maketext.java

A framework written in Java for implementing high-level and dynamic languages, compiling them into J

// Copyright (c) 2003, 2004  Per M.A. Bothner
// This is free software;  for terms and warranty disclaimer see ./COPYING.

package gnu.kawa.xml;
import gnu.mapping.*;
import gnu.lists.*;
import gnu.expr.*;
import gnu.bytecode.*;
import gnu.xml.*;

public class MakeText extends NodeConstructor
{
  public static final MakeText makeText = new MakeText();

  public int numArgs() { return 0x1001; }

  public Object apply1 (Object arg)
  {
    if (arg == null || (arg instanceof Values && ((Values) arg).isEmpty()))
      return arg;
    NodeTree node = new NodeTree();
    TextUtils.textValue(arg, new XMLFilter(node));
    return KText.make(node);
  }

  public static void text$X (Object arg, CallContext ctx)
  {
    if (arg == null || (arg instanceof Values && ((Values) arg).isEmpty()))
      return;
    Consumer saved = ctx.consumer;
    Consumer out = NodeConstructor.pushNodeContext(ctx);
    try
      {
        TextUtils.textValue(arg, out);
      }
    finally
      {
	NodeConstructor.popNodeContext(saved, ctx);
      }
  }

  public void apply (CallContext ctx)
  {
    text$X(ctx.getNextArg(null), ctx);
  }

  public void compile (ApplyExp exp, Compilation comp, Target target)
  {
    // We can't use NodeConstructor's compile method, because a node
    // constructor may return a non-node when given an empty sequence.  Sigh.
    ApplyExp.compile(exp, comp, target);
  }

  public void compileToNode (ApplyExp exp, Compilation comp,
				      ConsumerTarget target)
  {
    // This only gets called via NodeConstructor's compileChild.
    CodeAttr code = comp.getCode();
    Expression[] args = exp.getArgs();
    Expression texp = args[0];
    Variable cvar = target.getConsumerVariable();
    if (texp instanceof QuoteExp)
      {
        Object tval = ((QuoteExp) texp).getValue();
        if (tval instanceof String)
          {
            String str = (String) tval;
            String segments = CodeAttr.calculateSplit(str);
            int numSegments = segments.length();
            ClassType ctype = (ClassType) cvar.getType();
            Method writer = ctype.getMethod("write",
                                            new Type[] { Type.string_type });
            int segStart = 0;
            for (int seg = 0;  seg < numSegments;  seg++)
              {
                code.emitLoad(cvar);
                int segEnd = segStart + (int) segments.charAt(seg);
                code.emitPushString(str.substring(segStart, segEnd));
                code.emitInvoke(writer);
                segStart = segEnd;
              }
            return;
          }
      }
    texp.compile(comp, Target.pushObject);
    code.emitLoad(cvar);
    code.emitInvokeStatic(ClassType.make("gnu.xml.TextUtils")
                          .getDeclaredMethod("textValue", 2));
  }
}