Gopher2600/debugger/script/rescribe.go
2020-01-05 18:58:43 +00:00

104 lines
2.9 KiB
Go

// This file is part of Gopher2600.
//
// Gopher2600 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 3 of the License, or
// (at your option) any later version.
//
// Gopher2600 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 Gopher2600. If not, see <https://www.gnu.org/licenses/>.
//
// *** NOTE: all historical versions of this file, as found in any
// git repository, are also covered by the licence, even when this
// notice is not present ***
package script
import (
"gopher2600/debugger/terminal"
"gopher2600/errors"
"gopher2600/gui"
"io/ioutil"
"os"
"strings"
)
const commentLine = "#"
// check if line is prepended with commentLine (ignoring leading spaces)
func isOutputLine(line string) bool {
return strings.HasPrefix(strings.TrimSpace(line), commentLine)
}
// Rescribe represents an previously scribed script. The type implements the
// terminal.UserRead interface.
type Rescribe struct {
scriptFile string
lines []string
lineCt int
}
// RescribeScript is the preferred method of initialisation for the Rescribe
// type
func RescribeScript(scriptfile string) (*Rescribe, error) {
// open script and defer closing
f, err := os.Open(scriptfile)
if err != nil {
return nil, errors.New(errors.ScriptFileUnavailable, err)
}
defer func() {
_ = f.Close()
}()
buffer, err := ioutil.ReadAll(f)
if err != nil {
return nil, errors.New(errors.ScriptFileError, err)
}
scr := &Rescribe{scriptFile: scriptfile}
// convert buffer to an array of lines
scr.lines = strings.Split(string(buffer), "\n")
// pass over any lines starting with the commentLine, leaving the line
// counter at the first input line.
for isOutputLine(scr.lines[scr.lineCt]) {
scr.lineCt++
if scr.lineCt > len(scr.lines)-1 {
// we've reached the end of the file but that's okay. subsequent
// calls to UserRead() will result in an error, as would be
// expected.
return scr, nil
}
}
return scr, nil
}
// IsInteractive implements the terminal.UserRead interface
func (scr *Rescribe) IsInteractive() bool {
return false
}
// TermRead implements the terminal.UserRead interface
func (scr *Rescribe) TermRead(buffer []byte, _ terminal.Prompt, _ chan gui.Event, _ func(gui.Event) error) (int, error) {
if scr.lineCt > len(scr.lines)-1 {
return -1, errors.New(errors.ScriptEnd, scr.scriptFile)
}
command := len(scr.lines[scr.lineCt]) + 1
copy(buffer, []byte(scr.lines[scr.lineCt]))
scr.lineCt++
// pass over any lines starting with the commentLine
for scr.lineCt < len(scr.lines) && isOutputLine(scr.lines[scr.lineCt]) {
scr.lineCt++
}
return command, nil
}