crs.mod
来自「一个Modula-2语言分析器」· MOD 代码 · 共 373 行
MOD
373 行
IMPLEMENTATION MODULE CRS;
(* Scanner generated by Coco/R - assuming FileIO library will be available. *)
IMPORT FileIO, Storage;
CONST
noSym = 41; (*error token code*)
(* not only for errors but also for not finished states of scanner analysis *)
eof = 32C (* MS-DOS Keyboard eof char *);
EOF = FileIO.EOF;
EOL = FileIO.CR;
CR = FileIO.CR;
LF = FileIO.LF;
Long0 = FileIO.Long0;
Long1 = FileIO.Long1;
BlkSize = 16384;
TYPE
BufBlock = ARRAY [0 .. BlkSize-1] OF CHAR;
Buffer = ARRAY [0 .. 31] OF POINTER TO BufBlock;
StartTable = ARRAY [0 .. 255] OF INTEGER;
GetCH = PROCEDURE (INT32): CHAR;
VAR
lastCh,
ch: CHAR; (*current input character*)
curLine: INTEGER; (*current input line (may be higher than line)*)
lineStart: INT32; (*start position of current line*)
apx: INT32; (*length of appendix (CONTEXT phrase)*)
oldEols: INTEGER; (*number of EOLs in a comment*)
bp, bp0: INT32; (*current position in buf
(bp0: position of current token)*)
LBlkSize: INT32; (*BlkSize*)
inputLen: INT32; (*source file size*)
buf: Buffer; (*source buffer for low-level access*)
start: StartTable; (*start state for every character*)
CurrentCh: GetCH;
PROCEDURE ORDL (n: INT32): CARDINAL;
BEGIN
RETURN FileIO.ORDL(n)
END ORDL;
PROCEDURE Err (nr, line, col: INTEGER; pos: INT32);
BEGIN
INC(errors)
END Err;
PROCEDURE NextCh;
(* Return global variable ch *)
BEGIN
lastCh := ch; INC(bp); ch := CurrentCh(bp);
IF (ch = EOL) OR (ch = FileIO.LF) AND (lastCh # EOL) THEN
INC(curLine); lineStart := bp
END
END NextCh;
PROCEDURE Comment (): BOOLEAN;
VAR
level, startLine: INTEGER;
oldLineStart: INT32;
BEGIN
level := 1; startLine := curLine; oldLineStart := lineStart;
IF (ch = "/") THEN
NextCh;
IF (ch = "*") THEN
NextCh;
LOOP
IF (ch = "*") THEN
NextCh;
IF (ch = "/") THEN
DEC(level); NextCh;
IF level = 0 THEN RETURN TRUE END
END;
ELSIF ch = EOF THEN RETURN FALSE
ELSE NextCh END;
END; (* LOOP *)
ELSE
IF (ch = CR) OR (ch = LF) THEN
DEC(curLine); lineStart := oldLineStart
END;
DEC(bp); ch := lastCh;
END;
END;
IF (ch = "(") THEN
NextCh;
IF (ch = "*") THEN
NextCh;
LOOP
IF (ch = "*") THEN
NextCh;
IF (ch = ")") THEN
DEC(level); NextCh;
IF level = 0 THEN RETURN TRUE END
END;
ELSIF (ch = "(") THEN
NextCh;
IF (ch = "*") THEN INC(level); NextCh END;
ELSIF ch = EOF THEN RETURN FALSE
ELSE NextCh END;
END; (* LOOP *)
ELSE
IF (ch = CR) OR (ch = LF) THEN
DEC(curLine); lineStart := oldLineStart
END;
DEC(bp); ch := lastCh;
END;
END;
RETURN FALSE;
END Comment;
PROCEDURE Get (VAR sym: CARDINAL);
VAR
state: CARDINAL;
PROCEDURE Equal (s: ARRAY OF CHAR): BOOLEAN;
VAR
i: CARDINAL;
q: INT32;
BEGIN
IF nextLen # FileIO.SLENGTH(s) THEN RETURN FALSE END;
i := 1; q := bp0; INC(q);
WHILE i < nextLen DO
IF CurrentCh(q) # s[i] THEN RETURN FALSE END;
INC(i); INC(q)
END;
RETURN TRUE
END Equal;
PROCEDURE CheckLiteral;
BEGIN
CASE CurrentCh(bp0) OF
"A": IF Equal("ANY") THEN sym := 23;
END
| "C": IF Equal("CASE") THEN sym := 19;
ELSIF Equal("CHARACTERS") THEN sym := 10;
ELSIF Equal("CHR") THEN sym := 24;
ELSIF Equal("COMMENTS") THEN sym := 14;
ELSIF Equal("COMPILER") THEN sym := 5;
ELSIF Equal("CONTEXT") THEN sym := 34;
END
| "E": IF Equal("END") THEN sym := 9;
END
| "F": IF Equal("FROM") THEN sym := 15;
END
| "I": IF Equal("IGNORE") THEN sym := 18;
END
| "N": IF Equal("NAMES") THEN sym := 12;
ELSIF Equal("NESTED") THEN sym := 17;
END
| "P": IF Equal("PRAGMAS") THEN sym := 13;
ELSIF Equal("PRODUCTIONS") THEN sym := 6;
END
| "S": IF Equal("SYNC") THEN sym := 33;
END
| "T": IF Equal("TO") THEN sym := 16;
ELSIF Equal("TOKENS") THEN sym := 11;
END
| "W": IF Equal("WEAK") THEN sym := 28;
END
ELSE
END
END CheckLiteral;
BEGIN (*Get*)
WHILE (ch=' ') OR
(ch >= CHR(9)) & (ch <= CHR(10)) OR
(ch = CHR(13)) DO NextCh END;
IF ((ch = "/") OR (ch = "(")) & Comment() THEN Get(sym); RETURN END;
pos := nextPos; nextPos := bp;
col := nextCol; nextCol := FileIO.INTL(bp - lineStart);
line := nextLine; nextLine := curLine;
len := nextLen; nextLen := 0;
apx := FileIO.Long0; state := start[ORD(ch)]; bp0 := bp;
LOOP
NextCh; INC(nextLen);
CASE state OF
1: IF (ch >= "0") & (ch <= "9") OR
(ch >= "A") & (ch <= "Z") OR
(ch = "_") OR
(ch >= "a") & (ch <= "z") THEN
ELSE sym := 1; CheckLiteral; RETURN
END;
| 2: sym := 2; RETURN
| 3: sym := 3; RETURN
| 4: IF (ch >= "0") & (ch <= "9") THEN
ELSE sym := 4; RETURN
END;
| 5: IF (ch >= "0") & (ch <= "9") OR
(ch >= "A") & (ch <= "Z") OR
(ch = "_") OR
(ch >= "a") & (ch <= "z") THEN
ELSE sym := 42; RETURN
END;
| 6: IF (ch = CHR(0)) OR
(ch >= " ") & (ch <= "!") OR
(ch >= "#") THEN
ELSIF (ch = CHR(10)) OR
(ch = CHR(13)) THEN state := 3;
ELSIF (ch = '"') THEN state := 2;
ELSE sym := noSym; RETURN
END;
| 7: IF (ch = CHR(0)) OR
(ch >= " ") & (ch <= "&") OR
(ch >= "(") THEN
ELSIF (ch = CHR(10)) OR
(ch = CHR(13)) THEN state := 3;
ELSIF (ch = "'") THEN state := 2;
ELSE sym := noSym; RETURN
END;
| 8: sym := 7; RETURN
| 9: IF (ch = ".") THEN state := 12;
ELSIF (ch = ">") THEN state := 23;
ELSIF (ch = ")") THEN state := 25;
ELSE sym := 8; RETURN
END;
| 10: sym := 20; RETURN
| 11: sym := 21; RETURN
| 12: sym := 22; RETURN
| 13: IF (ch = ".") THEN state := 24;
ELSE sym := 25; RETURN
END;
| 14: sym := 26; RETURN
| 15: sym := 27; RETURN
| 16: sym := 29; RETURN
| 17: sym := 30; RETURN
| 18: sym := 31; RETURN
| 19: sym := 32; RETURN
| 20: IF (ch = ".") THEN state := 22;
ELSE sym := 35; RETURN
END;
| 21: sym := 36; RETURN
| 22: sym := 37; RETURN
| 23: sym := 38; RETURN
| 24: sym := 39; RETURN
| 25: sym := 40; RETURN
| 26: sym := 0; ch := 0C; DEC(bp); RETURN
ELSE sym := noSym; RETURN (*NextCh already done*)
END
END
END Get;
PROCEDURE GetString (pos: INT32; len: CARDINAL; VAR s: ARRAY OF CHAR);
VAR
i: CARDINAL;
p: INT32;
BEGIN
IF len > HIGH(s) THEN len := HIGH(s) END;
p := pos; i := 0;
WHILE i < len DO
s[i] := CharAt(p); INC(i); INC(p)
END;
s[len] := 0C;
END GetString;
PROCEDURE GetName (pos: INT32; len: CARDINAL; VAR s: ARRAY OF CHAR);
VAR
i: CARDINAL;
p: INT32;
BEGIN
IF len > HIGH(s) THEN len := HIGH(s) END;
p := pos; i := 0;
WHILE i < len DO
s[i] := CurrentCh(p); INC(i); INC(p)
END;
s[len] := 0C;
END GetName;
PROCEDURE CharAt (pos: INT32): CHAR;
VAR
ch: CHAR;
BEGIN
IF pos >= inputLen THEN RETURN FileIO.EOF END;
ch := buf[FileIO.ORDL(pos DIV LBlkSize)]^[FileIO.ORDL(pos MOD LBlkSize)];
IF ch # eof THEN RETURN ch ELSE RETURN FileIO.EOF END
END CharAt;
PROCEDURE CapChAt (pos: INT32): CHAR;
VAR
ch: CHAR;
BEGIN
IF pos >= inputLen THEN RETURN FileIO.EOF END;
ch := CAP(buf[FileIO.ORDL(pos DIV LBlkSize)]^[FileIO.ORDL(pos MOD LBlkSize)]);
IF ch # eof THEN RETURN ch ELSE RETURN FileIO.EOF END
END CapChAt;
PROCEDURE Reset;
VAR
len: INT32;
i, read: CARDINAL;
BEGIN (*assert: src has been opened*)
len := FileIO.Length(src); i := 0; inputLen := len;
WHILE len > LBlkSize DO
Storage.ALLOCATE(buf[i], BlkSize);
read := BlkSize; FileIO.ReadBytes(src, buf[i]^, read);
len := len - FileIO.INT(read); INC(i)
END;
Storage.ALLOCATE(buf[i], FileIO.ORDL(len) + 1);
read := FileIO.ORDL(len); FileIO.ReadBytes(src, buf[i]^, read);
buf[i]^[read] := EOF;
curLine := 1; lineStart := -FileIO.Long2; bp := -FileIO.Long1;
oldEols := 0; apx := FileIO.Long0; errors := 0;
NextCh;
END Reset;
BEGIN
CurrentCh := CharAt;
start[ 0] := 26; start[ 1] := 27; start[ 2] := 27; start[ 3] := 27;
start[ 4] := 27; start[ 5] := 27; start[ 6] := 27; start[ 7] := 27;
start[ 8] := 27; start[ 9] := 27; start[ 10] := 27; start[ 11] := 27;
start[ 12] := 27; start[ 13] := 27; start[ 14] := 27; start[ 15] := 27;
start[ 16] := 27; start[ 17] := 27; start[ 18] := 27; start[ 19] := 27;
start[ 20] := 27; start[ 21] := 27; start[ 22] := 27; start[ 23] := 27;
start[ 24] := 27; start[ 25] := 27; start[ 26] := 27; start[ 27] := 27;
start[ 28] := 27; start[ 29] := 27; start[ 30] := 27; start[ 31] := 27;
start[ 32] := 27; start[ 33] := 27; start[ 34] := 6; start[ 35] := 27;
start[ 36] := 5; start[ 37] := 27; start[ 38] := 27; start[ 39] := 7;
start[ 40] := 13; start[ 41] := 14; start[ 42] := 27; start[ 43] := 10;
start[ 44] := 27; start[ 45] := 11; start[ 46] := 9; start[ 47] := 27;
start[ 48] := 4; start[ 49] := 4; start[ 50] := 4; start[ 51] := 4;
start[ 52] := 4; start[ 53] := 4; start[ 54] := 4; start[ 55] := 4;
start[ 56] := 4; start[ 57] := 4; start[ 58] := 27; start[ 59] := 27;
start[ 60] := 20; start[ 61] := 8; start[ 62] := 21; start[ 63] := 27;
start[ 64] := 27; start[ 65] := 1; start[ 66] := 1; start[ 67] := 1;
start[ 68] := 1; start[ 69] := 1; start[ 70] := 1; start[ 71] := 1;
start[ 72] := 1; start[ 73] := 1; start[ 74] := 1; start[ 75] := 1;
start[ 76] := 1; start[ 77] := 1; start[ 78] := 1; start[ 79] := 1;
start[ 80] := 1; start[ 81] := 1; start[ 82] := 1; start[ 83] := 1;
start[ 84] := 1; start[ 85] := 1; start[ 86] := 1; start[ 87] := 1;
start[ 88] := 1; start[ 89] := 1; start[ 90] := 1; start[ 91] := 16;
start[ 92] := 27; start[ 93] := 17; start[ 94] := 27; start[ 95] := 1;
start[ 96] := 27; start[ 97] := 1; start[ 98] := 1; start[ 99] := 1;
start[100] := 1; start[101] := 1; start[102] := 1; start[103] := 1;
start[104] := 1; start[105] := 1; start[106] := 1; start[107] := 1;
start[108] := 1; start[109] := 1; start[110] := 1; start[111] := 1;
start[112] := 1; start[113] := 1; start[114] := 1; start[115] := 1;
start[116] := 1; start[117] := 1; start[118] := 1; start[119] := 1;
start[120] := 1; start[121] := 1; start[122] := 1; start[123] := 18;
start[124] := 15; start[125] := 19; start[126] := 27; start[127] := 27;
start[128] := 27; start[129] := 27; start[130] := 27; start[131] := 27;
start[132] := 27; start[133] := 27; start[134] := 27; start[135] := 27;
start[136] := 27; start[137] := 27; start[138] := 27; start[139] := 27;
start[140] := 27; start[141] := 27; start[142] := 27; start[143] := 27;
start[144] := 27; start[145] := 27; start[146] := 27; start[147] := 27;
start[148] := 27; start[149] := 27; start[150] := 27; start[151] := 27;
start[152] := 27; start[153] := 27; start[154] := 27; start[155] := 27;
start[156] := 27; start[157] := 27; start[158] := 27; start[159] := 27;
start[160] := 27; start[161] := 27; start[162] := 27; start[163] := 27;
start[164] := 27; start[165] := 27; start[166] := 27; start[167] := 27;
start[168] := 27; start[169] := 27; start[170] := 27; start[171] := 27;
start[172] := 27; start[173] := 27; start[174] := 27; start[175] := 27;
start[176] := 27; start[177] := 27; start[178] := 27; start[179] := 27;
start[180] := 27; start[181] := 27; start[182] := 27; start[183] := 27;
start[184] := 27; start[185] := 27; start[186] := 27; start[187] := 27;
start[188] := 27; start[189] := 27; start[190] := 27; start[191] := 27;
start[192] := 27; start[193] := 27; start[194] := 27; start[195] := 27;
start[196] := 27; start[197] := 27; start[198] := 27; start[199] := 27;
start[200] := 27; start[201] := 27; start[202] := 27; start[203] := 27;
start[204] := 27; start[205] := 27; start[206] := 27; start[207] := 27;
start[208] := 27; start[209] := 27; start[210] := 27; start[211] := 27;
start[212] := 27; start[213] := 27; start[214] := 27; start[215] := 27;
start[216] := 27; start[217] := 27; start[218] := 27; start[219] := 27;
start[220] := 27; start[221] := 27; start[222] := 27; start[223] := 27;
start[224] := 27; start[225] := 27; start[226] := 27; start[227] := 27;
start[228] := 27; start[229] := 27; start[230] := 27; start[231] := 27;
start[232] := 27; start[233] := 27; start[234] := 27; start[235] := 27;
start[236] := 27; start[237] := 27; start[238] := 27; start[239] := 27;
start[240] := 27; start[241] := 27; start[242] := 27; start[243] := 27;
start[244] := 27; start[245] := 27; start[246] := 27; start[247] := 27;
start[248] := 27; start[249] := 27; start[250] := 27; start[251] := 27;
start[252] := 27; start[253] := 27; start[254] := 27; start[255] := 27;
Error := Err; LBlkSize := FileIO.INT(BlkSize); lastCh := EOF;
END CRS.
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