#include "h.h"
#include <string.h>
static int const lp = '(', rp = ')';
static int let(ui c){return (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z'
    || c >= 0xa000 & c < 0xa490);}
extern int od; // number of primordial values
cp cx = code;
int cd = 0; // current depth
static void cb(ui o) {if(o>255) crsh("invalid op %x\n", 0);
     if(cx-code >= codesize) Bye("Too much code");
     *(cx++) = o;}
ui symbols[md];

void compile(){ui c;
  ui gc(){c = g(); return c;}
  ui gu(){while(1){if(gc()==';') while(gc()!=10) ; else return c;}} // filter comments
  ui sl(){while(gu() == ' ' || c==10) ; return c;} // filter white space
  if(sl() == lp) {
    void nrp(char * c){printf("%s didn't end with a right paren.", c); Bye("");};
    if(sl() == 0x3bb){ // 0x3bb is code point for lambda
        if(cd >= md) Bye("Too many nested levels");
        symbols[cd++] = sl(); cb(255); compile(); --cd;
        if(sl() != rp) nrp("Lambda");}
    else {back(); {cp twoth = cx+1; cb(254); cx+=2; compile();
        {ui siz = cx - (twoth+2);
         if (siz > 1<<16) Bye("Program too big to compile");
        *(us*)twoth = siz;} compile(); 
        if(sl() != rp) nrp("function application");}}}
  else if(c <= '9' && c >= '0') {nis x = c - '0';
     while (gc() <= '9' && c >= '0') {x = 10*x + c - '0';}
      cb(253); back();
      {void pb7(nis w, uchar e) {if(w>127) pb7(w>>7, 0); cb(w & 0x7f | e);}
      pb7(x, 128);}}
  else if(let(c)) {int j = cd;
      while(j--) if(c == symbols[j]) {cb(cd-j-1); return;}
      printf("Free variable %d deep, 0x%x, %c\n", cd-od, c, c); Bye("");}
  else {printf("Screwy text, expecting expression: 0x%x, %c\n", c, c);
        Bye("");}}