static void print_exec(struct exec *e, int indent, int bracket)
{
if (!e)
- return; // NOTEST
+ return;
switch (e->type) {
case Xbinode:
print_binode(cast(binode, e), indent, bracket); break;
do
code block
+For constructing these lists we use a `List` binode, which will be
+further detailed when Expression Lists are introduced.
+
###### Binode types
Func, List,
}
break;
+### Expression list
+
+We take a brief detour, now that we have expressions, to describe lists
+of expressions. These will be needed for function parameters and
+possibly other situations. They seem generic enough to introduce here
+to be used elsewhere.
+
+And ExpressionList will use the `List` type of `binode`, building up at
+the end. And place where they are used will probably call
+`reorder_bilist()` to get a more normal first/next arrangement.
+
+###### declare terminals
+ $TERM ,
+
+`List` execs have no implicit semantics, so they are never propagated or
+interpreted. The can be printed as a comma separate list, which is how
+they are parsed. Note they are also used for function formal parameter
+lists. In that case a separate function is used to print them.
+
+###### print binode cases
+ case List:
+ while (b) {
+ printf(" ");
+ print_exec(b->left, -1, bracket);
+ if (b->right)
+ printf(",");
+ b = cast(binode, b->right);
+ }
+ break;
+
+###### propagate binode cases
+ case List: abort(); // NOTEST
+###### interp binode cases
+ case List: abort(); // NOTEST
+
+###### Grammar
+
+ $*binode
+ ExpressionList -> ExpressionList , Expression ${
+ $0 = new(binode);
+ $0->op = List;
+ $0->left = $<1;
+ $0->right = $<3;
+ }$
+ | Expression ${
+ $0 = new(binode);
+ $0->op = List;
+ $0->left = NULL;
+ $0->right = $<1;
+ }$
+
### Expressions: Boolean
The next class of expressions to use the `binode` will be Boolean
expressions and prints the values separated by spaces and terminated
by a newline. No control of formatting is possible.
-`print` faces the same list-ordering issue as blocks, and uses the
-same solution.
+`print` uses `ExpressionList` to collect the expressions and stores them
+on the left side of a `Print` binode unlessthere is a trailing comma
+when the list is stored on the `right` side and no trailing newline is
+printed.
###### Binode types
Print,
##### expr precedence
- $TERM print ,
+ $TERM print
###### SimpleStatement Grammar
| print ExpressionList ${
- $0 = reorder_bilist($<2);
- }$
- | print ExpressionList , ${
$0 = new(binode);
$0->op = Print;
$0->right = NULL;
- $0->left = $<2;
- $0 = reorder_bilist($0);
+ $0->left = reorder_bilist($<EL);
}$
+ | print ExpressionList , ${ {
+ $0 = new(binode);
+ $0->op = Print;
+ $0->right = reorder_bilist($<EL);
+ $0->left = NULL;
+ } }$
| print ${
$0 = new(binode);
$0->op = Print;
+ $0->left = NULL;
$0->right = NULL;
}$
-###### Grammar
-
- $*binode
- ExpressionList -> ExpressionList , Expression ${
- $0 = new(binode);
- $0->op = Print;
- $0->left = $<1;
- $0->right = $<3;
- }$
- | Expression ${
- $0 = new(binode);
- $0->op = Print;
- $0->left = NULL;
- $0->right = $<1;
- }$
-
###### print binode cases
case Print:
do_indent(indent, "print");
- while (b) {
- if (b->left) {
- printf(" ");
- print_exec(b->left, -1, bracket);
- if (b->right)
- printf(",");
- }
- b = cast(binode, b->right);
- }
+ if (b->right) {
+ print_exec(b->right, -1, bracket);
+ printf(",");
+ } else
+ print_exec(b->left, -1, bracket);
if (indent >= 0)
printf("\n");
break;
case Print:
/* don't care but all must be consistent */
- propagate_types(b->left, c, ok, NULL, Rnolabel);
- propagate_types(b->right, c, ok, NULL, Rnolabel);
+ if (b->left)
+ b = cast(binode, b->left);
+ else
+ b = cast(binode, b->right);
+ while (b) {
+ propagate_types(b->left, c, ok, NULL, Rnolabel);
+ b = cast(binode, b->right);
+ }
break;
###### interp binode cases
case Print:
{
- char sep = 0;
- int eol = 1;
- for ( ; b; b = cast(binode, b->right))
- if (b->left) {
- if (sep)
- putchar(sep);
- left = interp_exec(c, b->left, <ype);
- print_value(ltype, &left);
- free_value(ltype, &left);
- if (b->right)
- sep = ' ';
- } else if (sep)
- eol = 0;
- ltype = Tnone;
- if (eol)
+ struct binode *b2 = cast(binode, b->left);
+ if (!b2)
+ b2 = cast(binode, b->right);
+ for (; b2; b2 = cast(binode, b2->right)) {
+ left = interp_exec(c, b2->left, <ype);
+ print_value(ltype, &left);
+ free_value(ltype, &left);
+ if (b2->right)
+ putchar(' ');
+ }
+ if (b->right == NULL)
printf("\n");
+ ltype = Tnone;
break;
}
###### print binode cases
case Func:
- case List:
do_indent(indent, "func main(");
for (b2 = cast(binode, b->left); b2; b2 = cast(binode, b2->right)) {
struct variable *v = cast(var, b2->left)->var;
break;
###### propagate binode cases
- case List:
case Func: abort(); // NOTEST
###### core functions
}
###### interp binode cases
- case List: abort(); // NOTEST
-
case Func:
rv = interp_exec(c, b->right, &rvtype);
break;
code / ocean / blobdiff