117 lines
2.9 KiB
Go
117 lines
2.9 KiB
Go
/*
|
|
Serene --- Yet an other Lisp
|
|
|
|
Copyright (c) 2020 Sameer Rahmani <lxsameer@gnu.org>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 2 of the License.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
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
|
|
// 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
|
|
}
|
|
|
|
var UnknownLocation *Location = &Location{knownLocation: false}
|
|
|
|
func (l *Location) GetStart() int {
|
|
return l.start
|
|
}
|
|
|
|
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
|
|
}
|
|
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
|
|
} else {
|
|
l.start = len(*l.source.Buffer) - 1
|
|
}
|
|
}
|
|
|
|
// 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
|
|
} else {
|
|
l.start = 0
|
|
}
|
|
}
|
|
|
|
// 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
|
|
} else {
|
|
l.end = len(*l.source.Buffer) - 1
|
|
}
|
|
}
|
|
|
|
// 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
|
|
} else {
|
|
l.end = 0
|
|
}
|
|
}
|
|
|
|
func (l *Location) IsKnownLocaiton() bool {
|
|
return l.knownLocation
|
|
}
|
|
|
|
// MakeLocation return a pointer to a `Location` in the given source `input`
|
|
// specified by the `start` and `end` boundaries
|
|
func MakeLocation(input *Source, start, end int) *Location {
|
|
return &Location{
|
|
source: *input,
|
|
start: start,
|
|
end: end,
|
|
knownLocation: true,
|
|
}
|
|
}
|
|
|
|
func MakeUnknownLocation() *Location {
|
|
return UnknownLocation
|
|
}
|