Implement the double_parens lint.

This commit is contained in:
Theemathas Chirananthavat 2016-12-28 12:03:49 -08:00
parent d76fa3dfd9
commit e1c540bfd1

View File

@ -1,5 +1,5 @@
use syntax::ast::*;
use rustc::lint::{EarlyContext, LintArray, LintPass, EarlyLintPass};
use rustc::lint::{EarlyContext, LintContext, LintArray, LintPass, EarlyLintPass};
/// **What it does:** Checks for unnecessary double parentheses.
///
@ -30,6 +30,33 @@ impl LintPass for DoubleParens {
impl EarlyLintPass for DoubleParens {
fn check_expr(&mut self, cx: &EarlyContext, expr: &Expr) {
// insert check here.
match expr.node {
ExprKind::Paren(ref in_paren) => {
match in_paren.node {
ExprKind::Paren(_) |
ExprKind::Tup(_) => {
cx.span_lint(DOUBLE_PARENS, expr.span, "Consider removing unnecessary double parentheses");
},
_ => {},
}
},
ExprKind::Call(_, ref params) => {
if params.len() == 1 {
let param = &params[0];
if let ExprKind::Paren(_) = param.node {
cx.span_lint(DOUBLE_PARENS, param.span, "Consider removing unnecessary double parentheses");
}
}
},
ExprKind::MethodCall(_, _, ref params) => {
if params.len() == 2 {
let param = &params[1];
if let ExprKind::Paren(_) = param.node {
cx.span_lint(DOUBLE_PARENS, param.span, "Consider removing unnecessary double parentheses");
}
}
},
_ => {},
}
}
}