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#include "lambda.h"
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "parser_table_p.h"
class Parser: protected parser_table
{
public:
union Value {
int ival;
// ### more...
};
public:
Parser();
~Parser();
bool parse();
protected:
inline void reallocateStack();
inline Value &sym(int index)
{ return sym_stack [tos + index - 1]; }
int nextToken();
void consumeRule(int ruleno);
protected:
int tos;
int stack_size;
Value *sym_stack;
int *state_stack;
int current_char;
unsigned in_tag: 1;
};
inline void Parser::reallocateStack()
{
if (! stack_size)
stack_size = 128;
else
stack_size <<= 1;
sym_stack = reinterpret_cast<Value*> (::realloc(sym_stack, stack_size * sizeof(Value)));
state_stack = reinterpret_cast<int*> (::realloc(state_stack, stack_size * sizeof(int)));
}
Parser::Parser():
tos(0),
stack_size(0),
sym_stack(0),
state_stack(0)
{
}
Parser::~Parser()
{
if (stack_size) {
::free(sym_stack);
::free(state_stack);
}
}
bool Parser::parse()
{
const int INITIAL_STATE = 0;
current_char = 0;
in_tag = 0;
int yytoken = -1;
reallocateStack();
tos = 0;
state_stack[++tos] = INITIAL_STATE;
while (true)
{
if (yytoken == -1 && - TERMINAL_COUNT != action_index [state_stack [tos]])
yytoken = nextToken();
int act = t_action (state_stack [tos], yytoken);
if (act == ACCEPT_STATE) {
return true;
}
else if (act > 0)
{
if (++tos == stack_size)
reallocateStack();
sym_stack [tos].ival = current_char; // ### save the token value here
state_stack [tos] = act;
yytoken = -1;
}
else if (act < 0)
{
int r = - act - 1;
tos -= rhs [r];
act = state_stack [tos++];
consumeRule (r);
state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT);
}
else
break;
}
return false;
}
int Parser::nextToken()
{
static int tokens[] = { ID, ID, ID, EOF_SYMBOL };
static int *tk = tokens;
return *tk++;
}
void Parser::consumeRule(int ruleno)
{
switch (ruleno) {
case Symbol:
printf("symbol\n");
break;
case SubExpression:
printf("sub-expr\n");
break;
case Appl:
printf("appl\n");
break;
case Abstr:
printf("abstr\n");
break;
}
}
/////////////////////////////
// entry point
/////////////////////////////
int main()
{
Parser parser;
if (parser.parse())
printf ("OK\n");
else
printf ("KO\n");
}
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