TP0201

Error: undefined name

Messages

• undefined name '<x>' (with help use 'None' for none)
• undefined type '<T>'
• module '<m>' has no definition '<x>'
• .NET namespace '<ns>' has no type '<x>' (M21)

Example

From the golden case tests/cases/m13/tp0201_is_none.tpn:

tp0201_is_none.tpn

let a: int? = None
if a is none:
    pass

The compiler reports:

tp0201_is_none.tpn:2:9: error TP0201: undefined name 'none'
  help: use 'None'

The specification lists every code.