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remove a magic number

This commit is contained in:
Rob Watson 2020-11-13 07:34:47 +01:00
parent 160130a29e
commit d4d441d4e3
1 changed files with 6 additions and 2 deletions
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8
weblog-proc-macro/src/weblog_impl.rs
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@ -6,6 +6,10 @@ use syn::parse::{Parse, ParseStream};
use syn::punctuated::Punctuated; use syn::punctuated::Punctuated;
use syn::{bracketed, parse_macro_input, Expr, Result, Token}; use syn::{bracketed, parse_macro_input, Expr, Result, Token};
// The maximum number of variadic arguments accepted by web-sys function
// groups such as `console::log_n`:
const MAX_VARIADIC_ARGS: usize = 7;
// quote_console_func builds and quotes a call to the browser's console API, based on the // quote_console_func builds and quotes a call to the browser's console API, based on the
// provided console function and argument types and the input token stream provider by // provided console function and argument types and the input token stream provider by
// the macro caller. // the macro caller.
@ -34,7 +38,7 @@ pub fn quote_console_func(
let num_variadic = cmp::max(num_provided - num_fixed, 0); let num_variadic = cmp::max(num_provided - num_fixed, 0);
let ident = { let ident = {
let func_name = if is_variadic && num_variadic <= 7 { let func_name = if is_variadic && num_variadic <= MAX_VARIADIC_ARGS {
format!("{}_{}", name, num_variadic) format!("{}_{}", name, num_variadic)
} else { } else {
name name
@ -47,7 +51,7 @@ pub fn quote_console_func(
for _ in 0..num_fixed { for _ in 0..num_fixed {
args.push(out_args.next().unwrap()); args.push(out_args.next().unwrap());
} }
if num_variadic > 7 { if num_variadic > MAX_VARIADIC_ARGS {
let variadic_args = out_args.collect::<Punctuated<_, Token![,]>>(); let variadic_args = out_args.collect::<Punctuated<_, Token![,]>>();
let ary = quote! { let ary = quote! {
&::std::iter::FromIterator::from_iter(::std::iter::IntoIterator::into_iter(::std::vec![#variadic_args])) &::std::iter::FromIterator::from_iter(::std::iter::IntoIterator::into_iter(::std::vec![#variadic_args]))