| package jp.ac.kobe_u.cs.prolog.builtin; |
| import jp.ac.kobe_u.cs.prolog.lang.*; |
| import java.io.*; |
| /** |
| <code>open/4</code><br> |
| @author Mutsunori Banbara (banbara@kobe-u.ac.jp) |
| @author Naoyuki Tamura (tamura@kobe-u.ac.jp) |
| @version 1.0 |
| */ |
| public class PRED_open_4 extends Predicate { |
| public static SymbolTerm SYM_NIL = SymbolTerm.makeSymbol("[]"); |
| public static SymbolTerm SYM_TEXT = SymbolTerm.makeSymbol("text"); |
| // public static SymbolTerm SYM_BINARY = SymbolTerm.makeSymbol("binary"); |
| public static SymbolTerm SYM_READ = SymbolTerm.makeSymbol("read"); |
| public static SymbolTerm SYM_WRITE = SymbolTerm.makeSymbol("write"); |
| public static SymbolTerm SYM_APPEND = SymbolTerm.makeSymbol("append"); |
| public static SymbolTerm SYM_INPUT = SymbolTerm.makeSymbol("input"); |
| public static SymbolTerm SYM_OUTPUT = SymbolTerm.makeSymbol("output"); |
| public static SymbolTerm SYM_ALIAS_1 = SymbolTerm.makeSymbol("alias", 1); |
| public static SymbolTerm SYM_MODE_1 = SymbolTerm.makeSymbol("mode", 1); |
| public static SymbolTerm SYM_TYPE_1 = SymbolTerm.makeSymbol("type", 1); |
| public static SymbolTerm SYM_FILE_NAME_1 = SymbolTerm.makeSymbol("file_name", 1); |
| |
| public Term arg1, arg2, arg3, arg4; |
| |
| public PRED_open_4(Term a1, Term a2, Term a3, Term a4, Predicate cont) { |
| arg1 = a1; |
| arg2 = a2; |
| arg3 = a3; |
| arg4 = a4; |
| this.cont = cont; |
| } |
| |
| public PRED_open_4(){} |
| |
| public void setArgument(Term[] args, Predicate cont) { |
| arg1 = args[0]; |
| arg2 = args[1]; |
| arg3 = args[2]; |
| arg4 = args[3]; |
| this.cont = cont; |
| } |
| |
| public int arity() { return 4; } |
| |
| public String toString() { |
| return "open(" + arg1 + "," + arg2 + "," + arg3 + "," + arg4 + ")"; |
| } |
| |
| public Predicate exec(Prolog engine) { |
| engine.setB0(); |
| File file; |
| Term alias = null; |
| Term opts = SYM_NIL; |
| JavaObjectTerm streamObject; |
| Term a1, a2, a3, a4; |
| a1 = arg1; |
| a2 = arg2; |
| a3 = arg3; |
| a4 = arg4; |
| |
| // stream |
| a3 = a3.dereference(); |
| if (! a3.isVariable()) |
| throw new IllegalTypeException(this, 3, "variable", a3); |
| // source_sink |
| a1 = a1.dereference(); |
| if (a1.isVariable()) |
| throw new PInstantiationException(this, 1); |
| if (! a1.isSymbol()) |
| throw new IllegalDomainException(this, 1, "source_sink", a1); |
| file = new File(((SymbolTerm) a1).name()); |
| // io_mode |
| a2 = a2.dereference(); |
| if (a2.isVariable()) |
| throw new PInstantiationException(this, 2); |
| if (! a2.isSymbol()) |
| throw new IllegalTypeException(this, 2, "atom", a2); |
| try { |
| if (a2.equals(SYM_READ)) { |
| if (! file.exists()) |
| throw new ExistenceException(this, 1, "source_sink", a1, ""); |
| PushbackReader in = |
| new PushbackReader(new BufferedReader(new FileReader(file)), engine.PUSHBACK_SIZE); |
| streamObject = new JavaObjectTerm(in); |
| opts = new ListTerm(SYM_INPUT, opts); |
| } else if (a2.equals(SYM_WRITE)) { |
| PrintWriter out = |
| new PrintWriter(new BufferedWriter(new FileWriter(file, false))); |
| streamObject = new JavaObjectTerm(out); |
| opts = new ListTerm(SYM_OUTPUT, opts); |
| } else if (a2.equals(SYM_APPEND)) { |
| PrintWriter out = |
| new PrintWriter(new BufferedWriter(new FileWriter(file, true))); |
| streamObject = new JavaObjectTerm(out); |
| opts = new ListTerm(SYM_OUTPUT, opts); |
| } else { |
| throw new IllegalDomainException(this, 2, "io_mode", a2); |
| } |
| } catch (IOException e) { |
| throw new PermissionException(this, "open", "source_sink", a1, ""); |
| } |
| if (engine.getStreamManager().containsKey(streamObject)) |
| throw new InternalException("stream object is duplicated"); |
| // stream_options |
| a4 = a4.dereference(); |
| Term tmp = a4; |
| while (! tmp.isNil()) { |
| if (tmp.isVariable()) |
| throw new PInstantiationException(this, 4); |
| if (! tmp.isList()) |
| throw new IllegalTypeException(this, 4, "list", a4); |
| Term car = ((ListTerm) tmp).car().dereference(); |
| if (car.isVariable()) |
| throw new PInstantiationException(this, 4); |
| if (car.isStructure()) { |
| SymbolTerm functor = ((StructureTerm) car).functor(); |
| Term[] args = ((StructureTerm) car).args(); |
| if (functor.equals(SYM_ALIAS_1)) { |
| alias = args[0].dereference(); |
| if (! alias.isSymbol()) |
| throw new IllegalDomainException(this, 4, "stream_option", car); |
| if (engine.getStreamManager().containsKey(alias)) |
| throw new PermissionException(this, "open", "source_sink", car, ""); |
| } else { |
| throw new IllegalDomainException(this, 4, "stream_option", car); |
| } |
| } else { |
| throw new IllegalDomainException(this, 4, "stream_option", car); |
| } |
| tmp = ((ListTerm) tmp).cdr().dereference(); |
| } |
| Term[] args1 = {SYM_TEXT}; |
| Term[] args2 = {a2}; |
| Term[] args3 = {SymbolTerm.makeSymbol(file.getAbsolutePath())}; |
| opts = new ListTerm(new StructureTerm(SYM_TYPE_1, args1), opts); |
| opts = new ListTerm(new StructureTerm(SYM_MODE_1, args2), opts); |
| opts = new ListTerm(new StructureTerm(SYM_FILE_NAME_1, args3), opts); |
| if (alias != null) { |
| engine.getStreamManager().put(alias, streamObject); |
| Term[] as = {alias}; |
| opts = new ListTerm(new StructureTerm(SYM_ALIAS_1, as), opts); |
| } |
| ((VariableTerm)a3).bind(streamObject, engine.trail); |
| engine.getStreamManager().put(streamObject, opts); |
| return cont; |
| } |
| } |
| |
| |
| |