Package constraint implements parsing and evaluation of build constraint lines.

ArchChar returns "?" and an error.

Import is shorthand for Default.Import.

ImportDir is shorthand for Default.ImportDir.

IsLocalImport reports whether the import path is a local import path, like ".", "..", "./foo", or "../foo".

If AllowBinary is set, Import can be satisfied by a compiled package object without corresponding sources.

If FindOnly is set, Import stops after locating the directory that should contain the sources for a package.

By default, Import searches vendor directories that apply in the given source directory before searching the GOROOT and GOPATH roots.

If ImportComment is set, parse import comments on package statements.

Default is the default Context for builds.

ToolDir is the directory containing build tools.

A Context specifies the supporting context for a build.

A Directive is a Go directive comment (//go:zzz...) found in a source file.

MultiplePackageError describes a directory containing multiple buildable Go source files for multiple packages.

NoGoError is the error used by [Import] to describe a directory containing no buildable Go source files.

A Package describes the Go package found in a directory.

An ImportMode controls the behavior of the Import method.