| package com.googlecode.prolog_cafe.builtin; |
| import com.googlecode.prolog_cafe.exceptions.ExistenceException; |
| import com.googlecode.prolog_cafe.exceptions.IllegalDomainException; |
| import com.googlecode.prolog_cafe.exceptions.IllegalTypeException; |
| import com.googlecode.prolog_cafe.exceptions.InternalException; |
| import com.googlecode.prolog_cafe.exceptions.PInstantiationException; |
| import com.googlecode.prolog_cafe.exceptions.PermissionException; |
| import com.googlecode.prolog_cafe.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.P4 { |
| private static final SymbolTerm SYM_TEXT = SymbolTerm.intern("text"); |
| private static final SymbolTerm SYM_READ = SymbolTerm.intern("read"); |
| private static final SymbolTerm SYM_WRITE = SymbolTerm.intern("write"); |
| private static final SymbolTerm SYM_APPEND = SymbolTerm.intern("append"); |
| private static final SymbolTerm SYM_INPUT = SymbolTerm.intern("input"); |
| private static final SymbolTerm SYM_OUTPUT = SymbolTerm.intern("output"); |
| private static final SymbolTerm SYM_ALIAS_1 = SymbolTerm.intern("alias", 1); |
| private static final SymbolTerm SYM_MODE_1 = SymbolTerm.intern("mode", 1); |
| private static final SymbolTerm SYM_TYPE_1 = SymbolTerm.intern("type", 1); |
| private static final SymbolTerm SYM_FILE_NAME_1 = SymbolTerm.intern("file_name", 1); |
| |
| public PRED_open_4(Term a1, Term a2, Term a3, Term a4, Operation cont) { |
| arg1 = a1; |
| arg2 = a2; |
| arg3 = a3; |
| arg4 = a4; |
| this.cont = cont; |
| } |
| |
| public Operation exec(Prolog engine) { |
| engine.requireFeature(Prolog.Feature.IO, this, arg1); |
| engine.setB0(); |
| File file; |
| Term alias = null; |
| Term opts = Prolog.Nil; |
| JavaObjectTerm streamObject; |
| Term a1, a2, a3, a4; |
| a1 = arg1; |
| a2 = arg2; |
| a3 = arg3; |
| a4 = arg4; |
| |
| // stream |
| a3 = a3.dereference(); |
| if (! (a3 instanceof VariableTerm)) |
| throw new IllegalTypeException(this, 3, "variable", a3); |
| // source_sink |
| a1 = a1.dereference(); |
| if (a1 instanceof VariableTerm) |
| throw new PInstantiationException(this, 1); |
| if (! (a1 instanceof SymbolTerm)) |
| throw new IllegalDomainException(this, 1, "source_sink", a1); |
| file = new File(((SymbolTerm) a1).name()); |
| // io_mode |
| a2 = a2.dereference(); |
| if (a2 instanceof VariableTerm) |
| throw new PInstantiationException(this, 2); |
| if (! (a2 instanceof SymbolTerm)) |
| 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 (! Prolog.Nil.equals(tmp)) { |
| if (tmp instanceof VariableTerm) |
| throw new PInstantiationException(this, 4); |
| if (! (tmp instanceof ListTerm)) |
| throw new IllegalTypeException(this, 4, "list", a4); |
| Term car = ((ListTerm) tmp).car().dereference(); |
| if (car instanceof VariableTerm) |
| throw new PInstantiationException(this, 4); |
| if (car instanceof StructureTerm) { |
| SymbolTerm functor = ((StructureTerm) car).functor(); |
| Term[] args = ((StructureTerm) car).args(); |
| if (functor.equals(SYM_ALIAS_1)) { |
| alias = args[0].dereference(); |
| if (! (alias instanceof SymbolTerm)) |
| 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(); |
| } |
| opts = new ListTerm(new StructureTerm(SYM_TYPE_1, SYM_TEXT), opts); |
| opts = new ListTerm(new StructureTerm(SYM_MODE_1, a2), opts); |
| opts = new ListTerm(new StructureTerm(SYM_FILE_NAME_1, SymbolTerm.create(file.getAbsolutePath())), opts); |
| if (alias != null) { |
| engine.getStreamManager().put(alias, streamObject); |
| opts = new ListTerm(new StructureTerm(SYM_ALIAS_1, alias), opts); |
| } |
| ((VariableTerm)a3).bind(streamObject, engine.trail); |
| engine.getStreamManager().put(streamObject, opts); |
| return cont; |
| } |
| } |
| |
| |
| |