#include <math.h></math.h>

#include <ctype.h></ctype.h>

#include <stdio.h></stdio.h>

#include <stdlib.h></stdlib.h>

#include <limits.h></limits.h>

#include <string.h></string.h>

typedef unsigned int U32;

typedef float        F32;

typedef enum {

  LT_NONE = 0,

  LT_KEY,

  LT_INT,

  LT_FLOAT,

} LexType;

typedef struct {

  LexType type;

  union {

    U32 u;

    F32 f;

  };

} Lex;

typedef struct {

  Lex *data;

  size_t size;

} LexList;

const char **keys;

int keysCnt;

static inline int iskey(const Lex *l, U32 k)

  { return l && l->type == LT_KEY && l->u == k; }

static inline const char* skipSpaces(const char *s)

  { while(isspace(*s)) ++s; return s; }

void lexPrint(const Lex *l, FILE *f) {

  if (!f) f = stdout;

  switch(l->type) {

  case LT_NONE:

    fprintf(f, "[none]");

    break;

  case LT_KEY:

    if (l->u < keysCnt) fprintf(f, "[key:%d:%s]", l->u, keys[l->u]);

                   else fprintf(f, "[key:%d]", l->u);

    break;

  case LT_INT:

    fprintf(f, "[int:%x:%d]", l->u, l->u);

    break;

  case LT_FLOAT:

    fprintf(f, "[float:%x:%g]", l->u, l->f);

    break;

  default:

    fprintf(f, "[unknown:%u:%08x]", l->type, l->u);

    break;

  }

}

void lexChainPrint(const Lex *l, FILE *f) {

  do { lexPrint(l, f); } while((l++)->type);

}

int lexParseEnd(Lex *l, const char **p) {

  const char *s = skipSpaces(*p);

  if (*s) return 0;

  l->type = LT_NONE;

  *p = s;

  return 1;

}

int lexParseKey(Lex *l, const char **p) {

  const char *s = skipSpaces(*p);

  size_t maxlen = 0;

  U32 key = 0;

  for(U32 i = 1; i < keysCnt; ++i) {

    size_t len = strlen(keys[i]);

    if (len > maxlen && 0 == strncmp(s, keys[i], len))

      { key = i; maxlen = len; }

  }

  if (!key) return 0;

  l->type = LT_KEY;

  l->u = key;

  *p = s + maxlen;

  return 1;

}

int lexParseNum(Lex *l, const char **p) {

  const char *s = skipSpaces(*p);

  const char *s0 = s;

  U32 factor = 10;

  if (*s == '0') {

    ++s;

    if (*s >= '0' && *s <= '7') factor = 8; else

      if (*s == 'x' || *s == 'X') { s0 = ++s; factor = 16; }

  }

  U32 iv = 0;

  double fv = 0;

  while(1) {

    U32 d = 0;

    if (*s >= '0' && *s <= '9') d = *s - '0'; else

      if (*s >= 'a' && *s <= 'f') d = *s - 'a' + 10; else

        if (*s >= 'A' && *s <= 'F') d = *s - 'A' + 10; else

          break;

    if (d >= factor) break;

    iv = iv*factor + d;

    fv = fv*factor + d;

    ++s;

  }

  int success = 0;

  if (s > s0) {

    l->type = LT_INT;

    l->u = iv;

    *p = s;

    success = 1;

  }

  if (factor != 10) return success;

  s0 = s;

  if (*s == '.') {

    ++s;

    double f = 1;

    while(*s >= '0' && *s <= '9')

      fv += (f *= 0.1)*(*s++ - '0');

  }

  if (s > s0 && (*s == 'e' || *s == 'E')) {

    double e = 0;

    double sign = (*s == '-' || *s == '+') && (*s++ == '-') ? -1 : 1;

    s0 = s;

    while(*s >= '0' && *s <= '9')

      e = e*10 + (*s++ - '0');

    fv *= pow(10, e*sign);

  }

  if (s <= s0) return success;

  if (*s == 'f') ++s;

  l->type = LT_FLOAT;

  l->f = fv;

  *p = s;

  return 1;

}

void lexListDeinit(LexList *ll)

  { free(ll->data); memset(ll, 0, sizeof(*ll)); }

Lex* lexListAdd(LexList *ll) {

  ++ll->size;

  ll->data = (Lex*)realloc(ll->data, sizeof(*ll->data) * ll->size);

  if (!ll->data) { fprintf(stderr, "out of memory\n"); exit(1); }

  Lex *l = ll->data + ll->size - 1;

  memset(l, 0, sizeof(*l));

  return l;

}

void lexListPrint(const LexList *ll, FILE *f) {

  if (!f) f = stdout;

  fprintf(f, "count %zu: ", ll->size);

  for(size_t i = 0; i < ll->size; ++i)

    lexPrint(ll->data + i, f);

  fprintf(f, "\n");

}

int lexListParse(LexList *ll, const char *s) {

  lexListDeinit(ll);

  Lex *l = lexListAdd(ll);

  while(1) {

    if (lexParseEnd(l, &s)) break;

    if (!lexParseKey(l, &s) && !lexParseNum(l, &s))

      { fprintf(stderr, "lex parse error at: %s\n", s); return 0; }

    l = lexListAdd(ll);

  }

  return 1;

}

Lex* lexParse(const char *s) {

  LexList ll = {};

  lexListParse(&ll, s);

  return ll.data;

}