PreventativeErrors
This class exposes combinators related to the Preventative Errors parser design pattern.
This extension class operates on values that are convertible to parsers. The combinators it enables allow for the parsing of known illegal values, providing richer error messages in case they succeed.
Type parameters
- P
-
the type of base value that this class is used on (the conversion to
Parsley
) is summoned automatically.
Value parameters
- con
-
a conversion that allows values convertible to parsers to be used.
- p
-
the value that this class is enabling methods on.
Attributes
- Constructor
-
This constructor should not be called manually, it is designed to be used via Scala's implicit resolution.
- Since
-
4.4.0
- Source
- patterns.scala
- Graph
-
- Supertypes
Members list
Value members
Concrete methods
Ensures this parser does not succeed, failing with an error as described by the given ErrorGen
object.
Ensures this parser does not succeed, failing with an error as described by the given ErrorGen
object.
If this parser succeeds, input is consumed and this combinator will fail, producing an error message using the given errGen
with width the same as the parsed data along with the given labels. However, if this parser fails, no input is consumed and this combinator succeeds. This parser will produce no evidence of running if it succeeds.
Value parameters
- err
-
the generator that produces the error message.
- labels
-
the labels that should be expected if this parser hadn't succeeded.
Attributes
- Since
-
4.4.0
- Note
-
when this combinator fails (and not this parser itself), it will generate errors rooted at the start of the parse (as if
amend
had been used) and the caret will span the entire successful parse of this parser.when this parser is not to be considered as a terminal error, use
atomic
around the entire combinator to allow for backtracking if this parser succeeds (and therefore fails). - Source
- patterns.scala
Ensures this parser does not succeed, failing with a vanilla error with an unexpected message and caret spanning the parse and a reason generated from this parser's result.
Ensures this parser does not succeed, failing with a vanilla error with an unexpected message and caret spanning the parse and a reason generated from this parser's result.
If this parser succeeds, input is consumed and this combinator will fail, producing an unexpected message the same width as the parse along with a reason generated from the successful parse along with the given labels. However, if this parser fails, no input is consumed and this combinator succeeds. This parser will produce no evidence of running if it succeeds.
Value parameters
- labels
-
the labels that should be expected if this parser hadn't succeeded.
- reason
-
a function that produces a reason for the error given the parsed result.
Attributes
- Since
-
4.4.0
- Note
-
when this combinator fails (and not this parser itself), it will generate errors rooted at the start of the parse (as if
amend
had been used) and the caret will span the entire successful parse of this parser.when this parser is not to be considered as a terminal error, use
atomic
around the entire combinator to allow for backtracking if this parser succeeds (and therefore fails). - Source
- patterns.scala
Ensures this parser does not succeed, failing with a vanilla error with an unexpected message and caret spanning the parse and a given reason.
Ensures this parser does not succeed, failing with a vanilla error with an unexpected message and caret spanning the parse and a given reason.
If this parser succeeds, input is consumed and this combinator will fail, producing an unexpected message the same width as the parse along with the given reason and given labels. However, if this parser fails, no input is consumed and this combinator succeeds. This parser will produce no evidence of running if it succeeds.
Value parameters
- labels
-
the labels that should be expected if this parser hadn't succeeded.
- reason
-
the reason that this parser is illegal.
Attributes
- Since
-
4.4.0
- Note
-
when this combinator fails (and not this parser itself), it will generate errors rooted at the start of the parse (as if
amend
had been used) and the caret will span the entire successful parse of this parser.when this parser is not to be considered as a terminal error, use
atomic
around the entire combinator to allow for backtracking if this parser succeeds (and therefore fails). - Source
- patterns.scala
Ensures this parser does not succeed, failing with a specialised error based on this parsers result if it does.
Ensures this parser does not succeed, failing with a specialised error based on this parsers result if it does.
If this parser succeeds, input is consumed and this combinator will fail, producing an error message based on the parsed result. However, if this parser fails, no input is consumed and this combinator succeeds. This parser will produce no evidence of running if it succeeds.
Value parameters
- msggen
-
the function that generates the error messages from the parsed value.
Attributes
- Since
-
4.4.0
- Note
-
when this combinator fails (and not this parser itself), it will generate errors rooted at the start of the parse (as if
amend
had been used) and the caret will span the entire successful parse of this parser.when this parser is not to be considered as a terminal error, use
atomic
around the entire combinator to allow for backtracking if this parser succeeds (and therefore fails). - Source
- patterns.scala
Ensures this parser does not succeed, failing with a fixed specialised error if it does.
Ensures this parser does not succeed, failing with a fixed specialised error if it does.
If this parser succeeds, input is consumed and this combinator will fail, producing an error message with the given messages. However, if this parser fails, no input is consumed and this combinator succeeds. This parser will produce no evidence of running if it succeeds.
Value parameters
- msg0
-
the first message in the error message.
- msgs
-
the remaining messages that will make up the error message.
Attributes
- Since
-
4.4.0
- Note
-
when this combinator fails (and not this parser itself), it will generate errors rooted at the start of the parse (as if
amend
had been used) and the caret will span the entire successful parse of this parser.when this parser is not to be considered as a terminal error, use
atomic
around the entire combinator to allow for backtracking if this parser succeeds (and therefore fails). - Source
- patterns.scala