load string.format;


#Placeholders '$x' are used to embed unformatted data into string,
#'x' is the index of additional format() argument (starting from 0).
#Supported data types: all numeric types, string, enum, list, array, map, tuple, none.
#Escaping: '$$'.


io.writeln('#General usage');
io.writeln(str.format("The values are $$$0, '$1' and {$2}.", 5, 'str', {1, 2, 3} ));


#Placeholders '$(format)' are meant for formatted printing,
#<format> ::= <placeholder ID> [<element>] [<numeric format>] [<alignment>]
#Placeholder ID should be argument index or name.


io.writeln(str.format("The values are $(x), $(y) and '$2'.", x = $enum, y = 0xFF, none));


#<alignment> ::= ('>' | '<' | '=') <field width>
#'<' -- align left,
#'>' -- align right,
#'=' -- align center.


io.writeln('\n#Alignment');
io.writeln(str.format('($(0<10))', 'left'));
io.writeln(str.format('($(0>10))', 'right'));
io.writeln(str.format('($(0=10))', 'center'));


#<numeric format> ::= : ['+' | ' '] ('i' | 'x' | 'X' | 'f' | 'g' | 'G') [.<precision>]
#'+' -- print sign,
#' ' -- print space if no sign,
#type specifiers and precision have the same meaning as in C/C++ printf(),
#integer and floating point arguments are implictly casted if required.


io.writeln('\n#Numeric format');
io.writeln(str.format('$(0:i), $(1:X.4), $(2:+f.2)', -1, 255, 3.3452));


#For containers, numeric format and alignment are applied to each element individually.


io.writeln('\n#Containers');
io.writeln(str.format('$(0:f.2>6)', {1, 2, 3}));


#<element> ::= ( '[' <index> | <slice> ']' | .<field name>)
#<slice> ::= [ <index> ] : [ <index> ]
#Indexing is supported for strings, lists, arrays, tuples,
#slicing -- for strings, lists and arrays,
#negative indexes are allowed,
#field name can be used for tuples with named items.


io.writeln('\n#Inner data access');
io.writeln(str.format('[$0][-1] = $(0[-1]); ($1).x = $(1.x:i)', [1, 2], (x = 1, y = 2)));
io.writeln(str.format('"$0"[:2] = $(0[:2]); [$1][1:1] = $(1[1:1])', 'string', [1, 2; 3, 4; 5, 6]));