source: branches/streams/abcl/src/org/armedbear/lisp/scripting/AbclScriptEngine.java

/*
 * AbclScriptEngine.java
 *
 * Copyright (C) 2008 Alessio Stalla
 *
 * 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, or (at your option) any later version.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.armedbear.lisp.scripting;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringWriter;
import java.util.Map;

import javax.script.*;

import org.armedbear.lisp.*;


public class AbclScriptEngine extends AbstractScriptEngine implements Invocable, Compilable {

    private Interpreter interpreter;
    /**
     * The function used to evaluate a string of code.
     */
    private Function evalScript;
    /**
     * The function used to evaluate a Lisp function.
     */
    private Function evalFunction;
    /**
     * The function used to compile Lisp code.
     */
    private Function compileScript;
    /**
     * The function used to evaluate a compiled script.
     */
    Function evalCompiledScript;

    protected AbclScriptEngine() {
  interpreter = Interpreter.getInstance();
  if(interpreter == null) {
      interpreter = Interpreter.createInstance();
  }
  loadFromClasspath("/org/armedbear/lisp/scripting/lisp/packages.lisp");
  loadFromClasspath("/org/armedbear/lisp/scripting/lisp/abcl-script.lisp");
  loadFromClasspath("/org/armedbear/lisp/scripting/lisp/config.lisp");
  if(getClass().getResource("/abcl-script-config.lisp") != null) {
            //TODO: find a way to log this if wanted
            //System.out.println("ABCL: loading configuration from " + getClass().getResource("/abcl-script-config.lisp"));
      loadFromClasspath("/abcl-script-config.lisp");
  }
  ((Function) interpreter.eval("#'abcl-script:configure-abcl")).execute(new JavaObject(this));
        //System.out.println("ABCL: configured");
  evalScript = (Function) this.findSymbol("EVAL-SCRIPT", "ABCL-SCRIPT").getSymbolFunction();
  compileScript = (Function) this.findSymbol("COMPILE-SCRIPT", "ABCL-SCRIPT").getSymbolFunction();
  evalCompiledScript = (Function) this.findSymbol("EVAL-COMPILED-SCRIPT", "ABCL-SCRIPT").getSymbolFunction();
  evalFunction = (Function) this.findSymbol("EVAL-FUNCTION", "ABCL-SCRIPT").getSymbolFunction();
    }
    
    public Interpreter getInterpreter() {
  return interpreter;
    }

    public void setStandardInput(InputStream stream, LispThread thread) {
  thread.setSpecialVariable(Symbol.STANDARD_INPUT, new Stream(Symbol.SYSTEM_STREAM, stream, Symbol.CHARACTER, true));
    }
    
    public void setStandardInput(InputStream stream) {
  setStandardInput(stream, LispThread.currentThread());
    }
    
    public void setInterpreter(Interpreter interpreter) {
  this.interpreter = interpreter;
    }

    public static String escape(String s) {
  StringBuffer b = new StringBuffer();
  int len = s.length();
  char c;
  for (int i = 0; i < len; ++i) {
      c = s.charAt(i);
      if (c == '\\' || c == '"') {
    b.append('\\');
      }
      b.append(c);
  }
  return b.toString();
    }

  public LispObject loadFromClasspath(String classpathResource) {
    InputStream istream = getClass().getResourceAsStream(classpathResource);
    Stream stream = new Stream(Symbol.SYSTEM_STREAM, istream, Symbol.CHARACTER);
    return load(stream);
  }

    public LispObject load(Stream stream) {
        Symbol keyword_verbose = Lisp.internKeyword("VERBOSE");
        Symbol keyword_print = Lisp.internKeyword("PRINT");
        /*
         * load (filespec &key (verbose *load-verbose*) (print *load-print*)
         * (if-does-not-exist t) (external-format :default)
         */
        return Symbol.LOAD.getSymbolFunction().execute
            (new LispObject[] { stream, keyword_verbose, Lisp.NIL,
                                keyword_print, Lisp.NIL,
                                Keyword.IF_DOES_NOT_EXIST, Lisp.T,
                                Keyword.EXTERNAL_FORMAT, Keyword.DEFAULT });
    }

  public LispObject load(String filespec) {
    return load(filespec, true);
  }

  public LispObject load(String filespec, boolean compileIfNecessary) {
    if (isCompiled(filespec) || !compileIfNecessary) {
      return interpreter.eval("(load \"" + escape(filespec) + "\")");
    } else {
      return compileAndLoad(filespec);
    }
  }

  public static boolean isCompiled(String filespec) {
    final String compiledExt = "." + Lisp._COMPILE_FILE_TYPE_.symbolValue().getStringValue();
    if (filespec.endsWith(compiledExt)) {
      return true;
    }
    File source;
    File compiled;
    if (filespec.endsWith(".lisp")) {
      source = new File(filespec);
      compiled = new File(filespec.substring(0, filespec.length() - 5)
          + compiledExt);
    } else {
      source = new File(filespec + ".lisp");
      compiled = new File(filespec + compiledExt);
    }
    if (!source.exists()) {
      throw new IllegalArgumentException("The source file " + filespec + " cannot be found");
    }
    return compiled.exists()
        && compiled.lastModified() >= source.lastModified();
  }

  public LispObject compileFile(String filespec) {
    return interpreter.eval("(compile-file \"" + escape(filespec) + "\")");
  }

  public LispObject compileAndLoad(String filespec) {
    return interpreter.eval("(load (compile-file \"" + escape(filespec) + "\"))");
  }

  public static boolean functionp(LispObject obj) {
    return obj instanceof Function;
  }

  public JavaObject jsetq(String symbol, Object value) {
    Symbol s = findSymbol(symbol);
    JavaObject jo;
    if (value instanceof JavaObject) {
      jo = (JavaObject) value;
    } else {
      jo = new JavaObject(value);
    }
    s.setSymbolValue(jo);
    return jo;
  }

  public Symbol findSymbol(String name, String pkg) {
    Cons values = (Cons) (interpreter.eval("(cl:multiple-value-list (find-symbol (symbol-name '#:"
                         + escape(name) + ")" + (pkg == null ? "" : " :" + escape(pkg))
                         + "))"));
    if(values.cadr() == Lisp.NIL) {
      return null;
    } else {
      return (Symbol) values.car();
    }
  }

  public Symbol findSymbol(String name) {
    //Known bug: doesn't handle escaped ':' e.g. |a:b|
    int i = name.indexOf(':');
    if(i < 0) { 
      return findSymbol(name, null);
    } else {
        if((i < name.length() - 1) && (name.charAt(i + 1) == ':')) {
      return findSymbol(name.substring(i + 2), name.substring(0, i));
        } else {
      return findSymbol(name.substring(i + 1), name.substring(0, i));
        }
    }
  }
  
  public Function findFunction(String name) {
    return (Function) interpreter.eval("#'" + name);
  }

  @Override
  public Bindings createBindings() {
    return new SimpleBindings();
  }

    private static LispObject makeBindings(Bindings bindings) {
    if (bindings == null || bindings.size() == 0) {
      return Lisp.NIL;
    }
    LispObject[] argList = new LispObject[bindings.size()];
    int i = 0;
    for (Map.Entry<String, Object> entry : bindings.entrySet()) {
      argList[i++] = Symbol.CONS.execute(new SimpleString(entry.getKey()),
                 JavaObject.getInstance(entry.getValue(), true));
    }
    return Symbol.LIST.getSymbolFunction().execute(argList);
  }

    Object eval(Function evaluator, LispObject code, ScriptContext ctx) throws ScriptException {
  LispObject retVal = null;
      Stream outStream = new Stream(Symbol.SYSTEM_STREAM, ctx.getWriter());
      Stream inStream  = new Stream(Symbol.SYSTEM_STREAM, ctx.getReader());
      retVal = evaluator.execute(makeBindings(ctx.getBindings(ScriptContext.GLOBAL_SCOPE)),
               makeBindings(ctx.getBindings(ScriptContext.ENGINE_SCOPE)),
               inStream, outStream,
               code, new JavaObject(ctx));
      return retVal.javaInstance();
    }
  
  @Override
  public Object eval(String code, ScriptContext ctx) throws ScriptException {
    return eval(evalScript, new SimpleString(code), ctx);
  }

  private static String toString(Reader reader) throws IOException {
    StringWriter w = new StringWriter();
    int i;
    i = reader.read();
    while (i != -1) {
      w.write(i);
      i = reader.read();
    }
    return w.toString();
  }
  
  @Override
  public Object eval(Reader code, ScriptContext ctx) throws ScriptException {
    try {
      return eval(toString(code), ctx);
    } catch (IOException e) {
      return new ScriptException(e);
    }
  }

  @Override
  public ScriptEngineFactory getFactory() {
    return new AbclScriptEngineFactory();
  }
  
  public <T> T getInterface(Class<T> clasz) {
    try {
      return getInterface(eval("(cl:find-package '#:ABCL-SCRIPT-USER)"), clasz);
    } catch (ScriptException e) {
      throw new Error(e);
    }
  }

  @SuppressWarnings("unchecked")
  public <T> T getInterface(Object thiz, Class<T> clasz) {
      Symbol s = findSymbol("jmake-proxy", "JAVA");
      JavaObject iface = new JavaObject(clasz);
      return (T) ((JavaObject) s.execute(iface, (LispObject) thiz)).javaInstance();
  }
  
    public Object invokeFunction(String name, Object... args) throws ScriptException, NoSuchMethodException {
  Symbol s;
  if(name.indexOf(':') >= 0) {
      s = findSymbol(name);
  } else {
      s = findSymbol(name, "ABCL-SCRIPT-USER");
  }
  if(s != null) {
      LispObject f = s.getSymbolFunction();
      if(f != null && f instanceof Function) {
    LispObject functionAndArgs = Lisp.NIL.push(f);
    for(int i = 0; i < args.length; ++i) {
        functionAndArgs = functionAndArgs.push(JavaObject.getInstance(args[i], true));
    }
    functionAndArgs = functionAndArgs.reverse();
    return eval(evalFunction, functionAndArgs, getContext());
      } else {
    throw new NoSuchMethodException(name);
      }
  } else {
      throw new NoSuchMethodException(name);
  }
    }

    public Object invokeMethod(Object thiz, String name, Object... args) throws ScriptException, NoSuchMethodException {
  throw new UnsupportedOperationException("Common Lisp does not have methods in the Java sense. Use invokeFunction instead.");
    }

    public class AbclCompiledScript extends CompiledScript {

  private LispObject function;
  
  public AbclCompiledScript(LispObject function) {
      this.function = function;
  }
  
  @Override
  public Object eval(ScriptContext context) throws ScriptException {
      return AbclScriptEngine.this.eval(evalCompiledScript, function, context);
  }
  
  @Override
  public ScriptEngine getEngine() {
      return AbclScriptEngine.this;
  }
  
    }

  
  @Override
  public CompiledScript compile(String script) throws ScriptException {
    try {
        Function f = (Function) compileScript.execute(new SimpleString(script));
        return new AbclCompiledScript(f);
    } catch(ClassCastException e) {
      throw new ScriptException(e);
    }
  }

  @Override
  public CompiledScript compile(Reader script) throws ScriptException {
    try {
      return compile(toString(script));
    } catch (IOException e) {
      throw new ScriptException(e);
    }
  }

}