CSV parser for Lasso

parse_csv.lasso

[ // Lasso 8
define_tag('parse_csv', -required='input'
	,	-optional='linebreak', -type='string', -copy
	,	-optional='fielddelimiter', -type='string', -copy
	,	-optional='fieldseparator', -type='string', -copy
	,	-optional='escapecharacter', -type='string', -copy
	,	-optional='optionaldelimiters', -copy
	,	-optional='firstrowfieldnames', -copy
	,	-optional='rowformat', -type='string', -copy

);	

	local(	'state'='out'
		,	'output'=array
		,	'row'=array
		,	'field'=string
		,	'char'=string
		,	'escaped'=false
		,	'unquoted'=false
		,	'fieldnames'=array
	);
	
	!local_defined('linebreak') ? local('linebreak'='\n');
	!local_defined('fielddelimiter') ? local('fielddelimiter'='"');
	!local_defined('fieldseparator') ? local('fieldseparator'=',');
	!local_defined('escapecharacter') ? local('escapecharacter'='\\');
	!local_defined('rowformat') ? local('rowformat'='array');
	local('optionaldelimiters'=(local_defined('optionaldelimiters') && #optionaldelimiters != false));
	local('firstrowfieldnames'=(local_defined('firstrowfieldnames') && #firstrowfieldnames != false));
	
	
	iterate(#input -> split(''), #char);
		select(#state);
		case('out');
			if(#char==#fielddelimiter);
				#state='in';
			else(#char==#fieldseparator);
				if(#firstrowfieldnames && #rowformat=='map' && #fieldnames -> size);
					if(#fieldnames -> size >= #row -> size + 1);
						#row -> insert(#fieldnames -> get(#row -> size + 1) = #field);
					/if;
				else;
					#row -> insert(#field);
				/if;
				#field=string;
			else(#char==#linebreak);
				if(#firstrowfieldnames && #rowformat=='map' && #fieldnames -> size);
					if(#fieldnames -> size >= #row -> size + 1);
						#row -> insert(#fieldnames -> get(#row -> size + 1) = #field);
					/if;
				else;
					#row -> insert(#field);
				/if;
				#output -> insert(#row);
				#field=string;
				#rowformat == 'map' ? 	#row = map | #row = array;
			else(#optionaldelimiters);
				#state='in';
				#unquoted=true;
				#field += #char;
			/if;
		case('in');
			if(!#escaped && #char == #escapecharacter);
				#escaped=true;
			else(#char==#fielddelimiter && !#escaped && !#unquoted);
				#state='out';
			else(#char==#fieldseparator && #optionaldelimiters && #unquoted && !#escaped);
				#state='out';
				#unquoted=false;
				if(#firstrowfieldnames && #rowformat=='map' && #fieldnames -> size);
					if(#fieldnames -> size >= #row -> size + 1);
						#row -> insert(#fieldnames -> get(#row -> size + 1) = #field);
					/if;
				else;
					#row -> insert(#field);
				/if;
				#field=string;			
			else(#char==#linebreak && #optionaldelimiters && #unquoted && !#escaped);
				#state='out';
				#unquoted=false;
				if(#firstrowfieldnames && #rowformat=='map' && #fieldnames -> size);
					if(#fieldnames -> size >= #row -> size + 1);
						#row -> insert(#fieldnames -> get(#row -> size + 1) = #field);
					/if;
				else;
					#row -> insert(#field);
				/if;
				#output -> insert(#row);
				#field=string;
				#rowformat == 'map' ? 	#row = map | #row = array;
				#field=string;			
			else;
				#field += #char;
				#escaped=false;
			/if;
		/select;
		if(#firstrowfieldnames && #output -> size == 1 && #fieldnames -> size == 0);
			#fieldnames = #output -> get(1);
			#output -> remove(1);
		else(!#firstrowfieldnames);
			#rowformat='array';
		/if;
	/iterate;
	if(#field -> size);
		if(#firstrowfieldnames && #rowformat=='map' && #fieldnames -> size);
			if(#fieldnames -> size >= #row -> size + 1);
				#row -> insert(#fieldnames -> get(#row -> size + 1) = #field);
			/if;
		else;
			#row -> insert(#field);
		/if;
	/if;
	#row -> size ? #output -> insert(#row);

	return(#output);

/define_tag;
]