pointer + 1;
end
if strcmp(funz{pointer}(1:3),'if ')
cond = evalin('caller',funz{pointer}(3:end));
if cond
pointer = pointer + 1;
else
while ~cond
pointer = pointer + 1;
if strcmp(funz{pointer}(1:7),'elseif ')
cond = evalin('caller',funz{pointer}(7:end));
else
if strcmp(funz{pointer}(1:5),'else ')
cond = 1;
end
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
break
end
end
pointer = pointer + 1;
end
continue
end
if pointer > length(funz)
break
end
if (strcmp(funz{pointer}(1:4),'for '))
bef = pointer;
extra = 0;
while true
pointer = pointer + 1;
if (strcmp(funz{pointer}(1:3),'if '))...
|| (strcmp(funz{pointer}(1:4),'for '))...
|| (strcmp(funz{pointer}(1:6),'while '))
extra = extra + 1;
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
if ~extra
pointer = pointer + 1;
break
else
extra = extra - 1;
end
end
end
np = bef;
range = funz{np}(1:end);
indz = strfind(range,'=');
var = funz{np}(4:indz(1)-1);
num_range = str2num(funz{np}(indz(1)+1:end)); %#ok<ST2NM>
if ~isempty(num_range)
pointer = np + 1;
evalin('caller',[var,' = ',num2str(num_range(1)),';']);
end
continue
end
if pointer > length(funz)
break
end
if (strcmp(funz{pointer}(1:5),'goto('))
evalin('caller',funz{pointer})
return
end
if (strcmp(funz{pointer}(1:6),'while '))
bef = pointer;
extra = 0;
while true
pointer = pointer + 1;
if (strcmp(funz{pointer}(1:3),'if '))...
|| (strcmp(funz{pointer}(1:4),'for '))...
|| (strcmp(funz{pointer}(1:6),'while '))
extra = extra + 1;
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
if ~extra
pointer = pointer + 1;
break
else
extra = extra - 1;
end
end
end
np = bef;
cond = evalin('caller',funz{np}(6:end));
if cond
pointer = np + 1;
end
continue
end
if pointer > length(funz)
break
end
if ((strcmp(funz{pointer}(1:5),'break')...
&& length(funz{pointer})==5)...
|| strcmp(funz{pointer}(1:6),'break '))
np = pointer;
extra = 0;
while ~(strcmp(funz{np}(1:6),'while '))...
&& ~(strcmp(funz{np}(1:4),'for '))
np = np - 1;
if (strcmp(funz{np}(1:3),'if '))
extra = extra + 1;
end
end
while true
pointer = pointer + 1;
if (strcmp(funz{pointer}(1:3),'if '))...
|| (strcmp(funz{pointer}(1:4),'for '))...
|| (strcmp(funz{pointer}(1:6),'while '))
extra = extra + 1;
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
if ~extra
pointer = pointer + 1;
break
else
extra = extra - 1;
end
end
end
continue
end
if pointer > length(funz)
break
end
if ((strcmp(funz{pointer}(1:8),'continue')...
&& length(funz{pointer})==8)...
|| strcmp(funz{pointer}(1:9),'continue '))
extra1 = 0;
extra2 = 0;
np = pointer;
while ~(strcmp(funz{np}(1:6),'while '))...
&& ~(strcmp(funz{np}(1:4),'for '))
np = np - 1;
if ((strcmp(funz{np}(1:3),'end')...
&& length(funz{np})==3)...
|| strcmp(funz{np}(1:4),'end '))
extra1 = extra1 + 1;
end
if strcmp(funz{np}(1:3),'if ') && ~extra1
extra2 = extra2 + 1;
end
if strcmp(funz{np}(1:4),'for ')
if ~extra1
break
else
extra1 = extra1 - 1;
end
end
if strcmp(funz{np}(1:6),'while ')
if ~extra1
break
else
extra1 = extra1 - 1;
end
end
end
while true
pointer = pointer + 1;
if (strcmp(funz{pointer}(1:3),'if '))...
|| (strcmp(funz{pointer}(1:4),'for '))...
|| (strcmp(funz{pointer}(1:6),'while '))
extra2 = extra2 + 1;
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
if ~extra2
pointer = pointer + 1;
break
else
extra2 = extra2 - 1;
end
end
end
if (strcmp(funz{np}(1:6),'while '))
cond = evalin('caller',funz{np}(6:end));
if cond
pointer = np + 1;
end
end
if (strcmp(funz{np}(1:4),'for '))
range = funz{np}(1:end);
indz = strfind(range,'=');
var = funz{np}(4:indz(1)-1);
getout = 0;
try
varh = evalin('caller',var);
catch %#ok<CTCH>
getout = 1;
end
if ~getout
num_range = str2num(funz{np}...
(indz(1)+1:end)); %#ok<ST2NM>
where_var = find(num_range == varh);
if ~(where_var == length(num_range)...
|| isempty(num_range))
pointer = np + 1;
evalin('caller',[var,' = ',...
num2str(num_range(where_var + 1)),';']);
end
else
num_range = str2num(funz{np}...
(indz(1)+1:end)); %#ok<ST2NM>
if ~isempty(num_range)
evalin('caller',...
[var,' = ',num2str(num_range(1)),';']);
pointer = np + 1;
end
end
end
continue
end
if pointer > length(funz)
break
end
if ((strcmp(funz{pointer}(1:3),'end')...
&& length(funz{pointer})==3)...
|| strcmp(funz{pointer}(1:4),'end '))
np = pointer;
permission = 1;
while np > 1
np = np - 1;
if (strcmp(funz{np}(1:9),'function '))
return
end
if (strcmp(funz{np}(1:3),'if '))
if permission
pointer = pointer + 1;
break
else
permission = permission + 1;
end
end
if pointer > length(funz)
break
end
if (strcmp(funz{np}(1:4),'for '))
if permission
range = funz{np}(1:end);
indz = strfind(range,'=');
var = funz{np}(4:indz(1)-1);
varh = evalin('caller',var);
num_range = str2num(funz{np}...
(indz(1)+1:end)); %#ok<ST2NM>
where_var = find(num_range == varh);
if where_var == length(num_range)...
|| isempty(num_range)
pointer = pointer + 1;
else
pointer = np + 1;
evalin('caller',[var,' = ',...
num2str(num_range(where_var + 1)),';']);
end
break
else
permission = permission + 1;
end
end
if pointer > length(funz)
break
end
if (strcmp(funz{np}(1:6),'while '))
if permission
cond = evalin('caller',funz{np}(6:end));
if cond
pointer = np + 1;
else
pointer = pointer + 1;
end
break
else
permission = permission + 1;
end
end
if ((strcmp(funz{np}(1:3),'end')...
&& length(funz{np})==3)...
|| strcmp(funz{np}(1:4),'end '))
permission = permission - 1;
end
end
continue
end
if pointer > length(funz)
break
end
evalin('caller',funz{pointer})
pointer = pointer + 1;
if pointer > length(funz)
break
end
end
% Thanks for Kamil Makiela for feedback that led to this line
fclose('all');
end
