From 7b81c088f79a19289008f635d2e2e4105a750b96 Mon Sep 17 00:00:00 2001
From: Marco Groppo <marco.groppo@gmail.com>
Date: Tue, 26 Mar 2019 23:12:46 +0100
Subject: [PATCH] Flip any binary expression except assignments.
---
crates/ra_assists/src/flip_binexpr.rs | 124 ++++++++++++--------------
1 file changed, 58 insertions(+), 66 deletions(-)
diff --git a/crates/ra_assists/src/flip_binexpr.rs b/crates/ra_assists/src/flip_binexpr.rs
index 8a0737b5563..ec377642e02 100644
--- a/crates/ra_assists/src/flip_binexpr.rs
+++ b/crates/ra_assists/src/flip_binexpr.rs
@@ -3,38 +3,26 @@ use ra_syntax::ast::{AstNode, BinExpr, BinOp};
use crate::{AssistCtx, Assist, AssistId};
-/// Flip binary comparison expressions (==, !=, >, >=, <, <=).
+/// Flip binary expression assist.
pub(crate) fn flip_binexpr(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
let expr = ctx.node_at_offset::<BinExpr>()?;
let lhs = expr.lhs()?.syntax();
let rhs = expr.rhs()?.syntax();
let op_range = expr.op()?.range();
- // The assist should be available only if the cursor is on the operator
+ // The assist should be applied only if the cursor is on the operator
let cursor_in_range = ctx.frange.range.is_subrange(&op_range);
- // The assist should be available only for these binary operators
- // (it should not change the meaning of the expression)
- let allowed_ops = [
- BinOp::EqualityTest,
- BinOp::NegatedEqualityTest,
- BinOp::GreaterTest,
- BinOp::GreaterEqualTest,
- BinOp::LesserTest,
- BinOp::LesserEqualTest,
- ];
- let op_kind = expr.op_kind()?;
- if !cursor_in_range || !allowed_ops.iter().any(|o| *o == op_kind) {
+ if !cursor_in_range {
return None;
}
- let new_op = match op_kind {
- BinOp::GreaterTest => Some("<"),
- BinOp::GreaterEqualTest => Some("<="),
- BinOp::LesserTest => Some(">"),
- BinOp::LesserEqualTest => Some(">="),
- _ => None,
- };
+ let action: FlipAction = expr.op_kind()?.into();
+ // The assist should not be applied for certain operators
+ if let FlipAction::DontFlip = action {
+ return None;
+ }
+
ctx.add_action(AssistId("flip_binexpr"), "flip binary expression", |edit| {
edit.target(op_range);
- if let Some(new_op) = new_op {
+ if let FlipAction::FlipAndReplaceOp(new_op) = action {
edit.replace(op_range, new_op);
}
edit.replace(lhs.range(), rhs.text());
@@ -44,14 +32,56 @@ pub(crate) fn flip_binexpr(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assis
ctx.build()
}
+enum FlipAction {
+ // Flip the expression
+ Flip,
+ // Flip the expression and replace the operator with this string
+ FlipAndReplaceOp(&'static str),
+ // Do not flip the expression
+ DontFlip,
+}
+
+impl From<BinOp> for FlipAction {
+ fn from(op_kind: BinOp) -> Self {
+ match op_kind {
+ BinOp::Assignment => FlipAction::DontFlip,
+ BinOp::AddAssign => FlipAction::DontFlip,
+ BinOp::DivAssign => FlipAction::DontFlip,
+ BinOp::MulAssign => FlipAction::DontFlip,
+ BinOp::RemAssign => FlipAction::DontFlip,
+ BinOp::ShrAssign => FlipAction::DontFlip,
+ BinOp::ShlAssign => FlipAction::DontFlip,
+ BinOp::SubAssign => FlipAction::DontFlip,
+ BinOp::BitOrAssign => FlipAction::DontFlip,
+ BinOp::BitAndAssign => FlipAction::DontFlip,
+ BinOp::BitXorAssign => FlipAction::DontFlip,
+ BinOp::GreaterTest => FlipAction::FlipAndReplaceOp("<"),
+ BinOp::GreaterEqualTest => FlipAction::FlipAndReplaceOp("<="),
+ BinOp::LesserTest => FlipAction::FlipAndReplaceOp(">"),
+ BinOp::LesserEqualTest => FlipAction::FlipAndReplaceOp(">="),
+ _ => FlipAction::Flip,
+ }
+ }
+}
+
#[cfg(test)]
mod tests {
use super::*;
- use crate::helpers::{check_assist, check_assist_target};
+ use crate::helpers::{ check_assist, check_assist_target, check_assist_not_applicable };
#[test]
- fn flip_eq_operands_for_simple_stmt() {
+ fn flip_binexpr_target_is_the_op() {
+ check_assist_target(flip_binexpr, "fn f() { let res = 1 ==<|> 2; }", "==")
+ }
+
+ #[test]
+ fn flip_binexpr_not_applicable_for_assignment() {
+ check_assist_not_applicable(flip_binexpr, "fn f() { let mut _x = 1; _x +=<|> 2 }")
+ }
+
+ #[test]
+ fn flip_binexpr_works_for_eq() {
check_assist(
flip_binexpr,
"fn f() { let res = 1 ==<|> 2; }",
@@ -60,16 +90,7 @@ mod tests {
}
#[test]
- fn flip_neq_operands_for_simple_stmt() {
- check_assist(
- flip_binexpr,
- "fn f() { let res = 1 !=<|> 2; }",
- "fn f() { let res = 2 !=<|> 1; }",
- )
- }
-
- #[test]
- fn flip_gt_operands_for_simple_stmt() {
+ fn flip_binexpr_works_for_gt() {
check_assist(
flip_binexpr,
"fn f() { let res = 1 ><|> 2; }",
@@ -78,25 +99,7 @@ mod tests {
}
#[test]
- fn flip_gteq_operands_for_simple_stmt() {
- check_assist(
- flip_binexpr,
- "fn f() { let res = 1 >=<|> 2; }",
- "fn f() { let res = 2 <=<|> 1; }",
- )
- }
-
- #[test]
- fn flip_lt_operands_for_simple_stmt() {
- check_assist(
- flip_binexpr,
- "fn f() { let res = 1 <<|> 2; }",
- "fn f() { let res = 2 ><|> 1; }",
- )
- }
-
- #[test]
- fn flip_lteq_operands_for_simple_stmt() {
+ fn flip_binexpr_works_for_lteq() {
check_assist(
flip_binexpr,
"fn f() { let res = 1 <=<|> 2; }",
@@ -105,7 +108,7 @@ mod tests {
}
#[test]
- fn flip_eq_operands_for_complex_stmt() {
+ fn flip_binexpr_works_for_complex_expr() {
check_assist(
flip_binexpr,
"fn f() { let res = (1 + 1) ==<|> (2 + 2); }",
@@ -114,7 +117,7 @@ mod tests {
}
#[test]
- fn flip_eq_operands_in_match_expr() {
+ fn flip_binexpr_works_inside_match() {
check_assist(
flip_binexpr,
r#"
@@ -135,15 +138,4 @@ mod tests {
"#,
)
}
-
- #[test]
- fn flip_eq_operands_target() {
- check_assist_target(flip_binexpr, "fn f() { let res = 1 ==<|> 2; }", "==")
- }
-
- #[test]
- fn flip_gt_operands_target() {
- check_assist_target(flip_binexpr, "fn f() { let res = 1 ><|> 2; }", ">")
- }
-
}