Theory Pascal

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theory Pascal
  imports LexYacc
  keywords "pascal" :: diag
begin

ml_lex_yacc [verbose] "Pascal" where
lex_user_declarations‹

(* Language-specific keyword hash table *)
structure KeyWord : sig
    val find : string -> (Position.T * Position.T -> (svalue, Position.T) token) option
end = struct
    val TableSize = 211
    val HashFactor = 5

    fun hash s = foldl (fn (c,v) => (v * HashFactor + (ord c)) mod TableSize) 0 (explode s)

    val HashTable = Array.array(TableSize, nil) : 
        (string * (Position.T * Position.T -> (svalue, Position.T) token)) list Array.array

    fun add (s, v) =
        let val i = hash s
        in Array.update(HashTable, i, (s, v) :: (Array.sub(HashTable, i))) end

    fun find s =
        let val i = hash s
            fun f ((key, v)::r) = if s = key then SOME v else f r
              | f nil = NONE
        in f (Array.sub(HashTable, i)) end

    val _ = List.app add [
         ("and",Tokens.YAND), ("array",Tokens.YARRAY), ("begin",Tokens.YBEGIN),
         ("case",Tokens.YCASE), ("const",Tokens.YCONST), ("div",Tokens.YDIV),
         ("do",Tokens.YDO), ("downto",Tokens.YDOWNTO), ("else",Tokens.YELSE),
         ("end",Tokens.YEND), ("extern",Tokens.YEXTERN), ("file",Tokens.YFILE),
         ("for",Tokens.YFOR), ("forward",Tokens.YFORWARD), ("function",Tokens.YFUNCTION),
         ("goto",Tokens.YGOTO), ("hex",Tokens.YHEX), ("if",Tokens.YIF),
         ("in",Tokens.YIN), ("label",Tokens.YLABEL), ("mod",Tokens.YMOD),
         ("nil",Tokens.YNIL), ("not",Tokens.YNOT), ("oct",Tokens.YOCT),
         ("of",Tokens.YOF), ("or",Tokens.YOR), ("packed",Tokens.YPACKED),
         ("procedure",Tokens.YPROCEDURE), ("program",Tokens.YPROG),
         ("record",Tokens.YRECORD), ("repeat",Tokens.YREPEAT), ("set",Tokens.YSET),
         ("then",Tokens.YTHEN), ("to",Tokens.YTO), ("type",Tokens.YTYPE),
         ("until",Tokens.YUNTIL), ("var",Tokens.YVAR), ("while",Tokens.YWHILE),
         ("with",Tokens.YWITH)
    ]
end
open KeyWord
›
lex_definitions‹
%s C B;
alpha=[A-Za-z];
digit=[0-9];
optsign=("+"|"-")?;
integer={digit}+;
frac="."{digit}+;
exp=(e|E){optsign}{digit}+;
octdigit=[0-7];
ws = [\ \t\r];

›
lex_rules‹
<INITIAL>{ws}+  => (lex());
<INITIAL>\n+    => (lex());
<INITIAL>{alpha}+ => (case find (String.map Char.toLower yytext) of 
                        SOME v => 
                          let val p = get_pos yypos
                              val _ = report_token (yypos, String.size yytext, Markup.keyword1, yytext, "")
                          in v(p, p) end
                      | _ => tok (yypos, yytext, Markup.free, "YID", "", Tokens.YID));
<INITIAL>{alpha}({alpha}|{digit})* => (tok (yypos, yytext, Markup.free, "YID", "", Tokens.YID));
<INITIAL>{optsign}{integer}({frac}{exp}?|{frac}?{exp}) => (tok (yypos, yytext, Markup.numeral, "YNUMB", "", Tokens.YNUMB));
<INITIAL>{optsign}{integer} => (tok (yypos, yytext, Markup.numeral, "YINT", "", Tokens.YINT));
<INITIAL>{octdigit}+(b|B)   => (tok (yypos, yytext, Markup.numeral, "YBINT", "", Tokens.YBINT));
<INITIAL>"'"([^']|"''")*"'" => (tok (yypos, yytext, Markup.string, "YSTRING", "", Tokens.YSTRING));
<INITIAL>"(*"   => (YYBEGIN C; lex());
<INITIAL>".."   => (tok (yypos, yytext, Markup.delimiter, "YDOTDOT", "", Tokens.YDOTDOT));
<INITIAL>"."    => (tok (yypos, yytext, Markup.delimiter, "YDOT", "", Tokens.YDOT));
<INITIAL>"("    => (tok (yypos, yytext, Markup.delimiter, "YLPAR", "", Tokens.YLPAR));
<INITIAL>")"    => (tok (yypos, yytext, Markup.delimiter, "YRPAR", "", Tokens.YRPAR));
<INITIAL>";"    => (tok (yypos, yytext, Markup.delimiter, "YSEMI", "", Tokens.YSEMI));
<INITIAL>","    => (tok (yypos, yytext, Markup.delimiter, "YCOMMA", "", Tokens.YCOMMA));
<INITIAL>":"    => (tok (yypos, yytext, Markup.delimiter, "YCOLON", "", Tokens.YCOLON));
<INITIAL>"^"    => (tok (yypos, yytext, Markup.operator, "YCARET", "", Tokens.YCARET));
<INITIAL>"["    => (tok (yypos, yytext, Markup.delimiter, "YLBRA", "", Tokens.YLBRA));
<INITIAL>"]"    => (tok (yypos, yytext, Markup.delimiter, "YRBRA", "", Tokens.YRBRA));
<INITIAL>"~"    => (tok (yypos, yytext, Markup.operator, "YTILDE", "", Tokens.YTILDE));
<INITIAL>"<"    => (tok (yypos, yytext, Markup.operator, "YLESS", "", Tokens.YLESS));
<INITIAL>"="    => (tok (yypos, yytext, Markup.operator, "YEQUAL", "", Tokens.YEQUAL));
<INITIAL>">"    => (tok (yypos, yytext, Markup.operator, "YGREATER", "", Tokens.YGREATER));
<INITIAL>"+"    => (tok (yypos, yytext, Markup.operator, "YPLUS", "", Tokens.YPLUS));
<INITIAL>"-"    => (tok (yypos, yytext, Markup.operator, "YMINUS", "", Tokens.YMINUS));
<INITIAL>"|"    => (tok (yypos, yytext, Markup.operator, "YBAR", "", Tokens.YBAR));
<INITIAL>"*"    => (tok (yypos, yytext, Markup.operator, "YSTAR", "", Tokens.YSTAR));
<INITIAL>"/"    => (tok (yypos, yytext, Markup.operator, "YSLASH", "", Tokens.YSLASH));
<INITIAL>"{"    => (YYBEGIN B; lex());
<INITIAL>.      => (tok (yypos, yytext, Markup.error, "YILLCH", "", Tokens.YILLCH));

<C>\n+          => (lex());
<C>[^()*\n]+    => (lex());
<C>"(*"         => (lex());
<C>"*)"         => (YYBEGIN INITIAL; lex());
<C>[*()]        => (lex());

<B>\n+          => (lex());
<B>[^{}\n]+     => (lex());
<B>"{"          => (lex());
<B>"}"          => (YYBEGIN INITIAL; lex());
›
and yacc_user_declarations‹
›
yacc_definitions‹
%eop EOF
%pure
%noshift EOF

%term
        YAND      | YARRAY    | YBEGIN     | YCASE  |
        YCONST    | YDIV      | YDO        | YDOTDOT |
        YTO       | YELSE     | YEND       | YFILE  |
        YFOR      | YFORWARD  | YPROCEDURE | YGOTO  |
        YID       | YIF       | YIN        | YINT   |
        YLABEL    | YMOD      | YNOT       | YNUMB  |
        YOF       | YOR       | YPACKED    | YNIL   | 
        YFUNCTION | YPROG     | YRECORD    | YREPEAT |
        YSET      | YSTRING   | YTHEN      | YDOWNTO |
        YTYPE     | YUNTIL    | YVAR       | YWHILE |
        YWITH     | YBINT     | YOCT       | YHEX   |
        YCASELAB  | YILLCH    | YEXTERN    |
        YDOT      | YLPAR     | YRPAR      | YSEMI  | YCOMMA  | YCOLON |  
        YCARET    | YLBRA     | YRBRA      | YTILDE |
        YLESS     | YEQUAL    | YGREATER   | YPLUS  | YMINUS | UNARYSIGN |  
        YBAR      | YSTAR     | YSLASH     | YAMP   | 
        EOF

%nonassoc YLESS YEQUAL  YGREATER        YIN
%left   YPLUS   YMINUS  YOR     YBAR
%left   UNARYSIGN
%left   YSTAR   YSLASH  YDIV    YMOD    YAND    YAMP
%left   YNOT

%nonterm goal | prog_hedr | block | decls | decl | labels | label_decl |
const_decl | type_decl | var_decl | proc_decl | pheadres | phead |
porf | params | param | ftype | param_list | const | number | const_list |
type' | simple_type | struct_type | simple_type_list | field_list |
fixed_part | field | variant_part | variant_list | variant | stat_list |
stat_lsth | cstat_list | cstat | stat | assign | expr | element_list |
element | variable | qual_var | wexpr | octhex | expr_list | wexpr_list |
relop | addop | divop | negop | var_list | id_list | const_id | type_id |
var_id | array_id | ptr_id | record_id | field_id | func_id 
| start_rule of unit option

%keyword
        YAND            YARRAY          YBEGIN          YCASE
        YCONST          YDIV            YDO
        YTO             YELSE           YEND            YFILE
        YFOR            YFORWARD        YPROCEDURE      YGOTO
        YIF             YIN
        YLABEL          YMOD            YNOT
        YOF             YOR             YPACKED         YNIL
        YFUNCTION       YPROG           YRECORD         YREPEAT
        YSET            YSTRING         YTHEN           YDOWNTO
        YTYPE           YUNTIL          YVAR            YWHILE
        YWITH           YOCT            YHEX
        YEXTERN         YAMP

%prefer YID YSEMI YCOMMA  YLBRA
%subst YCOMMA for YSEMI | YSEMI for YCOMMA
›
yacc_rules‹
start_rule: goal (SOME ())
goal:   prog_hedr decls block YDOT          ()
|       decls       ()
prog_hedr:      YPROG YID YLPAR id_list YRPAR YSEMI     ()
|       YPROG YID YSEMI    ()
block:  YBEGIN stat_list YEND    ()
decls:  decls decl    ()
|           ()
decl:   labels    ()
|       const_decl    ()
|       type_decl    ()
|       var_decl    ()
|       proc_decl    ()
labels: YLABEL label_decl YSEMI    ()
label_decl:     YINT    ()
|       label_decl YCOMMA YINT    ()
const_decl:     YCONST YID YEQUAL const YSEMI    ()
|       const_decl YID YEQUAL const YSEMI    ()
|       YCONST YID YEQUAL YID YSEMI    ()
|       const_decl YID YEQUAL YID YSEMI    ()
type_decl:      YTYPE YID YEQUAL type' YSEMI    ()
|       type_decl YID YEQUAL type' YSEMI    ()
var_decl:       YVAR id_list YCOLON type' YSEMI    ()
|       var_decl id_list YCOLON type' YSEMI    ()
proc_decl:      phead YFORWARD YSEMI    ()
|       phead YEXTERN YSEMI    ()
|       pheadres decls block YSEMI    ()
pheadres:       phead    ()
phead:  porf YID params ftype YSEMI    ()
porf:   YPROCEDURE    ()
|       YFUNCTION    ()
params: YLPAR param_list YRPAR    ()
|           ()
param:  id_list YCOLON type'    ()
|       YVAR id_list YCOLON type'    ()
|       YFUNCTION id_list params ftype    ()
|       YPROCEDURE id_list params ftype    ()
ftype:  YCOLON type'    ()
|           ()
param_list:     param    ()
|       param_list YSEMI param    ()
const:  YSTRING    ()
|       number    ()
|       YPLUS number    ()
|       YMINUS number    ()
|       YPLUS YID    ()
|       YMINUS YID    ()
number: YINT    ()
|       YBINT    ()
|       YNUMB    ()
const_list:     const    ()
|       const_list YCOMMA const    ()
|       YID    ()
|       const_list YCOMMA YID    ()
type':  simple_type    ()
|       YCARET YID    ()
|       struct_type    ()
|       YPACKED struct_type    ()
simple_type:    type_id    ()
|       YLPAR id_list YRPAR    ()
|       const YDOTDOT const    ()
|       YID YDOTDOT const    ()
|       const YDOTDOT YID    ()
|       YID YDOTDOT YID    ()
struct_type:    YARRAY YLBRA simple_type_list YRBRA YOF type'    ()
|       YFILE YOF type'    ()
|       YSET YOF simple_type    ()
|       YRECORD field_list YEND    ()
simple_type_list:       simple_type    ()
|       simple_type_list YCOMMA simple_type    ()
field_list:     fixed_part variant_part    ()
fixed_part:     field    ()
|       fixed_part YSEMI field    ()
field:      ()
|       id_list YCOLON type'    ()
variant_part:       ()
|       YCASE type_id YOF variant_list    ()
|       YCASE YID YCOLON type_id YOF variant_list    ()
variant_list:   variant    ()
|       variant_list YSEMI variant    ()
variant:           ()
|       const_list YCOLON YLPAR field_list YRPAR    ()
stat_list:      stat    ()
|       stat_lsth stat    ()
stat_lsth:      stat_list YSEMI    ()
cstat_list:     cstat    ()
|       cstat_list YSEMI cstat    ()
cstat:  const_list YCOLON stat    ()
|       YCASELAB stat    ()
|           ()
stat:       ()
|       YINT YCOLON stat    ()
|       YID    ()
|       YID YLPAR wexpr_list YRPAR ()
|       assign ()
|       YBEGIN stat_list YEND    ()
|       YCASE expr YOF cstat_list YEND    ()
|       YWITH var_list YDO stat    ()
|       YWHILE expr YDO stat    ()
|       YREPEAT stat_list YUNTIL expr    ()
|       YFOR assign YTO expr YDO stat    ()
|       YFOR assign YDOWNTO expr YDO stat    ()
|       YGOTO YINT    ()
|       YIF expr YTHEN stat    ()
|       YIF expr YTHEN stat YELSE stat    ()
assign: variable YCOLON YEQUAL expr    ()
|       YID YCOLON YEQUAL expr    ()
expr:   expr relop expr                 %prec YLESS    ()
|       YPLUS expr                      %prec UNARYSIGN    ()
|       YMINUS expr                     %prec UNARYSIGN    ()
|       expr addop expr                 %prec YPLUS    ()
|       expr divop expr                 %prec YSTAR    ()
|       YNIL    ()
|       YSTRING    ()
|       YINT    ()
|       YBINT    ()
|       YNUMB    ()
|       variable    ()
|       YID ()
|       YID YLPAR wexpr_list YRPAR    ()
|       YLPAR expr YRPAR    ()
|       negop expr                      %prec YNOT    ()
|       YLBRA element_list YRBRA    ()
|       YLBRA YRBRA    ()
element_list:   element    ()
|       element_list YCOMMA element    ()
element:        expr    ()
|       expr YDOTDOT expr    ()
variable:       qual_var    ()
qual_var:       YID YLBRA expr_list YRBRA    ()
|       qual_var YLBRA expr_list YRBRA    ()
|       YID YDOT field_id    ()
|       qual_var YDOT field_id    ()
|       YID YCARET    ()
|       qual_var YCARET    ()
wexpr:  expr    ()
|       expr YCOLON expr    ()
|       expr YCOLON expr YCOLON expr    ()
|       expr octhex    ()
|       expr YCOLON expr octhex    ()
octhex: YOCT    ()
|       YHEX    ()
expr_list:      expr    ()
|       expr_list YCOMMA expr    ()
wexpr_list:     wexpr    ()
|       wexpr_list YCOMMA wexpr    ()
relop:  YEQUAL  ()
|       YLESS   ()
|       YGREATER        ()
|       YLESS YGREATER  ()
|       YLESS YEQUAL    ()
|       YGREATER YEQUAL ()
|       YIN     ()
addop:  YPLUS   ()
|       YMINUS  ()
|       YOR     ()
|       YBAR    ()
divop:  YSTAR   ()
|       YSLASH  ()
|       YDIV    ()
|       YMOD    ()
|       YAND    ()
|       YAMP    ()
negop:  YNOT    ()
|       YTILDE    ()
var_list:       variable    ()
|       var_list YCOMMA variable    ()
|       YID    ()
|       var_list YCOMMA YID    ()
id_list:        YID    ()
|       id_list YCOMMA YID    ()
const_id:       YID    ()
type_id:        YID    ()
var_id: YID    ()
array_id:       YID    ()
ptr_id: YID    ()
record_id:      YID    ()
field_id:       YID    ()
func_id:        YID    ()
›

text‹Defining a simple Isar-toplevel command to test the Parser›
ML‹
fun run_pascal source thy = 
    let 
      val ctxt = Proof_Context.init_global thy
      val _ = Pascal.parse_source ctxt source 
    in thy end

val _ = Outer_Syntax.command @{command_keyword "pascal"}
        "Syntax check a Pascal block" 
        (Parse.input Parse.cartouche >> (fn source => Toplevel.theory (run_pascal source)))
›

text‹Testing the generated Pascal parser with syntax highlighting›
pascal‹
program myProg;
var x : integer;
begin
  x := 42 + 7;
  Writeln(x);
end.
›

end