/* * blogc: A blog compiler. * Copyright (C) 2015-2016 Rafael G. Martins * * This program can be distributed under the terms of the BSD License. * See the file LICENSE. */ #ifdef HAVE_CONFIG_H #include #endif /* HAVE_CONFIG_H */ #include #include #include #include "content-parser.h" // this is a half ass implementation of a markdown-like syntax. bugs are // expected. feel free to improve the parser and add new features. char* blogc_slugify(const char *str) { if (str == NULL) return NULL; char *new_str = sb_strdup(str); int diff = 'a' - 'A'; // just to avoid magic numbers for (size_t i = 0; new_str[i] != '\0'; i++) { if (new_str[i] >= 'a' && new_str[i] <= 'z') continue; if (new_str[i] >= '0' && new_str[i] <= '9') continue; if (new_str[i] >= 'A' && new_str[i] <= 'Z') new_str[i] += diff; else new_str[i] = '-'; } return new_str; } char* blogc_htmlentities(const char *str) { if (str == NULL) return NULL; sb_string_t *rv = sb_string_new(); for (size_t i = 0; str[i] != '\0'; i++) { switch (str[i]) { case '&': sb_string_append(rv, "&"); break; case '<': sb_string_append(rv, "<"); break; case '>': sb_string_append(rv, ">"); break; case '"': sb_string_append(rv, """); break; case '\'': sb_string_append(rv, "'"); break; case '/': sb_string_append(rv, "/"); break; default: sb_string_append_c(rv, str[i]); } } return sb_string_free(rv, false); } typedef enum { CONTENT_START_LINE = 1, CONTENT_EXCERPT, CONTENT_EXCERPT_END, CONTENT_HEADER, CONTENT_HEADER_TITLE_START, CONTENT_HEADER_TITLE, CONTENT_HTML, CONTENT_HTML_END, CONTENT_BLOCKQUOTE, CONTENT_BLOCKQUOTE_START, CONTENT_BLOCKQUOTE_END, CONTENT_CODE, CONTENT_CODE_START, CONTENT_CODE_END, CONTENT_UNORDERED_LIST_OR_HORIZONTAL_RULE, CONTENT_HORIZONTAL_RULE, CONTENT_UNORDERED_LIST_START, CONTENT_UNORDERED_LIST_END, CONTENT_ORDERED_LIST, CONTENT_ORDERED_LIST_SPACE, CONTENT_ORDERED_LIST_START, CONTENT_ORDERED_LIST_END, CONTENT_PARAGRAPH, CONTENT_PARAGRAPH_END, } blogc_content_parser_state_t; typedef enum { LINK_CLOSED = 1, LINK_IMAGE, LINK_TEXT, LINK_TEXT_CLOSE, LINK_URL, LINK_AUTO, LINK_AUTO_CLOSE, } blogc_content_parser_link_state_t; char* blogc_content_parse_inline(const char *src) { // this function is always called by blogc_content_parse or by itself, // then its safe to assume that src is always nul-terminated. size_t src_len = strlen(src); size_t current = 0; size_t start = 0; size_t start_state = 0; size_t end = 0; sb_string_t *rv = sb_string_new(); bool open_em_ast = false; bool open_strong_ast = false; bool open_em_und = false; bool open_strong_und = false; bool open_code = false; bool open_code_double = false; blogc_content_parser_link_state_t state = LINK_CLOSED; bool is_image = false; char *tmp = NULL; char *tmp2 = NULL; unsigned int open_bracket = 0; unsigned int spaces = 0; bool escape = false; while (current < src_len) { char c = src[current]; bool is_last = current == src_len - 1; if (escape) { if (state == LINK_CLOSED) sb_string_append_c(rv, c); current++; escape = false; continue; } if (c != ' ' && c != '\n' && c != '\r') spaces = 0; if (state == LINK_TEXT_CLOSE && c != ' ' && c != '\n' && c != '\r' && c != '(') { sb_string_append_c(rv, src[start_state]); tmp = blogc_content_parse_inline(src + start_state + 1); sb_string_append(rv, tmp); // no need to free here, we will exit the loop! break; } switch (c) { case '\\': if (state == LINK_CLOSED && (open_code || open_code_double)) { sb_string_append_c(rv, c); break; } if (!escape) escape = true; break; case '*': case '_': if (state == LINK_CLOSED && (open_code || open_code_double)) { sb_string_append_c(rv, c); break; } if (!is_last && src[current + 1] == c) { current++; if ((c == '*' && open_strong_ast) || (c == '_' && open_strong_und)) { if (state == LINK_CLOSED) sb_string_append(rv, ""); if (c == '*') open_strong_ast = false; else open_strong_und = false; break; } if (state == LINK_CLOSED) sb_string_append(rv, ""); if (c == '*') open_strong_ast = true; else open_strong_und = true; break; } if ((c == '*' && open_em_ast) || (c == '_' && open_em_und)) { if (state == LINK_CLOSED) sb_string_append(rv, ""); if (c == '*') open_em_ast = false; else open_em_und = false; break; } if (state == LINK_CLOSED) sb_string_append(rv, ""); if (c == '*') open_em_ast = true; else open_em_und = true; break; case '`': if (!is_last && src[current + 1] == c) { current++; if (state == LINK_CLOSED) sb_string_append_printf(rv, "<%scode>", open_code_double ? "/" : ""); open_code_double = !open_code_double; break; } if (state == LINK_CLOSED) sb_string_append_printf(rv, "<%scode>", open_code ? "/" : ""); open_code = !open_code; break; case '!': if (state == LINK_CLOSED) { if (open_code || open_code_double) { sb_string_append_c(rv, c); break; } if (!is_last && src[current + 1] != '[') { sb_string_append_c(rv, c); break; } state = LINK_IMAGE; is_image = true; start_state = current; } break; case '[': if (state == LINK_CLOSED && (open_code || open_code_double)) { sb_string_append_c(rv, c); break; } if (state == LINK_CLOSED || state == LINK_IMAGE) { if (state == LINK_CLOSED) start_state = current; state = LINK_TEXT; start = current + 1; open_bracket = 0; break; } if (state == LINK_TEXT) { if (current == start) { start = current + 1; state = LINK_AUTO; break; } open_bracket++; break; } break; case ']': if (state == LINK_AUTO) { end = current; state = LINK_AUTO_CLOSE; break; } if (state == LINK_AUTO_CLOSE) { state = LINK_CLOSED; tmp = sb_strndup(src + start, end - start); sb_string_append_printf(rv, "%s", tmp, tmp); end = 0; free(tmp); tmp = NULL; is_image = false; break; } if (state == LINK_TEXT) { if (open_bracket-- == 0) { state = LINK_TEXT_CLOSE; tmp = sb_strndup(src + start, current - start); tmp2 = blogc_content_parse_inline(tmp); free(tmp); tmp = NULL; } break; } if (state == LINK_CLOSED) sb_string_append_c(rv, c); break; case '(': if (state == LINK_TEXT_CLOSE) { state = LINK_URL; start = current + 1; break; } if (state == LINK_CLOSED) sb_string_append_c(rv, c); break; case ')': if (state == LINK_URL) { state = LINK_CLOSED; tmp = sb_strndup(src + start, current - start); if (is_image) sb_string_append_printf(rv, "\"%s\"", tmp, tmp2); else sb_string_append_printf(rv, "%s", tmp, tmp2); free(tmp); tmp = NULL; free(tmp2); tmp2 = NULL; is_image = false; break; } if (state == LINK_CLOSED) sb_string_append_c(rv, c); break; case ' ': if (state == LINK_CLOSED) { spaces++; sb_string_append_c(rv, c); } if (!is_last) break; case '\n': case '\r': if (state == LINK_CLOSED) { if (spaces >= 2) { sb_string_append(rv, "
"); spaces = 0; } if (c == '\n' || c == '\r') sb_string_append_c(rv, c); } break; case '-': if (state != LINK_CLOSED) break; if ((current < (src_len - 1) && src[current + 1] == '-') && !(open_code || open_code_double)) { if (current < (src_len - 2) && src[current + 2] == '-') { sb_string_append(rv, "—"); current += 2; } else { sb_string_append(rv, "–"); current += 1; } } else { sb_string_append_c(rv, c); } break; case '&': if (state == LINK_CLOSED) sb_string_append(rv, "&"); break; case '<': if (state == LINK_CLOSED) sb_string_append(rv, "<"); break; case '>': if (state == LINK_CLOSED) sb_string_append(rv, ">"); break; case '"': if (state == LINK_CLOSED) sb_string_append(rv, """); break; case '\'': if (state == LINK_CLOSED) sb_string_append(rv, "'"); break; case '/': if (state == LINK_CLOSED) sb_string_append(rv, "/"); break; default: if (state == LINK_CLOSED) sb_string_append_c(rv, c); } if (is_last && state != LINK_CLOSED) { sb_string_append_c(rv, src[start_state]); tmp = blogc_content_parse_inline(src + start_state + 1); sb_string_append(rv, tmp); // no need to free here, its the last iteration } current++; } free(tmp); free(tmp2); return sb_string_free(rv, false); } bool blogc_is_ordered_list_item(const char *str, size_t prefix_len) { if (str == NULL) return false; if (strlen(str) < 2) return false; size_t i; for (i = 0; str[i] >= '0' && str[i] <= '9'; i++); if (i == 0) return false; if (str[i] != '.') return false; for (i++; i < prefix_len && (str[i] == ' ' || str[i] == '\t'); i++); if (str[i] == '\0') return false; return i == prefix_len; } char* blogc_content_parse(const char *src, size_t *end_excerpt) { // src is always nul-terminated. size_t src_len = strlen(src); size_t current = 0; size_t start = 0; size_t start2 = 0; size_t end = 0; size_t eend = 0; size_t real_end = 0; unsigned int header_level = 0; char *prefix = NULL; size_t prefix_len = 0; char *tmp = NULL; char *tmp2 = NULL; char *parsed = NULL; char *slug = NULL; // this isn't empty because we need some reasonable default value in the // unlikely case that we need to print some line ending before evaluating // the "real" value. char line_ending[3] = "\n"; bool line_ending_found = false; char d = '\0'; sb_slist_t *lines = NULL; sb_slist_t *lines2 = NULL; sb_string_t *rv = sb_string_new(); sb_string_t *tmp_str = NULL; blogc_content_parser_state_t state = CONTENT_START_LINE; while (current < src_len) { char c = src[current]; bool is_last = current == src_len - 1; if (c == '\n' || c == '\r') { if ((current + 1) < src_len) { if ((c == '\n' && src[current + 1] == '\r') || (c == '\r' && src[current + 1] == '\n')) { if (!line_ending_found) { line_ending[0] = c; line_ending[1] = src[current + 1]; line_ending[2] = '\0'; line_ending_found = true; } real_end = current; c = src[++current]; is_last = current == src_len - 1; } } if (!line_ending_found) { line_ending[0] = c; line_ending[1] = '\0'; line_ending_found = true; } } switch (state) { case CONTENT_START_LINE: if (c == '\n' || c == '\r' || is_last) break; start = current; if (c == '.') { if (end_excerpt != NULL) { eend = rv->len; // fuck it state = CONTENT_EXCERPT; break; } } if (c == '#') { header_level = 1; state = CONTENT_HEADER; break; } if (c == '*' || c == '+' || c == '-') { start2 = current; state = CONTENT_UNORDERED_LIST_OR_HORIZONTAL_RULE; d = c; break; } if (c >= '0' && c <= '9') { start2 = current; state = CONTENT_ORDERED_LIST; break; } if (c == ' ' || c == '\t') { start2 = current; state = CONTENT_CODE; break; } if (c == '<') { state = CONTENT_HTML; break; } if (c == '>') { state = CONTENT_BLOCKQUOTE; start2 = current; break; } state = CONTENT_PARAGRAPH; break; case CONTENT_EXCERPT: if (end_excerpt != NULL) { if (c == '.') break; if (c == '\n' || c == '\r') { state = CONTENT_EXCERPT_END; break; } } eend = 0; state = CONTENT_PARAGRAPH; break; case CONTENT_EXCERPT_END: if (end_excerpt != NULL) { if (c == '\n' || c == '\r') { *end_excerpt = eend; state = CONTENT_START_LINE; break; } } eend = 0; state = CONTENT_PARAGRAPH_END; break; case CONTENT_HEADER: if (c == '#') { header_level += 1; break; } if (c == ' ' || c == '\t') { state = CONTENT_HEADER_TITLE_START; break; } state = CONTENT_PARAGRAPH; break; case CONTENT_HEADER_TITLE_START: if (c == ' ' || c == '\t') break; start = current; if (c != '\n' && c != '\r') { state = CONTENT_HEADER_TITLE; break; } case CONTENT_HEADER_TITLE: if (c == '\n' || c == '\r' || is_last) { end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); tmp = sb_strndup(src + start, end - start); parsed = blogc_content_parse_inline(tmp); slug = blogc_slugify(tmp); if (slug == NULL) sb_string_append_printf(rv, "%s%s", header_level, parsed, header_level, line_ending); else sb_string_append_printf(rv, "%s%s", header_level, slug, parsed, header_level, line_ending); free(slug); free(parsed); parsed = NULL; free(tmp); tmp = NULL; state = CONTENT_START_LINE; start = current; } break; case CONTENT_HTML: if (c == '\n' || c == '\r' || is_last) { state = CONTENT_HTML_END; end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); } if (!is_last) break; case CONTENT_HTML_END: if (c == '\n' || c == '\r' || is_last) { tmp = sb_strndup(src + start, end - start); sb_string_append_printf(rv, "%s%s", tmp, line_ending); free(tmp); tmp = NULL; state = CONTENT_START_LINE; start = current; } else state = CONTENT_HTML; break; case CONTENT_BLOCKQUOTE: if (c == ' ' || c == '\t') break; prefix = sb_strndup(src + start, current - start); state = CONTENT_BLOCKQUOTE_START; break; case CONTENT_BLOCKQUOTE_START: if (c == '\n' || c == '\r' || is_last) { end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); tmp = sb_strndup(src + start2, end - start2); if (sb_str_starts_with(tmp, prefix)) { lines = sb_slist_append(lines, sb_strdup(tmp + strlen(prefix))); state = CONTENT_BLOCKQUOTE_END; } else { state = CONTENT_PARAGRAPH; free(prefix); prefix = NULL; sb_slist_free_full(lines, free); lines = NULL; if (is_last) { free(tmp); tmp = NULL; continue; } } free(tmp); tmp = NULL; } if (!is_last) break; case CONTENT_BLOCKQUOTE_END: if (c == '\n' || c == '\r' || is_last) { tmp_str = sb_string_new(); for (sb_slist_t *l = lines; l != NULL; l = l->next) { if (l->next == NULL) sb_string_append_printf(tmp_str, "%s", l->data); else sb_string_append_printf(tmp_str, "%s%s", l->data, line_ending); } tmp = blogc_content_parse(tmp_str->str, NULL); sb_string_append_printf(rv, "
%s
%s", tmp, line_ending); free(tmp); tmp = NULL; sb_string_free(tmp_str, true); tmp_str = NULL; sb_slist_free_full(lines, free); lines = NULL; free(prefix); prefix = NULL; state = CONTENT_START_LINE; start2 = current; } else { start2 = current; state = CONTENT_BLOCKQUOTE_START; } break; case CONTENT_CODE: if (c == ' ' || c == '\t') break; prefix = sb_strndup(src + start, current - start); state = CONTENT_CODE_START; break; case CONTENT_CODE_START: if (c == '\n' || c == '\r' || is_last) { end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); tmp = sb_strndup(src + start2, end - start2); if (sb_str_starts_with(tmp, prefix)) { lines = sb_slist_append(lines, sb_strdup(tmp + strlen(prefix))); state = CONTENT_CODE_END; } else { state = CONTENT_PARAGRAPH; free(prefix); prefix = NULL; sb_slist_free_full(lines, free); lines = NULL; free(tmp); tmp = NULL; if (is_last) continue; break; } free(tmp); tmp = NULL; } if (!is_last) break; case CONTENT_CODE_END: if (c == '\n' || c == '\r' || is_last) { sb_string_append(rv, "
");
                    for (sb_slist_t *l = lines; l != NULL; l = l->next) {
                        char *tmp_line = blogc_htmlentities(l->data);
                        if (l->next == NULL)
                            sb_string_append_printf(rv, "%s", tmp_line);
                        else
                            sb_string_append_printf(rv, "%s%s", tmp_line,
                                line_ending);
                        free(tmp_line);
                    }
                    sb_string_append_printf(rv, "
%s", line_ending); sb_slist_free_full(lines, free); lines = NULL; free(prefix); prefix = NULL; state = CONTENT_START_LINE; start2 = current; } else { start2 = current; state = CONTENT_CODE_START; } break; case CONTENT_UNORDERED_LIST_OR_HORIZONTAL_RULE: if (c == d) { state = CONTENT_HORIZONTAL_RULE; if (is_last) continue; break; } if (c == ' ' || c == '\t') break; prefix = sb_strndup(src + start, current - start); state = CONTENT_UNORDERED_LIST_START; break; case CONTENT_HORIZONTAL_RULE: if (c == d && !is_last) { break; } if (c == '\n' || c == '\r' || is_last) { sb_string_append_printf(rv, "
%s", line_ending); state = CONTENT_START_LINE; start = current; d = '\0'; break; } state = CONTENT_PARAGRAPH; break; case CONTENT_UNORDERED_LIST_START: if (c == '\n' || c == '\r' || is_last) { end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); tmp = sb_strndup(src + start2, end - start2); tmp2 = sb_strdup_printf("%-*s", strlen(prefix), ""); if (sb_str_starts_with(tmp, prefix)) { if (lines2 != NULL) { tmp_str = sb_string_new(); for (sb_slist_t *l = lines2; l != NULL; l = l->next) { if (l->next == NULL) sb_string_append_printf(tmp_str, "%s", l->data); else sb_string_append_printf(tmp_str, "%s%s", l->data, line_ending); } sb_slist_free_full(lines2, free); lines2 = NULL; parsed = blogc_content_parse_inline(tmp_str->str); sb_string_free(tmp_str, true); lines = sb_slist_append(lines, sb_strdup(parsed)); free(parsed); parsed = NULL; } lines2 = sb_slist_append(lines2, sb_strdup(tmp + strlen(prefix))); } else if (sb_str_starts_with(tmp, tmp2)) { lines2 = sb_slist_append(lines2, sb_strdup(tmp + strlen(prefix))); } else { state = CONTENT_PARAGRAPH_END; free(tmp); tmp = NULL; free(tmp2); tmp2 = NULL; free(prefix); prefix = NULL; sb_slist_free_full(lines, free); sb_slist_free_full(lines2, free); lines = NULL; if (is_last) continue; break; } free(tmp); tmp = NULL; free(tmp2); tmp2 = NULL; state = CONTENT_UNORDERED_LIST_END; } if (!is_last) break; case CONTENT_UNORDERED_LIST_END: if (c == '\n' || c == '\r' || is_last) { if (lines2 != NULL) { // FIXME: avoid repeting the code below tmp_str = sb_string_new(); for (sb_slist_t *l = lines2; l != NULL; l = l->next) { if (l->next == NULL) sb_string_append_printf(tmp_str, "%s", l->data); else sb_string_append_printf(tmp_str, "%s%s", l->data, line_ending); } sb_slist_free_full(lines2, free); lines2 = NULL; parsed = blogc_content_parse_inline(tmp_str->str); sb_string_free(tmp_str, true); lines = sb_slist_append(lines, sb_strdup(parsed)); free(parsed); parsed = NULL; } sb_string_append_printf(rv, "
    %s", line_ending); for (sb_slist_t *l = lines; l != NULL; l = l->next) sb_string_append_printf(rv, "
  • %s
    • %s", l->data, line_ending); sb_string_append_printf(rv, "
%s", line_ending); sb_slist_free_full(lines, free); lines = NULL; free(prefix); prefix = NULL; state = CONTENT_START_LINE; start2 = current; } else { start2 = current; state = CONTENT_UNORDERED_LIST_START; } break; case CONTENT_ORDERED_LIST: if (c >= '0' && c <= '9') break; if (c == '.') { state = CONTENT_ORDERED_LIST_SPACE; break; } state = CONTENT_PARAGRAPH; if (is_last) continue; break; case CONTENT_ORDERED_LIST_SPACE: if (c == ' ' || c == '\t') break; prefix_len = current - start; state = CONTENT_ORDERED_LIST_START; if (c != '\n' && c != '\r' && !is_last) break; case CONTENT_ORDERED_LIST_START: if (c == '\n' || c == '\r' || is_last) { end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); tmp = sb_strndup(src + start2, end - start2); tmp2 = sb_strdup_printf("%-*s", prefix_len, ""); if (blogc_is_ordered_list_item(tmp, prefix_len)) { if (lines2 != NULL) { tmp_str = sb_string_new(); for (sb_slist_t *l = lines2; l != NULL; l = l->next) { if (l->next == NULL) sb_string_append_printf(tmp_str, "%s", l->data); else sb_string_append_printf(tmp_str, "%s%s", l->data, line_ending); } sb_slist_free_full(lines2, free); lines2 = NULL; parsed = blogc_content_parse_inline(tmp_str->str); sb_string_free(tmp_str, true); lines = sb_slist_append(lines, sb_strdup(parsed)); free(parsed); parsed = NULL; } lines2 = sb_slist_append(lines2, sb_strdup(tmp + prefix_len)); } else if (sb_str_starts_with(tmp, tmp2)) { lines2 = sb_slist_append(lines2, sb_strdup(tmp + prefix_len)); } else { state = CONTENT_PARAGRAPH_END; free(tmp); tmp = NULL; free(tmp2); tmp2 = NULL; free(parsed); parsed = NULL; sb_slist_free_full(lines, free); sb_slist_free_full(lines2, free); lines = NULL; if (is_last) continue; break; } free(tmp); tmp = NULL; free(tmp2); tmp2 = NULL; state = CONTENT_ORDERED_LIST_END; } if (!is_last) break; case CONTENT_ORDERED_LIST_END: if (c == '\n' || c == '\r' || is_last) { if (lines2 != NULL) { // FIXME: avoid repeting the code below tmp_str = sb_string_new(); for (sb_slist_t *l = lines2; l != NULL; l = l->next) { if (l->next == NULL) sb_string_append_printf(tmp_str, "%s", l->data); else sb_string_append_printf(tmp_str, "%s%s", l->data, line_ending); } sb_slist_free_full(lines2, free); lines2 = NULL; parsed = blogc_content_parse_inline(tmp_str->str); sb_string_free(tmp_str, true); lines = sb_slist_append(lines, sb_strdup(parsed)); free(parsed); parsed = NULL; } sb_string_append_printf(rv, "
    %s", line_ending); for (sb_slist_t *l = lines; l != NULL; l = l->next) sb_string_append_printf(rv, "
  1. %s
    2. %s", l->data, line_ending); sb_string_append_printf(rv, "
%s", line_ending); sb_slist_free_full(lines, free); lines = NULL; free(prefix); prefix = NULL; state = CONTENT_START_LINE; start2 = current; } else { start2 = current; state = CONTENT_ORDERED_LIST_START; } break; case CONTENT_PARAGRAPH: if (c == '\n' || c == '\r' || is_last) { state = CONTENT_PARAGRAPH_END; end = is_last && c != '\n' && c != '\r' ? src_len : (real_end != 0 ? real_end : current); } if (!is_last) break; case CONTENT_PARAGRAPH_END: if (c == '\n' || c == '\r' || is_last) { tmp = sb_strndup(src + start, end - start); parsed = blogc_content_parse_inline(tmp); sb_string_append_printf(rv, "

%s

%s", parsed, line_ending); free(parsed); parsed = NULL; free(tmp); tmp = NULL; state = CONTENT_START_LINE; start = current; } else state = CONTENT_PARAGRAPH; break; } current++; } return sb_string_free(rv, false); }