feat: Hover for literals showing additional value information

Author: Veykril

crates/hir/src/semantics.rs

@@ -433,7 +433,7 @@ impl<'db> SemanticsImpl<'db> {
                     .find_map(|token| {
                         self.resolve_offset_in_format_args(
                             ast::String::cast(token)?,
-                            offset - quote.end(),
+                            offset.checked_sub(quote.end())?,
                         )
                     })
                     .map(|(range, res)| (range + quote.end(), res));

crates/ide-assists/src/handlers/convert_integer_literal.rs

@@ -20,7 +20,7 @@ pub(crate) fn convert_integer_literal(acc: &mut Assists, ctx: &AssistContext<'_>
         _ => return None,
     };
     let radix = literal.radix();
-    let value = literal.value()?;
+    let value = literal.value().ok()?;
     let suffix = literal.suffix();
 
     let range = literal.syntax().text_range();

crates/ide/src/hover.rs

@@ -15,7 +15,7 @@ use ide_db::{
     FxIndexSet, RootDatabase,
 };
 use itertools::Itertools;
-use syntax::{ast, AstNode, SyntaxKind::*, SyntaxNode, T};
+use syntax::{ast, match_ast, AstNode, AstToken, SyntaxKind::*, SyntaxNode, T};
 
 use crate::{
     doc_links::token_as_doc_comment,
@@ -268,6 +268,64 @@ fn hover_simple(
                 let c = token.parent().and_then(|x| x.parent()).and_then(ast::ClosureExpr::cast)?;
                 render::closure_expr(sema, config, c)
             })
+        })
+        // tokens
+        .or_else(|| {
+            let mut res = HoverResult::default();
+            match_ast! {
+                match original_token {
+                    ast::String(string) => {
+                        res.markup = Markup::fenced_block_text(format_args!("{}", string.value()?));
+                    },
+                    ast::ByteString(string) => {
+                        res.markup = Markup::fenced_block_text(format_args!("{:?}", string.value()?));
+                    },
+                    ast::CString(string) => {
+                        let val = string.value()?;
+                        res.markup = Markup::fenced_block_text(format_args!("{}", std::str::from_utf8(val.as_ref()).ok()?));
+                    },
+                    ast::Char(char) => {
+                        let mut res = HoverResult::default();
+                        res.markup = Markup::fenced_block_text(format_args!("{}", char.value()?));
+                    },
+                    ast::Byte(byte) => {
+                        res.markup = Markup::fenced_block_text(format_args!("0x{:X}", byte.value()?));
+                    },
+                    ast::FloatNumber(num) => {
+                        res.markup = if num.suffix() == Some("f32") {
+                            match num.value_f32() {
+                                Ok(num) => {
+                                    Markup::fenced_block_text(format_args!("{num} (bits: 0x{:X})", num.to_bits()))
+                                },
+                                Err(e) => {
+                                    Markup::fenced_block_text(format_args!("{e}"))
+                                },
+                            }
+                        } else {
+                            match num.value() {
+                                Ok(num) => {
+                                    Markup::fenced_block_text(format_args!("{num} (bits: 0x{:X})", num.to_bits()))
+                                },
+                                Err(e) => {
+                                    Markup::fenced_block_text(format_args!("{e}"))
+                                },
+                            }
+                        };
+                    },
+                    ast::IntNumber(num) => {
+                        res.markup = match num.value() {
+                            Ok(num) => {
+                                Markup::fenced_block_text(format_args!("{num} (0x{num:X}|0x{num:b})"))
+                            },
+                            Err(e) => {
+                                Markup::fenced_block_text(format_args!("{e}"))
+                            },
+                        };
+                    },
+                    _ => return None
+                }
+            }
+            Some(res)
         });
 
     result.map(|mut res: HoverResult| {