func IsGoBuild(line string) bool
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 IsPlusBuild(line string) bool
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 PlusBuildLines(x Expr) ([]string, error)
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.
An AndExpr represents the expression X && Y.
type AndExpr struct {
X, Y Expr
}
func (x *AndExpr) Eval(ok func(tag string) bool) bool
func (x *AndExpr) String() string
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
// contains filtered or unexported methods
}
func Parse(line string) (Expr, error)
Parse parses a single build constraint line of the form “//go:build ...” or “// +build ...” and returns the corresponding boolean expression.
A NotExpr represents the expression !X (the negation of X).
type NotExpr struct {
X Expr
}
func (x *NotExpr) Eval(ok func(tag string) bool) bool
func (x *NotExpr) String() string
An OrExpr represents the expression X || Y.
type OrExpr struct {
X, Y Expr
}
func (x *OrExpr) Eval(ok func(tag string) bool) bool
func (x *OrExpr) String() string
A SyntaxError reports a syntax error in a parsed build expression.
type SyntaxError struct {
Offset int // byte offset in input where error was detected
Err string // description of error
}
func (e *SyntaxError) Error() string
A TagExpr is an Expr for the single tag Tag.
type TagExpr struct {
Tag string // for example, “linux” or “cgo”
}
func (x *TagExpr) Eval(ok func(tag string) bool) bool
func (x *TagExpr) String() string