Init

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "none-guard"
+version = "0.1.0"
+dependencies = [
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "134c189feb4956b20f6f547d2cf727d4c0fe06722b20a0eec87ed445a97f92da"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23e78b90f2fcf45d3e842032ce32e3f2d1545ba6636271dcbf24fa306d87be7a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"

Cargo.toml

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+[package]
+name = "none-guard"
+version = "0.1.0"
+edition = "2021"
+authors = ["Dominic Grimm <dominic@dergrimm.net>"]
+repository = "https://git.dergrimm.net/dergrimm/none-guard"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+proc-macro = true
+
+[dependencies]
+quote = "1.0.33"
+syn = "2.0.39"

LICENSE

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+MIT License
+
+Copyright (c) 2023 Dominic Grimm <dominic@dergrimm.net>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

examples/example.rs

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+use none_guard::NoneGuard;
+
+#[derive(NoneGuard)]
+struct Test {
+    x: Option<i32>,
+    y: Option<String>,
+    z: Option<f32>,
+}
+
+fn main() {
+    let x = Test {
+        x: Some(1),
+        y: None,
+        z: None,
+    };
+    dbg!(x.is_all_none());
+
+    let y = Test {
+        x: None,
+        y: Some("dd".to_string()),
+        z: Some(2.0),
+    };
+    dbg!(y.is_all_none());
+
+    let z = Test {
+        x: None,
+        y: None,
+        z: None,
+    };
+    dbg!(z.is_all_none());
+}

src/lib.rs

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+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput};
+
+#[proc_macro_derive(NoneGuard)]
+pub fn none_guard(input: TokenStream) -> TokenStream {
+    let ast = parse_macro_input!(input as DeriveInput);
+    let struct_name = &ast.ident;
+
+    if let syn::Data::Struct(s) = &ast.data {
+        let field_checks = s.fields.iter().map(|field| {
+            let name = &field.ident;
+            if let syn::Type::Path(type_path) = &field.ty {
+                if type_path.path.segments.len() == 1 {
+                    let segment = &type_path.path.segments.iter().next().unwrap();
+                    if segment.ident != "Option" {
+                        return quote! {
+                            compile_error!("All fields must be of type Option!");
+                        };
+                    }
+                } else {
+                    return quote! {
+                        compile_error!("All fields must be of type Option!");
+                    };
+                }
+            } else {
+                return quote! {
+                    compile_error!("All fields must be of type Option!");
+                };
+            }
+
+            quote! { self.#name.is_some() }
+        });
+
+        let is_some_checks = field_checks
+            .clone()
+            .reduce(|acc, e| {
+                dbg!(&acc, &e);
+
+                quote! { #acc && #e }
+            })
+            .unwrap();
+
+        let is_none_checks = field_checks
+            .map(|tok| quote! { !(#tok) })
+            .reduce(|acc, e| {
+                dbg!(&acc, &e);
+
+                quote! { #acc && #e }
+            })
+            .unwrap();
+
+        quote! {
+            impl #struct_name {
+                pub fn is_all_some(&self) -> bool {
+                    #is_some_checks
+                }
+
+                pub fn is_all_none(&self) -> bool {
+                    #is_none_checks
+                }
+            }
+        }
+        .into()
+    } else {
+        quote! {
+            compile_error!("CheckAllNone macro can only be used with structs!");
+        }
+        .into()
+    }
+}