shortcode/shortcodes.rl

#include <string.h>
#include "shortcodes.h"

%%{
  machine shortcode;

  action mark {
    mark = p;
  }

  spc = space*;
  sep = space+;
  path = (alnum | '/' )+;

  name = (alpha+ path?)
    > mark
    %{ sc_list[c_sc].name.start = mark-start;
       sc_list[c_sc].name.len = p-mark;
       sc_list[c_sc].matching = 0;
      };
  argname = alpha+
    > mark
    % {
      sc_list[c_sc].argnames[sc_list[c_sc].argcount].start = mark-start;
      sc_list[c_sc].argnames[sc_list[c_sc].argcount].len = p-mark;
    };
  qvalue = ('"' [^"]* '"')
    > mark
    % {
      sc_list[c_sc].argvals[sc_list[c_sc].argcount].start = mark-start+1;
      sc_list[c_sc].argvals[sc_list[c_sc].argcount].len = p-mark-2;
      sc_list[c_sc].argcount++;
    };

  value = alnum+
    > mark
    % {
      sc_list[c_sc].argvals[sc_list[c_sc].argcount].start = mark-start;
      sc_list[c_sc].argvals[sc_list[c_sc].argcount].len = p-mark;
      sc_list[c_sc].argcount++;
    };

  arg = ((argname '=')? (value|qvalue));

  start_p = ('{{%');
  end_p = '%}}';

  start_b = ('{{<');
  end_b = '>}}';

  content = spc name (sep arg)* spc;

  start = start_p | start_b ;
  end = end_p | end_b ;

  mismatched = ((start_p content end_b) | (start_b content end_p)) 
  @{
    // Since it's mismatched, remove the name
    sc_list[c_sc].name.start = 0;
    sc_list[c_sc].name.len=0;
    result.errors[result.errcount].position = p-start-2;
    result.errors[result.errcount].code = ERR_MISMATCHED_BRACKET;
    result.errcount++;
  };

  shortcode = ((start_p content end_p) | (start_b content end_b))
  > {
      sc_list[c_sc].whole.start = p-start-1;
    }
  @ {
      sc_list[c_sc].whole.len = p-start-sc_list[c_sc].whole.start+1;
      data_mark = p+1;
      c_sc++;
    };

  closing_shortcode = (start spc '/' name spc end)
  > {
    // Starting a "closing" shortcode ( {{ /foo }}), 
    // close data (if previous shortcode is opening)
    // If previous shortcode was closing, then previous 
    // text can't be data.
    if (sc_list[c_sc-1].matching == 0) {
      sc_list[c_sc-1].data.start = data_mark-start;
      sc_list[c_sc-1].data.len = p-data_mark-1;
    }
  };

  matched_shortcode = (shortcode any* closing_shortcode)
  @ {
    if (
        sc_list[c_sc-1].name.len != sc_list[c_sc].name.len ||
        strncmp(
          start + sc_list[c_sc-1].name.start,
          start + sc_list[c_sc].name.start,
          sc_list[c_sc-1].name.len) !=0) 
    {
      result.errors[result.errcount].position = 
          sc_list[c_sc].whole.start;
      result.errors[result.errcount].code = ERR_MISMATCHED_CLOSING_TAG;
      result.errcount++;
    } else {
      // The previous shortcode is matching (mark it)
      sc_list[c_sc-1].matching = 1;
      sc_list[c_sc-1].whole.len = p-start-sc_list[c_sc-1].whole.start + 1;
    }
    // Reuse the closing shortcode tag entry for next one
    sc_list[c_sc].name.start = 0;
    sc_list[c_sc].name.len=0;
};

  main := (any* (shortcode | matched_shortcode | mismatched))*;
}%%


sc_result parse(char *input) {

  %%write data;
  char *eof, *ts, *te = 0;
  int cs, act = 0;

  char *start = input;
  char *p = input;
  char *pe = p + strlen(input);

  sc_result result;
  shortcode *sc_list = result.sc; 
  int c_sc = 0;

  char *mark = p;
  char *data_mark = p;

  %% write init;
  %% write exec;

  return result;
}