#![feature(macro_metavar_expr)] // `curly` = Right hand side curly brackets // `no_rhs_dollar` = No dollar sign at the right hand side meta variable "function" // `round` = Left hand side round brackets macro_rules! curly__no_rhs_dollar__round { ( $( $i:ident ),* ) => { ${ count(i) } }; } macro_rules! curly__no_rhs_dollar__no_round { ( $i:ident ) => { ${ count(i) } }; //~^ ERROR `count` can not be placed inside the inner-most repetition } macro_rules! curly__rhs_dollar__round { ( $( $i:ident ),* ) => { ${ count($i) } }; //~^ ERROR expected identifier, found `$` //~| ERROR expected expression, found `$` } macro_rules! curly__rhs_dollar__no_round { ( $i:ident ) => { ${ count($i) } }; //~^ ERROR expected identifier, found `$` //~| ERROR expected expression, found `$` } macro_rules! no_curly__no_rhs_dollar__round { ( $( $i:ident ),* ) => { count(i) }; //~^ ERROR cannot find function `count` in this scope //~| ERROR cannot find value `i` in this scope } macro_rules! no_curly__no_rhs_dollar__no_round { ( $i:ident ) => { count(i) }; //~^ ERROR cannot find function `count` in this scope //~| ERROR cannot find value `i` in this scope } macro_rules! no_curly__rhs_dollar__round { ( $( $i:ident ),* ) => { count($i) }; //~^ ERROR variable 'i' is still repeating at this depth } macro_rules! no_curly__rhs_dollar__no_round { ( $i:ident ) => { count($i) }; //~^ ERROR cannot find function `count` in this scope } // Other scenarios macro_rules! dollar_dollar_in_the_lhs { ( $$ $a:ident ) => { //~^ ERROR unexpected token: $ }; } macro_rules! extra_garbage_after_metavar { ( $( $i:ident ),* ) => { ${count() a b c} //~^ ERROR unexpected token: a //~| ERROR expected expression, found `$` ${count(i a b c)} //~^ ERROR unexpected token: a ${count(i, 1 a b c)} //~^ ERROR unexpected token: a ${count(i) a b c} //~^ ERROR unexpected token: a ${ignore(i) a b c} //~^ ERROR unexpected token: a ${ignore(i a b c)} //~^ ERROR unexpected token: a ${index() a b c} //~^ ERROR unexpected token: a ${index(1 a b c)} //~^ ERROR unexpected token: a ${index() a b c} //~^ ERROR unexpected token: a ${index(1 a b c)} //~^ ERROR unexpected token: a }; } const IDX: usize = 1; macro_rules! metavar_depth_is_not_literal { ( $( $i:ident ),* ) => { ${ index(IDX) } }; //~^ ERROR meta-variable expression depth must be a literal //~| ERROR expected expression, found `$` } macro_rules! metavar_in_the_lhs { ( ${ length() } ) => { //~^ ERROR unexpected token: { //~| ERROR expected one of: `*`, `+`, or `?` }; } macro_rules! metavar_token_without_ident { ( $( $i:ident ),* ) => { ${ ignore() } }; //~^ ERROR expected identifier //~| ERROR expected expression, found `$` } macro_rules! metavar_with_literal_suffix { ( $( $i:ident ),* ) => { ${ index(1u32) } }; //~^ ERROR only unsuffixes integer literals are supported in meta-variable expressions //~| ERROR expected expression, found `$` } macro_rules! metavar_without_parens { ( $( $i:ident ),* ) => { ${ count{i} } }; //~^ ERROR meta-variable expression parameter must be wrapped in parentheses //~| ERROR expected expression, found `$` } macro_rules! open_brackets_without_tokens { ( $( $i:ident ),* ) => { ${ {} } }; //~^ ERROR expected expression, found `$` //~| ERROR expected identifier } macro_rules! unknown_count_ident { ( $( $i:ident )* ) => { ${count(foo)} //~^ ERROR variable `foo` is not recognized in meta-variable expression }; } macro_rules! unknown_ignore_ident { ( $( $i:ident )* ) => { ${ignore(bar)} //~^ ERROR variable `bar` is not recognized in meta-variable expression }; } macro_rules! unknown_metavar { ( $( $i:ident ),* ) => { ${ aaaaaaaaaaaaaa(i) } }; //~^ ERROR unrecognized meta-variable expression //~| ERROR expected expression } fn main() { curly__no_rhs_dollar__round!(a, b, c); curly__no_rhs_dollar__no_round!(a); curly__rhs_dollar__round!(a, b, c); curly__rhs_dollar__no_round!(a); no_curly__no_rhs_dollar__round!(a, b, c); no_curly__no_rhs_dollar__no_round!(a); no_curly__rhs_dollar__round!(a, b, c); no_curly__rhs_dollar__no_round!(a); //~^ ERROR cannot find value `a` in this scope extra_garbage_after_metavar!(a); metavar_depth_is_not_literal!(a); metavar_token_without_ident!(a); metavar_with_literal_suffix!(a); metavar_without_parens!(a); open_brackets_without_tokens!(a); unknown_count_ident!(a); unknown_ignore_ident!(a); unknown_metavar!(a); }