761 lines
16 KiB
Plaintext
761 lines
16 KiB
Plaintext
(*
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BSD 2-Clause License
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Copyright (c) 2018-2020, Anton Krotov
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All rights reserved.
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*)
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MODULE SCAN;
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IMPORT TXT := TEXTDRV, AVL := AVLTREES, ARITH, S := STRINGS, ERRORS, LISTS;
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CONST
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LEXLEN = 1024;
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lxUNDEF* = 0; lxIDENT* = 1; lxINTEGER* = 2; lxHEX* = 3;
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lxCHAR* = 4; lxFLOAT* = 5; lxSTRING* = 6; lxCOMMENT* = 7;
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lxEOF* = 8;
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lxPLUS* = 21; lxMINUS* = 22; lxMUL* = 23; lxSLASH* = 24;
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lxNOT* = 25; lxAND* = 26; lxPOINT* = 27; lxCOMMA* = 28;
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lxSEMI* = 29; lxBAR* = 30; lxLROUND* = 31; lxLSQUARE* = 32;
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lxLCURLY* = 33; lxCARET* = 34; lxEQ* = 35; lxNE* = 36;
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lxLT* = 37; lxGT* = 38; lxCOLON* = 39; lxRROUND* = 40;
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lxRSQUARE* = 41; lxRCURLY* = 42; lxLE* = 43; lxGE* = 44;
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lxASSIGN* = 45; lxRANGE* = 46;
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lxKW = 51;
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lxARRAY* = 51; lxBEGIN* = 52; lxBY* = 53; lxCASE* = 54;
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lxCONST* = 55; lxDIV* = 56; lxDO* = 57; lxELSE* = 58;
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lxELSIF* = 59; lxEND* = 60; lxFALSE* = 61; lxFOR* = 62;
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lxIF* = 63; lxIMPORT* = 64; lxIN* = 65; lxIS* = 66;
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lxMOD* = 67; lxMODULE* = 68; lxNIL* = 69; lxOF* = 70;
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lxOR* = 71; lxPOINTER* = 72; lxPROCEDURE* = 73; lxRECORD* = 74;
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lxREPEAT* = 75; lxRETURN* = 76; lxTHEN* = 77; lxTO* = 78;
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lxTRUE* = 79; lxTYPE* = 80; lxUNTIL* = 81; lxVAR* = 82;
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lxWHILE* = 83;
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lxERROR01* = -1; lxERROR02* = -2; lxERROR03* = -3; lxERROR04* = -4;
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lxERROR05* = -5; lxERROR06* = -6; lxERROR07* = -7; lxERROR08* = -8;
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lxERROR09* = -9; lxERROR10* = -10; lxERROR11* = -11; lxERROR12* = -12;
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lxERROR13* = -13;
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TYPE
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LEXSTR* = ARRAY LEXLEN OF CHAR;
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DEF = POINTER TO RECORD (LISTS.ITEM)
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ident: LEXSTR
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END;
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IDENT* = POINTER TO RECORD (AVL.DATA)
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s*: LEXSTR;
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offset*, offsetW*: INTEGER;
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key: INTEGER
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END;
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POSITION* = RECORD
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line*, col*: INTEGER
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END;
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LEX* = RECORD
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s*: LEXSTR;
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length*: INTEGER;
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sym*: INTEGER;
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pos*: POSITION;
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ident*: IDENT;
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string*: IDENT;
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value*: ARITH.VALUE;
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error*: INTEGER;
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over: BOOLEAN
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END;
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SCANNER* = TXT.TEXT;
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VAR
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idents: AVL.NODE;
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delimiters: ARRAY 256 OF BOOLEAN;
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NewIdent: IDENT;
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upto, LowerCase, _if: BOOLEAN;
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def: LISTS.LIST;
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PROCEDURE nodecmp (a, b: AVL.DATA): INTEGER;
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RETURN ORD(a(IDENT).s > b(IDENT).s) - ORD(a(IDENT).s < b(IDENT).s)
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END nodecmp;
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PROCEDURE enterid* (s: LEXSTR): IDENT;
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VAR
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newnode: BOOLEAN;
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node: AVL.NODE;
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BEGIN
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NewIdent.s := s;
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idents := AVL.insert(idents, NewIdent, nodecmp, newnode, node);
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IF newnode THEN
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NEW(NewIdent);
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NewIdent.offset := -1;
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NewIdent.offsetW := -1;
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NewIdent.key := 0
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END
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RETURN node.data(IDENT)
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END enterid;
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PROCEDURE putchar (VAR lex: LEX; c: CHAR);
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BEGIN
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IF lex.length < LEXLEN - 1 THEN
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lex.s[lex.length] := c;
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INC(lex.length);
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lex.s[lex.length] := 0X
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ELSE
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lex.over := TRUE
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END
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END putchar;
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PROCEDURE nextc (text: TXT.TEXT): CHAR;
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BEGIN
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TXT.next(text)
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RETURN text.peak
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END nextc;
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PROCEDURE ident (text: TXT.TEXT; VAR lex: LEX);
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VAR
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c: CHAR;
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BEGIN
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c := text.peak;
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ASSERT(S.letter(c));
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WHILE S.letter(c) OR S.digit(c) DO
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putchar(lex, c);
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c := nextc(text)
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END;
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IF lex.over THEN
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lex.sym := lxERROR06
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ELSE
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lex.ident := enterid(lex.s);
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IF lex.ident.key # 0 THEN
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lex.sym := lex.ident.key
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ELSE
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lex.sym := lxIDENT
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END
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END
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END ident;
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PROCEDURE number (text: TXT.TEXT; VAR lex: LEX);
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VAR
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c: CHAR;
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hex: BOOLEAN;
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error, sym: INTEGER;
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BEGIN
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c := text.peak;
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ASSERT(S.digit(c));
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error := 0;
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sym := lxINTEGER;
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hex := FALSE;
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WHILE S.digit(c) DO
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putchar(lex, c);
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c := nextc(text)
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END;
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WHILE S.hexdigit(c) DO
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putchar(lex, c);
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c := nextc(text);
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hex := TRUE
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END;
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IF c = "H" THEN
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putchar(lex, c);
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TXT.next(text);
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sym := lxHEX
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ELSIF c = "X" THEN
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putchar(lex, c);
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TXT.next(text);
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sym := lxCHAR
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ELSIF c = "." THEN
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IF hex THEN
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sym := lxERROR01
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ELSE
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c := nextc(text);
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IF c # "." THEN
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putchar(lex, ".");
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sym := lxFLOAT
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ELSE
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sym := lxINTEGER;
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text.peak := 7FX;
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upto := TRUE
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END;
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WHILE S.digit(c) DO
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putchar(lex, c);
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c := nextc(text)
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END;
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IF c = "E" THEN
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putchar(lex, c);
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c := nextc(text);
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IF (c = "+") OR (c = "-") THEN
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putchar(lex, c);
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c := nextc(text)
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END;
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IF S.digit(c) THEN
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WHILE S.digit(c) DO
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putchar(lex, c);
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c := nextc(text)
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END
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ELSE
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sym := lxERROR02
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END
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END
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END
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ELSIF hex THEN
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sym := lxERROR01
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END;
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IF lex.over & (sym >= 0) THEN
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sym := lxERROR07
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END;
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IF sym = lxINTEGER THEN
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ARITH.iconv(lex.s, lex.value, error)
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ELSIF (sym = lxHEX) OR (sym = lxCHAR) THEN
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ARITH.hconv(lex.s, lex.value, error)
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ELSIF sym = lxFLOAT THEN
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ARITH.fconv(lex.s, lex.value, error)
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END;
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CASE error OF
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|0:
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|1: sym := lxERROR08
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|2: sym := lxERROR09
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|3: sym := lxERROR10
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|4: sym := lxERROR11
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|5: sym := lxERROR12
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END;
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lex.sym := sym
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END number;
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PROCEDURE string (text: TXT.TEXT; VAR lex: LEX; quot: CHAR);
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VAR
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c: CHAR;
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n: INTEGER;
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BEGIN
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c := nextc(text);
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n := 0;
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WHILE (c # quot) & (c # 0X) & ~text.eol & ~text.eof DO
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putchar(lex, c);
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c := nextc(text);
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INC(n)
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END;
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IF c = quot THEN
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TXT.next(text);
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IF lex.over THEN
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lex.sym := lxERROR05
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ELSE
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IF n # 1 THEN
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lex.sym := lxSTRING
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ELSE
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lex.sym := lxCHAR;
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ARITH.setChar(lex.value, ORD(lex.s[0]))
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END
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END
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ELSE
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lex.sym := lxERROR03
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END;
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IF lex.sym = lxSTRING THEN
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lex.string := enterid(lex.s);
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lex.value.typ := ARITH.tSTRING;
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lex.value.string := lex.string
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END
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END string;
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PROCEDURE comment (text: TXT.TEXT);
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VAR
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c: CHAR;
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cond, depth: INTEGER;
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BEGIN
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cond := 0;
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depth := 1;
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REPEAT
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c := text.peak;
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TXT.next(text);
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IF c = "*" THEN
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IF cond = 1 THEN
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cond := 0;
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INC(depth)
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ELSE
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cond := 2
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END
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ELSIF c = ")" THEN
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IF cond = 2 THEN
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DEC(depth)
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END;
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cond := 0
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ELSIF c = "(" THEN
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cond := 1
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ELSE
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cond := 0
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END
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UNTIL (depth = 0) OR text.eof
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END comment;
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PROCEDURE delimiter (text: TXT.TEXT; VAR lex: LEX; c: CHAR);
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VAR
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sym: INTEGER;
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BEGIN
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putchar(lex, c);
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c := nextc(text);
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CASE lex.s[0] OF
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|"+":
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sym := lxPLUS
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|"-":
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sym := lxMINUS
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|"*":
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sym := lxMUL
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|"/":
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sym := lxSLASH;
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IF c = "/" THEN
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sym := lxCOMMENT;
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REPEAT
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TXT.next(text)
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UNTIL text.eol OR text.eof
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END
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|"~":
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sym := lxNOT
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|"&":
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sym := lxAND
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|".":
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sym := lxPOINT;
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IF c = "." THEN
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sym := lxRANGE;
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putchar(lex, c);
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TXT.next(text)
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END
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|",":
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sym := lxCOMMA
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|";":
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sym := lxSEMI
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|"|":
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sym := lxBAR
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|"(":
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sym := lxLROUND;
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IF c = "*" THEN
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sym := lxCOMMENT;
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TXT.next(text);
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comment(text)
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END
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|"[":
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sym := lxLSQUARE
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|"{":
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sym := lxLCURLY
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|"^":
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sym := lxCARET
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|"=":
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sym := lxEQ
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|"#":
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sym := lxNE
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|"<":
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sym := lxLT;
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IF c = "=" THEN
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sym := lxLE;
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putchar(lex, c);
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TXT.next(text)
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END
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|">":
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sym := lxGT;
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IF c = "=" THEN
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sym := lxGE;
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putchar(lex, c);
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TXT.next(text)
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END
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|":":
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sym := lxCOLON;
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IF c = "=" THEN
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sym := lxASSIGN;
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putchar(lex, c);
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TXT.next(text)
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END
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|")":
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sym := lxRROUND
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|"]":
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sym := lxRSQUARE
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|"}":
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sym := lxRCURLY
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END;
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lex.sym := sym
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END delimiter;
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PROCEDURE Next* (text: SCANNER; VAR lex: LEX);
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VAR
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c: CHAR;
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PROCEDURE check (cond: BOOLEAN; text: SCANNER; lex: LEX; errno: INTEGER);
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BEGIN
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IF ~cond THEN
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ERRORS.ErrorMsg(text.fname, lex.pos.line, lex.pos.col, errno)
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END
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END check;
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PROCEDURE IsDef (str: ARRAY OF CHAR): BOOLEAN;
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VAR
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cur: DEF;
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BEGIN
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cur := def.first(DEF);
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WHILE (cur # NIL) & (cur.ident # str) DO
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cur := cur.next(DEF)
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END
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RETURN cur # NIL
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END IsDef;
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PROCEDURE Skip (text: SCANNER);
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VAR
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i: INTEGER;
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BEGIN
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i := 0;
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WHILE (i <= text.ifc) & ~text._skip[i] DO
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INC(i)
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END;
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text.skip := i <= text.ifc
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END Skip;
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PROCEDURE prep_if (text: SCANNER; VAR lex: LEX);
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VAR
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skip: BOOLEAN;
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BEGIN
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INC(text.ifc);
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text._elsif[text.ifc] := lex.sym = lxELSIF;
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IF lex.sym = lxIF THEN
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INC(text.elsec);
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text._else[text.elsec] := FALSE
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END;
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_if := TRUE;
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skip := TRUE;
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text.skip := FALSE;
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Next(text, lex);
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check(lex.sym = lxLROUND, text, lex, 64);
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Next(text, lex);
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check(lex.sym = lxIDENT, text, lex, 22);
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REPEAT
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IF IsDef(lex.s) THEN
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skip := FALSE
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END;
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Next(text, lex);
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IF lex.sym = lxBAR THEN
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Next(text, lex);
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check(lex.sym = lxIDENT, text, lex, 22)
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ELSE
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check(lex.sym = lxRROUND, text, lex, 33)
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END
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UNTIL lex.sym = lxRROUND;
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_if := FALSE;
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text._skip[text.ifc] := skip;
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Skip(text);
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Next(text, lex)
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END prep_if;
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PROCEDURE prep_end (text: SCANNER; VAR lex: LEX);
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BEGIN
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check(text.ifc > 0, text, lex, 118);
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IF lex.sym = lxEND THEN
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WHILE text._elsif[text.ifc] DO
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DEC(text.ifc)
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END;
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DEC(text.ifc);
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DEC(text.elsec)
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ELSIF (lex.sym = lxELSE) OR (lex.sym = lxELSIF) THEN
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check(~text._else[text.elsec], text, lex, 118);
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text._skip[text.ifc] := ~text._skip[text.ifc];
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text._else[text.elsec] := lex.sym = lxELSE
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END;
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Skip(text);
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IF lex.sym = lxELSIF THEN
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prep_if(text, lex)
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ELSE
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Next(text, lex)
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END
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END prep_end;
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BEGIN
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REPEAT
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c := text.peak;
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WHILE S.space(c) DO
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c := nextc(text)
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END;
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lex.s[0] := 0X;
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lex.length := 0;
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lex.pos.line := text.line;
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lex.pos.col := text.col;
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lex.ident := NIL;
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lex.over := FALSE;
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IF S.letter(c) THEN
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ident(text, lex)
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ELSIF S.digit(c) THEN
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number(text, lex)
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ELSIF (c = '"') OR (c = "'") THEN
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string(text, lex, c)
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ELSIF delimiters[ORD(c)] THEN
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delimiter(text, lex, c)
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ELSIF c = "$" THEN
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IF S.letter(nextc(text)) THEN
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ident(text, lex);
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IF lex.sym = lxIF THEN
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IF ~_if THEN
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prep_if(text, lex)
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END
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ELSIF (lex.sym = lxEND) OR (lex.sym = lxELSE) OR (lex.sym = lxELSIF) THEN
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IF ~_if THEN
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prep_end(text, lex)
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END
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ELSE
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check(FALSE, text, lex, 119)
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|
END
|
|
ELSE
|
|
check(FALSE, text, lex, 119)
|
|
END
|
|
ELSIF c = 0X THEN
|
|
lex.sym := lxEOF;
|
|
text.skip := FALSE;
|
|
IF text.eof THEN
|
|
INC(lex.pos.col)
|
|
END
|
|
ELSIF (c = 7FX) & upto THEN
|
|
upto := FALSE;
|
|
lex.sym := lxRANGE;
|
|
putchar(lex, ".");
|
|
putchar(lex, ".");
|
|
DEC(lex.pos.col);
|
|
TXT.next(text)
|
|
ELSE
|
|
putchar(lex, c);
|
|
TXT.next(text);
|
|
lex.sym := lxERROR04
|
|
END;
|
|
|
|
IF lex.sym < 0 THEN
|
|
lex.error := -lex.sym
|
|
ELSE
|
|
lex.error := 0
|
|
END
|
|
|
|
UNTIL (lex.sym # lxCOMMENT) & ~text.skip
|
|
|
|
END Next;
|
|
|
|
|
|
PROCEDURE open* (name: ARRAY OF CHAR): SCANNER;
|
|
RETURN TXT.open(name)
|
|
END open;
|
|
|
|
|
|
PROCEDURE close* (VAR scanner: SCANNER);
|
|
BEGIN
|
|
TXT.close(scanner)
|
|
END close;
|
|
|
|
|
|
PROCEDURE init* (lower: BOOLEAN);
|
|
VAR
|
|
i: INTEGER;
|
|
delim: ARRAY 23 OF CHAR;
|
|
|
|
|
|
PROCEDURE enterkw (key: INTEGER; kw: LEXSTR);
|
|
VAR
|
|
id: IDENT;
|
|
upper: LEXSTR;
|
|
|
|
BEGIN
|
|
IF LowerCase THEN
|
|
id := enterid(kw);
|
|
id.key := key
|
|
END;
|
|
upper := kw;
|
|
S.UpCase(upper);
|
|
id := enterid(upper);
|
|
id.key := key
|
|
END enterkw;
|
|
|
|
|
|
BEGIN
|
|
upto := FALSE;
|
|
LowerCase := lower;
|
|
|
|
FOR i := 0 TO 255 DO
|
|
delimiters[i] := FALSE
|
|
END;
|
|
|
|
delim := "+-*/~&.,;|([{^=#<>:)]}";
|
|
|
|
FOR i := 0 TO LEN(delim) - 2 DO
|
|
delimiters[ORD(delim[i])] := TRUE
|
|
END;
|
|
|
|
NEW(NewIdent);
|
|
NewIdent.s := "";
|
|
NewIdent.offset := -1;
|
|
NewIdent.offsetW := -1;
|
|
NewIdent.key := 0;
|
|
|
|
idents := NIL;
|
|
|
|
enterkw(lxARRAY, "array");
|
|
enterkw(lxBEGIN, "begin");
|
|
enterkw(lxBY, "by");
|
|
enterkw(lxCASE, "case");
|
|
enterkw(lxCONST, "const");
|
|
enterkw(lxDIV, "div");
|
|
enterkw(lxDO, "do");
|
|
enterkw(lxELSE, "else");
|
|
enterkw(lxELSIF, "elsif");
|
|
enterkw(lxEND, "end");
|
|
enterkw(lxFALSE, "false");
|
|
enterkw(lxFOR, "for");
|
|
enterkw(lxIF, "if");
|
|
enterkw(lxIMPORT, "import");
|
|
enterkw(lxIN, "in");
|
|
enterkw(lxIS, "is");
|
|
enterkw(lxMOD, "mod");
|
|
enterkw(lxMODULE, "module");
|
|
enterkw(lxNIL, "nil");
|
|
enterkw(lxOF, "of");
|
|
enterkw(lxOR, "or");
|
|
enterkw(lxPOINTER, "pointer");
|
|
enterkw(lxPROCEDURE, "procedure");
|
|
enterkw(lxRECORD, "record");
|
|
enterkw(lxREPEAT, "repeat");
|
|
enterkw(lxRETURN, "return");
|
|
enterkw(lxTHEN, "then");
|
|
enterkw(lxTO, "to");
|
|
enterkw(lxTRUE, "true");
|
|
enterkw(lxTYPE, "type");
|
|
enterkw(lxUNTIL, "until");
|
|
enterkw(lxVAR, "var");
|
|
enterkw(lxWHILE, "while")
|
|
|
|
END init;
|
|
|
|
|
|
PROCEDURE NewDef* (str: ARRAY OF CHAR);
|
|
VAR
|
|
item: DEF;
|
|
|
|
BEGIN
|
|
NEW(item);
|
|
COPY(str, item.ident);
|
|
LISTS.push(def, item)
|
|
END NewDef;
|
|
|
|
|
|
BEGIN
|
|
def := LISTS.create(NIL)
|
|
END SCAN. |