Elm.Compiler.Error

type Error

= ParseError ParseError

| DesugarError DesugarError

| TypeError TypeError

| EmitError EmitError

The top-level error type that breaks down into specific error types.

toString : Error -> String

An English description of the error. Feel free to write your own though!

type ParseError

= ModuleNameDoesntMatchFilePath

{ moduleName : ModuleName

, filePath : FilePath

}

| EmptySourceDirectories

| InvalidElmJson Error

| ParseProblem (List (DeadEnd ParseContext ParseProblem))

Errors encountered during parsing from String to AST.

The DeadEnd type in this definition is the one from elm/parser.

type ParseProblem

= ExpectingPortKeyword

| ExpectingEffectKeyword

| ExpectingModuleKeyword

| ExpectingModuleName

| ExpectingExposingKeyword

| ExpectingExposingAllSymbol

| ExpectingExposingListLeftParen

| ExpectingExposingListRightParen

| ExpectingExposingListSeparatorComma

| ExpectingExposedTypeDoublePeriod

| ExpectingVarName

| ExpectingTypeOrConstructorName

| ExposingListCantBeEmpty

| ExpectingImportKeyword

| ExpectingAsKeyword

| ExpectingModuleNameWithoutDots

| ExpectingModuleNamePart

| ExpectingQualifiedVarNameDot

| ExpectingEqualsSign

| ExpectingMinusSign

| ExpectingNumber

| ExpectingSingleQuote

| ExpectingChar

| ExpectingEscapeBackslash

| ExpectingEscapeCharacter Char

| ExpectingUnicodeEscapeLeftBrace

| ExpectingUnicodeEscapeRightBrace

| InvalidUnicodeCodePoint

| ExpectingDoubleQuote

| ExpectingTripleQuote

| ExpectingPlusOperator

| ExpectingConsOperator

| ExpectingConcatOperator

| ExpectingModuleDot

| ExpectingBackslash

| ExpectingRightArrow

| ExpectingLeftParen

| ExpectingRightParen

| ExpectingLeftBracket

| ExpectingRightBracket

| ExpectingListSeparator

| ExpectingTupleSeparator

| ExpectingNotBeginningOfLine

| ExpectingIf

| ExpectingThen

| ExpectingElse

| ExpectingTrue

| ExpectingFalse

| ExpectingLet

| ExpectingIn

| ExpectingUnit

| InvalidNumber

| TriedToParseCharacterStoppingDelimiter

| CompilerBug String

The specific problem the parser encountered. Together with ParseContext and the location info this should give you enough info about what's wrong.

type ParseContext

= InNumber

| InChar

| InCharEscapeMode

| InUnicodeCharacter

| InString

| InDoubleQuoteString

| InTripleQuoteString

| InExpr

| InIf

| InLet

| InLetBinding

| InLambda

| InList

| InUnit

| InTuple

| InTuple3

Context information about what was the parser trying to do at the time of the error. Was it trying to parse an if expression? A list? etc.

type DesugarError

= VarNotInEnvOfModule

{ var :

{ module_ : Maybe ModuleName

, name : VarName

}

, module_ : ModuleName

}

Errors encountered during desugaring from the Frontend AST to Canonical AST.

type TypeError

= TypeMismatch Type Type

| OccursCheckFailed Int Type

Errors encountered during typechecking.

type EmitError

= MainDeclarationNotFound

| ModuleNotFoundForVar

{ module_ : ModuleName

, var : VarName

}

| ModuleNotFoundForType

{ module_ : ModuleName

, type_ : VarName

}

| DeclarationNotFound

{ module_ : ModuleName

, name : VarName

}

Errors encountered during emitting. As you're free to do the emit phase however you want, this is only returned from the helpers in Stage.Emit in the compiler CLI.

TODO: maybe expose Stage.Emit in this library (probably under the name Elm.Compiler.Emit or something similar)

elm-in-elm/compiler/1.0.0

Modules