Merge #1604

1604: Fix failing type interference for floating point literal r=matklad a=theotherphil

Fixes #1592

Co-authored-by: Phil Ellison <phil.j.ellison@gmail.com>

Author: bors[bot]

crates/ra_hir/src/ty/tests.rs

@@ -334,6 +334,8 @@ fn infer_literals() {
         infer(r##"
 fn test() {
     5i32;
+    5f32;
+    5f64;
     "hello";
     b"bytes";
     'c';
@@ -351,18 +353,20 @@ fn test() {
 }
 "##),
         @r###"
-[11; 201) '{     ...o"#; }': ()
+[11; 221) '{     ...o"#; }': ()
 [17; 21) '5i32': i32
-[27; 34) '"hello"': &str
-[40; 48) 'b"bytes"': &[u8]
-[54; 57) ''c'': char
-[63; 67) 'b'b'': u8
-[73; 77) '3.14': f64
-[83; 87) '5000': i32
-[93; 98) 'false': bool
-[104; 108) 'true': bool
-[114; 182) 'r#"   ...    "#': &str
-[188; 198) 'br#"yolo"#': &[u8]"###
+[27; 31) '5f32': f32
+[37; 41) '5f64': f64
+[47; 54) '"hello"': &str
+[60; 68) 'b"bytes"': &[u8]
+[74; 77) ''c'': char
+[83; 87) 'b'b'': u8
+[93; 97) '3.14': f64
+[103; 107) '5000': i32
+[113; 118) 'false': bool
+[124; 128) 'true': bool
+[134; 202) 'r#"   ...    "#': &str
+[208; 218) 'br#"yolo"#': &[u8]"###
     );
 }
 

crates/ra_syntax/src/ast/expr_extensions.rs

@@ -239,16 +239,32 @@ impl ast::Literal {
     pub fn kind(&self) -> LiteralKind {
         match self.token().kind() {
             INT_NUMBER => {
-                let allowed_suffix_list = [
+                let int_suffix_list = [
                     "isize", "i128", "i64", "i32", "i16", "i8", "usize", "u128", "u64", "u32",
                     "u16", "u8",
                 ];
+
+                // The lexer treats e.g. `1f64` as an integer literal. See
+                // https://github.com/rust-analyzer/rust-analyzer/issues/1592
+                // and the comments on the linked PR.
+                let float_suffix_list = ["f32", "f64"];
+
                 let text = self.token().text().to_string();
-                let suffix = allowed_suffix_list
+
+                let float_suffix = float_suffix_list
                     .iter()
                     .find(|&s| text.ends_with(s))
                     .map(|&suf| SmolStr::new(suf));
-                LiteralKind::IntNumber { suffix }
+
+                if float_suffix.is_some() {
+                    LiteralKind::FloatNumber { suffix: float_suffix }
+                } else {
+                    let suffix = int_suffix_list
+                        .iter()
+                        .find(|&s| text.ends_with(s))
+                        .map(|&suf| SmolStr::new(suf));
+                    LiteralKind::IntNumber { suffix }
+                }
             }
             FLOAT_NUMBER => {
                 let allowed_suffix_list = ["f64", "f32"];