diff options
Diffstat (limited to 'exercises/error_handling')
| -rw-r--r-- | exercises/error_handling/errors5.rs | 4 | ||||
| -rw-r--r-- | exercises/error_handling/errors6.rs | 33 |
2 files changed, 23 insertions, 14 deletions
diff --git a/exercises/error_handling/errors5.rs b/exercises/error_handling/errors5.rs index 1b11800..365a869 100644 --- a/exercises/error_handling/errors5.rs +++ b/exercises/error_handling/errors5.rs @@ -43,8 +43,8 @@ impl PositiveNonzeroInteger { impl fmt::Display for CreationError { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { let description = match *self { - CreationError::Negative => "Number is negative", - CreationError::Zero => "Number is zero", + CreationError::Negative => "number is negative", + CreationError::Zero => "number is zero", }; f.write_str(description) } diff --git a/exercises/error_handling/errors6.rs b/exercises/error_handling/errors6.rs index cee7250..0f6b27a 100644 --- a/exercises/error_handling/errors6.rs +++ b/exercises/error_handling/errors6.rs @@ -10,11 +10,20 @@ // I AM NOT DONE +use std::num::ParseIntError; + // This is a custom error type that we will be using in `parse_pos_nonzero()`. #[derive(PartialEq, Debug)] enum ParsePosNonzeroError { - CreationError, - ParseIntError + Creation(CreationError), + ParseInt(ParseIntError) +} + +impl ParsePosNonzeroError { + fn from_creation(err: CreationError) -> ParsePosNonzeroError { + ParsePosNonzeroError::Creation(err) + } + // TODO: add another error conversion function here. } fn parse_pos_nonzero(s: &str) @@ -24,7 +33,7 @@ fn parse_pos_nonzero(s: &str) // when `parse()` returns an error. let x: i64 = s.parse().unwrap(); PositiveNonzeroInteger::new(x) - .or(Err(ParsePosNonzeroError::CreationError)) + .map_err(ParsePosNonzeroError::from_creation) } // Don't change anything below this line. @@ -54,17 +63,18 @@ mod test { #[test] fn test_parse_error() { - assert_eq!( + // We can't construct a ParseIntError, so we have to pattern match. + assert!(matches!( parse_pos_nonzero("not a number"), - Err(ParsePosNonzeroError::ParseIntError) - ); + Err(ParsePosNonzeroError::ParseInt(_)) + )); } #[test] fn test_negative() { assert_eq!( parse_pos_nonzero("-555"), - Err(ParsePosNonzeroError::CreationError) + Err(ParsePosNonzeroError::Creation(CreationError::Negative)) ); } @@ -72,15 +82,14 @@ mod test { fn test_zero() { assert_eq!( parse_pos_nonzero("0"), - Err(ParsePosNonzeroError::CreationError) + Err(ParsePosNonzeroError::Creation(CreationError::Zero)) ); } #[test] fn test_positive() { - assert_eq!( - parse_pos_nonzero("42"), - Ok(PositiveNonzeroInteger(42)) - ); + let x = PositiveNonzeroInteger::new(42); + assert!(x.is_ok()); + assert_eq!(parse_pos_nonzero("42"), Ok(x.unwrap())); } } |
