/* $OpenBSD: match.c,v 1.9 2003/05/20 03:08:55 cloder Exp $ */ /* * Limited parenthesis matching routines * * The hacks in this file implement automatic matching * of (), [], {}, and * other characters. It would be better to have a full-blown syntax table, * but there's enough overhead in the editor as it is. * * Since I often edit Scribe code, I've made it possible to blink arbitrary * characters -- just bind delimiter characters to "blink-matching-paren-hack" */ #include "def.h" #include "key.h" static int balance(void); static void displaymatch(LINE *, int); /* * Balance table. When balance() encounters a character that is to be * matched, it first searches this table for a balancing left-side character. * If the character is not in the table, the character is balanced by itself. * This is to allow delimiters in Scribe documents to be matched. */ static struct balance { char left, right; } bal[] = { { '(', ')' }, { '[', ']' }, { '{', '}' }, { '<', '>' }, { '\0', '\0' } }; /* * Hack to show matching paren. Self-insert character, then show matching * character, if any. Bound to "blink-matching-paren-command". */ int showmatch(int f, int n) { int i, s; if (f & FFRAND) return FALSE; for (i = 0; i < n; i++) { if ((s = selfinsert(FFRAND, 1)) != TRUE) return s; /* unbalanced -- warn user */ if (balance() != TRUE) ttbeep(); } return TRUE; } /* * Search for and display a matching character. * * This routine does the real work of searching backward * for a balancing character. If such a balancing character * is found, it uses displaymatch() to display the match. */ static int balance(void) { LINE *clp; int cbo; int c; int i; int rbal; int lbal; int depth; rbal = key.k_chars[key.k_count - 1]; /* See if there is a matching character -- default to the same */ lbal = rbal; for (i = 0; bal[i].right != '\0'; i++) if (bal[i].right == rbal) { lbal = bal[i].left; break; } /* * Move behind the inserted character. We are always guaranteed * that there is at least one character on the line, since one was * just self-inserted by blinkparen. */ clp = curwp->w_dotp; cbo = curwp->w_doto - 1; /* init nesting depth */ depth = 0; for (;;) { if (cbo == 0) { clp = lback(clp); /* beginning of line */ if (clp == curbp->b_linep) return (FALSE); cbo = llength(clp) + 1; } if (--cbo == llength(clp)) c = '\n'; /* end of line */ else c = lgetc(clp, cbo); /* somewhere in middle */ /* * Check for a matching character. If still in a nested * level, pop out of it and continue search. This check * is done before the nesting check so single-character * matches will work too. */ if (c == lbal) { if (depth == 0) { displaymatch(clp, cbo); return (TRUE); } else depth--; } /* Check for another level of nesting. */ if (c == rbal) depth++; } /* NOTREACHED */ } /* * Display matching character. Matching characters that are not in the * current window are displayed in the echo line. If in the current window, * move dot to the matching character, sit there a while, then move back. */ static void displaymatch(LINE *clp, int cbo) { LINE *tlp; int tbo; int cp; int bufo; int c; int inwindow; char buf[NLINE]; /* * Figure out if matching char is in current window by * searching from the top of the window to dot. */ inwindow = FALSE; for (tlp = curwp->w_linep; tlp != lforw(curwp->w_dotp); tlp = lforw(tlp)) if (tlp == clp) inwindow = TRUE; if (inwindow == TRUE) { tlp = curwp->w_dotp; /* save current position */ tbo = curwp->w_doto; curwp->w_dotp = clp; /* move to new position */ curwp->w_doto = cbo; curwp->w_flag |= WFMOVE; update(); /* show match */ ttwait(1000); /* wait for key or 1 second */ curwp->w_dotp = tlp; /* return to old position */ curwp->w_doto = tbo; curwp->w_flag |= WFMOVE; update(); } else { /* match is not in this window, so display line in echo area */ bufo = 0; for (cp = 0; cp < llength(clp); cp++) { c = lgetc(clp, cp); if (c != '\t' #ifdef NOTAB || (curbp->b_flag & BFNOTAB) #endif ) if (ISCTRL(c)) { buf[bufo++] = '^'; buf[bufo++] = CCHR(c); } else buf[bufo++] = c; else do { buf[bufo++] = ' '; } while (bufo & 7); } buf[bufo++] = '\0'; ewprintf("Matches %s", buf); } }