using the external call interface
Here is yet another version of the infix calculator, modified to demonstrate builtin functions that produce formatted text and information for use in diagnostics. It also makes calls on two external procedures whatabout and thisabout.
a ruleset
First, the source code - calc.lmn:
.calc()
'?' expr :N '=' whatabout("this", "that", N); <- eof - ;
'!' expr :N '=' thisabout("baff", "biff", N); <- eof -
say
"variable name: " "N" nl
"variable value: " N nl
"originating state index: " $(varSi (N)) nl
"grammar of originating context: " $(varGsy(N)) nl
"L symbol in mismatch that started the originating context: " $(varLsy(N)) nl
"R symbol in mismatch that started the originating context: " $(varRsy(N)) nl
"name of input file or source object: " $(varIfn(N)) nl
"absolute input position: " $(varCp (N)) nl
"line number: " $(varLn (N)) nl
"character position in line: " $(varCn (N)) nl
output
;
'@' expr :N '=' thisabout("waff", "wiff", N); <- eof -
say
$(format("%60s: %20s", "variable name" ,"N" )) nl
$(format("%60s: %20s", "variable value" , N )) nl
$(format("%60s: %20s", "originating state index" , varSi (N))) nl
$(format("%60s: %20s", "grammar of originating context" , varGsy(N))) nl
$(format("%60s: %20s", "L symbol in mismatch that started the originating context" , varLsy(N))) nl
$(format("%60s: %20s", "R symbol in mismatch that started the originating context" , varRsy(N))) nl
$(format("%60s: %20s", "name of input file or source object" , varIfn(N))) nl
$(format("%60s: %20s", "absolute input position" , varCp (N))) nl
$(format("%60s: %20s", "line number" , varLn (N))) nl
$(format("%60s: %20s", "character position in line" , varCn (N))) nl
$(format("%60s: %20s %s", "you can use any number of arguments" , varCn (N), "(like this)")) nl
output
;
'#' expr :N '=' thisabout("waff", "wiff", N); <- eof - ;
't' expr :N ';' trOn (N); <- eof - ; 'z' expr :N ';' trOff(N); <- eof - ;
- anything <- line - ; eof <- line eof; '\n' <- line ;
'\n' <- eof - ;
say output <- eof - ;
- line var Z; <- eof - say "error: " $(format("line %s char %s", varLn(N), varCn(N))) nl output;
- expr :N '='; <- eof - say "the answer is " N nl output;
- out <- output - ; nl <- output - '\n' ;
.calc(0B)
'(' expr :N ')' <- opnd:N ;
.calc() - opnd :A op <- expr - ; - <- op expr:A;
.calc(10L) '+' expr :B <- op opnd:(A + B); '-' expr :B <- op opnd:(A - B);
.calc(12L) '*' expr :B <- op opnd:(A * B); '/' expr :B <- op opnd:(A / B);
.calc(18L) '-' opnd :A <- opnd:(- A);
.calc(20L)
' ' <- - ;
'0' % { repeat .[0-7] % } octal yes toOct :N <- opnd :N;
[0-9] % { repeat .[0-9] % } { option '.' % repeat [0-9] % } toNum :N <- opnd :N;
'0x' .[0-9a-zA-Z] % { repeat .[0-9a-zA-Z] % } { option '.' % repeat [0-9] % } toHex :N <- opnd :N;
'0b' .[01] % { repeat .[01] % } toBin :N <- opnd :N;
.calc() - <- octal yes; '.' <- octal no ; 'x' <- octal no ; 'b' <- octal no ;
a main program in D
Next, the versions of the main program, including the external procedures that are to be invoked when the rules are applied. This is calcMaind.d, the main program in the D language:
import lm.lmd; import lm.licenseGnuGPLv2;
extern (C) mode lmdInit(inout stream s);
int main(char[][]args) {
writefln("hello from calcMaind");
application a = new application(args, &lmdInit);
int result = a.start();
return result;
}
extern (C) element whatabout(inout stream s, element x, element y, element z) {
writefln("--- whatabout %10s %10s %10s %8s", x, y, z, z.toVal());
var v = z.toVar();
if(v) {
state sta = v.vvc.st;
writefln("%60s: %20s", "variable name" , z);
writefln("%60s: %20s", "variable value" , z.toVal());
writefln("%60s: %20s", "originating state index" , sta.si);
writefln("%60s: %20s", "grammar of originating context" , sta.gr.sy);
writefln("%60s: %20s", "L symbol in mismatch that started the originating context" , sta.lsy);
writefln("%60s: %20s", "R symbol in mismatch that started the originating context" , sta.rsy);
writefln("%60s: %20s", "name of input file or source object" , sta.input.filename);
writefln("%60s: %20s", "absolute input position" , sta.cp);
writefln("%60s: %20s", "line number" , sta.ln);
writefln("%60s: %20s", "character position in line" , sta.cn);
}
return null; }
extern (C) element thisabout(inout stream s, element x, element y, element z) {
writefln("--- thisabout %10s %10s %10s %8s", x, y, z, z.toVal());
return null;
}
a main program in C
Here is the equivalent main program in the C language - calcMainc.c:
// C main calling C compiled rule set using lmcMain to process args #include <lm/lmc.h> #include <lm/licenseGnuGPLv2.h> #include <stdio.h>
int lmcMain(int argc, char ** argv);
int main(int argc, char ** argv)
{
printf("hello from calcMainc\n");
int result = lmcMain(argc, argv);
return result;
}
element whatabout(stream s, element x, element y, element z) {
printf("--- whatabout %10s %10s %10s %8g\n", toCstring(s, x), toCstring(s, y), toCstring(s, z), toNum(s, toVal(s, z)));
var v = toVar(s, z);
if(v) {
printf("%60s: %20s\n", "variable name", toCstring(s, z));
printf("%60s: %20g\n", "variable value", toNum(s, toVal(s, z)));
printf("%60s: %20g\n", "originating state index", toNum(s, varSi (s, v)));
printf("%60s: %20s\n", "grammar of originating context", toCstring(s, varGsy (s, v)));
printf("%60s: %20s\n", "L symbol in mismatch that started the originating context", toCstring(s, varLsy(s, v)));
printf("%60s: %20s\n", "R symbol in mismatch that started the originating context", toCstring(s, varRsy(s, v)));
printf("%60s: %20s\n", "name of input file or source object", toCstring(s, varIfn(s, v)));
printf("%60s: %20g\n", "absolute input position", toNum(s, varCp (s, v)));
printf("%60s: %20g\n", "line number", toNum(s, varLn (s, v)));
printf("%60s: %20g\n", "character position in line", toNum(s, varCn (s, v)));
}
return null; }
element thisabout(stream s, element x, element y, element z) {
printf("--- thisabout %10s %10s %10s %8g\n", toCstring(s, x), toCstring(s, y), toCstring(s, z), toNum(s, toVal(s, z)));
return null;
}
compile the D and C versions
Make two different programs calc.gdc and calc.gcc from the same calc.lmn source, one wrapped as as a D program, the other as a C program:
peri@p2 examples]$ make calc.gdc calc.gcc lmn2d -o calc.d calc.lmn /opt/gdc/bin/gdc -o calc.gdc -I/usr/include -finline-functions -O3 calcMaind.d calc.d -ldl /usr/lib/liblm -Wl,-rpath,/usr/lib/ lmn2c -o calc.c calc.lmn gcc -c calc.c -o calcc.o gcc -c calcMainc.c -o calcMainc.o gcc -o calc.gcc calcc.o calcMainc.o -ldl /usr/lib/liblm -Wl,-rpath,/usr/lib/ -L/opt/gdc/lib/ -lgphobos -lm -lpthread -lc [peri@p2 examples]$
some input
Here is some input that was prepared earlier:
[peri@p2 examples]$ cat calc.input 1= 2= 1+1= 10= 0x10= 0b10= 10.5= 0x10.8= ?1= ?2= ?1+1= ?3*(10-3)= !1= !2= !1+1= !3*(10-3)= @1= @2= @1+1= @3*(10-3)=
compare results
Finally, apply the two programs to the same input and compare the results:
[peri@p2 examples]$ ./calc.gdc calc.input >d.out [peri@p2 examples]$ ./calc.gcc calc.input >c.out [peri@p2 examples]$ diff d.out c.out 1c1 < hello from calcMaind --- > hello from calcMainc
results from D version
The output produced from calc.gdc (the D language version) was:
[peri@p2 examples]$ cat d.out
hello from calcMaind
the answer is 1
the answer is 2
the answer is 2
the answer is 10
the answer is 16
the answer is 2
the answer is 10.5
the answer is 16.5
--- whatabout this that N 1
variable name: N
variable value: 1
originating state index: 88
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: ?
name of input file or source object: calc.input
absolute input position: 44
line number: 9
character position in line: 1
--- whatabout this that N 2
variable name: N
variable value: 2
originating state index: 94
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: ?
name of input file or source object: calc.input
absolute input position: 49
line number: 9
character position in line: 6
--- whatabout this that N 2
variable name: N
variable value: 2
originating state index: 99
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: ?
name of input file or source object: calc.input
absolute input position: 53
line number: 10
character position in line: 1
--- whatabout this that N 21
variable name: N
variable value: 21
originating state index: 110
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: ?
name of input file or source object: calc.input
absolute input position: 60
line number: 10
character position in line: 8
--- thisabout baff biff N 1
variable name: N
variable value: 1
originating state index: 128
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: !
name of input file or source object: calc.input
absolute input position: 71
line number: 11
character position in line: 1
--- thisabout baff biff N 2
variable name: N
variable value: 2
originating state index: 175
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: !
name of input file or source object: calc.input
absolute input position: 76
line number: 11
character position in line: 6
--- thisabout baff biff N 2
variable name: N
variable value: 2
originating state index: 221
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: !
name of input file or source object: calc.input
absolute input position: 80
line number: 12
character position in line: 1
--- thisabout baff biff N 21
variable name: N
variable value: 21
originating state index: 273
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: !
name of input file or source object: calc.input
absolute input position: 87
line number: 12
character position in line: 8
--- thisabout waff wiff N 1
variable name: N
variable value: 1
originating state index: 332
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: @
name of input file or source object: calc.input
absolute input position: 98
line number: 13
character position in line: 1
you can use any number of arguments: 1 (like this)
--- thisabout waff wiff N 2
variable name: N
variable value: 2
originating state index: 373
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: @
name of input file or source object: calc.input
absolute input position: 104
line number: 14
character position in line: 1
you can use any number of arguments: 1 (like this)
--- thisabout waff wiff N 2
variable name: N
variable value: 2
originating state index: 412
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: @
name of input file or source object: calc.input
absolute input position: 108
line number: 15
character position in line: 1
you can use any number of arguments: 1 (like this)
--- thisabout waff wiff N 21
variable name: N
variable value: 21
originating state index: 456
grammar of originating context: calc
L symbol in mismatch that started the originating context: eof
R symbol in mismatch that started the originating context: @
name of input file or source object: calc.input
absolute input position: 114
line number: 16
character position in line: 1
you can use any number of arguments: 1 (like this)