constructivism_macro_gen 0.1.0

Macro helper for constructivist
Documentation 
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use std::str::FromStr;

use proc_macro::TokenStream;
use quote::quote;
use syn::{self, parse_macro_input, LitStr, parse::Parse, Type, Token};

struct ConstructivismSettnigs {
    pub domain: String,
    pub value_type: String,
}

impl Parse for ConstructivismSettnigs {
    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
        let domain: LitStr = input.parse()?;
        let domain = domain.value();
        let mut value_type = format!("::syn::Expr");
        if input.peek(Token![,]) {
            input.parse::<Token![,]>()?;
            let vt = input.parse::<Type>()?;
            let vt = quote! { #vt };
            value_type = vt.to_string();
        }
        Ok(ConstructivismSettnigs { domain, value_type })
    }
}

#[proc_macro]
pub fn implement_constructivism_macro(input: TokenStream) -> TokenStream {
    let settings = parse_macro_input!(input as ConstructivismSettnigs);
    // let path = settings.domain;
    // let path = format!("\"{path}\"");
    let source = include_str!("constructivism_macro.include");
    let exact_domain = format!("\"{}\"", settings.domain);
    let source = source.replace("\"constructivism\"", &exact_domain);
    let exact_value = format!("type ConstrctivismValue = {};", settings.value_type);
    let source = source.replace("type ConstrctivismValue = syn::Expr;", &exact_value);
    match TokenStream::from_str(&source) {
        Err(e) => {
            let e = e.to_string();
            TokenStream::from(quote! { compile_error!("Can't parse constructivism_macro: {}", #e) })
        }
        Ok(stream) => stream,
    }
}