| umNextIndex | Language.PureScript.Errors, Language.PureScript |
| umSkolemMap | Language.PureScript.Errors, Language.PureScript |
| umUnknownMap | Language.PureScript.Errors, Language.PureScript |
| UnableToParseModule | Language.PureScript.Bundle |
| UnacceptableVersion | Language.PureScript.Publish.ErrorsWarnings |
| Unary | Language.PureScript.CoreImp.AST, Language.PureScript.CoreImp |
| UnaryMinus | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnaryOperator | Language.PureScript.CoreImp.AST, Language.PureScript.CoreImp |
| Unconditional | Language.PureScript.CST.Types, Language.PureScript.CST |
| Undefined | Language.PureScript.Environment, Language.PureScript |
| undefined | Language.PureScript.Constants |
| UndefinedTypeVariable | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| unexpectedBinder | Language.PureScript.CST.Utils |
| unexpectedDecl | Language.PureScript.CST.Utils |
| unexpectedExpr | Language.PureScript.CST.Utils |
| unexpectedInstBinding | Language.PureScript.CST.Utils |
| unexpectedLabel | Language.PureScript.CST.Utils |
| unexpectedLetBinding | Language.PureScript.CST.Utils |
| unexpectedName | Language.PureScript.CST.Utils |
| unexpectedQual | Language.PureScript.CST.Utils |
| unexpectedRecordLabeled | Language.PureScript.CST.Utils |
| unexpectedRecordUpdate | Language.PureScript.CST.Utils |
| unexpectedToks | Language.PureScript.CST.Utils |
| Unicode | Language.PureScript.CST.Types, Language.PureScript.CST |
| unifyRows | Language.PureScript.TypeChecker.Unify |
| unifyTypes | Language.PureScript.TypeChecker.Unify |
| unit | Language.PureScript.Constants |
| Unknown | Language.PureScript.TypeChecker.Monad, Language.PureScript.TypeChecker, Language.PureScript |
| UnknownClass | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnknownExport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnknownExportDataConstructor | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnknownImport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnknownImportDataConstructor | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnknownName | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| unknownsInType | Language.PureScript.TypeChecker.Unify |
| unMake | Language.PureScript.Make.Monad, Language.PureScript.Make, Language.PureScript |
| UnnecessaryFFIModule | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| unsafeCheckCurrentModule | Language.PureScript.TypeChecker.Monad, Language.PureScript.TypeChecker, Language.PureScript |
| unsafeCoerce | Language.PureScript.Constants |
| unsafeCoerceFn | Language.PureScript.Constants |
| unsafeIndex | Language.PureScript.Constants |
| unsafePartial | Language.PureScript.Constants |
| unsafePreparePackage | Language.PureScript.Publish |
| unSupplyT | Control.Monad.Supply, Language.PureScript |
| UnsupportedExport | Language.PureScript.Bundle |
| UnsupportedModulePath | Language.PureScript.Bundle |
| unThunk | Language.PureScript.CoreImp.Optimizer.Inliner, Language.PureScript.CoreImp |
| UnusableDeclaration | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedDctorExplicitImport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedDctorImport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedExplicitImport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedFFIImplementations | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedIdent | Language.PureScript.Names, Language.PureScript |
| UnusedImport | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnusedTypeVar | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UnverifiableSuperclassInstance | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| unwindLayout | Language.PureScript.CST.Layout |
| unwrapErrorMessage | Language.PureScript.Errors, Language.PureScript |
| unwrapMatch | Language.PureScript.Ide.Util |
| unwrapParserError | Language.PureScript.CST |
| unwrapTypeDeclaration | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| updateImportedModules | Language.PureScript.Interactive.Types, Language.PureScript.Interactive |
| updateLets | Language.PureScript.Interactive.Types, Language.PureScript.Interactive |
| updateLoadedExterns | Language.PureScript.Interactive.Types, Language.PureScript.Interactive |
| updateReExports | Language.PureScript.Docs.Convert.ReExports |
| UploadedPackage | Language.PureScript.Docs.Types, Language.PureScript.Docs |
| upperToModuleName | Language.PureScript.CST.Utils |
| usagesIdentifier | Language.PureScript.Ide.Command |
| usagesModule | Language.PureScript.Ide.Command |
| usagesNamespace | Language.PureScript.Ide.Command |
| UsagesResult | Language.PureScript.Ide.Types |
| UsedImports | Language.PureScript.Linter.Imports, Language.PureScript.Linter, Language.PureScript |
| usedTypeVariables | Language.PureScript.Types, Language.PureScript |
| UserDefinedWarning | Language.PureScript.AST.Declarations, Language.PureScript.AST, Language.PureScript.Errors, Language.PureScript |
| UserError | |
| 1 (Type/Class) | Language.PureScript.Publish.ErrorsWarnings |
| 2 (Data Constructor) | Language.PureScript.Publish.ErrorsWarnings |
| userError | Language.PureScript.Publish |