kubernetes/vendor/sigs.k8s.io/kustomize/api/filters/refvar/expand.go

const operator …

const referenceOpener …

const referenceCloser …

// syntaxWrap returns the input string wrapped by the expansion syntax.
func syntaxWrap(input string) string { … }

type MappingFunc …

// MakePrimitiveReplacer returns a MappingFunc that uses a map to do
// replacements, and a histogram to count map hits.
//
// Func behavior:
//
// If the input key is NOT found in the map, the key is wrapped up as
// as a variable declaration string and returned, e.g. key FOO becomes $(FOO).
// This string is presumably put back where it was found, and might get replaced
// later.
//
// If the key is found in the map, the value is returned if it is a primitive
// type (string, bool, number), and the hit is counted.
//
// If it's not a primitive type (e.g. a map, struct, func, etc.) then this
// function doesn't know what to do with it and it returns the key wrapped up
// again as if it had not been replaced.  This should probably be an error.
func MakePrimitiveReplacer(
	counts map[string]int, someMap map[string]interface{ … }

// DoReplacements replaces variable references in the input string
// using the mapping function.
func DoReplacements(input string, mapping MappingFunc) interface{ … }

// tryReadVariableName attempts to read a variable name from the input
// string and returns the content read from the input, whether that content
// represents a variable name to perform mapping on, and the number of bytes
// consumed in the input string.
//
// The input string is assumed not to contain the initial operator.
func tryReadVariableName(input string) (string, bool, int) { … }