PRINTER¶

Companion mod for printers.

6.66.1. type printer¶

`printer` is an output port of strings.

`printer` provides sequential forward operations to the underlying destination.

Example

:STR_PRINTER.require_from('kink/io/')

:P <- STR_PRINTER.new("\r\n")
P.print_line('foo')
P.print('bar')
stdout.print_line(P.str.repr) # => "foo\r\nbar"

6.66.1.1. Printer.print(Str ...[$config={}])¶

`print` writes `Str`.

• C.on_success($success): default = {}

• C.on_error($error): default = a fun which raises an exception

If `Str` is written without an IO error, `print` tail-calls $success with no arg.

If an IO error occurs, `print` tail-calls $error with an `exception`.

Preconditions

`Str` must be a `str`

$success must be a fun which takes no arg

$error must be a fun which takes an `exception`

Example

:STR_PRINTER.require_from('kink/io/')

:P <- STR_PRINTER.new("\r\n")
P.print('foo')
P.print('bar')
stdout.print_line(P.str.repr) # => "foobar"

Example: IO error

:FILE.require_from('kink/io/')
:CONTROL.require_from('kink/')
:CHARSET.require_from('kink/')

:P <- FILE.open_to_print('/tmp/print.txt' CHARSET.utf8 "\r\n")
P.close

P.print('foo'){(:C)
  C.on_error{(:Exc)
    stderr.print_line(Exc.message)
  }
}
# => already closed

P.print('foo')
# Output:
#   -- main exception
#   [..root..]
#   {..call by host..}
#   ,,,
#   already closed

6.66.1.2. Printer.print_line(Str ...[$config={}])¶

`print_line` writes `Str` and `newline`.

• C.on_success($success): default = {}

• C.on_error($error): default = a fun which raises an exception

If `Str` and `newline` are written without an IO error, `print_line` tail-calls $success with no arg.

If an IO error occurs, `print_line` tail-calls $error with an `exception`.

Preconditions

`Str` must be a `str`

$success must be a fun which takes no arg

$error must be a fun which takes an `exception`

Example

:STR_PRINTER.require_from('kink/io/')

:P <- STR_PRINTER.new("\r\n")
P.print_line('foo')
P.print_line('bar')
stdout.print_line(P.str.repr) # => "foo\r\nbar\r\n"

Example: IO error

:FILE.require_from('kink/io/')
:CONTROL.require_from('kink/')
:CHARSET.require_from('kink/')

:P <- FILE.open_to_print('/tmp/print.txt' CHARSET.utf8 "\r\n")
P.close

P.print_line('foo'){(:C)
  C.on_error{(:Exc)
    stderr.print_line(Exc.message)
  }
}
# => already closed

P.print_line('foo')
# Output:
#   -- main exception
#   [..root..]
#   {..call by host..}
#   ,,,
#   already closed

6.66.1.3. Printer.newline¶

`newline` returns a `str` of the newline used by `print_line`.

6.66.2. PRINTER.is?(Val)¶

`is?` returns whether `Val` is a `printer`.

6.66.3. PRINTER.mixin¶

`mixin` returns a mixin trait which provides Printer.print_line method.

`print_line` will be implemented using `newline` and `print` methods.