+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
#include <string>
#include <map>
#include <stack>
enum ValueType { VAL_NUM, VAL_VEC, VAL_STR };
struct Value {
ValueType type;
- char *str;
+ std::string s;
float v[4];
};
+struct ParserState;
+
+typedef bool (*Func)(ParserState*);
+
+struct FuncDesc {
+ Func func;
+ int arity;
+};
+
struct ParserState {
FILE *fp;
const char *fname;
std::stack<Value> val;
std::map<std::string, Value> var;
- std::string last_mod_var;
+ std::map<std::string, FuncDesc> func;
std::map<std::string, Gear*> gears;
+ std::stack<Gear*> cur_gear;
+ Motor *cur_motor;
};
#define MAX_ID_LEN 31
static bool machine(ParserState *ps);
static bool expect(ParserState *ps, char c);
static bool statement(ParserState *ps);
-static bool ident(ParserState *ps, std::string *s);
-static bool gear(ParserState *ps);
static bool expression(ParserState *ps);
+static bool term(ParserState *ps);
+static bool vector(ParserState *ps);
+static bool function(ParserState *ps, const char *name);
static char *get_ident(ParserState *ps, char *buf, int bsz);
+static bool get_number(ParserState *ps, float *num);
+static char *get_string(ParserState *ps, char *buf, int bsz);
static bool nextchar(ParserState *ps);
static void putback(ParserState *ps, char c);
+static void errmsg(ParserState *ps, const char *fmt, ...);
static void expected(ParserState *ps, const char *str);
static void set_var(ParserState *ps, const char *name, const Value &value);
static bool have_var(ParserState *ps, const char *name);
static const Value &get_var(ParserState *ps, const char *name);
+static void set_func(ParserState *ps, const char *name, Func func, int nargs = 0);
+static bool have_func(ParserState *ps, const char *name);
+static Func get_func(ParserState *ps, const char *name);
+static int get_func_arity(ParserState *ps, const char *name);
+
+static Gear *begin_gear(ParserState *ps);
+static bool end_gear(ParserState *ps);
+static Gear *this_gear(ParserState *ps);
static void update_gear_vars(ParserState *ps, Gear *gear);
static bool set_gear_var(Gear *gear, const char *name, const Value &val);
+static void update_motor_vars(ParserState *ps, Motor *motor);
+static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val);
+
+// built-in functions
+static bool func_adjacent(ParserState *ps);
+
+
bool parse_machine(Machine *mcn, const char *fname)
{
FILE *fp = fopen(fname, "rb");
pstate.nerrors = 0;
pstate.fp = fp;
pstate.mcn = mcn;
- pstate.nextc = fgetc(fp); // prime the parser
+ pstate.nextc = 0;
pstate.savedc = -1;
+ pstate.cur_motor = 0;
+
+ // init built-in function table
+ set_func(&pstate, "adjacent", func_adjacent, 2);
+ nextchar(&pstate);
bool res = machine(&pstate);
fclose(fp);
return res;
return true;
}
-static bool expect(ParserState *ps, int c)
+static bool expect(ParserState *ps, char c)
{
if(c != ps->nextc) {
char buf[2] = {0, 0};
}
if(strcmp(id, "gear") == 0) {
- if(!get_ident(ps, id, sizeof id)) {
- fprintf(stderr, "gear name missing\n");
+ if(!expect(ps, '{')) {
return false;
}
- expect(ps, '{');
- Gear *gear = new Gear;
- gear->name = id;
- ps->gears[id] = gear;
+ Gear *gear = begin_gear(ps);
+ if(!gear) return false;
+
update_gear_vars(ps, gear);
while(ps->nextc != '}') {
if(!statement(ps)) {
return false;
}
- update_gear_vars(ps, gear);
}
expect(ps, '}');
- ps->mcn->add_gear(gear);
+ if(!end_gear(ps)) {
+ return false;
+ }
+ return true;
+ }
+
+ if(strcmp(id, "motor") == 0) {
+ if(!expect(ps, '{')) {
+ return false;
+ }
+ if(ps->cur_motor) {
+ errmsg(ps, "nested motors not allowed");
+ return false;
+ }
+
+ ps->cur_motor = new Motor;
+ update_motor_vars(ps, ps->cur_motor);
+
+ while(ps->nextc != '}') {
+ if(!statement(ps)) {
+ return false;
+ }
+ }
+ expect(ps, '}');
+
+ ps->mcn->add_motor(ps->cur_motor->drive, ps->cur_motor->speed);
+ delete ps->cur_motor;
+ ps->cur_motor = 0;
+ return true;
}
if(ps->nextc == '=') {
set_var(ps, id, ps->val.top());
ps->val.pop();
- ps->last_mod_var = id;
+ return true;
}
+
+ expected(ps, "expression");
+ return false;
}
static bool expression(ParserState *ps)
{
- // TODO
+ return term(ps);
+}
+
+static bool term(ParserState *ps)
+{
+ if(ps->nextc == '+') {
+ expect(ps, '+');
+ return expression(ps);
+ }
+ if(ps->nextc == '-') {
+ expect(ps, '-');
+ if(!expression(ps)) {
+ return false;
+ }
+
+ Value &v = ps->val.top();
+ switch(v.type) {
+ case VAL_VEC:
+ v.v[3] = -v.v[3];
+ v.v[2] = -v.v[2];
+ v.v[1] = -v.v[1];
+ case VAL_NUM:
+ v.v[0] = -v.v[0];
+ break;
+
+ default:
+ expected(ps, "number or vector after an unary -");
+ return false;
+ }
+ return true;
+ }
+ if(isalpha(ps->nextc)) {
+ char buf[MAX_ID_LEN];
+ if(!get_ident(ps, buf, sizeof buf)) {
+ return false;
+ }
+
+ if(ps->nextc == '(') {
+ if(!function(ps, buf)) {
+ return false;
+ }
+ } else if(have_var(ps, buf)) {
+ ps->val.push(get_var(ps, buf));
+ } else {
+ errmsg(ps, "unknown identifier: %s", buf);
+ return false;
+ }
+ return true;
+ }
+ if(isdigit(ps->nextc)) {
+ float num;
+ if(!get_number(ps, &num)) {
+ return false;
+ }
+
+ Value v;
+ v.type = VAL_NUM;
+ v.v[0] = num;
+ ps->val.push(v);
+ return true;
+ }
+ if(ps->nextc == '[') {
+ return vector(ps);
+ }
+ if(ps->nextc == '"') {
+ char buf[MAX_ID_LEN];
+ if(!get_string(ps, buf, sizeof buf)) {
+ return false;
+ }
+
+ Value v;
+ v.type = VAL_STR;
+ v.s = buf;
+ ps->val.push(v);
+ return true;
+ }
+
+ expected(ps, "term");
+ return false;
+}
+
+static bool vector(ParserState *ps)
+{
+ int nelem;
+ if(!expect(ps, '[') ||
+ !expression(ps) ||
+ !expect(ps, ',') ||
+ !expression(ps) ||
+ !expect(ps, ',') ||
+ !expression(ps)) {
+ return false;
+ }
+
+ if(ps->nextc == ']') {
+ expect(ps, ']');
+ nelem = 3;
+ } else {
+ if(!expect(ps, ',') || !expression(ps) || !expect(ps, ']')) {
+ return false;
+ }
+ nelem = 4;
+ }
+
+ Value vec;
+ vec.type = VAL_VEC;
+ vec.v[3] = 1.0f;
+
+ for(int i=0; i<nelem; i++) {
+ const Value &tmp = ps->val.top();
+ if(tmp.type != VAL_NUM) {
+ expected(ps, "numbers as vector elements");
+ return false;
+ }
+ vec.v[i] = tmp.v[0];
+ ps->val.pop();
+ }
+
+ ps->val.push(vec);
+ return true;
+}
+
+static bool function(ParserState *ps, const char *name)
+{
+ if(!expect(ps, '(')) {
+ return false;
+ }
+
+ if(!have_func(ps, name)) {
+ errmsg(ps, "unknown function: %s", name);
+ return false;
+ }
+
+ int nargs = 0;
+ while(ps->nextc != ')') {
+ if(nargs && !expect(ps, ',')) {
+ return false;
+ }
+ if(!expression(ps)) {
+ return false;
+ }
+ ++nargs;
+ }
+ expect(ps, ')');
+
+ int arity = get_func_arity(ps, name);
+ if(arity != nargs) {
+ errmsg(ps, "function %s expects %d arguments", name, arity);
+ return false;
+ }
+ Func func = get_func(ps, name);
+ assert(func);
+
+ if(!func(ps)) {
+ errmsg(ps, "function %s failed", name);
+ return false;
+ }
+ return true;
}
static char *get_ident(ParserState *ps, char *buf, int bsz)
expected(ps, "identifier");
return 0;
}
- while((isalnum(ps->nextc) || ps->nextc == '_')) {
+ while(isalnum(ps->nextc) || ps->nextc == '_') {
if(bsz > 1) {
*ptr++ = ps->nextc;
--bsz;
nextchar(ps);
}
*ptr = 0;
+ printf("get_ident -> \"%s\"\n", buf);
+ return buf;
+}
+
+static bool get_number(ParserState *ps, float *num)
+{
+ char buf[256], *ptr = buf, *end = buf + sizeof buf;
+ bool found_point = false;
+
+ if(!isdigit(ps->nextc)) {
+ expected(ps, "number");
+ return false;
+ }
+
+ while(isdigit(ps->nextc) || (ps->nextc == '.' && !found_point)) {
+ if(ptr < end) {
+ *ptr++ = ps->nextc;
+ }
+ if(ps->nextc == '.') {
+ found_point = true;
+ }
+ nextchar(ps);
+ }
+ *ptr = 0;
+
+ *num = atof(buf);
+ printf("get_number -> %f\n", *num);
+ return true;
+}
+
+static char *get_string(ParserState *ps, char *buf, int bsz)
+{
+ char *ptr = buf;
+ if(!expect(ps, '"')) {
+ return 0;
+ }
+
+ while(ps->nextc != -1 && ps->nextc != '"') {
+ if(bsz > 1) {
+ *ptr++ = ps->nextc;
+ --bsz;
+ }
+ if((ps->nextc = fgetc(ps->fp)) == '\n') {
+ ++ps->nline;
+ }
+ }
+ *ptr = 0;
+
+ if(ps->nextc == -1) {
+ return 0;
+ }
+ nextchar(ps);
+
+ printf("get_string -> \"%s\"\n", buf);
return buf;
}
-static bool skip_line(FILE *fp)
+static bool skip_line(ParserState *ps)
{
int c;
- while((c = fgetc(fp)) != -1 && c != '\n');
- return c != -1;
+ while((c = fgetc(ps->fp)) != -1 && c != '\n');
+ if(c != -1) {
+ ps->nextc = fgetc(ps->fp);
+ return true;
+ }
+ return false;
}
static bool nextchar(ParserState *ps)
while((ps->nextc = fgetc(ps->fp)) != -1) {
if(ps->nextc == '#') {
- if(!skip_line(ps->fp)) {
+ if(!skip_line(ps)) {
return false;
}
++ps->nline;
}
}
+ /*if(ps->nextc != -1) {
+ printf("DBG: nextchar -> %c\n", ps->nextc);
+ } else {
+ printf("DBG: nextchar -> EOF\n");
+ }*/
return ps->nextc != -1;
}
ps->nextc = c;
}
+static void errmsg(ParserState *ps, const char *fmt, ...)
+{
+ fprintf(stderr, "%s line %d error: ", ps->fname, ps->nline);
+
+ va_list ap;
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+
+ fputc('\n', stderr);
+}
+
static void expected(ParserState *ps, const char *str)
{
- fprintf(stderr, "%s line %d error, expected: %s\n", ps->fname, ps->nline, str);
+ errmsg(ps, "expected: %s", str);
++ps->nerrors;
}
static void set_var(ParserState *ps, const char *name, const Value &value)
{
ps->var[name] = value;
+
+ Gear *gear = this_gear(ps);
+ if(gear) {
+ set_gear_var(gear, name, value);
+ }
+
+ if(ps->cur_motor) {
+ set_motor_var(ps, ps->cur_motor, name, value);
+ }
}
static bool have_var(ParserState *ps, const char *name)
return ps->var[name];
}
+static void set_func(ParserState *ps, const char *name, Func func, int nargs)
+{
+ FuncDesc fdesc;
+ fdesc.func = func;
+ fdesc.arity = nargs;
+ ps->func[name] = fdesc;
+}
+
+static bool have_func(ParserState *ps, const char *name)
+{
+ return ps->func.find(name) != ps->func.end();
+}
+
+static Func get_func(ParserState *ps, const char *name)
+{
+ return ps->func[name].func;
+}
+
+static int get_func_arity(ParserState *ps, const char *name)
+{
+ return ps->func[name].arity;
+}
+
static void print_value(const Value &val, FILE *fp)
{
switch(val.type) {
break;
case VAL_STR:
- fprintf(fp, "\"%s\"", val.str);
+ fprintf(fp, "\"%s\"", val.s.c_str());
break;
default:
// Gear-specific stuff
-static void update_gear_vars(ParserState *ps, Gear *gear)
+static Gear *begin_gear(ParserState *ps)
+{
+ Gear *res = new Gear;
+ ps->cur_gear.push(res);
+ return res;
+}
+
+static bool end_gear(ParserState *ps)
{
- if(!ps->last_mod_var.empty()) {
- const char *name = ps->last_mod_var.c_str();
- set_gear_var(gear, name, get_var(ps, name));
- ps->last_mod_var.clear();
- return;
+ if(ps->cur_gear.empty()) {
+ errmsg(ps, "parser error: unbalanced end_gear");
+ return false;
+ }
+ Gear *gear = ps->cur_gear.top();
+ ps->cur_gear.pop();
+
+ printf("DBG: end_gear: %s\n", gear->name.c_str());
+
+ if(gear->name.empty() || ps->gears[gear->name]) {
+ char buf[32];
+ sprintf(buf, "gear%04d", (int)ps->gears.size());
+ gear->name = buf;
}
+ printf("DBG: adding gear: %s\n", gear->name.c_str());
+ ps->gears[gear->name] = gear;
+ ps->mcn->add_gear(gear);
+ return true;
+}
+static Gear *this_gear(ParserState *ps)
+{
+ return ps->cur_gear.empty() ? 0 : ps->cur_gear.top();
+}
+
+static void update_gear_vars(ParserState *ps, Gear *gear)
+{
std::map<std::string, Value>::const_iterator it = ps->var.begin();
while(it != ps->var.end()) {
set_gear_var(gear, it->first.c_str(), it->second);
}
}
-
#define ASSERT_TYPE(v, t) \
do { \
if((v).type != (t)) { \
static bool set_gear_var(Gear *gear, const char *name, const Value &val)
{
- if(strcmp(name, "position") == 0) {
+ if(strcmp(name, "name") == 0) {
+ ASSERT_TYPE(val, VAL_STR);
+ gear->name = val.s;
+
+ } else if(strcmp(name, "position") == 0) {
ASSERT_TYPE(val, VAL_VEC);
gear->pos = VVEC3(val);
return true;
}
+
+
+// motor stuff
+
+static void update_motor_vars(ParserState *ps, Motor *motor)
+{
+ std::map<std::string, Value>::const_iterator it = ps->var.begin();
+ while(it != ps->var.end()) {
+ set_motor_var(ps, motor, it->first.c_str(), it->second);
+ ++it;
+ }
+}
+
+static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val)
+{
+ if(strcmp(name, "drive") == 0) {
+ ASSERT_TYPE(val, VAL_STR);
+ Gear *gear = ps->gears[val.s];
+ if(!gear) {
+ errmsg(ps, "undefined gear: %s", val.s.c_str());
+ return false;
+ }
+ int idx = ps->mcn->get_gear_index(gear);
+ assert(idx >= 0);
+ motor->drive = idx;
+
+ } else if(strcmp(name, "speed") == 0) {
+ ASSERT_TYPE(val, VAL_NUM);
+ motor->speed = val.v[0];
+
+ } else {
+ return false;
+ }
+ return true;
+}
+
+
+// built-in functions
+static bool func_adjacent(ParserState *ps)
+{
+ Value val_dir = ps->val.top(); ps->val.pop();
+ Value val_gear_name = ps->val.top(); ps->val.pop();
+
+ if(val_gear_name.type != VAL_STR) {
+ expected(ps, "gear name (string) as 1st arg to adjacent");
+ return false;
+ }
+ if(val_dir.type != VAL_VEC) {
+ expected(ps, "direction vector as 2nd arg to adjacent");
+ return false;
+ }
+
+ Gear *gthis = this_gear(ps);
+ if(!gthis) {
+ errmsg(ps, "adjacent: called outside of a gear block");
+ return false;
+ }
+
+ Gear *gother = ps->gears[val_gear_name.s];
+ if(!gother) {
+ errmsg(ps, "adjacent: gear \"%s\" not found", val_gear_name.s.c_str());
+ return false;
+ }
+
+ Vec3 dir = Vec3(val_dir.v[0], val_dir.v[1], val_dir.v[2]);
+
+ float sum_radii = gthis->radius + gother->radius;
+ float avg_teeth_len = (gthis->teeth_length + gother->teeth_length) * 0.5;
+ Vec3 pos = gother->pos + normalize(dir) * (sum_radii - avg_teeth_len * 0.75);
+
+ Value res;
+ res.type = VAL_VEC;
+ res.v[0] = pos.x;
+ res.v[1] = pos.y;
+ res.v[2] = pos.z;
+ ps->val.push(res);
+ return true;
+}
projects / antikythera / commitdiff