Document the location.go file

bootstrap/pkg/ast/location.go

@@ -18,10 +18,21 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 package ast
 
+// ILocatable describes something that can be located in a source
+type ILocatable interface {
+	GetLocation() *Location
+}
+
+// Location is used to point to a specific location in the source
+// code (before parse). It can point to a single point or a range.
 type Location struct {
-	start         int
-	end           int
-	source        Source
+	start int
+	end   int
+	// Where this location is pointing too ?
+	source Source
+
+	// Is it a known location or not ? For example builtins doesn't
+	// have a knowen location
 	knownLocation bool
 }
 
@@ -35,6 +46,9 @@ func (l *Location) GetEnd() int {
 	return l.end
 }
 
+// GetSource returns the source of the current location or the "builtin"
+// source to indicate that the source of this location is not known in
+// the context of source code
 func (l *Location) GetSource() *Source {
 	if l.IsKnownLocaiton() {
 		return &l.source
@@ -42,6 +56,8 @@ func (l *Location) GetSource() *Source {
 	return GetBuiltinSource()
 }
 
+// IncStart increases the start pointer of the location by `x` with respect
+// to the boundaries of the source
 func (l *Location) IncStart(x int) {
 	if x+l.start < len(*l.source.Buffer) {
 		l.start += x
@@ -50,6 +66,8 @@ func (l *Location) IncStart(x int) {
 	}
 }
 
+// DecStart decreases the start pointer of the location by `x` with respect
+// to the boundaries of the source
 func (l *Location) DecStart(x int) {
 	if l.start-x >= 0 {
 		l.start -= x
@@ -59,6 +77,8 @@ func (l *Location) DecStart(x int) {
 
 }
 
+// IncEnd increases the end pointer of the location by `x` with respect
+// to the boundaries of the source
 func (l *Location) IncEnd(x int) {
 	if x+l.end < len(*l.source.Buffer) {
 		l.end += x
@@ -68,6 +88,8 @@ func (l *Location) IncEnd(x int) {
 
 }
 
+// DecEnd decreases the end pointer of the location by `x` with respect
+// to the boundaries of the source
 func (l *Location) DecEnd(x int) {
 	if l.end-x >= 0 {
 		l.end -= x
@@ -80,10 +102,8 @@ func (l *Location) IsKnownLocaiton() bool {
 	return l.knownLocation
 }
 
-type ILocatable interface {
-	GetLocation() *Location
-}
-
+// MakeLocation returns a pointer to a `Location` in the given source `input`
+// specified by the `start` and `end` boundaries
 func MakeLocation(input *Source, start int, end int) *Location {
 	return &Location{
 		source:        *input,