Fix operator precedence according to Brian W. Kernighan and Lorinda

[mandoc.git] / roff_term.c

diff --git a/roff_term.c b/roff_term.c
index 3240b93eb2efc1771cdd72d6fd41ff04cb5e979a..b5ec764963ea8f9e4a2576c3873143cd844c0914 100644 (file)
--- a/roff_term.c
+++ b/roff_term.c
@@ -1,4 +1,4 @@
-/*     $Id: roff_term.c,v 1.9 2017/06/07 17:38:26 schwarze Exp $ */
+/*     $Id: roff_term.c,v 1.14 2017/06/24 14:38:33 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -19,6 +19,7 @@
 #include <assert.h>
 #include <stddef.h>
 
+#include "mandoc.h"
 #include "roff.h"
 #include "out.h"
 #include "term.h"
@@ -32,6 +33,7 @@ static        void      roff_term_pre_ce(ROFF_TERM_ARGS);
 static void      roff_term_pre_ft(ROFF_TERM_ARGS);
 static void      roff_term_pre_ll(ROFF_TERM_ARGS);
 static void      roff_term_pre_mc(ROFF_TERM_ARGS);
+static void      roff_term_pre_po(ROFF_TERM_ARGS);
 static void      roff_term_pre_sp(ROFF_TERM_ARGS);
 static void      roff_term_pre_ta(ROFF_TERM_ARGS);
 static void      roff_term_pre_ti(ROFF_TERM_ARGS);
@@ -42,6 +44,8 @@ static        const roff_term_pre_fp roff_term_pre_acts[ROFF_MAX] = {
        roff_term_pre_ft,  /* ft */
        roff_term_pre_ll,  /* ll */
        roff_term_pre_mc,  /* mc */
+       roff_term_pre_po,  /* po */
+       roff_term_pre_ce,  /* rj */
        roff_term_pre_sp,  /* sp */
        roff_term_pre_ta,  /* ta */
        roff_term_pre_ti,  /* ti */
@@ -69,33 +73,34 @@ roff_term_pre_br(ROFF_TERM_ARGS)
 static void
 roff_term_pre_ce(ROFF_TERM_ARGS)
 {
-       const struct roff_node  *nch;
+       const struct roff_node  *nc1, *nc2;
        size_t                   len, lm;
 
        roff_term_pre_br(p, n);
        lm = p->tcol->offset;
-       n = n->child->next;
-       while (n != NULL) {
-               nch = n;
+       nc1 = n->child->next;
+       while (nc1 != NULL) {
+               nc2 = nc1;
                len = 0;
                do {
-                       if (n->type == ROFFT_TEXT) {
+                       if (nc2->type == ROFFT_TEXT) {
                                if (len)
                                        len++;
-                               len += term_strlen(p, nch->string);
+                               len += term_strlen(p, nc2->string);
                        }
-                       nch = nch->next;
-               } while (nch != NULL && (n->type != ROFFT_TEXT ||
-                   (n->flags & NODE_LINE) == 0));
+                       nc2 = nc2->next;
+               } while (nc2 != NULL && (nc2->type != ROFFT_TEXT ||
+                   (nc2->flags & NODE_LINE) == 0));
                p->tcol->offset = len >= p->tcol->rmargin ? 0 :
                    lm + len >= p->tcol->rmargin ? p->tcol->rmargin - len :
+                   n->tok == ROFF_rj ? p->tcol->rmargin - len :
                    (lm + p->tcol->rmargin - len) / 2;
-               while (n != nch) {
-                       if (n->type == ROFFT_TEXT)
-                               term_word(p, n->string);
+               while (nc1 != nc2) {
+                       if (nc1->type == ROFFT_TEXT)
+                               term_word(p, nc1->string);
                        else
-                               roff_term_pre(p, n);
-                       n = n->next;
+                               roff_term_pre(p, nc1);
+                       nc1 = nc1->next;
                }
                p->flags |= TERMP_NOSPACE;
                term_flushln(p);
@@ -150,6 +155,28 @@ roff_term_pre_mc(ROFF_TERM_ARGS)
                p->flags |= TERMP_ENDMC;
 }
 
+static void
+roff_term_pre_po(ROFF_TERM_ARGS)
+{
+       struct roffsu    su;
+       static int       po, polast;
+       int              ponew;
+
+       if (n->child != NULL &&
+           a2roffsu(n->child->string, &su, SCALE_EM) != NULL) {
+               ponew = term_hen(p, &su);
+               if (*n->child->string == '+' ||
+                   *n->child->string == '-')
+                       ponew += po;
+       } else
+               ponew = polast;
+       polast = po;
+       po = ponew;
+
+       ponew = po - polast + (int)p->tcol->offset;
+       p->tcol->offset = ponew > 0 ? ponew : 0;
+}
+
 static void
 roff_term_pre_sp(ROFF_TERM_ARGS)
 {
@@ -157,7 +184,7 @@ roff_term_pre_sp(ROFF_TERM_ARGS)
        int              len;
 
        if (n->child != NULL) {
-               if (a2roffsu(n->child->string, &su, SCALE_VS) == 0)
+               if (a2roffsu(n->child->string, &su, SCALE_VS) == NULL)
                        su.scale = 1.0;
                len = term_vspan(p, &su);
        } else
@@ -201,9 +228,9 @@ roff_term_pre_ti(ROFF_TERM_ARGS)
        } else
                sign = 0;
 
-       if (a2roffsu(cp, &su, SCALE_EM) == 0)
+       if (a2roffsu(cp, &su, SCALE_EM) == NULL)
                return;
-       len = term_hspan(p, &su) / 24;
+       len = term_hen(p, &su);
 
        if (sign == 0) {
                p->ti = len - p->tcol->offset;