Update lexer, start of implementing parser

Jan Breuer

2013-03-22 4d39507183e0ace2d73f04817a398e858b66b677

 libscpi/src/lexer.c

@@ -217,79 +217,62 @@
}

/* 7.6.1 <COMMAND PROGRAM HEADER> */
int SCPI_LexCommonProgramHeader(lex_state_t * state, token_t * token) {
    token->ptr = state->pos;
    
static int skipCommonProgramHeader(lex_state_t * state) {
    if (skipStar(state)) {
        if(!skipProgramMnemonic(state)) {
            state->pos--;
        } else {
            return 1;
        }
    }
    
    token->len = state->pos - token->ptr;
    
    if((token->len > 0)) {
        token->type = TokCommonProgramHeader;
    } else {
        token->type = TokUnknown;
        state->pos = token->ptr;
        token->len = 0;
    }
    
    return token->len;
    return 0;
}

int SCPI_LexCompoundProgramHeader(lex_state_t * state,  token_t * token) {
    token->ptr = state->pos;
static int skipCompoundProgramHeader(lex_state_t * state) {
    const char * rollback = state->pos;
    
    skipColon(state);
    
    if(skipProgramMnemonic(state)) {
        while(skipColon(state)) {
            if(!skipProgramMnemonic(state)) {
                // TODO: lexer error
                break;
                state->pos = rollback;
                return 0;
            }
        }
    }
    
    token->len = state->pos - token->ptr;
    
    if((token->len > 0)) {
        token->type = TokCompoundProgramHeader;
        return 1;
    } else {
        token->type = TokUnknown;
        state->pos = token->ptr;
        token->len = 0;
        state->pos = rollback;        
        return 0;
    }
    
    return token->len;
}

int SCPI_LexProgramHeader(lex_state_t * state,  token_t * token) {
    int res;
    
    res = SCPI_LexCommonProgramHeader(state, token);
    if(res > 0) return res;
    
    res = SCPI_LexCompoundProgramHeader(state, token);
    if(res > 0) return res;
    
    return 0;
}

int SCPI_LexQuestion(lex_state_t * state, token_t * token) {
    token->ptr = state->pos;
    token->type = TokUnknown;
    
    if (skipChr(state, '?')) {
        token->len = 1;
        token->type = TokQuiestion;
    } else {
        token->len = 0;
        token->type = TokUnknown;
    if(skipCommonProgramHeader(state)) {
        if (skipChr(state, '?')) {
            token->type = TokCommonQueryProgramHeader;
        } else {
            token->type = TokCommonProgramHeader;
        }
    } else if(skipCompoundProgramHeader(state)) {
        if (skipChr(state, '?')) {
            token->type = TokCompoundQueryProgramHeader;
        } else {
            token->type = TokCompoundProgramHeader;
        }
    }
    
    return token->len;
    if (token->type != TokUnknown) {
        token->len = state->pos - token->ptr;
    } else {
        token->len = 0;
        state->pos = token->ptr;
    }
    
    return token->len;    
}

/* 7.7.1 <CHARACTER PROGRAM DATA> */