juno-compiler/src/JunoUnparse.i3

 Copyright (C) 1992, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Last modified on Thu Mar 28 14:47:43 PST 1996 by heydon                   
      modified on Tue Aug 31 21:59:50 PST 1993 by gnelson                  


INTERFACE JunoUnparse;

 Provides procedures for unparsing Juno modules, top-level module blocks,
   commands, and expressions. A number of valid tokens may be specified so
   that incorrect programs may be unparsed up to the point of failure.


   Each of these procedures unparses some subtype of JunoAST.T to a writer
   wr at an initial indentation level of indent to a maximum width of
   width characters. Those procedures taking a tokens argument unparse at
   most the specified number of tokens. In all cases, the writer is left
   positioned just after the last character of the last token written; no
   new-line is appended.


   Those procedures that take a private argument will supress the unparsing
   of public predicate, function, and procedure bodies when private = FALSE.


   For each of the unparsing procedures, a TRUE value for debug will cause
   AST's to be printed out with debugging information. In particular, variable
   indices will be added. 


IMPORT JunoAST, Wr, Formatter, Real AS R;

CONST Prec: CARDINAL = R.MaxSignifDigits - 1;

PROCEDURE Block(wr: Wr.T; ast: JunoAST.Block; tokens: CARDINAL;
  indent: CARDINAL := 0; width: CARDINAL := 75; prec := Prec;
  debug := FALSE; private := TRUE) RAISES {Wr.Failure};

PROCEDURE Cmd(wr: Wr.T; ast: JunoAST.Cmd; tokens: CARDINAL;
  indent: CARDINAL := 0; width: CARDINAL := 75; prec := Prec; debug := FALSE)
  RAISES {Wr.Failure};

PROCEDURE Expr(wr: Wr.T; ast: JunoAST.Expr; tokens: CARDINAL;
  indent: CARDINAL := 0; width: CARDINAL := 75; prec := Prec; debug := FALSE)
  RAISES {Wr.Failure};

PROCEDURE P(wr: Wr.T; ast: JunoAST.T; indent: CARDINAL := 0;
  width: CARDINAL := 75; prec := Prec; debug := FALSE; private := TRUE;
  errast: JunoAST.T := NIL) RAISES {Wr.Failure};

 Procedure P will unparse any kind of AST, so long as it does not
   contain a parse error. If an ``error AST'' is supplied, the characters
   \001 and \002 will be placed in the output stream to delimit
   the extent of the error AST. 

PROCEDURE ToFmt(fmt: Formatter.T; ast: JunoAST.T; indent: CARDINAL := 0;
  prec := Prec; debug := FALSE; private := TRUE; errast: JunoAST.T := NIL)
  RAISES {Wr.Failure};

 Like P above, but the output is written to the formatter f. The
   formatter is flushed but not closed at the end of this procedure. 

PROCEDURE Debug(r: REFANY);

 Unparse the JunoAST.T or JunoValue.T r to stderr. Real numbers are
   unparsed to Prec precision. 

END JunoUnparse.