scheme

Tools for modeling Scheme datastructures used in LilyPond.

---

Classes

Scheme	Abjad model of Scheme code.
SchemeAssociativeList	Abjad model of Scheme associative list.
SchemeColor	Abjad model of Scheme color.
SchemeMoment	Abjad model of Scheme moment.
SchemePair	Abjad model of Scheme pair.
SchemeSymbol	Abjad model of Scheme symbol.
SchemeVector	Abjad model of Scheme vector.
SchemeVectorConstant	Abjad model of Scheme vector constant.
SpacingVector	Abjad model of Scheme spacing vector.

class abjad.scheme.Scheme(value=None, force_quotes=None, quoting=None, verbatim=None)

Abjad model of Scheme code.

A Scheme boolean value:

>>> scheme = abjad.Scheme(True)
>>> print(format(scheme))
##t

A nested Scheme expession:

>>> scheme = abjad.Scheme([
...     ('left', (1, 2, False)),
...     ('right', (1, 2, 3.3)),
...     ])
>>> print(format(scheme))
#((left (1 2 #f)) (right (1 2 3.3)))

A list:

>>> scheme_1 = abjad.Scheme([1, 2, 3])
>>> scheme_2 = abjad.Scheme((1, 2, 3))
>>> format(scheme_1) == format(scheme_2)
True

Scheme wraps nested variable-length arguments in a tuple.

A quoted Scheme expression:

>>> scheme = abjad.Scheme((1, 2, 3), quoting="'#")
>>> print(format(scheme))
#'#(1 2 3)

Use the quoting keyword to prepend Scheme’s various quote, unquote, unquote-splicing characters to formatted output.

A Scheme expression with forced quotes:

>>> scheme = abjad.Scheme('nospaces', force_quotes=True)
>>> print(format(scheme))
#"nospaces"

Use this in certain override situations when LilyPond’s Scheme interpreter treats unquoted strings as symbols instead of strings. The string must contain no whitespace for this to work.

A Scheme expression of LilyPond functions:

>>> function_1 = 'tuplet-number::append-note-wrapper'
>>> function_2 = 'tuplet-number::calc-denominator-text'
>>> string = abjad.Scheme('4', force_quotes=True)
>>> scheme = abjad.Scheme([function_1, function_2, string])
>>> abjad.f(scheme)
abjad.Scheme(
    [
        'tuplet-number::append-note-wrapper',
        'tuplet-number::calc-denominator-text',
        abjad.Scheme(
            '4',
            force_quotes=True,
            ),
        ]
    )

>>> print(format(scheme))
#(tuplet-number::append-note-wrapper tuplet-number::calc-denominator-text "4")

A Scheme lambda expression of LilyPond function that takes a markup with a quoted string argument. Setting verbatim to true causes the expression to format exactly as-is without modifying quotes or whitespace:

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> scheme = abjad.Scheme(string, verbatim=True)
>>> abjad.f(scheme)
abjad.Scheme(
    '(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))',
    verbatim=True,
    )

>>> print(format(scheme))
#(lambda (grob) (grob-interpret-markup grob #{ \markup \musicglyph #"noteheads.s0harmonic" #}))

More examples:

>>> abjad.Scheme(True)
Scheme(True)

>>> abjad.Scheme(False)
Scheme(False)

>>> abjad.Scheme(None)
Scheme(None)

>>> abjad.Scheme('hello')
Scheme('hello')

>>> abjad.Scheme('hello world')
Scheme('hello world')

>>> abjad.Scheme([abjad.Scheme('foo'), abjad.Scheme(3.14159)])
Scheme([Scheme('foo'), Scheme(3.14159)])

>>> abjad.Scheme([
...     abjad.SchemePair(('padding', 1)),
...     abjad.SchemePair(('attach-dir', -1)),
...     ])
Scheme([SchemePair(('padding', 1)), SchemePair(('attach-dir', -1))])

Scheme takes an optional quoting keyword, for prepending quote/unquote ticks:

>>> str(abjad.Scheme(['fus', 'ro', 'dah'], quoting = "',"))
"',(fus ro dah)"

__str__ of abjad.Scheme returns the abjad.Scheme formatted value without the hash mark, while format(Scheme) returns the formatted value with the hash mark, allowing for nested abjad.Scheme expressions:

>>> scheme = abjad.Scheme(['fus', 'ro', 'dah'], quoting = "'")
>>> str(scheme)
"'(fus ro dah)"

>>> format(scheme)
"#'(fus ro dah)"

Scheme attempts to format Python values into abjad.Scheme equivalents:

>>> format(abjad.Scheme(True))
'##t'

>>> format(abjad.Scheme(False))
'##f'

>>> format(abjad.Scheme(None))
'##f'

>>> format(abjad.Scheme('hello world'))
'#"hello world"'

>>> format(abjad.Scheme([1, 2, 3]))
'#(1 2 3)'

>>> format(abjad.Scheme([
...     abjad.SchemePair(('padding', 1)),
...     abjad.SchemePair(('attach-dir', -1)),
...     ],
...     quoting="'",
...     ))
"#'((padding . 1) (attach-dir . -1))"

---

Attributes Summary

__format__	Formats scheme.
__str__	Gets string representation of Scheme object.
force_quotes	Is true when quotes should be forced in output.
format_embedded_scheme_value	Formats embedded Scheme value.
format_scheme_value	Formats value as Scheme would.
lilypond_color_constants
quoting	Gets Scheme quoting string.
value	Gets value.
verbatim	Is true when formatting should format value absolutely verbatim.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

quoting

Gets Scheme quoting string.

Return type:Optional[str]

value

Gets value.

Return type:Any

verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeAssociativeList(value=None)

Abjad model of Scheme associative list.

>>> scheme_alist = abjad.SchemeAssociativeList([
...     ('space', 2),
...     ('padding', 0.5),
...     ])
>>> abjad.f(scheme_alist)
abjad.SchemeAssociativeList(
    [
        abjad.SchemePair(('space', 2)),
        abjad.SchemePair(('padding', 0.5)),
        ]
    )

>>> print(format(scheme_alist))
#'((space . 2) (padding . 0.5))

Scheme associative lists are immutable.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeColor(value=None, force_quotes=None, quoting=None, verbatim=None)

Abjad model of Scheme color.

>>> abjad.SchemeColor('ForestGreen')
SchemeColor('ForestGreen')

>>> note = abjad.Note("c'4")
>>> scheme_color = abjad.SchemeColor('ForestGreen')
>>> abjad.override(note).note_head.color = scheme_color
>>> abjad.show(note) 

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeMoment(duration=(0, 1))

Abjad model of Scheme moment.

Initializes with two integers:

>>> abjad.SchemeMoment((2, 68))
SchemeMoment((2, 68))

Scheme moments are immutable.

---

Attributes Summary

__eq__	Is true when argument is a scheme moment with the same value as that of this scheme moment.
__ge__	Return a >= b.
__gt__	Return a > b.
__hash__	Hashes scheme moment.
__le__	Return a <= b.
__lt__	Is true when argument is a scheme moment with value greater than that of this scheme moment.
duration	Gets duration of Scheme moment.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

__eq__(argument)

Is true when argument is a scheme moment with the same value as that of this scheme moment.

>>> abjad.SchemeMoment((2, 68)) == abjad.SchemeMoment((2, 68))
True

Otherwise false:

>>> abjad.SchemeMoment((2, 54)) == abjad.SchemeMoment((2, 68))
False

Return type:bool

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

__ge__(other, NotImplemented=NotImplemented)

Return a >= b. Computed by @total_ordering from (not a < b).

__gt__(other, NotImplemented=NotImplemented)

Return a > b. Computed by @total_ordering from (not a < b) and (a != b).

__hash__()

Hashes scheme moment.

Redefined in tandem with __eq__.

Return type:int

__le__(other, NotImplemented=NotImplemented)

Return a <= b. Computed by @total_ordering from (a < b) or (a == b).

__lt__(argument)

Is true when argument is a scheme moment with value greater than that of this scheme moment.

>>> abjad.SchemeMoment((1, 68)) < abjad.SchemeMoment((1, 32))
True

Otherwise false:

>>> abjad.SchemeMoment((1, 68)) < abjad.SchemeMoment((1, 78))
False

Return type:bool

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

duration

Gets duration of Scheme moment.

>>> abjad.SchemeMoment((2, 68)).duration
NonreducedFraction(2, 68)

Return type:NonreducedFraction

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemePair(value=(None, None))

Abjad model of Scheme pair.

Initializes from two values:

>>> abjad.SchemePair(('spacing', 4))
SchemePair(('spacing', 4))

REGRESSION:

Right-hand side string forces quotes:

>>> scheme_pair = abjad.SchemePair(('font-name', 'Times'))
>>> format(scheme_pair)
'#\'(font-name . "Times")'

Right-hand side nonstring does not force quotes:

>>> scheme_pair = abjad.SchemePair(('spacing', 4))
>>> format(scheme_pair)
"#'(spacing . 4)"

---

Attributes Summary

__format__	Formats Scheme pair.
left	Gets left value.
right	Gets right value.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

__format__(format_specification='')

Formats Scheme pair.

>>> scheme_pair = abjad.SchemePair((-1, 1))

>>> format(scheme_pair)
"#'(-1 . 1)"

>>> abjad.f(scheme_pair)
abjad.SchemePair((-1, 1))

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

left

Gets left value.

Return type:Any

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

right

Gets right value.

Return type:Any

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeSymbol(symbol='cross')

Abjad model of Scheme symbol.

>>> scheme = abjad.SchemeSymbol('cross')
>>> scheme
SchemeSymbol('cross')

>>> print(format(scheme))
#'cross

---

Attributes Summary

symbol

Gets symbol string.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

symbol

Gets symbol string.

Return type:str

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeVector(value=[])

Abjad model of Scheme vector.

Scheme vector of boolean values:

>>> scheme = abjad.SchemeVector([True, True, False])
>>> scheme
SchemeVector(True, True, False)

>>> print(format(scheme))
#'(#t #t #f)

Scheme vector of symbols:

>>> scheme = abjad.SchemeVector(['foo', 'bar', 'blah'])
>>> scheme
SchemeVector('foo', 'bar', 'blah')

>>> print(format(scheme))
#'(foo bar blah)

Scheme vectors and Scheme vector constants differ in only their LilyPond input format.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SchemeVectorConstant(value=[])

Abjad model of Scheme vector constant.

Scheme vector constant of boolean values:

>>> scheme = abjad.SchemeVectorConstant([True, True, False])
>>> scheme
SchemeVectorConstant(True, True, False)

>>> print(format(scheme))
#'#(#t #t #f)

Scheme vectors and Scheme vector constants differ in only their LilyPond input format.

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]

class abjad.scheme.SpacingVector(basic_distance=0, minimum_distance=0, padding=12, stretchability=0)

Abjad model of Scheme spacing vector.

>>> vector = abjad.SpacingVector(0, 0, 12, 0)

>>> abjad.f(vector)
abjad.SpacingVector(
    abjad.SchemePair(('basic-distance', 0)),
    abjad.SchemePair(('minimum-distance', 0)),
    abjad.SchemePair(('padding', 12)),
    abjad.SchemePair(('stretchability', 0))
    )

Use to set paper block spacing attributes:

>>> staff = abjad.Staff("c'8 d'8 e'8 f'8")
>>> lilypond_file = abjad.LilyPondFile.new(staff)
>>> vector = abjad.SpacingVector(0, 0, 12, 0)
>>> lilypond_file.paper_block.system_system_spacing = vector

---

Special methods

(AbjadValueObject).__copy__(*arguments)

Copies Abjad value object.

Returns new Abjad value object.

(AbjadValueObject).__eq__(argument)

Is true when all initialization values of Abjad value object equal the initialization values of argument.

Returns true or false.

(Scheme).__format__(format_specification='')

Formats scheme.

Scheme LilyPond format:

>>> scheme = abjad.Scheme('foo')
>>> format(scheme)
'#foo'

Scheme storage format:

>>> abjad.f(scheme)
abjad.Scheme(
    'foo'
    )

Return type:str

(AbjadValueObject).__hash__()

Hashes Abjad value object.

Returns integer.

(AbjadObject).__repr__()

Gets interpreter representation of Abjad object.

Returns string.

(Scheme).__str__()

Gets string representation of Scheme object.

Return type:str

---

Class & static methods

static (Scheme).format_embedded_scheme_value(value, force_quotes=False)

Formats embedded Scheme value.

Return type:str

static (Scheme).format_scheme_value(value, force_quotes=False, verbatim=False)

Formats value as Scheme would.

Some basic values:

>>> abjad.Scheme.format_scheme_value(1)
'1'

>>> abjad.Scheme.format_scheme_value('foo')
'foo'

>>> abjad.Scheme.format_scheme_value('bar baz')
'"bar baz"'

>>> abjad.Scheme.format_scheme_value([1.5, True, False])
'(1.5 #t #f)'

Strings without whitespace can be forcibly quoted via the force_quotes keyword:

>>> abjad.Scheme.format_scheme_value(
...     'foo',
...     force_quotes=True,
...     )
'"foo"'

Set verbatim to true to format value exactly (with only hash preprended):

>>> string = '(lambda (grob) (grob-interpret-markup grob'
>>> string += r' #{ \markup \musicglyph #"noteheads.s0harmonic" #}))'
>>> abjad.Scheme.format_scheme_value(string, verbatim=True)
'(lambda (grob) (grob-interpret-markup grob #{ \\markup \\musicglyph #"noteheads.s0harmonic" #}))'

Hash symbol at the beginning of a string does not result in quoted output:

>>> string = '#1-finger'
>>> abjad.Scheme.format_scheme_value(string)
'#1-finger'

Return type:str

---

Read-only properties

(Scheme).force_quotes

Is true when quotes should be forced in output.

Return type:Optional[bool]

(Scheme).quoting

Gets Scheme quoting string.

Return type:Optional[str]

(Scheme).value

Gets value.

Return type:Any

(Scheme).verbatim

Is true when formatting should format value absolutely verbatim. Whitespace, quotes, and all other parts of value are left intact.

Return type:Optional[bool]