RFC FS-1005 - Underscore literals

src/fsharp/FSharp.Core/prim-types.fs

@@ -2504,10 +2504,15 @@ namespace Microsoft.FSharp.Core
             let rec parse n acc = if n < l then parse (n+1) (acc *.. 2UL +.. (match s.Chars(n) with '0' -> 0UL | '1' -> 1UL | _ -> formatError())) else acc in          
             parse p 0UL
 
+        let inline removeUnderscores (s:string) =
+            match s with
+            | null -> null
+            | s -> s.Replace("_", "")
+
         let ParseUInt32 (s:string) = 
             if System.Object.ReferenceEquals(s,null) then
                 raise( new System.ArgumentNullException("s") )
-            let s = s.Trim() 
+            let s = removeUnderscores (s.Trim())
             let l = s.Length 
             let mutable p = 0 
             let specifier = get0OXB s &p l 
@@ -2524,7 +2529,7 @@ namespace Microsoft.FSharp.Core
         let ParseInt32 (s:string) = 
             if System.Object.ReferenceEquals(s,null) then
                 raise( new System.ArgumentNullException("s") )
-            let s = s.Trim() 
+            let s = removeUnderscores (s.Trim())
             let l = s.Length 
             let mutable p = 0 
             let sign = getSign32 s &p l 
@@ -2543,7 +2548,7 @@ namespace Microsoft.FSharp.Core
         let ParseInt64 (s:string) = 
             if System.Object.ReferenceEquals(s,null) then
                 raise( new System.ArgumentNullException("s") )
-            let s = s.Trim() 
+            let s = removeUnderscores (s.Trim())
             let l = s.Length 
             let mutable p = 0 
             let sign = getSign64 s &p l 
@@ -2562,7 +2567,7 @@ namespace Microsoft.FSharp.Core
         let ParseUInt64     (s:string) : uint64 = 
             if System.Object.ReferenceEquals(s,null) then
                 raise( new System.ArgumentNullException("s") )
-            let s = s.Trim() 
+            let s = removeUnderscores (s.Trim())
             let l = s.Length 
             let mutable p = 0 
             let specifier = get0OXB s &p l 
@@ -4144,8 +4149,8 @@ namespace Microsoft.FSharp.Core
         let inline ParseUInt16 (s:string)     = (# "conv.ovf.u2" (ParseUInt32 s) : uint16 #)
         let inline ParseIntPtr (s:string)  = (# "conv.ovf.i"  (ParseInt64 s)  : nativeint #)
         let inline ParseUIntPtr (s:string) = (# "conv.ovf.u"  (ParseInt64 s)  : unativeint #)
-        let inline ParseDouble (s:string)   = Double.Parse(s,NumberStyles.Float, CultureInfo.InvariantCulture)
-        let inline ParseSingle (s:string) = Single.Parse(s,NumberStyles.Float, CultureInfo.InvariantCulture)
+        let inline ParseDouble (s:string)   = Double.Parse(removeUnderscores s,NumberStyles.Float, CultureInfo.InvariantCulture)
+        let inline ParseSingle (s:string) = Single.Parse(removeUnderscores s,NumberStyles.Float, CultureInfo.InvariantCulture)
 
 
         [<NoDynamicInvocation>]

src/fsharp/lex.fsl

@@ -82,7 +82,13 @@ let parseOctalUInt64 (s:string) p l =
     let rec parse n acc = if n < l then parse (n+1) (acc * 8UL + (let c = s.[n] in if c >= '0' && c <= '7' then Convert.ToUInt64 c - Convert.ToUInt64 '0' else formatError())) else acc 
     parse p 0UL
 
+let removeUnderscores (s:string) =
+    match s with
+    | null -> null
+    | s -> s.Replace("_", "")
+
 let parseInt32 (s:string) = 
+    let s = removeUnderscores s
     let l = s.Length 
     let mutable p = 0 
     let sign = getSign32 s &p l 
@@ -175,11 +181,12 @@ let anychar = [^'\n''\r']
 let anystring = anychar*
 let op_char = '!'|'$'|'%'|'&'|'*'|'+'|'-'|'.'|'/'|'<'|'='|'>'|'?'|'@'|'^'|'|'|'~'|':'
 let ignored_op_char = '.' | '$' | '?'
+let separator = '_'
 let xinteger = 
-  (  '0' ('x'| 'X')  hex + 
-   | '0' ('o'| 'O')  (['0'-'7']) + 
-   | '0' ('b'| 'B')  (['0'-'1']) + )
-let integer = digit+
+  (  '0' ('x'| 'X')  hex ((hex | separator)* hex)?
+   | '0' ('o'| 'O')  (['0'-'7']) (((['0'-'7']) | separator)* (['0'-'7']))?
+   | '0' ('b'| 'B')  (['0'-'1']) (((['0'-'1']) | separator)* (['0'-'1']))?)
+let integer = digit ((digit | separator)* digit)?
 let int8 = integer 'y'
 let uint8 = (xinteger | integer) 'u' 'y' 
 let int16 = integer 's'
@@ -196,8 +203,8 @@ let xint8 = xinteger 'y'
 let xint16 = xinteger 's'
 let xint = xinteger 
 let xint32 = xinteger 'l'
-let floatp = digit+ '.' digit*  
-let floate = digit+ ('.' digit* )? ('e'| 'E') ['+' '-']? digit+
+let floatp = digit ((digit | separator)* digit)? '.' (digit (digit | separator)*)?  
+let floate = digit ((digit | separator)* digit)? ('.' (digit (digit | separator)*)? )? ('e'| 'E') ['+' '-']? digit (digit | separator)*
 let float = floatp | floate 
 let bignum =  integer ('I'  | 'N' | 'Z' | 'Q' | 'R' | 'G')
 let ieee64 = float

tests/fsharpqa/Source/Conformance/BasicGrammarElements/Constants/BasicConstants.fs

@@ -40,4 +40,60 @@ let boolConst2 = false
 
 let unitConst = ()
 
+let creditCardNumber = 1234_5678_9012_3456L
+if creditCardNumber <> 1234567890123456L then
+    failwith "Wrong parsing"
+
+let socialSecurityNumber = 999_99_9999L
+if socialSecurityNumber <> 999999999L then
+    failwith "Wrong parsing"
+
+let pi =    3.14_15F
+if pi <> 3.1415F then
+    failwith "Wrong parsing"
+
+let hexBytes = 0xFF_EC_DE_5E
+if hexBytes <> 0xFFECDE5E then
+    failwith "Wrong parsing"
+
+let hexWords = 0xCAFE_BABE
+if hexWords <> 0xCAFEBABE then
+    failwith "Wrong parsing"
+
+let maxLong = 0x7fff_ffff_ffff_ffffL
+if maxLong <> 0x7fffffffffffffffL then
+    failwith "Wrong parsing"
+
+let nybbles = 0b0010_0101
+if nybbles <> 0b00100101 then
+    failwith "Wrong parsing"
+
+let bytes = 0b11010010_01101001_10010100_10010010
+if bytes <> 0b11010010011010011001010010010010 then
+    failwith "Wrong parsing"
+
+let x2 = 5_2
+if x2 <> 52 then
+    failwith "Wrong parsing"
+
+let x4 = 5_______2
+if x4 <> 52 then
+    failwith "Wrong parsing"
+
+let x7 = 0x5_2
+if x7 <> 0x52 then
+    failwith "Wrong parsing"
+
+let x9 = 0_52
+if x9 <> 052 then
+    failwith "Wrong parsing"
+
+let x10 = 05_2
+if x10 <> 052 then
+    failwith "Wrong parsing"
+
+let x14 = 0o5_2
+if x14 <> 0o52 then
+    failwith "Wrong parsing"
+
 exit 0