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include <lexnum.h>
include <ctype.h>
include <evexpr.h>
# Parse definitions.
define CONSTANT 257
define IDENTIFIER 258
define NEWLINE 259
define YYEOS 260
define PLUS 261
define MINUS 262
define STAR 263
define SLASH 264
define EXPON 265
define CONCAT 266
define QUEST 267
define COLON 268
define LT 269
define GT 270
define LE 271
define EQ 272
define NE 273
define SE 274
define AND 275
define OR 276
define NOT 277
define AT 278
define GE 279
define UMINUS 280
# XEV_GETTOK -- Lexical analyzer for EVEXPR. Returns the token code as the
# function value. If the token is an operand (identifier or constant) the
# operand value is returned in OUT.
int procedure xev_gettok (ip, out)
pointer ip # pointer into input string (expression)
pointer out # pointer to yacc YYLVAL token value operand
char ch
long lval
double dval
pointer ip_start
int nchars, token, junk
int stridx(), lexnum(), gctod(), gctol()
define ident_ 91
begin
while (IS_WHITE(Memc[ip]))
ip = ip + 1
ch = Memc[ip]
switch (ch) {
case 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z':
# Return an identifier.
ident_
ip_start = ip
while (IS_ALNUM(ch) || stridx (ch, "_.$@#%&;[]\\^{}~") > 0) {
ip = ip + 1
ch = Memc[ip]
}
nchars = ip - ip_start
call xev_initop (out, nchars, TY_CHAR)
call strcpy (Memc[ip_start], O_VALC(out), nchars)
return (IDENTIFIER)
case 'I', '.', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
# Return a numeric constant. The character I vectors here so
# that we can check for INDEF, a legal number.
token = lexnum (Memc, ip, nchars)
switch (token) {
case LEX_OCTAL:
junk = gctol (Memc, ip, lval, 8)
call xev_initop (out, 0, TY_INT)
O_VALI(out) = lval
case LEX_DECIMAL:
junk = gctol (Memc, ip, lval, 10)
call xev_initop (out, 0, TY_INT)
O_VALI(out) = lval
case LEX_HEX:
junk = gctol (Memc, ip, lval, 16)
call xev_initop (out, 0, TY_INT)
O_VALI(out) = lval
case LEX_REAL:
junk = gctod (Memc, ip, dval)
call xev_initop (out, 0, TY_REAL)
if (IS_INDEFD (dval))
O_VALR(out) = INDEFR
else
O_VALR(out) = dval
default:
goto ident_
}
return (CONSTANT)
case '\'', '"':
# Return a string constant.
ip_start = ip + 1
for (ip=ip+1; Memc[ip] != ch && Memc[ip] != EOS; ip=ip+1)
;
nchars = ip - ip_start
if (Memc[ip] == EOS)
call xev_error ("missing closing quote in string constant")
else
ip = ip + 1
call xev_initop (out, nchars, TY_CHAR)
call strcpy (Memc[ip_start], O_VALC(out), nchars)
return (CONSTANT)
case '+':
token = PLUS
case '-':
token = MINUS
case '*':
if (Memc[ip+1] == '*') {
ip = ip + 1
token = EXPON
} else
token = STAR
case '/':
if (Memc[ip+1] == '/') {
ip = ip + 1
token = CONCAT
} else
token = SLASH
case '?':
if (Memc[ip+1] == '=') {
ip = ip + 1
token = SE
} else
token = QUEST
case ':':
token = COLON
case '@':
token = AT
case '<':
if (Memc[ip+1] == '=') {
ip = ip + 1
token = LE
} else
token = LT
case '>':
if (Memc[ip+1] == '=') {
ip = ip + 1
token = GE
} else
token = GT
case '!':
if (Memc[ip+1] == '=') {
ip = ip + 1
token = NE
} else
token = NOT
case '=':
if (Memc[ip+1] == '=') {
ip = ip + 1
token = EQ
} else
token = EQ
case '&':
if (Memc[ip+1] == '&') {
ip = ip + 1
token = AND
} else
token = AND
case '|':
if (Memc[ip+1] == '|') {
ip = ip + 1
token = OR
} else
token = OR
case '(', ')', ',':
token = ch
default:
if (ch == '\n')
token = NEWLINE
else if (ch == EOS)
token = YYEOS
else {
# Anything we don't understand is assumed to be an identifier.
goto ident_
}
}
ip = ip + 1
return (token)
end
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