Add "parseArgs"

Add "parseArgs" function, from WORMTRACK repo (rev e7b56ae).

Author: onnodb

parseArgs.m

@@ -0,0 +1,139 @@
+function [argStruct] = parseArgs(args, defArgStruct, flagParamNames)
+% Helper function for parsing varargin.
+%
+% INPUT:
+% args = 'varargin' 1xN cell array
+% defArgStruct = struct with argument names and corresponding default
+%                values.
+% flagParamNames = 1xM cell array with names of parameters that don't
+%                  require a value. If they appear in 'args', their value
+%                  will be set to 1. (Optional)
+%
+% OUTPUT:
+% argStruct = struct with parsed arguments/values. Flags are guaranteed to
+%             get assigned either a true/false value by parseArgs.
+%
+% EXAMPLES:
+% >> argStruct = parseArgs(varargin, struct('param1', 0.1, 'otherParam', 'test')); 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Initialization
+
+if nargin < 3
+    flagParamNames = {};
+end
+
+if ~(isscalar(defArgStruct) && isstruct(defArgStruct))
+    error('PARSEARGS:InvalidDefArgStruct', 'Invalid default parameter specification: should be a single struct');
+end
+
+% Create matrix of accepted parameter names
+validParamNames = fieldnames(defArgStruct);
+
+for i = 1:length(flagParamNames)
+    if ~isValidParamName(flagParamNames{i}, validParamNames)
+        error('PARSEARGS:InvalidFlagParamName', 'Invalid flag parameter name "%s"', flagParamNames{i});
+    end
+end
+
+argStruct = defArgStruct;
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Parse!
+
+parseStates = struct('paramName', 1, 'paramValue', 2);
+curParseState = parseStates.paramName;
+curParamName = '';
+curArgIdx = 1;
+
+while curArgIdx <= length(args)
+    if curParseState == parseStates.paramName
+        curParamName = parseParamName(args{curArgIdx}, validParamNames);
+        if isempty(curParamName)
+            error('PARSEARGS:InvalidArgument', 'Invalid argument "%s"', args{curArgIdx});
+        end
+        if isFlagParam(curParamName, flagParamNames)
+            % Flag parameter!
+            % Value might be explicitly specified...
+            if length(args) > curArgIdx
+                if islogical(args{curArgIdx+1}) || isnumeric(args{curArgIdx+1})
+                    % Flag value is explicitly specified
+                    if args{curArgIdx+1}
+                        argStruct.(curParamName) = true;    % make sure we explicitly assign true/false
+                    else
+                        argStruct.(curParamName) = false;
+                    end
+                    
+                    % --> paramName (skip 1 arg)
+                    curArgIdx = curArgIdx + 2;
+                    curParseState = parseStates.paramName;
+%^^^
+                    continue;
+                end
+            end
+            
+            % Apparently, value was not explicitly specified: turn it on
+            argStruct.(curParamName) = true;
+            
+            % --> paramName
+            curArgIdx = curArgIdx + 1;
+            curParseState = parseStates.paramName;
+%^^^
+            continue;
+        else
+            % Not a flag parameter
+            % --> paramValue
+            curArgIdx = curArgIdx + 1;
+            curParseState = parseStates.paramValue;
+%^^^
+            continue;
+        end
+    elseif curParseState == parseStates.paramValue
+        % Save parameter value
+        argStruct.(curParamName) = args{curArgIdx};
+        
+        % --> paramName
+        curArgIdx = curArgIdx + 1;
+        curParseState = parseStates.paramName;
+%^^^
+        continue;
+    else
+        error('Invalid parse state in parseArgs!');
+    end
+end % while
+
+% Are we missing anything?
+if curParseState == parseStates.paramValue
+    error('PARSEARGS:MissingArgumentValue', 'Missing value for argument "%s"', curParamName);
+end
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+    function [valid] = isValidParamName(paramName, validParamNames)
+        valid = ~isempty(parseParamName(paramName, validParamNames));
+    end
+    
+    function [parsedParamName] = parseParamName(paramName, validParamNames)
+        parsedParamName = '';
+        for j = 1:length(validParamNames)
+            if strcmpi(paramName, validParamNames{j})
+                parsedParamName = validParamNames{j};
+                return
+            end
+        end
+    end
+
+    function [isFlag] = isFlagParam(paramName, flagParamNames)
+        isFlag = false;
+        for j = 1:length(flagParamNames)
+            if strcmpi(paramName, flagParamNames{j})
+                isFlag = true;
+                return
+            end
+        end
+    end
+
+end
+