pike.git / src / builtin.cmod

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pike.git/src/builtin.cmod:1:   /* -*- c -*- -  * $Id: builtin.cmod,v 1.30 2001/06/05 00:03:57 mast Exp $ +  * $Id: builtin.cmod,v 1.31 2001/06/05 10:11:52 hubbe Exp $    */      #include "global.h"   #include "interpret.h"   #include "svalue.h"   #include "opcodes.h"   #include "pike_macros.h"   #include "object.h"   #include "program.h"   #include "array.h"
pike.git/src/builtin.cmod:549:       default:    SIMPLE_BAD_ARG_ERROR("function_object",1,"function");    }    pop_n_elems(args);    push_int(0);   }          + /*! @decl int random(int max) +  *! +  *! This function returns a random number in the range 0 - @[max]-1. +  *! +  *! @seealso +  *! @[random_seed()] +  */ + PIKEFUN mixed random(mixed arg) +  efun; +  optflags OPT_TRY_OPTIMIZE|OPT_EXTERNAL_DEPEND; +  type function(int:int)|function(object:mixed)|function(array(1=mixed):1)|function(mapping(2=mixed:3=mixed):array(2|3))|function(multiset(4=mixed):4)|function(float:float); + { +  switch(arg->type) +  { +  case T_OBJECT: +  pop_n_elems(args-1); +  apply(Pike_sp[-1].u.object,"_random",0); +  stack_swap(); +  pop_stack(); +  return; +  +  case T_INT: +  { +  INT_TYPE i=arg->u.integer; +  pop_n_elems(args); +  if(i <= 0) +  { +  push_int(0); +  }else{ +  push_int( my_rand() % i); +  } +  return; +  } +  +  case T_FLOAT: +  { +  FLOAT_TYPE f=arg->u.float_number; +  pop_n_elems(args); +  if(f<=0.0) +  { +  push_float(0.0); +  }else{ + #define N 1048576 +  push_float(f * (my_rand()%N/((float)N)) + +  f * (my_rand()%N/( ((float)N) * ((float)N) ))); +  +  } +  return; +  } +  +  case T_ARRAY: +  { +  struct array *a=arg->u.array; +  if(!a->size) +  SIMPLE_BAD_ARG_ERROR("random", 1, "array with elements in it"); +  push_svalue(a->item + (my_rand() % a->size)); +  stack_swap(); +  pop_stack(); +  return; +  } +  +  case T_MULTISET: +  { +  struct multiset *m=arg->u.multiset; +  if(!m->ind->size) +  SIMPLE_BAD_ARG_ERROR("random", 1, "multiset with elements in it"); +  push_svalue(m->ind->item + (my_rand() % m->ind->size)); +  stack_swap(); +  pop_stack(); +  return; +  } +  +  case T_MAPPING: +  { +  struct mapping *m=arg->u.mapping; +  struct mapping_data *md=m->data; +  size_t bucket, count; +  struct keypair *k; +  +  if(!m_sizeof(m)) +  SIMPLE_BAD_ARG_ERROR("random", 1, "mapping with elements in it"); +  +  /* Find a random, nonempty bucket */ +  bucket=my_rand() % md->hashsize; +  while(! md->hash[bucket] ) +  if(++bucket > (size_t)md->hashsize) +  bucket=0; +  +  /* Count entries in bucket */ +  count=0; +  for(k=md->hash[bucket];k;k=k->next) count++; +  +  /* Select a random entry in this bucket */ +  count = my_rand() % count; +  k=md->hash[bucket]; +  while(count-- > 0) k=k->next; +  +  /* Push result and return */ +  push_svalue(&k->ind); +  push_svalue(&k->val); +  f_aggregate(2); +  stack_swap(); +  pop_stack(); +  return; +  } +  } + } +  +    void init_builtin(void)   {   INIT   }