Print parse trees with infix notation

Fixes #62.

src/common/cell.c

@@ -249,9 +249,9 @@ static int print_string(char* dest, size_t space,
 /*}}}*/
 
 /* printtok   -- print a single token, passed by address, although not changed */ /*{{{*/
-size_t printtok(char* dest, size_t size, size_t field_width,
-		StringFormat sf, FloatFormat ff,
-		int digits, ErrorFormat ef, const Token *tok)
+size_t ptokatprec(char* dest, size_t size, size_t field_width, StringFormat sf,
+		  FloatFormat ff,  int digits, ErrorFormat ef, const Token *tok,
+		  FunctionPrecedence atprec)
 {
   if (debug_level > 2) {
     printf("..Entering printtok; bufsize %d, field_width %d, qs %d, ff %s,"
@@ -381,17 +381,76 @@ size_t printtok(char* dest, size_t size, size_t field_width,
     /* FUNCALL */ /*{{{*/
     case FUNCALL:
     {
-      cur += print_fident(dest+cur, size-cur-1, tok->u.funcall.fident);
-      if (tok->u.funcall.argc >= 0 && cur + 2 < size) /* -1 args is bare func */
+      FunctionIdentifier fid = tok->u.funcall.fident;
+      if (tok->u.funcall.argc <= 0)
       {
-	dest[cur++] = '\(';
+	cur += print_fident(dest+cur, size-cur-1, fid);
+	if (tok->u.funcall.argc == 0)
+	{
+	  if (cur < size - 2) { dest[cur++] = '('; dest[cur++] = ')'; }
+	  else cur += 2;
+	}
+	break;
+      }
+      FunctionPrecedence fp = tfunc[fid].precedence;
+      switch (fp)
+      {
+      case PREFIX_FUNC: {
+	cur += print_fident(dest+cur, size-cur-1, fid);
+	if (cur < size) dest[cur++] = '(';
 	for (size_t ai = 0; ai < tok->u.funcall.argc && cur < size-1; ++ai)
 	{
 	  if (ai > 0 && cur < size) dest[cur++] = ',';
-	  cur += printtok(dest+cur, size-cur-1, field_width-cur, sf, ff,
-			  digits, ef, tok->u.funcall.argv + ai);
+	  /* The commas eliminate the need for precedence worries in arguments*/
+	  cur += ptokatprec(dest+cur, size-cur-1, field_width-cur, sf, ff,
+			    digits, ef, tok->u.funcall.argv + ai,
+			    NO_PRECEDENCE);
 	}
 	if (cur < size) dest[cur++] = ')';
+	break;
+      }
+      case PREFIX_NEG: {
+	assert(tok->u.funcall.argc == 1);
+	assert(tfunc[fid].display_symbol != NULL);
+	if (fp < atprec && cur < size) dest[cur++] = '(';
+	if (cur < size) {
+	  strncpy(dest+cur, tfunc[fid].display_symbol, size-cur-1);
+	  cur += strlen(tfunc[fid].display_symbol);
+	}
+	cur += ptokatprec(dest+cur, size-cur-1, field_width-cur, sf, ff,
+			  digits, ef, tok->u.funcall.argv, fp);
+	if (fp < atprec && cur < size) dest[cur++] = ')';
+	break;
+      }
+      default: /* infix argument */
+	assert(tok->u.funcall.argc > 1);
+	if (fp < atprec && cur < size) dest[cur++] = '(';
+	for (size_t ai = 0; ai < tok->u.funcall.argc && cur < size-1; ++ ai)
+	{
+	  bool parenarg = false;
+	  if (ai > 0) {
+	    if (fp < INFIX_MUL && cur < size) dest[cur++] = ' ';
+	    const char *use = tfunc[fid].display_symbol;
+	    if (use == NULL) use = tfunc[fid].name;
+	    strncpy(dest+cur, use, size-cur-1);
+	    cur += strlen(use);
+	    if (fp < INFIX_MUL && cur < size) dest[cur++] = ' ';
+	  } else if (fp > PREFIX_NEG) {
+	    char powbuf[4096];
+	    size_t arglen = ptokatprec(powbuf, sizeof(powbuf), 0, sf, ff,
+				       digits, ef, tok->u.funcall.argv, fp);
+	    assert(arglen < sizeof(powbuf)-1);
+	    if (powbuf[0] == '-') {
+	      parenarg = true;
+	      if (cur < size) dest[cur++] = '(';
+	    }
+	  }
+	  cur += ptokatprec(dest+cur, size-cur-1, field_width-cur, sf, ff,
+			    digits, ef, tok->u.funcall.argv + ai, fp);
+	  if (parenarg && cur < size) dest[cur++] = ')';
+	}
+	if (fp < atprec && cur < size) dest[cur++] = ')';
+	break;
       }
       break;
     }
@@ -439,6 +498,16 @@ size_t printtok(char* dest, size_t size, size_t field_width,
 }
 /*}}}*/
 
+/* printtok   -- print a single token, passed by address, although not changed */ /*{{{*/
+size_t printtok(char* dest, size_t size, size_t field_width,
+		StringFormat sf, FloatFormat ff,
+		int digits, ErrorFormat ef, const Token *tok)
+{
+  return ptokatprec(dest, size, field_width, sf, ff, digits, ef, tok,
+		    NO_PRECEDENCE);
+}
+/*}}}*/
+
 /* print      -- print token sequence */ /*{{{*/
 void print(char *s, size_t size, size_t chars, StringFormat sf, FloatFormat ff,
 	   int digits, Token **n)

src/common/func.c

@@ -390,7 +390,7 @@ static Token at_func(int argc, const Token argv[], LocConvention lcon)
     strcat(result.u.err, location.u.err);
     /* don't free the location if it is the same as an argument, because
        those get freed later: */
-    for (size_t i = 0; i < argc; ++i)
+    for (int i = 0; i < argc; ++i)
       if (argv[i].type == EEK & argv[i].u.err == location.u.err) return result;
     tfree(&location);
     return result;

src/common/func.h

@@ -36,8 +36,8 @@ typedef struct Token_struc Token;
 
 typedef enum /* In increasing order of precedence */
   {
-   INFIX_CONC, INFIX_REL, INFIX_PLUS, INFIX_MUL, PREFIX_NEG,
-   INFIX_POW, PREFIX_FUNC
+   NO_PRECEDENCE, INFIX_CONC, INFIX_REL, INFIX_PLUS, INFIX_MUL,
+   PREFIX_NEG, INFIX_POW, PREFIX_FUNC
   } FunctionPrecedence;
 
 typedef enum { FUNCT, MACRO } EvaluationStrategy;