Implement FromStr for SVGMeasure

Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6748e8def348ed4d14996fa801f4122cd763fff530258cdc03f64b25f89d3a5a"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "askama"
 version = "0.12.0"
@@ -77,6 +86,8 @@ version = "0.1.0"
 dependencies = [
  "askama",
  "derive_more",
+ "lazy_static",
+ "regex",
  "strum",
  "strum_macros",
 ]
@@ -96,6 +107,12 @@ dependencies = [
  "libm",
 ]
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libm"
 version = "0.2.7"
@@ -173,6 +190,35 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81bc1d4caf89fac26a70747fe603c130093b53c773888797a6329091246d651a"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fed1ceff11a1dddaee50c9dc8e4938bd106e9d89ae372f192311e7da498e3b69"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5ea92a5b6195c6ef2a0295ea818b312502c6fc94dde986c5553242e18fd4ce2"
+
 [[package]]
 name = "rustc_version"
 version = "0.4.0"

dyesub-tool/Cargo.toml

@@ -6,5 +6,7 @@ edition = "2021"
 [dependencies]
 askama = "0.12.0"
 derive_more = "0.99.17"
+lazy_static = "1.4.0"
+regex = "1.9.3"
 strum = "0.25.0"
 strum_macros = "0.25.2"

dyesub-tool/src/svg/measure.rs

@@ -1,10 +1,16 @@
 use super::SVGUnit;
 use std::cmp::Ordering;
 use std::fmt;
+use std::num::ParseFloatError;
+use std::str::FromStr;
 use std::{
     fmt::Display,
     ops::{Add, Div, Mul, Sub},
 };
+use lazy_static::lazy_static;
+use regex::Regex;
+use derive_more::From;
+use strum::ParseError;
 
 #[derive(Debug, Clone, Copy)]
 pub struct SVGMeasure {
@@ -29,6 +35,32 @@ impl SVGMeasure {
     }
 }
 
+#[derive(From, Debug)]
+pub enum SVGUnitParseError {
+    ParseMeasure(ParseFloatError),
+    ParseUnit(ParseError),
+    Invalid,
+}
+
+impl FromStr for SVGMeasure {
+    type Err = SVGUnitParseError;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s == "0" {
+            return Ok(SVGMeasure::new(0.0, SVGUnit::Pixel));
+        }
+        lazy_static! {
+            static ref RE: Regex = Regex::new(r"^([\d.]+)([a-zA-Z]+)$").unwrap();
+        }
+        if let Some(captures) = RE.captures(s) {
+            let measure = captures[1].parse::<f64>()?;
+            let unit = captures[2].parse::<SVGUnit>()?;
+            Ok(SVGMeasure::new(measure, unit))
+        } else {
+            Err(SVGUnitParseError::Invalid)
+        }
+    }
+}
+
 const EQ_TOLERANCE: f64 = 0.00001;
 
 impl PartialEq for SVGMeasure {

dyesub-tool/src/svg/tests.rs

@@ -1,3 +1,5 @@
+use std::str::FromStr;
+
 use crate::svg::{SVGMeasure, SVGUnit};
 
 #[test]
@@ -52,3 +54,13 @@ fn cmp() {
     assert!(m_10cm > m_5mm);
     assert!(m_5mm < m_10cm);
 }
+
+#[test]
+fn from_str() {
+    let m_10cm = SVGMeasure::new(10.0, SVGUnit::Centimeter);
+    let m_5mm = SVGMeasure::new(5.0, SVGUnit::Millimeter);
+    let m_0 = SVGMeasure::new(0.0, SVGUnit::Pixel);
+    assert_eq!(m_10cm, SVGMeasure::from_str("10cm").unwrap());
+    assert_eq!(m_5mm, SVGMeasure::from_str("5mm").unwrap());
+    assert_eq!(m_0, SVGMeasure::from_str("0").unwrap());
+}

flake.nix

@@ -51,7 +51,7 @@ Updating `cargoHash`:
           pname = "dyesub-tool";
           version = "0.1.0";
           buildAndTestSubdir = "dyesub-tool";
-          cargoHash = "sha256-WUA3ysG7SlylV1y5nkPxLRGVa4NktFjpawE97d3b36I=";
+          cargoHash = "sha256-QlLyKDZZ+/bB4xBv0j9GoL6Ur3Okdskkazi4WlHhx6Y=";
           meta = meta // {
             description = "A tool for generating dye sublimation transfer sheet SVGs for Japanese thumb shift 拇指シフト keycaps.";
           };