MasterLinux / dzen_lang_parser

A parser for dzen

#Dzen language parser This library provides a parser to interpret the Dzen in-text formating and control language. See https://github.com/robm/dzen for more information about Dzen.

#How-to use ###The beginning Currently there is just one entry point which accepts a cstring and returns a token list.

dzen_list *list = dzen_parse("^fg(red)I'm red text ^fg(blue)I am blue");

###Token iteration To iterate through a dzen_list you can use a dzen_list_iterator which is created with the help of dzen_list_iterator_create(dzen_list *list).

dzen_list_iterator *it = dzen_list_iterator_create(list);

Now you can iterate from the first token to the last or backward.

// iterate forward
while (dzen_list_iterate_forward(it)) {
    char *string_val = it->token->string_value;
}

// iterate backward
while (dzen_list_iterate_backward(it)) {
    char *string_val = it->token->string_value;
}

###The end After working with the token list and an iterator you have to de-allocated these. Whenever you use an iterator you can use dzen_list_iterator_destroy(dzen_list_iterator *iterator). This function frees the iterator only. So it is required to destroy the list also with the help of 'dzen_list_destroy(dzen_list *list)'.

// free list first
dzen_list_destroy(it->list);

// free iterator
dzen_list_iterator_destroy(it);

#Dzen language token A language token represents a logical unit of the input string like a function, a text or a parameter. So the following example input "^fg(red)I'm red text ^fg(blue)I am blue" results in a list with 4 token:

1. Function >> DZEN_TOKEN_TYPE_FUNCTION >> ^fg(red)
2. Text >> DZEN_TOKEN_TYPE_TEXT >> I'm red text
3. Function >> DZEN_TOKEN_TYPE_FUNCTION >> ^fg(blue)
4. Text >> DZEN_TOKEN_TYPE_TEXT >> I am blue

##Token structure A token consists of the following information.

struct dzen_lang_token {
    dzen_token_type type;
    dzen_token_value_modifier *value_modifier;
    char *value;
    struct dzen_token *parameter_list;
};

• type
  • The type of the token like a function or a text
• value_modifier
  • A list of value modifier. Could be NULL
  • For example a modifier is used to represent the + or - in the ^p(+-X) function
• value
  • The value of the token, like the name of a function. Could be NULL
• parameter_list
  • A list of parameter. Could be NULL
  • This field is usually used for parameter with multiple info like the size parameter 2x3 where 2 is the first token in this list and 3 the second one

##Token types ###Function A function consists of a name and a parameter list.