Add parser tests for constants

parser/fspl/parser_test.go

@@ -11,7 +11,11 @@ testString (test,
 - Union: (| Int F64 *:U8 (. x:Int y:Int))
 - Array: 16:16:16:Int
 - StructArray: 31:24:340920:(. x:Int y:Int)
-- String: *:U8`,
+- String: *:U8
++ FileDescriptor: I32
+| stdin  0
+| stdout 1
+| stderr 2`,
 // input
 `
 BasicInt: Int
@@ -29,6 +33,10 @@ StructArray: 31:24:340920:(.
 	x:Int
 	y:Int)
 String: *:U8
++ FileDescriptor: I32
+| stdin  0
+| stdout 1
+| stderr 2
 `)
 }
 
@@ -75,7 +83,8 @@ testString (test,
 - [for s:String] = for i:Index e:Byte in str if [> i 3] then [break e]
 - [for s:String] = for e:Byte in s [break e]
 - [matchToInt u:(| Int F64)]:Int = match u | u:Int u | u:F64 [~ Int u] * 0
-- [switch x:Int] = switch x | 0 5 | 1 4 | 2 3 * 0`,
+- [switch x:Int] = switch x | 0 5 | 1 4 | 2 3 * 0
+- [whatFile fd:FD]:String = switch fd | FD.stdin 'in' | FD.stdout 'out' * '?'`,
 // input
 `
 [var]          = sdfdf
@@ -134,6 +143,10 @@ testString (test,
 	| 1 4
 	| 2 3
 	* 0
+[whatFile fd:FD]:String = switch fd
+	| FD.stdin  'in'
+	| FD.stdout 'out'
+	* '?'
 `)
 }