constraint.Expr
// An Expr is a build tag constraint expression.
// The underlying concrete type is *AndExpr, *OrExpr, *NotExpr, or *TagExpr.
type Expr interface {
// String returns the string form of the expression,
// using the boolean syntax used in //go:build lines.
String() string
// Eval reports whether the expression evaluates to true.
// It calls ok(tag) as needed to find out whether a given build tag
// is satisfied by the current build configuration.
Eval(ok func(tag string) bool) bool
}
constraint.IsGoBuild
// IsGoBuild reports whether the line of text is a “//go:build” constraint.
// It only checks the prefix of the text, not that the expression itself parses.
func IsGoBuild(line string) bool
constraint.IsPlusBuild
// IsPlusBuild reports whether the line of text is a “// +build” constraint.
// It only checks the prefix of the text, not that the expression itself parses.
func IsPlusBuild(line string) bool
constraint.Parse
// Parse parses a single build constraint line of the form “//go:build ...” or “// +build ...”
// and returns the corresponding boolean expression.
func Parse(line string) (Expr, error)
constraint.PlusBuildLines
// PlusBuildLines returns a sequence of “// +build” lines that evaluate to the build expression x.
// If the expression is too complex to convert directly to “// +build” lines, PlusBuildLines returns an error.
func PlusBuildLines(x Expr) ([]string, error)