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|
use std::num::{ParseFloatError, ParseIntError};
use std::str::FromStr;
use iced::Length;
use super::Value;
#[derive(Debug, thiserror::Error, Clone, PartialEq)]
pub enum ParseLengthError {
#[error("float parsing error: {0}")]
ParseFloatError(ParseFloatError),
#[error("int parsing error: {0}")]
ParseIntError(ParseIntError),
#[error("invalid type")]
InvalidType,
#[error("invalid prefix")]
InvalidPrefix,
#[error("missing prefix")]
MissingPrefix,
#[error("cannot parse length from empty string")]
Empty,
}
impl From<ParseFloatError> for ParseLengthError {
fn from(value: ParseFloatError) -> Self {
Self::ParseFloatError(value)
}
}
impl From<ParseIntError> for ParseLengthError {
fn from(value: ParseIntError) -> Self {
Self::ParseIntError(value)
}
}
impl Value for Length {
type Err = ParseLengthError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let s = s.trim();
if s.is_empty() {
return Err(ParseLengthError::Empty);
}
if !s.contains(|c: char| c.is_ascii_digit()) {
match s {
"fill" => Ok(Self::Fill),
"shrink" => Ok(Self::Shrink),
_ => Err(ParseLengthError::InvalidType),
}
} else {
if s.starts_with(|c: char| !c.is_alphabetic()) {
return Err(ParseLengthError::MissingPrefix);
}
let (prefix, value) = s.split_at(2);
match prefix.to_lowercase().as_str() {
"fx" => Ok(Self::Fixed(f32::from_str(value)?)),
"fp" => Ok(Self::FillPortion(u16::from_str(value)?)),
_ => Err(ParseLengthError::InvalidPrefix),
}
}
}
fn to_string(&self) -> String {
match self {
Self::Fill => String::from("fill"),
Self::Shrink => String::from("shrink"),
Self::Fixed(value) => format!("fx{}", value),
Self::FillPortion(value) => format!("fp{}", value),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn can_parse_fill() {
assert_eq!(Length::from_str("fill"), Ok(Length::Fill))
}
#[test]
fn can_parse_shrink_with_space() {
assert_eq!(Length::from_str("shrink "), Ok(Length::Shrink))
}
#[test]
fn can_parse_fill_portion() {
assert_eq!(Length::from_str("fp15"), Ok(Length::FillPortion(15)))
}
#[test]
fn can_parse_fixed_with_spaces() {
assert_eq!(Length::from_str(" fx3.1 "), Ok(Length::Fixed(3.1)))
}
#[test]
fn cant_parse_invalid_type() {
assert_eq!(
Length::from_str("fillportion"),
Err(ParseLengthError::InvalidType)
)
}
#[test]
fn cant_parse_invalid_prefix() {
assert_eq!(
Length::from_str("f2.0"),
Err(ParseLengthError::InvalidPrefix),
)
}
#[test]
fn cant_parse_invalid_float() {
assert_eq!(
Length::from_str(" fx2.a"),
Err(ParseLengthError::ParseFloatError(
f32::from_str("2.a").expect_err("float parse should fail")
))
)
}
#[test]
fn cant_parse_invalid_integer() {
assert_eq!(
Length::from_str("fp1a "),
Err(ParseLengthError::ParseIntError(
u16::from_str("1a").expect_err("integer parse should fail")
))
)
}
#[test]
fn cant_parse_with_missing_prefix() {
assert_eq!(Length::from_str("24"), Err(ParseLengthError::MissingPrefix))
}
#[test]
fn cant_parse_empty_string() {
assert_eq!(Length::from_str(" "), Err(ParseLengthError::Empty))
}
}
|
