the type of input elements
the type of input elements
The fatal failure case of ParseResult: contains an error-message and the remaining input
The failure case of ParseResult: contains an error-message and the remaining input
The parser input is an abstract reader of input elements
The parser input is an abstract reader of input elements
A common super-class for unsuccessful parse results
A parser whose ~ combinator disallows back-tracking
A base class for parser results
The root class of parsers
The success case of ParseResult: contains the result and the remaining input
An extractor so NoSuccess(msg, next) can be used in matches
The parser that matches an element in the domain of the partial function f'
If
f' is defined on the first element in the input, f' is applied to it to produce
this parser's result
The parser that matches an element in the domain of the partial function f'
If
f' is defined on the first element in the input, f' is applied to it to produce
this parser's result.
Example: The parser accept("name", {case Identifier(n) => Name(n)})
accepts an Identifier(n)
and returns a Name(n)
.
a description of the kind of element this parser expects (for error messages)
a partial function that determines when this parser is successful and what its output is
A parser that succeeds if f' is applicable to the first element of the input,
applying
f' to it to produce the result.
A parser that matches only the given list of element es'
accept(es) succeeds if the input subsequently provides the elements in the list
es'
A parser that matches only the given list of element es'
accept(es) succeeds if the input subsequently provides the elements in the list
es'.
the list of expected elements
a Parser that recognizes a specified list of elements
A parser that matches only the given element e'
The method is implicit so that elements can automatically be lifted to their parsers
A parser that matches only the given element e'
The method is implicit so that elements can automatically be lifted to their parsers.
For example, when parsing
Token's, Identifier("new") (which is a Token') can be used directly,
instead of first creating a
Parser' using accept(Identifier("new")).
the Elem' that must be the next piece of input for the returned parser to succeed
a tParser' that succeeds if
e' is the next available input.
A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator,
produces a left-associative function that combines the elements it separates
A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator,
produces a left-associative function that combines the elements it separates.
a parser that parses the first element
a parser that parses the subsequent elements
a parser that parses the token(s) separating the elements, yielding a left-associative function that combines two elements into one
A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator,
produces a left-associative function that combines the elements it separates
A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator,
produces a left-associative function that combines the elements it separates.
From: J. Fokker. Functional parsers. In J. Jeuring and E. Meijer, editors, Advanced Functional Programming, volume 925 of Lecture Notes in Computer Science, pages 1--23. Springer, 1995.
a parser that parses the elements
a parser that parses the token(s) separating the elements, yielding a left-associative function that combines two elements into one
A parser generator that generalises the rep1sep generator so that q', which parses the separator,
produces a right-associative function that combines the elements it separates
A parser generator that generalises the rep1sep generator so that q', which parses the separator,
produces a right-associative function that combines the elements it separates. Additionally,
The right-most (last) element and the left-most combinating function have to be supplied.
rep1sep(p: Parser[T], q) corresponds to chainr1(p, q ^^ cons, cons, Nil) (where val cons = (x: T, y: List[T]) => x :: y)
a parser that parses the elements
a parser that parses the token(s) separating the elements, yielding a right-associative function that combines two elements into one
the "last" (left-most) combination function to be applied
the "first" (right-most) element to be combined
Wrap a parser so that its failures become errors (the | combinator will give up as soon as it encounters an error, on failure it simply tries the next alternative)
Wrap a parser so that its failures become errors (the | combinator will give up as soon as it encounters an error, on failure it simply tries the next alternative)
A parser that matches only the given element e'
elem(e) succeeds if the input starts with an element
e'
A parser that matches only the given element e'
elem(e) succeeds if the input starts with an element
e'
the Elem' that must be the next piece of input for the returned parser to succeed
a Parser' that succeeds if
e' is the next available input (and returns it).
A parser matching input elements that satisfy a given predicate
A parser matching input elements that satisfy a given predicate
elem(kind, p) succeeds if the input starts with an element e' for which p(e) is true.
The element kind, used for error messages
A predicate that determines which elements match. @return
This method is used to compare the receiver object (this
)
with the argument object (arg0
) for equivalence
This method is used to compare the receiver object (this
)
with the argument object (arg0
) for equivalence.
The default implementations of this method is an equivalence relation:
x
of type Any
,
x.equals(x)
should return true
.x
and y
of type
Any
, x.equals(y)
should return true
if and only
if y.equals(x)
returns true
.x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns
true
, then x.equals(z)
should return true
.
If you override this method, you should verify that
your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to
override hashCode
to ensure that objects that are
"equal" (o1.equals(o2)
returns true
)
hash to the same Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
A parser that results in an error
A parser that results in an error
The error message describing the failure.
A parser that always fails with the specified error message.
A parser that always fails
A parser that always fails
The error message describing the failure.
A parser that always fails with the specified error message.
A parser generator for guard expressions
A parser generator for guard expressions. The resulting parser will fail or succeed just like the one given as parameter but it will not consume any input.
a Parser' that is to be applied to the input
A parser that returns success if and only if 'p' succeeds but never consumes any input
Returns a hash code value for the object
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash
codes (o1.hashCode.equals(o2.hashCode)
) yet not be
equal (o1.equals(o2)
returns false
). A
degenerate implementation could always return 0
.
However, it is required that if two objects are equal
(o1.equals(o2)
returns true
) that they
have identical hash codes
(o1.hashCode.equals(o2.hashCode)
). Therefore, when
overriding this method, be sure to verify that the behavior is
consistent with the equals
method.
Wrap a parser so that its failures&errors become success and vice versa -- it never consumes any input
Wrap a parser so that its failures&errors become success and vice versa -- it never consumes any input
A parser generator for optional sub-phrases
A parser generator for optional sub-phrases.
opt(p) is a parser that returns Some(x)' if
p' returns x' and
None' if p' fails
A Parser' that is tried on the input
a Parser' that always succeeds: either with the result provided by
p' or
with the empty result
A parser generator delimiting whole phrases (i
A parser generator delimiting whole phrases (i.e. programs).
phrase(p)
succeeds if p
succeeds and
no input is left over after p
.
the parser that must consume all input for the resulting parser to succeed.
a parser that has the same result as p', but that only succeeds
if
p
consumed all the input.
positioned' decorates a parser's result with the start position of the input it consumed
positioned' decorates a parser's result with the start position of the input it consumed.
a Parser' whose result conforms to
Positional'.
A parser that has the same behaviour as p', but which marks its result with the
start position of the input it consumed, if it didn't already have a position.
A parser generator for repetitions
A parser generator for repetitions.
rep(p) repeatedly uses p' to parse the input until
p' fails (the result is a List
of the consecutive results of p')
a Parser' that is to be applied successively to the input
A parser that returns a list of results produced by repeatedly applying p' to the input.
A parser generator for non-empty repetitions
A parser generator for non-empty repetitions.
rep1(f, p) first uses f' (which must succeed) and then repeatedly uses
p' to
parse the input until p' fails
(the result is a
List' of the consecutive results of f' and
p')
a Parser' that parses the first piece of input
a Parser' that is to be applied successively to the rest of the input (if any)
A parser that returns a list of results produced by first applying f' and then
repeatedly
p' to the input (it only succeeds if f' matches).
A parser generator for non-empty repetitions
A parser generator for non-empty repetitions.
rep1(p) repeatedly uses p' to parse the input until
p' fails -- p' must succeed at least
once (the result is a
List' of the consecutive results of p')
a Parser' that is to be applied successively to the input
A parser that returns a list of results produced by repeatedly applying p' to the input
(and that only succeeds if
p' matches at least once).
A parser generator for non-empty repetitions
A parser generator for non-empty repetitions.
rep1sep(p, q) repeatedly applies p' interleaved with
q' to parse the input, until p' fails.
The parser
p' must succeed at least once.
a Parser' that is to be applied successively to the input
a Parser' that parses the elements that separate the elements parsed by
p'
(interleaved with q')
A parser that returns a list of results produced by repeatedly applying p' to the input
(and that only succeeds if
p' matches at least once).
The results of p' are collected in a list. The results of
q' are discarded.
A parser generator for a specified number of repetitions
A parser generator for a specified number of repetitions.
repN(n, p) uses p' exactly
n' time to parse the input
(the result is a List' of the
n' consecutive results of p')
the exact number of times p' must succeed
a Parser' that is to be applied successively to the input
A parser that returns a list of results produced by repeatedly applying p' to the input
(and that only succeeds if
p' matches exactly n' times).
A parser generator for interleaved repetitions
A parser generator for interleaved repetitions.
repsep(p, q) repeatedly uses p' interleaved with
q' to parse the input, until p' fails.
(The result is a
List' of the results of p'.)
Example: repsep(term, ",")
parses a comma-separated list of term's,
yielding a list of these terms
a Parser' that is to be applied successively to the input
a Parser' that parses the elements that separate the elements parsed by
p'
A parser that returns a list of results produced by repeatedly applying p' (interleaved
with
q') to the input.
The results of p' are collected in a list. The results of
q' are discarded.
A parser that always succeeds
A parser that always succeeds
The result for the parser
A parser that always succeeds, with the given result v'
Returns a string representation of the object
Returns a string representation of the object.
The default representation is platform dependent.
Parsers
is a component that provides generic parser combinators.It requires the type of the elements these parsers should parse (each parser is polymorphic in the type of result it produces).
There are two aspects to the result of a parser: (1) success or failure, and (2) the result. A
Parser[T]
provides both kinds of information.The term
parser combinator refers to the fact that these parsers are constructed from primitive parsers and composition operators, such as sequencing, alternation, optionality, repetition, lifting, and so on.
A
primitive parser is a parser that accepts or rejects a single piece of input, based on a certain criterion, such as whether the input...
Even more primitive parsers always produce the same result, irrespective of the input.