Package java_cup

Class emit

  • public class emit
extends java.lang.Object
    This class handles emitting generated code for the resulting parser. The various parse tables must be constructed, etc. before calling any routines in this class.

    Three classes are produced by this code:

    symbol constant class
    this contains constant declarations for each terminal (and optionally each non-terminal).
    action class
    this non-public class contains code to invoke all the user actions that were embedded in the parser specification.
    parser class
    the specialized parser class consisting primarily of some user supplied general and initialization code, and the parse tables.

    Three parse tables are created as part of the parser class:

    production table
    lists the LHS non terminal number, and the length of the RHS of each production.
    action table
    for each state of the parse machine, gives the action to be taken (shift, reduce, or error) under each lookahead symbol.
    reduce-goto table
    when a reduce on a given production is taken, the parse stack is popped back a number of elements corresponding to the RHS of the production. This reveals a prior state, which we transition out of under the LHS non terminal symbol for the production (as if we had seen the LHS symbol rather than all the symbols matching the RHS). This table is indexed by non terminal numbers and indicates how to make these transitions.

    In addition to the method interface, this class maintains a series of public global variables and flags indicating how misc. parts of the code and other output is to be produced, and counting things such as number of conflicts detected (see the source code and public variables below for more details).

    This class is "static" (contains only static data and methods).

    Version:
    last update: 11/25/95
    Author:
    Scott Hudson
    See Also:
    java_cup.main

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static boolean _genericlabels  
      protected static boolean _locations  
      protected static boolean _lr_values  
      protected static boolean _xmlactions  
      static java.lang.String action_code
      User declarations for direct inclusion in user action class.
      static long action_code_time
      Time to produce action code class.
      static long action_table_time
      Time to produce the action table.
      static java.lang.String class_type_argument
      TUM changes; proposed by Henning Niss 20050628: Type arguments for class declaration
      static long goto_table_time
      Time to produce the reduce-goto table.
      static java.util.Stack import_list
      List of imports (Strings containing class names) to go with actions.
      static java.lang.String init_code
      User code for user_init() which is called during parser initialization.
      static int not_reduced
      Count of the number on non-reduced productions found.
      static boolean nowarn
      Do we skip warnings?
      static int num_conflicts
      Number of conflict found while building tables.
      static java.lang.String package_name
      Package that the resulting code goes into (null is used for unnamed).
      static java.lang.String parser_class_name
      Name of the generated parser class.
      static java.lang.String parser_code
      User declarations for direct inclusion in parser class.
      static long parser_time
      Time to produce parser class.
      static java.lang.String prefix
      The prefix placed on names that pollute someone else's name space.
      static long production_table_time
      Time to produce the production table.
      static java.lang.String scan_code
      User code for scan() which is called to get the next Symbol.
      static production start_production
      The start production of the grammar.
      static java.lang.String symbol_const_class_name
      Name of the generated class for symbol constants.
      static long symbols_time
      Time to produce symbol constant class.
      static int unused_non_term
      Count of unused non terminals.
      static int unused_term
      Count of unused terminals.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void clear()  
      protected static void do_action_table​(java.io.PrintWriter out, parse_action_table act_tab, boolean compact_reduces)
      Emit the action table.
      protected static int do_escaped​(java.io.PrintWriter out, char c)  
      protected static int do_newline​(java.io.PrintWriter out, int nchar, int nbytes)  
      protected static void do_reduce_table​(java.io.PrintWriter out, parse_reduce_table red_tab)
      Emit the reduce-goto table.
      protected static void do_table_as_string​(java.io.PrintWriter out, short[][] sa)  
      protected static void emit_action_code​(java.io.PrintWriter out, production start_prod)
      Emit code for the non-public class holding the actual action code.
      protected static void emit_package​(java.io.PrintWriter out)
      Emit a package spec if the user wants one.
      protected static void emit_production_table​(java.io.PrintWriter out)
      Emit the production table.
      protected static void emit_xmlaction_code​(java.io.PrintWriter out, production start_prod)
      Emit code for generic XML parsetree output.
      static boolean locations()  
      static boolean lr_values()
      whether or not to emit code for left and right values
      static void parser​(java.io.PrintWriter out, parse_action_table action_table, parse_reduce_table reduce_table, int start_st, production start_prod, boolean compact_reduces, boolean suppress_scanner)
      Emit the parser subclass with embedded tables.
      protected static java.lang.String pre​(java.lang.String str)
      Build a string with the standard prefix.
      protected static void set_genericlabels​(boolean b)  
      protected static void set_locations​(boolean b)  
      protected static void set_lr_values​(boolean b)  
      protected static void set_xmlactions​(boolean b)  
      static void symbols​(java.io.PrintWriter out, boolean emit_non_terms, boolean sym_interface)
      Emit code for the symbol constant class, optionally including non terms, if they have been requested.
      protected static java.lang.String typeArgument()
      TUM changes; proposed by Henning Niss 20050628 Build a string with the specified type arguments, if present, otherwise an empty string.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • prefix

        public static java.lang.String prefix
        The prefix placed on names that pollute someone else's name space.

      • package_name

        public static java.lang.String package_name
        Package that the resulting code goes into (null is used for unnamed).

      • symbol_const_class_name

        public static java.lang.String symbol_const_class_name
        Name of the generated class for symbol constants.

      • parser_class_name

        public static java.lang.String parser_class_name
        Name of the generated parser class.

      • class_type_argument

        public static java.lang.String class_type_argument
        TUM changes; proposed by Henning Niss 20050628: Type arguments for class declaration

      • action_code

        public static java.lang.String action_code
        User declarations for direct inclusion in user action class.

      • parser_code

        public static java.lang.String parser_code
        User declarations for direct inclusion in parser class.

      • init_code

        public static java.lang.String init_code
        User code for user_init() which is called during parser initialization.

      • scan_code

        public static java.lang.String scan_code
        User code for scan() which is called to get the next Symbol.

      • start_production

        public static production start_production
        The start production of the grammar.

      • import_list

        public static java.util.Stack import_list
        List of imports (Strings containing class names) to go with actions.

      • num_conflicts

        public static int num_conflicts
        Number of conflict found while building tables.

      • nowarn

        public static boolean nowarn
        Do we skip warnings?

      • not_reduced

        public static int not_reduced
        Count of the number on non-reduced productions found.

      • unused_term

        public static int unused_term
        Count of unused terminals.

      • unused_non_term

        public static int unused_non_term
        Count of unused non terminals.

      • symbols_time

        public static long symbols_time
        Time to produce symbol constant class.

      • parser_time

        public static long parser_time
        Time to produce parser class.

      • action_code_time

        public static long action_code_time
        Time to produce action code class.

      • production_table_time

        public static long production_table_time
        Time to produce the production table.

      • action_table_time

        public static long action_table_time
        Time to produce the action table.

      • goto_table_time

        public static long goto_table_time
        Time to produce the reduce-goto table.

      • _lr_values

        protected static boolean _lr_values

      • _locations

        protected static boolean _locations

      • _xmlactions

        protected static boolean _xmlactions

      • _genericlabels

        protected static boolean _genericlabels

    • Method Detail

      • lr_values

        public static boolean lr_values()
        whether or not to emit code for left and right values

      • locations

        public static boolean locations()

      • set_lr_values

        protected static void set_lr_values​(boolean b)

      • set_locations

        protected static void set_locations​(boolean b)

      • set_genericlabels

        protected static void set_genericlabels​(boolean b)

      • set_xmlactions

        protected static void set_xmlactions​(boolean b)

      • clear

        public static void clear()

      • pre

        protected static java.lang.String pre​(java.lang.String str)
        Build a string with the standard prefix.
        Parameters:
        str - string to prefix.

      • typeArgument

        protected static java.lang.String typeArgument()
        TUM changes; proposed by Henning Niss 20050628 Build a string with the specified type arguments, if present, otherwise an empty string.

      • emit_package

        protected static void emit_package​(java.io.PrintWriter out)
        Emit a package spec if the user wants one.
        Parameters:
        out - stream to produce output on.

      • symbols

        public static void symbols​(java.io.PrintWriter out,
                           boolean emit_non_terms,
                           boolean sym_interface)
        Emit code for the symbol constant class, optionally including non terms, if they have been requested.
        Parameters:
        out - stream to produce output on.
        emit_non_terms - do we emit constants for non terminals?
        sym_interface - should we emit an interface, rather than a class?

      • emit_action_code

        protected static void emit_action_code​(java.io.PrintWriter out,
                                       production start_prod)
                                throws internal_error
        Emit code for the non-public class holding the actual action code.
        Parameters:
        out - stream to produce output on.
        start_prod - the start production of the grammar.
        Throws:
        internal_error

      • emit_production_table

        protected static void emit_production_table​(java.io.PrintWriter out)
        Emit the production table.
        Parameters:
        out - stream to produce output on.

      • do_action_table

        protected static void do_action_table​(java.io.PrintWriter out,
                                      parse_action_table act_tab,
                                      boolean compact_reduces)
                               throws internal_error
        Emit the action table.
        Parameters:
        out - stream to produce output on.
        act_tab - the internal representation of the action table.
        compact_reduces - do we use the most frequent reduce as default?
        Throws:
        internal_error

      • do_reduce_table

        protected static void do_reduce_table​(java.io.PrintWriter out,
                                      parse_reduce_table red_tab)
        Emit the reduce-goto table.
        Parameters:
        out - stream to produce output on.
        red_tab - the internal representation of the reduce-goto table.

      • do_table_as_string

        protected static void do_table_as_string​(java.io.PrintWriter out,
                                         short[][] sa)

      • do_newline

        protected static int do_newline​(java.io.PrintWriter out,
                                int nchar,
                                int nbytes)

      • do_escaped

        protected static int do_escaped​(java.io.PrintWriter out,
                                char c)

      • parser

        public static void parser​(java.io.PrintWriter out,
                          parse_action_table action_table,
                          parse_reduce_table reduce_table,
                          int start_st,
                          production start_prod,
                          boolean compact_reduces,
                          boolean suppress_scanner)
                   throws internal_error
        Emit the parser subclass with embedded tables.
        Parameters:
        out - stream to produce output on.
        action_table - internal representation of the action table.
        reduce_table - internal representation of the reduce-goto table.
        start_st - start state of the parse machine.
        start_prod - start production of the grammar.
        compact_reduces - do we use most frequent reduce as default?
        suppress_scanner - should scanner be suppressed for compatibility?
        Throws:
        internal_error

      • emit_xmlaction_code

        protected static void emit_xmlaction_code​(java.io.PrintWriter out,
                                          production start_prod)
                                   throws internal_error
        Emit code for generic XML parsetree output.
        Parameters:
        out - stream to produce output on.
        start_prod - the start production of the grammar.
        Throws:
        internal_error