Package eu.bandm.tools.formatfrontends

Class GenericCompiler

java.lang.Object
eu.bandm.tools.tdom.runtime.BaseVisitor
eu.bandm.tools.formatfrontends.absy.Visitor
eu.bandm.tools.formatfrontends.GenericCompiler
All Implemented Interfaces:
PCDataVisitor
Direct Known Subclasses:
Tdom2format, UMod2format.Compiler
public abstract class GenericCompiler extends eu.bandm.tools.formatfrontends.absy.Visitor
Base class for different compilers which generate format-generating java sources, realizing the code generation for the common constructs of the format description language.

A specialization of this class generates code for generating formats by acting as a visitor of the format language tdom model, and creating code which (in most cases) is also a visitor, of some target model.

Any derived visitor has to act as follows:
  1. It has to construct some target class (with the appropriate base class, specific fields, interface methods, etc)
  2. It has to call initTransformerClass(GeneratedClass) on this class.
  3. It has to define the visit() methods for all the specific language constructs.
  4. It has to call compileOnePattern(Element_pattern) for each expression it wants to translate. This method intializes internal registers, calls visit(), and finally relocates all constant expressions to initializer blocks.
    The format result (which contains code to construct the required format) is left in fresult, The caller has to store this code in the generated class according to its need.
  5. During the execution of the specific code, the following registers are relevant:
    • fresult (read/write) holding the code = translation result. ("f-result" = "functional result"),
    • isdynamic (read/write) must be set by custom code to true in most cases, ie. when the constructed format will not be constant, but will depend on the data.
    • checkedmode (read) if we are at the left of some "?" operator,
  6. Whenever a sub-structure of aggreate type has to be compiled, a sub-class of GenericCompiler.Subformat can be defined. This class reduces all relevant parameters from the font-end constructs for aggregates (fold operators, code, etc.) into interal values and stores them, for easy recursion.

  • Field Details

    • WRAPPEDCLASS_Object

      public static final EnvironmentClass WRAPPEDCLASS_Object

    • WRAPPEDCLASS_Lists

      public static final EnvironmentClass WRAPPEDCLASS_Lists
      Attention, refers NOT to java.util, but to eu.bandm.tools.ops, and is for convenience of derived compilers only.

    • WRAPPEDCLASS_Function

      public static final EnvironmentClass WRAPPEDCLASS_Function
      Refers to eu.bandm.tools.ops, and is for convenience of derived compilers only.

    • WRAPPEDCLASS_Format

      public static final EnvironmentClass WRAPPEDCLASS_Format

    • REF_FORMAT_Format

      public static final Format REF_FORMAT_Format
      The format which refers to Format

    • REF_FORMAT_Formats

      public static final Format REF_FORMAT_Formats
      The format which refers to Formats

    • WRAPPEDCLASS_TakeAlternativeException

      public static final EnvironmentClass WRAPPEDCLASS_TakeAlternativeException

    • WRAPPEDCLASS_MapoidFormatter

      public static final EnvironmentClass WRAPPEDCLASS_MapoidFormatter
      For convenience of derived compilers only.

    • WRAPPEDCLASS_MapEntry

      public static final EnvironmentClass WRAPPEDCLASS_MapEntry
      For convenience of derived compilers only.

    • WRAPPEDCLASS_ListoidFormatter

      public static final EnvironmentClass WRAPPEDCLASS_ListoidFormatter
      For convenience of derived compilers only.

    • WRAPPEDCLASS_TryerCatcher

      public static final EnvironmentClass WRAPPEDCLASS_TryerCatcher

    • WRAPPEDCLASS_CompoundConstructor

      public static final EnvironmentClass WRAPPEDCLASS_CompoundConstructor

    • NAME_METHOD_THROW_TAKE_ALTERNATIVE

      public final String NAME_METHOD_THROW_TAKE_ALTERNATIVE
      name of the method generated for convenience for throwing TakeAlternativeException.
      See Also:

    • callFunctionForRaisingException

      public final Format callFunctionForRaisingException
      format for calling the method which throws TakeAlternativeException, cf NAME_METHOD_THROW_TAKE_ALTERNATIVE.

    • NAME_VAR_DEFAULT_INDENT

      protected String NAME_VAR_DEFAULT_INDENT
      name of the generated field which holds the default idententation, normally "default_indent".

    • NAME_VAR_MODE

      protected String NAME_VAR_MODE
      name of the generated field which holds the current mode, normally "mode".

    • NAME_CONST_FORMAT_EMPTY

      protected String NAME_CONST_FORMAT_EMPTY
      name of the generated field which holds an empty format, normally "format_empty".

    • MODIF_CONST

      protected static final int MODIF_CONST
      modifier used for all fields generated to hold constant format expressions (= "protected static final").
      See Also:

    • NAME_VAR_FORMAT_RESULT

      protected String NAME_VAR_FORMAT_RESULT
      name of the generated field which holds the resulting format. such a field is NOT necesarry and not created iff the generated code (including facade code !) can be fully functional.

    • exprCache

      protected Map<String,Format> exprCache

    • rec

      protected MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> rec
      Needed ONLY because ".getReceiver()" is of type "? super M", which does not wokr.

    • targetclass

      protected GeneratedClass targetclass
      class into which to generate all const field definitions.

    • isdynamic

      protected boolean isdynamic
      indicates whether the code currently contained in fresult does generate formats "dynamically" (which implies that its result can NOT be stored in a constant field).

    • checkedmode

      protected boolean checkedmode
      are we currently visiting left part of a "?" operator ?

    • fresult

      protected Format fresult
      accumulator for format generating functional code. (of course coded in form of a format !-).

    • constcache

      protected final Map<String,Format> constcache
      Maps "fresult" contents (=unformatted java code, used as a key) to the name of the constant fields which will hold the code's result.

  • Constructor Details

  • Method Details

    • setMsgReceiver

      protected void setMsgReceiver(MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> rec)

    • getMsgReceiver

      protected MessageReceiver<SimpleMessage<XMLDocumentIdentifier>> getMsgReceiver()

    • getCurrentModel

      protected abstract Format getCurrentModel()
      Currently only needed to compile escapeToJava() in the variant operating directly on the model element. Introduced 20170428.

    • refer

      protected Format refer(CompoundConstructor c)

    • expr

      protected Format expr(String code)

    • warning

      protected void warning(Location<XMLDocumentIdentifier> loc, String text)

    • error

      protected void error(Location<XMLDocumentIdentifier> loc, String text)

    • initTransformerClass

      public void initTransformerClass(GeneratedClass gc)
      Creates standard fields for the generated format generating class. (Like "default indent", "result" as intermediate storage, a cache of the empty format, a method to throw the "take alternative" exception, etc.) Must be called. This is ensured by the field targetclass, which otherwise stays =null.

    • create_resultfield

      public void create_resultfield(GeneratedClass gc)
      creates a field "Format result=Format.empty;" for formatting wisitors which need such a temp storage (ie. are not purely functinal code).
      Currently used by UMod2format and Tdom2format.

    • compileOnePattern

      public void compileOnePattern(eu.bandm.tools.formatfrontends.absy.Element_pattern el)
      called from derived code for translating one(1) rule. (1) initialize registers, (2) call visit(el) and (3) leave result in fresult. after return, the contents of fresult (=format representing format-generating code) must be stored to somewhere by the calling code!

    • checkconst

      protected void checkconst()
      Whenever possible, store the code from fresult into an initializer of a new constant, and replace fresult by a reference to this (or to an already existing constant).

    • process_compound

      protected void process_compound(eu.bandm.tools.formatfrontends.absy.Element[] subs, String constr)

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_beneath element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_beside element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_line element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_block element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_append element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_tabular element)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • compileModeSwitch

      protected void compileModeSwitch(eu.bandm.tools.formatfrontends.absy.Element_cases el)
      Compiles a switch statement with $mode as its selector. Defaults to the empty format.

    • compileCallToFormatText

      protected void compileCallToFormatText(Format model)
      compiles a call to Formats.text(String), if model != null. otherwise an exception or an empty format, if not left of a "?".

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_alternative element)
      Compiles the cascade of alternatives/catch clauses from the front end representation ...? ... ? ... ? ... .

      <!ELEMENT alternative (beneath, catchcase?) >
      <!ELEMENT catchcase (alternative?) >
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_nullException el)
      Creates code for the $throw element. This causes explicit failure, i.e. throwing of an instance of TakeAlternativeException. This is sensible when eg. done out of one (or some) of the cases of a $switch statement. It may only be used to the left side of a ? operator, which results in the corresponding right side to be executed.
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_prior el)
      <!ELEMENT prior (number, (number | appendOp)?, pattern, pattern) > It directly maps its arguments to a call of Format.prior(int, int, eu.bandm.tools.format.Format, eu.bandm.tools.format.Format).
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_literal el)
      Creates code for one literal, which might also be empty. Consequently, is compiles to Format.literal(String) or to Format.empty
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_whitespace el)
      Creates code for whitespace. The width of the input is preserved in the generated format. Creates a call to Format.space(int)
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_escapeToJava element)
      Creates code for a java escape.
      The syntax in the front end language is "$java 'my.package.Class.method'(formatsAsArgument..)". or "$java 'my.package.Class.method'". The first argument must point to some static function from Format to Format. If there is a second argument, it is a "block" construct of formats which are arguments to the function. Otherwise the current model element is the only argument.
      Attention: "$java" is now one level higher than "atom"; can be used as an instance of "atom" simply by additional parentheses "($java x.y(..))"
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor

    • visit

      public void visit(eu.bandm.tools.formatfrontends.absy.Element_indent element)
      creates code for indentation.
      Supports two variants: with inline constant, or without, reading a runtime variable for default indentation. The name of this variable is defined by NAME_VAR_DEFAULT_INDENT
      Overrides:
      visit in class eu.bandm.tools.formatfrontends.absy.Visitor