Wirth-AT-grammars/TurboPascal3-grammar/turbo_pascal3.lst

Coco/R - Compiler-Compiler V1.53
Released by Pat Terry 17 September 2002
Source file: turbo_pascal3.atg

Listing:

    1  (* Tags: TURBO3, TURBOPASCAL, TP3, BORLAND *)
    2  COMPILER Pascal
    3  (* J & W Pascal - not Turbo Pascal *)
    4  (* This grammar is not LL(1) *)
    5  
    6  CHARACTERS
    7    eol      = CHR(13) .
    8    letter   = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" .
    9    digit    = "0123456789".
   10    noQuote1 = ANY - "'" - eol .
   11  
   12  IGNORE CHR(9) .. CHR(13)
   13  IGNORE CASE
*****         ^ IGNORE CASE must appear earlier
   14  
   15  COMMENTS FROM "(*" TO "*)"
   16  COMMENTS FROM "{" TO "}"
   17  
   18  TOKENS
   19    identifier  =  letter { letter | digit } .
   20    integer     =  digit { digit } | digit { digit }  CONTEXT ("..") .
   21    real        =  digit { digit } "." digit { digit }
   22                   [ "E" ["+" | "-"] digit { digit } ]
   23                   |  digit { digit } "E" ["+" | "-"] digit { digit }  .
   24    string      = "'" { noQuote1 | "''" } "'" .
   25  
   26  PRODUCTIONS
*****  ^ could not make deterministic automaton
   27  
   28    Pascal            = "program"  NewIdent [ ExternalFiles ] ";"
   29                        Block "." .
   30  
   31    ExternalFiles     = "(" NewIdentList ")" .
   32  
   33    Block             =  DeclarationPart StatementPart .
   34  
   35    DeclarationPart   = LabelDeclarations ConstDefinitions
   36                        TypeDefinitions VarDeclarations
   37                        { ProcDeclarations } .
   38  
   39  (* -------------------------------------------------------------------- *)
   40  
   41    LabelDeclarations = [ "label" Labels ";" ] .
   42  
   43    Labels            = Label { "," Label } .
   44  
   45    Label             = UnsignedInt .
   46  
   47  (* -------------------------------------------------------------------- *)
   48  
   49    ConstDefinitions  = [ "const" ConstDef { ConstDef } ] .
   50  
   51    ConstDef          = NewIdent "=" Constant ";" .
   52  
   53    Constant          = [ "+" | "-" ] ( UnsignedNumber | ConstIdent ) | String .
   54  
   55    UnsignedNumber    = UnsignedInt | UnsignedReal .
   56  
   57    ConstIdent        = identifier .
   58  
   59  (* -------------------------------------------------------------------- *)
   60  
   61    TypeDefinitions   = [ "type" TypeDef { TypeDef } ] .
   62  
   63    TypeDef           = NewIdent "=" Type ";" .
   64  
   65    Type              = SimpleType | [ "packed" ] StructType | "^" TypeIdent .
   66  
   67    SimpleType        = TypeIdent | EnumerationType | SubrangeType .
   68  
   69    TypeIdent         = identifier .
   70  
   71    EnumerationType   = "(" NewIdentList ")" .
   72  
   73    SubrangeType      = Constant ".." Constant .
   74  
   75    StructType        = ArrayType | RecordType | SetType | FileType .
   76  
   77    ArrayType         = "array" "[" IndexList "]" "of" Type .
   78  
   79    IndexList         = SimpleType { "," SimpleType } .
   80  
   81    RecordType        = "record" FieldList "end" .
   82  
   83    SetType           = "set" "of" SimpleType .
   84  
   85    FileType          = "file" "of" Type .
   86  
   87    FieldList         = [ ( fixedPart [ ";" VariantPart ] | VariantPart ) [ ";" ] ] .
   88  
   89    fixedPart         = RecordSection { ";" RecordSection } .
   90  
   91    RecordSection     = NewIdentList ":" Type .
   92  
   93    VariantPart       = "case" VariantSelector "of" Variant { ";" Variant } .
   94  
   95    VariantSelector   = [ NewIdent ":" ] TypeIdent .
   96  
   97    Variant           = CaseLabelList ":" "(" FieldList ")" .
   98  
   99  (* -------------------------------------------------------------------- *)
  100  
  101    VarDeclarations   = [ "var" VarDecl { VarDecl } ] .
  102  
  103    VarDecl           = NewIdentList ":" Type ";" .
  104  
  105  (* -------------------------------------------------------------------- *)
  106  
  107    ProcDeclarations  = ( ProcHeading | FuncHeading ) ";" Body ";" .
  108  
  109    ProcHeading       = "procedure" NewIdent [ FormalParams ] .
  110  
  111    FuncHeading       = "function" NewIdent [ FormalParams ] ReturnType .
  112  
  113    ReturnType        = [ (* empty if forward referenced *) ":" TypeIdent ] .
  114  
  115    Body              = Block | "forward" .
  116  
  117    FormalParams      = "(" FormalSection { ";" FormalSection } ")"  .
  118  
  119    FormalSection     = [ "var" ] ParamGroup | ProcHeading | FuncHeading .
  120  
  121    ParamGroup        = NewIdentList ":" ParamType .
  122  
  123    ParamType         =   TypeIdent
  124                        | "array" "[" IndexSpecList "]" "of" ParamType
  125                        | "packed" "array" "[" IndexSpec "]" "of" TypeIdent .
  126  
  127    IndexSpecList     = IndexSpec { ";" IndexSpec } .
  128  
  129    IndexSpec         = NewIdent ".." NewIdent ":" TypeIdent .
  130  
  131  (* -------------------------------------------------------------------- *)
  132  
  133    StatementPart     = CompoundStatement .
  134  
  135    CompoundStatement = "begin" StatementSequence "end" .
  136  
  137    StatementSequence = Statement { ";" Statement } .
  138  
  139    Statement         = [ Label ":" ]
  140                        [   AssignmentOrCall
  141                          | CompoundStatement
  142                          | GotoStatement
  143                          | WhileStatement
  144                          | RepeatStatement
  145                          | IfStatement
  146                          | CaseStatement
  147                          | ForStatement
  148                          | WithStatement ] .
  149  
  150    AssignmentOrCall  = Designator ( ":=" Expression | [ ActualParams ] ) .
  151  
  152    ActualParams      = "(" ActualParameter { "," ActualParameter } ")" .
  153  
  154    ActualParameter   = Expression [ FieldWidth (* only in i/o *) ] .
  155  
  156    FieldWidth        = ":" IntegerExpression [ ":" IntegerExpression ] .
  157  
  158    GotoStatement     = "goto" Label .
  159  
  160    WhileStatement    = "while" BooleanExpression "do" Statement .
  161  
  162    RepeatStatement   = "repeat" StatementSequence "until" BooleanExpression .
  163  
  164    IfStatement       = "if" BooleanExpression "then" Statement
  165                        [ "else" Statement ] .
  166  
  167    CaseStatement     = "case" OrdinalExpression "of" CaseList "end" .
  168  
  169    CaseList          = OneCase { ";" OneCase } [ ";" ] .
  170  
  171    OneCase           = CaseLabelList ":" Statement .
  172  
  173    CaseLabelList     = CaseLabel { "," CaseLabel } .
  174  
  175    CaseLabel         = Constant .
  176  
  177    ForStatement      = "for" ControlVariable ":=" OrdinalExpression
  178                        ( "to" | "downto" ) OrdinalExpression "do" Statement .
  179  
  180    ControlVariable   = identifier .
  181  
  182    WithStatement     = "with" RecVarList "do" Statement .
  183  
  184    RecVarList        = Designator { "," Designator } .
  185  
  186  (* -------------------------------------------------------------------- *)
  187  
  188    IntegerExpression = Expression .
  189  
  190    BooleanExpression = Expression .
  191  
  192    OrdinalExpression = Expression .
  193  
  194    Expression        = SimpleExpression [ RelOp SimpleExpression ] .
  195  
  196    RelOp             = "=" | "<" | ">" | "<=" | ">=" | "<>" | "in" .
  197  
  198    SimpleExpression  = ( "+" Term | "-" Term | Term ) { AddOp Term } .
  199  
  200    AddOp             = "+" | "-" | "or" .
  201  
  202    Term              = Factor { MulOp Factor } .
  203  
  204    MulOp             = "*" | "/" | "div" | "mod" | "and" .
  205  
  206    Factor            =   Designator [ ActualParams ]
  207                        | UnsignedLiteral
  208                        | SetConstructor
  209                        | "(" Expression ")"
  210                        | "not" Factor .
  211  
  212    Designator        = identifier { "." identifier | "[" ExpList "]" | "^" } .
  213  
  214    ExpList           = Expression { "," Expression } .
  215  
  216    UnsignedLiteral   = UnsignedNumber | "nil" | String .
  217  
  218    SetConstructor    = "[" Member { "," Member } "]" .
  219  
  220    Member            = Expression [ ".." Expression ] .
  221  
  222  (* -------------------------------------------------------------------- *)
  223  
  224    NewIdentList      = NewIdent { "," NewIdent } .
  225  
  226    NewIdent          = identifier .
  227  
  228    UnsignedInt       = integer .
  229  
  230    UnsignedReal      = real .
  231  
  232    String            = string .
  233  
  234  END Pascal.

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