]> ocean-lang.org Git - ocean/blobdiff - csrc/oceani.mdc
oceani: move comment printing from print_exec() to where later
[ocean] / csrc / oceani.mdc
index e032a7d5a268e76c5f6e459e666859640fbcab22..c687fddca5ea7a17521fe730c81d8381d61bbb6e 100644 (file)
@@ -37,9 +37,9 @@ boolean operators.
 
 Some operators that have only recently been added, and so have not
 generated all that much experience yet are "and then" and "or else" as
-short-circuit Boolean operators, and the "if ... else" trinary
-operator which can select between two expressions based on a third
-(which appears syntactically in the middle).
+short-circuit Boolean operators (which have since been remove), and the
+"if ...  else" trinary operator which can select between two expressions
+based on a third (which appears syntactically in the middle).
 
 The "func" clause currently only allows a "main" function to be
 declared.  That will be extended when proper function support is added.
@@ -425,10 +425,12 @@ executables.  This allows for expressions and lists etc.  Other times an
 executable is something quite specific like a constant or variable name.
 So we define a `struct exec` to be a general executable with a type, and
 a `struct binode` which is a subclass of `exec`, forms a node in a
-binary tree, and holds an operation.  There will be other subclasses,
-and to access these we need to be able to `cast` the `exec` into the
-various other types.  The first field in any `struct exec` is the type
-from the `exec_types` enum.
+binary tree, and holds an operation.  The simplest operation is "List"
+which can be used to combine several execs together.
+
+There will be other subclasses, and to access these we need to be able
+to `cast` the `exec` into the various other types.  The first field in
+any `struct exec` is the type from the `exec_types` enum.
 
 ###### macros
        #define cast(structname, pointer) ({            \
@@ -461,6 +463,7 @@ from the `exec_types` enum.
        struct binode {
                struct exec;
                enum Btype {
+                       List,
                        ## Binode types
                } op;
                struct exec *left, *right;
@@ -531,7 +534,9 @@ and we need `free_binode`.
 
 Printing an `exec` requires that we know the current indent level for
 printing line-oriented components.  As will become clear later, we
-also want to know what sort of bracketing to use.
+also want to know what sort of bracketing to use.  It will also be used
+to sometime print comments after an exec to explain some of the results
+of analysis.
 
 ###### ast functions
 
@@ -547,6 +552,7 @@ also want to know what sort of bracketing to use.
        {
                struct binode *b2;
                switch(b->op) {
+               case List: abort(); // must be handled by parent NOTEST
                ## print binode cases
                }
        }
@@ -554,24 +560,13 @@ also want to know what sort of bracketing to use.
        static void print_exec(struct exec *e, int indent, int bracket)
        {
                if (!e)
-                       return;
+                       return; // NOTEST
                switch (e->type) {
                case Xbinode:
                        print_binode(cast(binode, e), indent, bracket); break;
                ## print exec cases
                }
-               if (e->to_free) {
-                       struct variable *v;
-                       do_indent(indent, "/* FREE");
-                       for (v = e->to_free; v; v = v->next_free) {
-                               printf(" %.*s", v->name->name.len, v->name->name.txt);
-                               printf("[%d,%d]", v->scope_start, v->scope_end);
-                               if (v->frame_pos >= 0)
-                                       printf("(%d+%d)", v->frame_pos,
-                                              v->type ? v->type->size:0);
-                       }
-                       printf(" */\n");
-               }
+               ## print exec extras
        }
 
 ###### forward decls
@@ -598,7 +593,7 @@ the value can only be assigned once, when the variable is declared.
 
 ###### ast
 
-       enum val_rules {Rboolok = 1<<0,};
+       enum val_rules {Rboolok = 1<<0, Rrefok = 1<<1,};
        enum prop_err {Efail = 1<<0, Eretry = 1<<1, Eruntime = 1<<2,
                       Emaycopy = 1<<3, Erval = 1<<4, Econst = 1<<5};
 
@@ -621,6 +616,7 @@ the value can only be assigned once, when the variable is declared.
                {
                        struct binode *b = cast(binode, prog);
                        switch (b->op) {
+                       case List: abort(); // NOTEST
                        ## propagate binode cases
                        }
                        break;
@@ -740,6 +736,7 @@ in `rval`.
                        struct type *ltype, *rtype;
                        ltype = rtype = Tnone;
                        switch (b->op) {
+                       case List: abort();     // NOTEST
                        ## interp binode cases
                        }
                        free_value(ltype, &left);
@@ -1157,7 +1154,7 @@ A separate function encoding these cases will simplify some code later.
        {
                int cmp;
                if (tl != tr)
-                       return tl - tr; // NOTEST
+                       return tl - tr;
                switch (tl->vtype) {
                case Vlabel: cmp = left->label == right->label ? 0 : 1; break;
                case Vnum: cmp = mpq_cmp(left->num, right->num); break;
@@ -1274,13 +1271,13 @@ executable.
                $0->val.bool = 0;
        }$
        | NUMBER ${ {
-               char tail[3];
+               char tail[3] = "";
                $0 = new_val(Tnum, $1);
-               if (number_parse($0->val.num, tail, $1.txt) == 0)
-                       mpq_init($0->val.num);  // UNTESTED
-                       if (tail[0])
-                               tok_err(c, "error: unsupported number suffix",
-                                       &$1);
+               if (number_parse($0->val.num, tail, $1.txt) == 0) {
+                       mpq_init($0->val.num);
+                       tok_err(c, "error: unsupported number format", &$NUM);
+               } else if (tail[0])
+                       tok_err(c, "error: unsupported number suffix", &$1);
        } }$
        | STRING ${ {
                char tail[3];
@@ -1516,7 +1513,9 @@ cannot nest, so a declaration while a name is in-scope is an error.
 
 When a scope closes, the values of the variables might need to be freed.
 This happens in the context of some `struct exec` and each `exec` will
-need to know which variables need to be freed when it completes.
+need to know which variables need to be freed when it completes.  To
+improve visibility, we add a comment when printing any `exec` that
+embodies a scope to list the variables that must be freed when it ends.
 
 ####### exec fields
        struct variable *to_free;
@@ -1534,6 +1533,20 @@ need to know which variables need to be freed when it completes.
                }
        }
 
+###### print exec extras
+       if (e->to_free) {
+               struct variable *v;
+               do_indent(indent, "/* FREE");
+               for (v = e->to_free; v; v = v->next_free) {
+                       printf(" %.*s", v->name->name.len, v->name->name.txt);
+                       printf("[%d,%d]", v->scope_start, v->scope_end);
+                       if (v->frame_pos >= 0)
+                               printf("(%d+%d)", v->frame_pos,
+                                      v->type ? v->type->size:0);
+               }
+               printf(" */\n");
+       }
+
 ###### ast functions
        static void variable_unlink_exec(struct variable *v)
        {
@@ -2023,7 +2036,7 @@ tell if it was set or not later.
        {
                if (!v->global) {
                        if (!c->local || !v->type)
-                               return NULL;    // UNTESTED
+                               return NULL;    // NOTEST
                        if (v->frame_pos + v->type->size > c->local_size) {
                                printf("INVALID frame_pos\n");  // NOTEST
                                exit(2);                        // NOTEST
@@ -2049,7 +2062,7 @@ tell if it was set or not later.
                        t->prepare_type(c, t, 1);       // NOTEST
 
                if (c->global_size & (t->align - 1))
-                       c->global_size = (c->global_size + t->align) & ~(t->align-1);   // NOTEST
+                       c->global_size = (c->global_size + t->align) & ~(t->align-1);
                if (!v) {
                        v = &scratch;
                        v->type = t;
@@ -2096,7 +2109,7 @@ stack.
                        if (v->merged != v)
                                continue;
                        if (!t)
-                               continue;
+                               continue;       // NOTEST
                        if (v->frame_pos >= 0)
                                continue;
                        while (done && done->scope_end < v->scope_start)
@@ -2328,21 +2341,42 @@ different phases of parse, analyse, print, interpret.
 Being "complex" the language will naturally have syntax to access
 specifics of objects of these types.  These will fit into the grammar as
 "Terms" which are the things that are combined with various operators to
-form "Expression".  Where a Term is formed by some operation on another
+form an "Expression".  Where a Term is formed by some operation on another
 Term, the subordinate Term will always come first, so for example a
 member of an array will be expressed as the Term for the array followed
 by an index in square brackets.  The strict rule of using postfix
 operations makes precedence irrelevant within terms.  To provide a place
-to put the grammar for each terms of each type, we will start out by
+to put the grammar for terms of each type, we will start out by
 introducing the "Term" grammar production, with contains at least a
 simple "Value" (to be explained later).
 
+We also take this opportunity to introduce the "ExpressionsList" which
+is a simple comma-separated list of expressions - it may be used in
+various places.
+
+###### declare terminals
+       $TERM ,
+
 ###### Grammar
        $*exec
        Term ->  Value ${ $0 = $<1; }$
        | Variable ${ $0 = $<1; }$
        ## term 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 = $<1;
+       }$
+
 Thus far the complex types we have are arrays and structs.
 
 #### Arrays
@@ -2398,16 +2432,16 @@ with a const size by whether they are prepared at parse time or not.
                struct value *vsize;
                mpz_t q;
                if (type->array.static_size)
-                       return 1;       // UNTESTED
+                       return 1;       // NOTEST - guard against reentry
                if (type->array.unspec && parse_time)
-                       return 1;       // UNTESTED
+                       return 1;       // NOTEST - unspec is still incomplete
                if (parse_time && type->array.vsize && !type->array.vsize->global)
-                       return 1;       // UNTESTED
+                       return 1;       // NOTEST - should be impossible
 
                if (type->array.vsize) {
                        vsize = var_value(c, type->array.vsize);
                        if (!vsize)
-                               return 1;       // UNTESTED
+                               return 1;       // NOTEST - should be impossible
                        mpz_init(q);
                        mpz_tdiv_q(q, mpq_numref(vsize->num), mpq_denref(vsize->num));
                        type->array.size = mpz_get_si(q);
@@ -2416,7 +2450,7 @@ with a const size by whether they are prepared at parse time or not.
                if (!parse_time)
                        return 1;
                if (type->array.member->size <= 0)
-                       return 0;       // UNTESTED
+                       return 0;       // NOTEST - error caught before here
 
                type->array.static_size = 1;
                type->size = type->array.size * type->array.member->size;
@@ -2468,19 +2502,15 @@ with a const size by whether they are prepared at parse time or not.
                /* Both are arrays, so we can look at details */
                if (!type_compat(require->array.member, have->array.member, 0))
                        return 0;
-               if (have->array.unspec && require->array.unspec) {
-                       if (have->array.vsize && require->array.vsize &&
-                           have->array.vsize != require->array.vsize)  // UNTESTED
-                               /* sizes might not be the same */
-                               return 0;       // UNTESTED
-                       return 1;
-               }
+               if (have->array.unspec && require->array.unspec &&
+                   have->array.size != require->array.size)
+                       return 0;       // NOTEST
                if (have->array.unspec || require->array.unspec)
-                       return 1;       // UNTESTED
+                       return 1;
                if (require->array.vsize == NULL && have->array.vsize == NULL)
                        return require->array.size == have->array.size;
 
-               return require->array.vsize == have->array.vsize;       // UNTESTED
+               return require->array.vsize == have->array.vsize;
        }
 
        static void array_print_type(struct type *type, FILE *f)
@@ -2554,29 +2584,18 @@ with a const size by whether they are prepared at parse time or not.
                $0->array.vsize = v;
        } }$
 
-###### Grammar
-       $*type
-       OptType -> Type ${ $0 = $<1; }$
-               | ${ $0 = NULL; }$
-
 ###### formal type grammar
 
-       | [ IDENTIFIER :: OptType ] Type ${ {
-               struct variable *v = var_decl(c, $ID.txt);
-
-               v->type = $<OT;
-               v->constant = 1;
-               if (!v->type)
-                       v->type = Tnum;
-               $0 = add_anon_type(c, &array_prototype, "array[var]");
-               $0->array.member = $<6;
+       | [ ] Type ${ {
+               $0 = add_anon_type(c, &array_prototype, "array[]");
+               $0->array.member = $<Type;
                $0->array.size = 0;
                $0->array.unspec = 1;
-               $0->array.vsize = v;
+               $0->array.vsize = NULL;
        } }$
 
 ###### Binode types
-       Index,
+       Index, Length,
 
 ###### term grammar
 
@@ -2588,6 +2607,13 @@ with a const size by whether they are prepared at parse time or not.
                $0 = b;
        } }$
 
+       | Term [ ] ${ {
+               struct binode *b = new(binode);
+               b->op = Length;
+               b->left = $<Term;
+               $0 = b;
+       } }$
+
 ###### print binode cases
        case Index:
                print_exec(b->left, -1, bracket);
@@ -2596,6 +2622,11 @@ with a const size by whether they are prepared at parse time or not.
                printf("]");
                break;
 
+       case Length:
+               print_exec(b->left, -1, bracket);
+               printf("[]");
+               break;
+
 ###### propagate binode cases
        case Index:
                /* left must be an array, right must be a number,
@@ -2615,6 +2646,20 @@ with a const size by whether they are prepared at parse time or not.
                }
                break;
 
+       case Length:
+               /* left must be an array, result is a number
+                */
+               t = propagate_types(b->left, c, perr, NULL, 0);
+               if (!t || t->compat != array_compat) {
+                       type_err(c, "error: %1 cannot provide length", prog, t, 0, NULL);
+                       return NULL;
+               }
+               if (!type_compat(type, Tnum, rules))
+                       type_err(c, "error: have %1 but need %2", prog,
+                                        Tnum, rules, type);
+               return Tnum;
+               break;
+
 ###### interp binode cases
        case Index: {
                mpz_t q;
@@ -2640,6 +2685,13 @@ with a const size by whether they are prepared at parse time or not.
                ltype = NULL;
                break;
        }
+       case Length: {
+               lleft = linterp_exec(c, b->left, &ltype);
+               mpq_set_ui(rv.num, ltype->array.size, 1);
+               ltype = NULL;
+               rvtype = Tnum;
+               break;
+       }
 
 #### Structs
 
@@ -2951,10 +3003,17 @@ function will be needed.
        | SimpleFieldList EOL ${ $0 = $<SFL; }$
 
        FieldLines -> SimpleFieldList Newlines ${ $0 = $<SFL; }$
-       | FieldLines SimpleFieldList Newlines ${
-               $SFL->prev = $<FL;
-               $0 = $<SFL;
-       }$
+       | FieldLines SimpleFieldList Newlines ${ {
+               struct fieldlist *f = $<SFL;
+
+               if (f) {
+                       $0 = f;
+                       while (f->prev)
+                               f = f->prev;
+                       f->prev = $<FL;
+               } else
+                       $0 = $<FL;
+       } }$
 
        SimpleFieldList -> Field ${ $0 = $<F; }$
        | SimpleFieldList ; Field ${
@@ -2996,10 +3055,10 @@ function will be needed.
                        if (fl->type->print && fl->init) {
                                fprintf(f, " = ");
                                if (fl->type == Tstr)
-                                       fprintf(f, "\"");       // UNTESTED
+                                       fprintf(f, "\"");
                                print_value(fl->type, fl->init, f);
                                if (fl->type == Tstr)
-                                       fprintf(f, "\"");       // UNTESTED
+                                       fprintf(f, "\"");
                        }
                        fprintf(f, "\n");
                }
@@ -3128,6 +3187,9 @@ anything in the heap or on the stack.  A reference can be assigned
        static int reference_compat(struct type *require, struct type *have,
                                    enum val_rules rules)
        {
+               if (rules & Rrefok)
+                       if (require->reference.referent == have)
+                               return 1;
                if (have->compat != require->compat)
                        return 0;
                if (have->reference.referent != require->reference.referent)
@@ -3155,7 +3217,6 @@ anything in the heap or on the stack.  A reference can be assigned
                return Tnone;
        }
 
-
        static struct type reference_prototype = {
                .print_type = reference_print_type,
                .cmp_eq = reference_cmp,
@@ -3173,8 +3234,8 @@ anything in the heap or on the stack.  A reference can be assigned
        | @ IDENTIFIER ${ {
                struct type *t = find_type(c, $ID.txt);
                if (!t) {
-                       t = add_type(c, $ID.txt, NULL); // UNTESTED
-                       t->first_use = $ID;     // UNTESTED
+                       t = add_type(c, $ID.txt, NULL);
+                       t->first_use = $ID;
                }
                $0 = find_anon_type(c, &reference_prototype, "@%.*s",
                                    $ID.txt.len, $ID.txt.txt);
@@ -3325,7 +3386,7 @@ anything in the heap or on the stack.  A reference can be assigned
 ###### Expressions: dereference
 
 ###### Binode types
-       Deref,
+       Deref, AddressOf,
 
 ###### term grammar
 
@@ -3341,6 +3402,9 @@ anything in the heap or on the stack.  A reference can be assigned
                print_exec(b->left, -1, bracket);
                printf("@");
                break;
+       case AddressOf:
+               print_exec(b->left, -1, bracket);
+               break;
 
 ###### propagate binode cases
        case Deref:
@@ -3354,13 +3418,30 @@ anything in the heap or on the stack.  A reference can be assigned
                        return t->reference.referent;
                break;
 
+       case AddressOf:
+               /* left must be lval, we create reference to it */
+               if (!type || type->free != reference_free)
+                       t = propagate_types(b->left, c, perr, type, 0); // NOTEST impossible
+               else
+                       t = propagate_types(b->left, c, perr,
+                                           type->reference.referent, 0);
+               if (t)
+                       t = find_anon_type(c, &reference_prototype, "@%.*s",
+                                       t->name.len, t->name.txt);
+               return t;
+
 ###### interp binode cases
-       case Deref: {
+       case Deref:
                left = interp_exec(c, b->left, &ltype);
                lrv = left.ref;
                rvtype = ltype->reference.referent;
                break;
-       }
+
+       case AddressOf:
+               rv.ref = linterp_exec(c, b->left, &rvtype);
+               rvtype = find_anon_type(c, &reference_prototype, "@%.*s",
+                                       rvtype->name.len, rvtype->name.txt);
+               break;
 
 
 #### Functions
@@ -3460,6 +3541,14 @@ further detailed when Expression Lists are introduced.
                return 0;
        }
 
+       static struct exec *take_addr(struct exec *e)
+       {
+               struct binode *rv = new(binode);
+               rv->op = AddressOf;
+               rv->left = e;
+               return rv;
+       }
+
        static void function_check_args(struct parse_context *c, enum prop_err *perr,
                                        struct type *require, struct exec *args)
        {
@@ -3471,13 +3560,22 @@ further detailed when Expression Lists are introduced.
 
                while (param) {
                        struct var *pv = cast(var, param->left);
+                       struct type *t = pv->var->type, *t2;
                        if (!arg) {
                                type_err(c, "error: insufficient arguments to function.",
                                         args, NULL, 0, NULL);
                                break;
                        }
                        *perr = 0;
-                       propagate_types(arg->left, c, perr, pv->var->type, 0);
+                       t2 = propagate_types(arg->left, c, perr, t, Rrefok);
+                       if (t->free == reference_free &&
+                           t->reference.referent == t2 &&
+                           !(*perr & Erval)) {
+                               arg->left = take_addr(arg->left);
+                       } else if (!(*perr & Efail) && !type_compat(t2, t, 0)) {
+                               type_err(c, "error: cannot pass rval when reference expected",
+                                        arg->left, NULL, 0, NULL);
+                       }
                        param = cast(binode, param->right);
                        arg = cast(binode, arg->right);
                }
@@ -3488,6 +3586,7 @@ further detailed when Expression Lists are introduced.
 
        static void function_print(struct type *type, struct value *val, FILE *f)
        {
+               fprintf(f, "\n");
                print_exec(val->function, 1, 0);
        }
 
@@ -3521,7 +3620,6 @@ further detailed when Expression Lists are introduced.
                        } else
                                type_print(type->function.return_type, f);
                }
-               fprintf(f, "\n");
        }
 
        static void function_free_type(struct type *t)
@@ -3544,9 +3642,6 @@ further detailed when Expression Lists are introduced.
 
        $TERM func
 
-###### Binode types
-       List,
-
 ###### Grammar
 
        $*variable
@@ -3808,75 +3903,21 @@ there.
                struct binode *b2 = cast(binode, b->right);
                left = interp_exec(c, b->left, &ltype);
                if (left.bool)
-                       rv = interp_exec(c, b2->left, &rvtype); // UNTESTED
+                       rv = interp_exec(c, b2->left, &rvtype);
                else
                        rv = interp_exec(c, b2->right, &rvtype);
                }
                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 then`" and "`or else`" are similar to `and` and `or`
-have same corresponding precendence.  The difference is that they don't
+expressions.  `and` and `or` are short-circuit operators that don't
 evaluate the second expression if not necessary.
 
 ###### Binode types
        And,
-       AndThen,
        Or,
-       OrElse,
        Not,
 
 ###### declare terminals
@@ -3892,14 +3933,6 @@ evaluate the second expression if not necessary.
                b->right = $<3;
                $0 = b;
        } }$
-       | Expression or else Expression ${ {
-               struct binode *b = new(binode);
-               b->op = OrElse;
-               b->left = $<1;
-               b->right = $<4;
-               $0 = b;
-       } }$
-
        | Expression and Expression ${ {
                struct binode *b = new(binode);
                b->op = And;
@@ -3907,14 +3940,6 @@ evaluate the second expression if not necessary.
                b->right = $<3;
                $0 = b;
        } }$
-       | Expression and then Expression ${ {
-               struct binode *b = new(binode);
-               b->op = AndThen;
-               b->left = $<1;
-               b->right = $<4;
-               $0 = b;
-       } }$
-
        | not Expression ${ {
                struct binode *b = new(binode);
                b->op = Not;
@@ -3930,13 +3955,6 @@ evaluate the second expression if not necessary.
                print_exec(b->right, -1, bracket);
                if (bracket) printf(")");
                break;
-       case AndThen:
-               if (bracket) printf("(");
-               print_exec(b->left, -1, bracket);
-               printf(" and then ");
-               print_exec(b->right, -1, bracket);
-               if (bracket) printf(")");
-               break;
        case Or:
                if (bracket) printf("(");
                print_exec(b->left, -1, bracket);
@@ -3944,13 +3962,6 @@ evaluate the second expression if not necessary.
                print_exec(b->right, -1, bracket);
                if (bracket) printf(")");
                break;
-       case OrElse:
-               if (bracket) printf("(");
-               print_exec(b->left, -1, bracket);
-               printf(" or else ");
-               print_exec(b->right, -1, bracket);
-               if (bracket) printf(")");
-               break;
        case Not:
                if (bracket) printf("(");
                printf("not ");
@@ -3960,9 +3971,7 @@ evaluate the second expression if not necessary.
 
 ###### propagate binode cases
        case And:
-       case AndThen:
        case Or:
-       case OrElse:
        case Not:
                /* both must be Tbool, result is Tbool */
                propagate_types(b->left, c, perr, Tbool, 0);
@@ -3975,21 +3984,11 @@ evaluate the second expression if not necessary.
 
 ###### interp binode cases
        case And:
-               rv = interp_exec(c, b->left, &rvtype);
-               right = interp_exec(c, b->right, &rtype);
-               rv.bool = rv.bool && right.bool;
-               break;
-       case AndThen:
                rv = interp_exec(c, b->left, &rvtype);
                if (rv.bool)
                        rv = interp_exec(c, b->right, NULL);
                break;
        case Or:
-               rv = interp_exec(c, b->left, &rvtype);
-               right = interp_exec(c, b->right, &rtype);
-               rv.bool = rv.bool || right.bool;
-               break;
-       case OrElse:
                rv = interp_exec(c, b->left, &rvtype);
                if (!rv.bool)
                        rv = interp_exec(c, b->right, NULL);
@@ -4085,9 +4084,9 @@ expression operator, and the `CMPop` non-terminal will match one of them.
                if (t)
                        propagate_types(b->right, c, perr, t, 0);
                else {
-                       t = propagate_types(b->right, c, perr, NULL, 0);        // UNTESTED
-                       if (t)  // UNTESTED
-                               t = propagate_types(b->left, c, perr, t, 0);    // UNTESTED
+                       t = propagate_types(b->right, c, perr, NULL, 0);        // NOTEST
+                       if (t)  // NOTEST
+                               t = propagate_types(b->left, c, perr, t, 0);    // NOTEST
                }
                if (!type_compat(type, Tbool, 0))
                        type_err(c, "error: Comparison returns %1 but %2 expected", prog,
@@ -4249,9 +4248,10 @@ parentheses around an expression converts it into a Term,
                if (bracket) printf(")");
                break;
        case Bracket:
-               printf("(");
+               /* Avoid double brackets... */
+               if (!bracket) printf("(");
                print_exec(b->right, indent, bracket);
-               printf(")");
+               if (!bracket) printf(")");
                break;
 
 ###### propagate binode cases
@@ -4287,7 +4287,7 @@ parentheses around an expression converts it into a Term,
                /* op must be string, result is number */
                propagate_types(b->left, c, perr, Tstr, 0);
                if (!type_compat(type, Tnum, 0))
-                       type_err(c,     // UNTESTED
+                       type_err(c,
                          "error: Can only convert string to number, not %1",
                                prog, type, 0, NULL);
                *perr |= Erval;
@@ -4377,19 +4377,19 @@ parentheses around an expression converts it into a Term,
                rvtype = Tnum;
 
                struct text tx = right.str;
-               char tail[3];
+               char tail[3] = "";
                int neg = 0;
                if (tx.txt[0] == '-') {
-                       neg = 1;        // UNTESTED
-                       tx.txt++;       // UNTESTED
-                       tx.len--;       // UNTESTED
+                       neg = 1;
+                       tx.txt++;
+                       tx.len--;
                }
                if (number_parse(rv.num, tail, tx) == 0)
-                       mpq_init(rv.num);       // UNTESTED
+                       mpq_init(rv.num);
                else if (neg)
-                       mpq_neg(rv.num, rv.num);        // UNTESTED
+                       mpq_neg(rv.num, rv.num);
                if (tail[0])
-                       printf("Unsupported suffix: %.*s\n", tx.len, tx.txt);   // UNTESTED
+                       printf("Unsupported suffix: %.*s\n", tx.len, tx.txt);
 
                break;
        case Test:
@@ -4489,7 +4489,8 @@ the common header for all reductions to use.
        Block -> { IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
        |        { SimpleStatements } ${ $0 = reorder_bilist($<SS); }$
        |        SimpleStatements ; ${ $0 = reorder_bilist($<SS); }$
-       |        SimpleStatements EOL ${ $0 = reorder_bilist($<SS); }$
+       |        SimpleStatements EOL ${ $0 = reorder_bilist($<SS); 
+               }$
        |        IN OptNL Statementlist OUT ${ $0 = $<Sl; }$
 
        OpenBlock -> OpenScope { IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
@@ -4498,7 +4499,7 @@ the common header for all reductions to use.
        |        OpenScope SimpleStatements EOL ${ $0 = reorder_bilist($<SS); }$
        |        IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
 
-       UseBlock -> { OpenScope IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
+       UseBlock -> { IN OpenScope OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
        |        { OpenScope SimpleStatements } ${ $0 = reorder_bilist($<SS); }$
        |        IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
 
@@ -4512,7 +4513,7 @@ the common header for all reductions to use.
 
        ComplexStatements -> ComplexStatements ComplexStatement ${
                if ($2 == NULL) {
-                       $0 = $<1;
+                       $0 = $<1;       // NOTEST - impossible
                } else {
                        $0 = new(binode);
                        $0->op = Block;
@@ -4522,7 +4523,7 @@ the common header for all reductions to use.
        }$
        | ComplexStatement ${
                if ($1 == NULL) {
-                       $0 = NULL;
+                       $0 = NULL;      // NOTEST - impossible
                } else {
                        $0 = new(binode);
                        $0->op = Block;
@@ -4562,25 +4563,13 @@ the common header for all reductions to use.
 
 ###### print binode cases
        case Block:
-               if (indent < 0) {
-                       // simple statement
-                       if (b->left == NULL)    // UNTESTED
-                               printf("pass"); // UNTESTED
-                       else
-                               print_exec(b->left, indent, bracket);   // UNTESTED
-                       if (b->right) { // UNTESTED
-                               printf("; ");   // UNTESTED
-                               print_exec(b->right, indent, bracket);  // UNTESTED
-                       }
-               } else {
-                       // block, one per line
-                       if (b->left == NULL)
-                               do_indent(indent, "pass\n");
-                       else
-                               print_exec(b->left, indent, bracket);
-                       if (b->right)
-                               print_exec(b->right, indent, bracket);
-               }
+               // block, one per line
+               if (b->left == NULL)
+                       do_indent(indent, "pass\n");
+               else
+                       print_exec(b->left, indent, bracket);
+               if (b->right)
+                       print_exec(b->right, indent, bracket);
                break;
 
 ###### propagate binode cases
@@ -4596,7 +4585,9 @@ the common header for all reductions to use.
                struct binode *e;
 
                for (e = b; e; e = cast(binode, e->right)) {
-                       t = propagate_types(e->left, c, perr, NULL, rules);
+                       *perr |= *perr_local;
+                       *perr_local = 0;
+                       t = propagate_types(e->left, c, perr_local, NULL, rules);
                        if ((rules & Rboolok) && (t == Tbool || t == Tnone))
                                t = NULL;
                        if (t == Tnone && e->right)
@@ -4667,11 +4658,16 @@ printed.
 
        case Print:
                do_indent(indent, "print");
-               if (b->right) {
-                       print_exec(b->right, -1, bracket);
+               b2 = cast(binode, b->left ?: b->right);
+               while (b2) {
+                       printf(" ");
+                       print_exec(b2->left, -1, bracket);
+                       if (b2->right)
+                               printf(",");
+                       b2 = cast(binode, b2->right);
+               }
+               if (b->right)
                        printf(",");
-               } else
-                       print_exec(b->left, -1, bracket);
                if (indent >= 0)
                        printf("\n");
                break;
@@ -4797,7 +4793,7 @@ be declared at any time.
 
        case Assign:
        case Declare:
-               /* Both must match and not be labels,
+               /* Both must match, or left may be ref and right an lval
                 * Type must support 'dup',
                 * For Assign, left must not be constant.
                 * result is Tnone
@@ -4808,7 +4804,19 @@ be declared at any time.
                        return Tnone;
 
                if (t) {
-                       propagate_types(b->right, c, perr_local, t, 0);
+                       struct type *t2 = propagate_types(b->right, c, perr_local,
+                                                         t, Rrefok);
+                       if (!t2 || t2 == t || (*perr_local & Efail))
+                               ; // No more effort needed
+                       else if (t->free == reference_free &&
+                                t->reference.referent == t2 &&
+                                !(*perr_local & Erval))
+                               b->right = take_addr(b->right);
+                       else if (t->free == reference_free &&
+                                t->reference.referent == t2 &&
+                                (*perr_local & Erval))
+                               type_err(c, "error: Cannot assign an rval to a reference.",
+                                        b, NULL, 0, NULL);
                } else {
                        t = propagate_types(b->right, c, perr_local, NULL, 0);
                        if (t)
@@ -4853,10 +4861,10 @@ be declared at any time.
                val = var_value(c, v);
                if (v->type->prepare_type)
                        v->type->prepare_type(c, v->type, 0);
-               if (b->right)
-                       dinterp_exec(c, b->right, val, v->type, 0);
-               else
+               if (!b->right)
                        val_init(v->type, val);
+               else
+                       dinterp_exec(c, b->right, val, v->type, 0);
                break;
        }
 
@@ -5280,9 +5288,7 @@ casepart` to track a list of case parts.
 
 ###### propagate binode cases
        case Loop:
-               t = propagate_types(b->right, c, perr_local, Tnone, 0);
-               if (!type_compat(Tnone, t, 0))
-                       *perr |= Efail; // UNTESTED
+               propagate_types(b->right, c, perr_local, Tnone, 0);
                return propagate_types(b->left, c, perr, type, rules);
 
 ###### propagate exec cases
@@ -5302,13 +5308,9 @@ casepart` to track a list of case parts.
                struct casepart *cp;
 
                t = propagate_types(cs->forpart, c, perr, Tnone, 0);
-               if (!type_compat(Tnone, t, 0))
-                       *perr |= Efail; // UNTESTED
 
                if (cs->looppart) {
                        t = propagate_types(cs->thenpart, c, perr, Tnone, 0);
-                       if (!type_compat(Tnone, t, 0))
-                               *perr |= Efail; // UNTESTED
                }
                if (cs->casepart == NULL) {
                        propagate_types(cs->condpart, c, perr, Tbool, 0);
@@ -5320,9 +5322,9 @@ casepart` to track a list of case parts.
                             cp && !t; cp = cp->next)
                                t = propagate_types(cp->value, c, perr, NULL, 0);
                        if (!t && cs->condpart)
-                               t = propagate_types(cs->condpart, c, perr, NULL, Rboolok);      // UNTESTED
+                               t = propagate_types(cs->condpart, c, perr, NULL, Rboolok);      // NOTEST
                        if (!t && cs->looppart)
-                               t = propagate_types(cs->looppart, c, perr, NULL, Rboolok);      // UNTESTED
+                               t = propagate_types(cs->looppart, c, perr, NULL, Rboolok);      // NOTEST
                        // Now we have a type (I hope) push it down
                        if (t) {
                                for (cp = cs->casepart; cp; cp = cp->next)
@@ -5338,8 +5340,8 @@ casepart` to track a list of case parts.
                        type = propagate_types(cs->elsepart, c, perr, NULL, rules);
                for (cp = cs->casepart;
                     cp && !type;
-                    cp = cp->next)     // UNTESTED
-                       type = propagate_types(cp->action, c, perr, NULL, rules);       // UNTESTED
+                    cp = cp->next)     // NOTEST
+                       type = propagate_types(cp->action, c, perr, NULL, rules);       // NOTEST
                if (type) {
                        if (!cs->looppart)
                                propagate_types(cs->thenpart, c, perr, type, rules);
@@ -5437,7 +5439,7 @@ various declarations in the parse context.
        | DeclarationList Declaration
 
        Declaration -> ERROR Newlines ${
-               tok_err(c,      // UNTESTED
+               tok_err(c,      // NOTEST
                        "error: unhandled parse error", &$1);
        }$
        | DeclareConstant
@@ -5743,10 +5745,13 @@ is a bit more interesting at this level.
                                struct value *val = var_value(&context, v);
                                printf("func %.*s", v->name->name.len, v->name->name.txt);
                                v->type->print_type_decl(v->type, stdout);
-                               if (brackets)
-                                       print_exec(val->function, 0, brackets);
-                               else
+                               if (brackets) {
+                                       printf(" {\n");
+                                       print_exec(val->function, 1, brackets);
+                                       printf("}\n");
+                               } else {
                                        print_value(v->type, val, stdout);
+                               }
                                printf("/* frame size %d */\n", v->type->function.local_size);
                                target -= 1;
                        }
@@ -5848,15 +5853,12 @@ is a bit more interesting at this level.
                        struct value *vl = var_value(c, v->var);
                        struct value arg;
                        struct type *t;
-                       mpq_t argcq;
                        int i;
 
                        switch (anum++) {
                        case 0: /* argv */
                                t = v->var->type;
-                               mpq_init(argcq);
-                               mpq_set_ui(argcq, argc, 1);
-                               memcpy(var_value(c, t->array.vsize), &argcq, sizeof(argcq));
+                               t->array.size = argc;
                                t->prepare_type(c, t, 0);
                                array_init(v->var->type, vl);
                                for (i = 0; i < argc; i++) {
@@ -5910,7 +5912,7 @@ things which will likely grow as the languages grows.
                name:string
                alive:Boolean
 
-       func main(argv:[argc::]string)
+       func main(argv:[]string)
                print "Hello World, what lovely oceans you have!"
                print "Are there", five, "?"
                print pi, pie, "but", cake
@@ -5938,7 +5940,7 @@ things which will likely grow as the languages grows.
                a : number
                a = A;
                b:number = B
-               if a > 0 and then b > 0:
+               if a > 0 and b > 0:
                        while a != b:
                                if a < b:
                                        b = b - a