/****************************************************************************
**
** This file is part of the $PACKAGE_NAME$.
**
** Copyright (C) $THISYEAR$ $COMPANY_NAME$.
**
** $QT_EXTENDED_DUAL_LICENSE$
**
****************************************************************************/

#include <QList>
#include <QByteArray>


QT_BEGIN_NAMESPACE
struct Keyword {
    const char *lexem;
    const char *token;
};

struct State
{
    State(const char* token) : token(token)
    {
        ::memset(next, 0, sizeof(next));
    }
    State(const State &other) : token(other.token)
    {
        ::memcpy(next, other.next, sizeof(next));
    }
    State &operator=(const State &other)
    {
        token = other.token;
        ::memcpy(next, other.next, sizeof(next));
        return *this;
    }

    QByteArray token;
    int next[128];
};

Keyword keywords[] =
{
    {"<", "LANGLE" },
    {">", "RANGLE" },
    {"+", "PLUS" },
    {"-", "MINUS" },
    {"*", "STAR" },
    {"==", "EQUALS" },
    {"&&", "AND" },
    {".", "DOT"},
    {"true", "TOKEN_TRUE"},
    {"false", "TOKEN_FALSE"},
    {" ", "WHITESPACE"},
    {"\t", "WHITESPACE"},
    {0, 0}
};

bool is_character(char s)
{
    return (s >= 'a' && s <= 'z') ||
           (s >= 'A' && s <= 'Z') ||
           (s >= '0' && s <= '9') ||
           s == '_';
}

void newState(QList<State> &states, const char *token, const char *lexem)
{
    int state = 0;
    bool character = is_character(*lexem);

    while(*lexem) {
        int next = states[state].next[(int)*lexem];

        if(!next) {
            next = states.size();
            states += State(character?"CHARACTER":"INCOMPLETE");
            states[state].next[(int)*lexem] = next;
        }

        state = next;
        ++lexem;
        character = character && is_character(*lexem);
    }

    states[state].token = token;
}

void newState(QList<State> &states, const char *token, char lexem)
{
    int next = states[0].next[(int)lexem];
    if(!next) {
        next = states.size();
        states += State(token);
        states[0].next[(int)lexem] = next;
    } else {
        states[next].token = token;
    }
}

int main()
{
    QList<State> states;
    states += State("NOTOKEN");

    // identifiers
    for (int cc = 'a'; cc <= 'z'; ++cc)
        newState(states, "CHARACTER", cc);
    for (int cc = 'A'; cc <= 'Z'; ++cc)
        newState(states, "CHARACTER", cc);
    newState(states, "CHARACTER", '_');

    // add digits
    for(int cc = '0'; cc <= '9'; ++cc)
        newState(states, "DIGIT", cc);

    // keywords
    for(int ii = 0; keywords[ii].lexem; ++ii)
        newState(states, keywords[ii].token, keywords[ii].lexem);

    ::printf("static const struct\n{\n"
             "    Token token;\n"
             "    char next[128];\n"
             "} keywords[] = {\n");

    for(int ii = 0; ii < states.size(); ++ii) {
        printf("%s    { %s, { ", ii?",\n":"", states[ii].token.data());
        for(int jj = 0; jj < 128; jj++) 
            printf("%s%d", jj?",":"", states[ii].next[jj]);
        printf(" } }");
    }

    printf("\n};\n");
}
QT_END_NAMESPACE