Errors

Errors defines a format for describing human readable error messages, that can also quote some source, in order to identify the source of an error.

Errors and Error Messages

type alias Error =

{ code : Int

, title : String

, body : String

, args : Dict String String

, sources : List SourceLines

}

Common Error definition, for reporting errors to users.

This contains all the information needed to build a nice human readable error message. The body is written in mdgriffith/elm-markup and looks like this:

There was an error in your code.


|> Source
    label = Look, here it is:
    pos = 0


Please fix it. This is not a helpful error message.

type alias ErrorMessage =

{ title : String

, body : String

}

Defines the content of an error message.

The body is written in mdgriffith/elm-markup and looks like this:

There was an error in your code.


|> Source
    label = Look, here it is:
    pos = 0


Please fix it. This is not a helpful error message.

An ErrorMessage will be combined with some lines of source code that it can quote, in order to produce an Error.

Instantiating Error Messages into Errors

type alias ErrorBuilder pos err =

(pos -> SourceLines) -> err -> Error

Defines the signature of a function for building Errors. This keeps the positional information variable, but requires a function to turn source code positions into quotes lines of source code.

Typically implementation of this will use the lookupError functions and an error catalogue of error messages.

lookupError :

Dict Int ErrorMessage

-> Int

-> Dict String String

-> List SourceLines

-> Error

Looks up an ErrorMessage in an error catalogue and fills in its quoted source code and parameters to produce an Error.

lookupErrorNoArgs : Dict Int ErrorMessage -> Int -> List SourceLines -> Error

Looks up an ErrorMessage in an error catalogue and fills in its quoted source code to produce an Error.

Error formatting and printing

document : Renderer content -> Error -> Document (List content)

elm-markup Document describing the format of an error.

asConsoleString : Error -> String

Renders an Error as a String for printing to the console with ANSI colours.

htmlRenderer : Renderer (Html msg)

Renders an Error as HTML.

the-sett/salix/4.0.3

Errors

Errors and Error Messages

Instantiating Error Messages into Errors

Error formatting and printing

Modules