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|
%{
include <ctype.h>
define YYMAXDEPTH 32
define YYOPLEN 1
define yyparse unit_parse
define SZ_SHORTSTR 31
%L
include "parseunits.com"
char units[SZ_FNAME]
int num_unstr()
pointer mul_unstr(), div_unstr(), pow_unstr(), set_unstr()
%}
%token Y_WRONG Y_DONE Y_LPAR Y_RPAR Y_CU Y_SQ Y_ID Y_NUM
%left Y_DIV
%left Y_MUL
%right Y_POW
%%
unit : expr Y_DONE {
# Normal exit. Return pointer to units structure
if (debug == YES)
call eprintf ("\n")
tun = Memi[$1]
return (OK)
}
| error {
# Syntax error
if (debug == YES)
call eprintf ("\n")
return (ERR)
}
;
expr : Y_LPAR expr Y_RPAR {
# Parenthesized expression
Memi[$$] = Memi[$1]
}
| expr Y_MUL expr {
# Multiply two units expressions
Memi[$$] = mul_unstr (Memi[$1], Memi[$3])
call free_unstr (Memi[$1])
call free_unstr (Memi[$3])
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| expr Y_DIV expr {
# Divide two units expressions
Memi[$$] = div_unstr (Memi[$1], Memi[$3])
call free_unstr (Memi[$1])
call free_unstr (Memi[$3])
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| expr Y_POW Y_NUM {
# Raise expression to a power
Memi[$$] = pow_unstr (Memi[$1], num_unstr (Memc[Memi[$3]]))
call free_unstr (Memi[$1])
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| termlist {
# List of terms
Memi[$$] = Memi[$1]
}
;
termlist: termlist term {
# Implicit multiplication
Memi[$$] = mul_unstr (Memi[$1], Memi[$2])
call free_unstr (Memi[$1])
call free_unstr (Memi[$2])
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| term {
# Simple term
Memi[$$] = Memi[$1]
}
;
term : Y_ID Y_POW Y_NUM {
# Raise units to a power
Memi[$$] = set_unstr (abrev, Memc[Memi[$1]],
num_unstr (Memc[Memi[$3]]))
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| Y_ID Y_NUM {
# Implicitly raise to a power
Memi[$$] = set_unstr (abrev, Memc[Memi[$1]],
num_unstr (Memc[Memi[$2]]))
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| Y_CU Y_ID {
# Cubic prefix
Memi[$$] = set_unstr (abrev, Memc[Memi[$2]], 3)
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| Y_SQ Y_ID {
# Square prefix
Memi[$$] = set_unstr (abrev, Memc[Memi[$2]], 2)
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
| Y_ID {
# Simple name
Memi[$$] = set_unstr (abrev, Memc[Memi[$1]], 1)
if (debug == YES) {
call str_unstr (Memi[$$], units, SZ_FNAME)
call eprintf ("Units are %s\n")
call pargstr (units)
}
}
;
%%
# PARSE_UNITS -- Parse a units string into the internal format
pointer procedure parse_units (ab, units)
pointer ab # i: abbreviation hash table
char units[ARB] # i: expression to be parsed
#--
include "parseunits.com"
int len, fd
pointer sp
string syntax "Syntax error in units"
bool yydebug
int strlen(), stropen(), yyparse()
int get_token()
extern get_token
begin
len = strlen (units) + 1
fd = stropen (units, len, READ_ONLY)
call smark (sp)
call salloc (tokbuf, SZ_FNAME, TY_CHAR)
debug = NO
yydebug = (debug == YES)
nxttok = 0
abrev = ab
tun = NULL
if (yyparse (fd, yydebug, get_token) == ERR)
call tuniterr (syntax, units)
call close (fd)
call sfree (sp)
return (tun)
end
# GET_TOKEN -- Retrieve next token from units string
int procedure get_token (fd, value)
int fd # i: File containing expression to be lexed
pointer value # o: Address on parse stack to store token
#--
include "parseunits.com"
char ch
int type, index, powers[4]
pointer sp, typename, token
string pownames "sq,square,cu,cubic"
data powers / Y_SQ, Y_SQ, Y_CU, Y_CU /
bool streq()
int getc(), word_match()
begin
call smark (sp)
call salloc (typename, SZ_FNAME, TY_CHAR)
token = tokbuf + nxttok
Memi[value] = token
repeat {
ch = getc (fd, ch)
} until (ch != ' ' && ch != '\t')
if (ch == EOF) {
type = Y_DONE
call strcpy ("END", Memc[typename], SZ_FNAME)
} else if (IS_ALPHA (ch)) {
type = Y_ID
call strcpy ("IDENT", Memc[typename], SZ_FNAME)
while (IS_ALPHA (ch)) {
Memc[tokbuf+nxttok] = ch
nxttok = nxttok + 1
ch = getc (fd, ch)
}
call ungetc (fd, ch)
Memc[tokbuf+nxttok] = EOS
index = word_match (Memc[token], pownames)
if (index > 0) {
type = powers[index]
call strcpy ("POWER", Memc[typename], SZ_FNAME)
} else if (streq (Memc[token], "per")) {
type = Y_DIV
call strcpy ("DIV", Memc[typename], SZ_FNAME)
}
} else if (ch == '-' || IS_DIGIT (ch)) {
type = Y_NUM
call strcpy ("NUMBER", Memc[typename], SZ_FNAME)
Memc[tokbuf+nxttok] = ch
nxttok = nxttok + 1
ch = getc (fd, ch)
while (IS_DIGIT (ch)) {
Memc[tokbuf+nxttok] = ch
nxttok = nxttok + 1
ch = getc (fd, ch)
}
call ungetc (fd, ch)
} else {
Memc[tokbuf+nxttok] = ch
nxttok = nxttok + 1
switch (ch) {
case '*':
ch = getc (fd, ch)
if (ch == '*') {
type = Y_POW
call strcpy ("EXPON", Memc[typename], SZ_FNAME)
Memc[tokbuf+nxttok] = ch
nxttok = nxttok + 1
} else {
type = Y_MUL
call strcpy ("MUL", Memc[typename], SZ_FNAME)
call ungetc (fd, ch)
}
case '/':
type = Y_DIV
call strcpy ("DIV", Memc[typename], SZ_FNAME)
case '^':
type = Y_POW
call strcpy ("EXPON", Memc[typename], SZ_FNAME)
default:
type = Y_WRONG
call strcpy ("ERROR", Memc[typename], SZ_FNAME)
}
}
Memc[tokbuf+nxttok] = EOS
nxttok = nxttok + 1
if (debug == YES) {
call eprintf ("Token is %s [%s]\n")
if (Memc[token] == EOS) {
call pargstr ("EOS")
} else {
call pargstr (Memc[token])
}
call pargstr (Memc[typename])
}
call sfree (sp)
return (type)
end
|
