Implement FromAbbrevStr derive macro

gribberish/src/templates/product/parameters/meteorological.rs

@@ -1,8 +1,8 @@
-use gribberish_macros::{DisplayDescription, FromValue, ToParameter};
+use gribberish_macros::{DisplayDescription, FromAbbrevStr, FromValue, ToParameter};
 use gribberish_types::Parameter;
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum TemperatureProduct {
     #[abbrev = "TMP"]
     #[unit = "K"]
@@ -55,7 +55,7 @@ pub enum TemperatureProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum MoistureProduct {
     #[description = "specific humidity"]
     #[abbrev = "SPFH"]
@@ -143,7 +143,7 @@ pub enum MoistureProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum MomentumProduct {
     #[description = "wind direction"]
     #[abbrev = "WDIR"]
@@ -212,7 +212,7 @@ pub enum MomentumProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum CloudProduct {
     #[description = "total cloud cover"]
     #[abbrev = "TCDC"]
@@ -238,7 +238,7 @@ pub enum CloudProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum MassProduct {
     #[abbrev = "PRES"]
     #[unit = "pa"]
@@ -263,7 +263,7 @@ pub enum MassProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum RadarProduct {
     #[description = "base spectrum width"]
     #[abbrev = "BSWID"]
@@ -285,7 +285,7 @@ pub enum RadarProduct {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum ForecastRadarImagery {
     #[description = "echo top"]
     #[abbrev = "RETOP"]
@@ -303,7 +303,7 @@ pub enum ForecastRadarImagery {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum Electromagnetics {
     #[abbrev = "LTNGSD"]
     #[unit = "m-2 s-1"]
@@ -331,7 +331,7 @@ pub enum Electromagnetics {
 }
 
 #[repr(u8)]
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 pub enum PhysicalAtmosphericProperties {
     #[description = "visibility"]
     #[abbrev = "VIS"]

macros/src/lib.rs

@@ -185,3 +185,58 @@ fn generate_parameter_attributes(enum_data: &ItemEnum) -> TokenStream {
         }
     }).into()
 }
+
+
+#[proc_macro_derive(FromAbbrevStr, attributes(name, abbrev))]
+pub fn from_abbrev_str(input: TokenStream) -> TokenStream {
+    // Parse the input tokens into a syntax tree
+    let input = parse_macro_input!(input as DeriveInput);
+    let item: Item = input.into();
+
+    if let Item::Enum(e) = item {
+        // Build the output, possibly using quasi-quotation
+        let expanded = generate_from_abbrev_str(&e);
+
+        // Hand the output tokens back to the compiler
+        TokenStream::from(expanded)
+    } else {
+        panic!("Only Enums are supported for DisplayDescription!");
+    }
+}
+
+fn generate_from_abbrev_str(enum_data: &ItemEnum) -> TokenStream {
+    let name: &syn::Ident = &enum_data.ident;
+    let variants: &syn::punctuated::Punctuated<syn::Variant, syn::token::Comma> =
+        &enum_data.variants;
+    let variant_names = variants.into_iter().map(|v| v.ident.clone());
+
+    let variant_abbreviations = variants.into_iter().map(|v| {
+        let abbrev_attribute = v.attrs.iter().find(|a| a.path.is_ident("abbrev"));
+        match abbrev_attribute {
+            Some(a) => a
+                .tokens
+                .to_string()
+                .replace("=", "")
+                .replace("\"", "")
+                .trim()
+                .to_string(),
+            None => v.ident.to_string().to_lowercase(),
+        }
+    });
+
+    (quote! {
+        impl std::str::FromStr for #name {
+            type Err = gribberish_types::ParseAbbrevError;
+
+            fn from_str(s: &str) -> Result<Self, Self::Err> {
+                match s {
+                    #(
+                        #variant_abbreviations => Ok(#name::#variant_names),
+                    )*
+                    _ => Err(gribberish_types::ParseAbbrevError(format!("Unrecognised abbreviation: {s}"))),
+                }
+            }
+        }
+    })
+    .into()
+}

macros/tests/enum.rs

@@ -1,7 +1,8 @@
-use gribberish_macros::{DisplayDescription, FromValue, ToParameter};
+use gribberish_macros::{DisplayDescription, FromAbbrevStr, FromValue, ToParameter};
 use gribberish_types::Parameter;
+use std::str::FromStr;
 
-#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter)]
+#[derive(Eq, PartialEq, Debug, DisplayDescription, FromValue, ToParameter, FromAbbrevStr)]
 enum Shape {
     #[description = "rectangle"]
     #[abbrev = "rect"]
@@ -52,4 +53,12 @@ fn shape_parameter_attributes() {
     let circle: Shape = 2u8.into();
     assert_eq!(circle.unit(), "radius");
     assert_eq!(circle.name(), "round one");
-}
+}
+
+#[test]
+fn shape_from_abbrev_str() {
+    assert_eq!(Shape::from_str("rect"), Ok(Shape::Rectangle));
+    assert_eq!(Shape::from_str("tri"), Ok(Shape::Triangle));
+    assert_eq!(Shape::from_str("cir"), Ok(Shape::Circle));
+    assert!(Shape::from_str("foo").is_err());
+}

types/src/lib.rs

@@ -1,6 +1,10 @@
-
 pub struct Parameter {
     pub name: String,
     pub unit: String,
     pub abbrev: String,
-}
+}
+
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct ParseAbbrevError(pub String);
+