oceani: don't let error in one statement hides errors in next.

[ocean] / csrc / oceani.mdc

diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc
index dca205570c9af2c1ae704e0a58c04f01bdd96782..f97652d025ca4c90ef8e183ac45bea0eed41a677 100644 (file)
--- a/csrc/oceani.mdc
+++ b/csrc/oceani.mdc
@@ -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
 
 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.
 
 The "func" clause currently only allows a "main" function to be
 declared.  That will be extended when proper function support is added.


@@ -367,14 +367,14 @@ context so indicate that parsing failed.
        static void fput_loc(struct exec *loc, FILE *f);
        static void type_err(struct parse_context *c,
                             char *fmt, struct exec *loc,
        static void fput_loc(struct exec *loc, FILE *f);
        static void type_err(struct parse_context *c,
                             char *fmt, struct exec *loc,

-                            struct type *t1, int rules, struct type *t2);
+                            struct type *t1, enum val_rules rules, struct type *t2);

        static void tok_err(struct parse_context *c, char *fmt, struct token *t);
 
 ###### core functions
 
        static void type_err(struct parse_context *c,
                             char *fmt, struct exec *loc,
        static void tok_err(struct parse_context *c, char *fmt, struct token *t);
 
 ###### core functions
 
        static void type_err(struct parse_context *c,
                             char *fmt, struct exec *loc,

-                            struct type *t1, int rules, struct type *t2)
+                            struct type *t1, enum val_rules rules, struct type *t2)

        {
                fprintf(stderr, "%s:", c->file_name);
                fput_loc(loc, stderr);
        {
                fprintf(stderr, "%s:", c->file_name);
                fput_loc(loc, stderr);


@@ -592,21 +592,24 @@ passed by reference.  It has `Efail` set when an error is found, and
 any expression cannot be evaluated a compile time, `Eruntime` is set.
 If the expression can be copied, `Emaycopy` is set.
 
 any expression cannot be evaluated a compile time, `Eruntime` is set.
 If the expression can be copied, `Emaycopy` is set.
 

-If it remains unchanged at `0`, then no more propagation is needed.
+If `Erval` is set, then the value cannot be assigned to because it is
+a temporary result.  If `Erval` is clear but `Econst` is set, then
+the value can only be assigned once, when the variable is declared.

 
 ###### ast
 
 
 ###### ast
 

-       enum val_rules {Rboolok = 1<<1, Rnoconstant = 1<<2};
+       enum val_rules {Rboolok = 1<<0, Rrefok = 1<<1,};

        enum prop_err {Efail = 1<<0, Eretry = 1<<1, Eruntime = 1<<2,
        enum prop_err {Efail = 1<<0, Eretry = 1<<1, Eruntime = 1<<2,

-                      Emaycopy = 1<<3};
+                      Emaycopy = 1<<3, Erval = 1<<4, Econst = 1<<5};

 
 ###### forward decls
        static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
 
 ###### forward decls
        static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,

-                                           struct type *type, int rules);
+                                           struct type *type, enum val_rules rules);

 ###### core functions
 
        static struct type *__propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
 ###### core functions
 
        static struct type *__propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,

-                                             struct type *type, int rules)
+                                             enum prop_err *perr_local,
+                                             struct type *type, enum val_rules rules)

        {
                struct type *t;
 
        {
                struct type *t;
 


@@ -628,11 +631,13 @@ If it remains unchanged at `0`, then no more propagation is needed.
        }
 
        static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
        }
 
        static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,

-                                           struct type *type, int rules)
+                                           struct type *type, enum val_rules rules)

        {
                int pre_err = c->parse_error;
        {
                int pre_err = c->parse_error;

-               struct type *ret = __propagate_types(prog, c, perr, type, rules);
+               enum prop_err perr_local = 0;
+               struct type *ret = __propagate_types(prog, c, perr, &perr_local, type, rules);

 
 

+               *perr |= perr_local & (Efail | Eretry);

                if (c->parse_error > pre_err)
                        *perr |= Efail;
                return ret;
                if (c->parse_error > pre_err)
                        *perr |= Efail;
                return ret;


@@ -986,7 +991,7 @@ which might be reported in error messages.
 ###### forward decls
 
        static void free_value(struct type *type, struct value *v);
 ###### forward decls
 
        static void free_value(struct type *type, struct value *v);

-       static int type_compat(struct type *require, struct type *have, int rules);
+       static int type_compat(struct type *require, struct type *have, enum val_rules rules);

        static void type_print(struct type *type, FILE *f);
        static void val_init(struct type *type, struct value *v);
        static void dup_value(struct type *type,
        static void type_print(struct type *type, FILE *f);
        static void val_init(struct type *type, struct value *v);
        static void dup_value(struct type *type,


@@ -1051,11 +1056,12 @@ A separate function encoding these cases will simplify some code later.
 
 ###### type functions
 
 
 ###### type functions
 

-       int (*compat)(struct type *this, struct type *other);
+       int (*compat)(struct type *this, struct type *other, enum val_rules rules);

 
 ###### ast functions
 
 
 ###### ast functions
 

-       static int type_compat(struct type *require, struct type *have, int rules)
+       static int type_compat(struct type *require, struct type *have,
+                              enum val_rules rules)

        {
                if ((rules & Rboolok) && have == Tbool)
                        return 1;       // NOTEST
        {
                if ((rules & Rboolok) && have == Tbool)
                        return 1;       // NOTEST


@@ -1063,7 +1069,7 @@ A separate function encoding these cases will simplify some code later.
                        return 1;
 
                if (require->compat)
                        return 1;
 
                if (require->compat)

-                       return require->compat(require, have);
+                       return require->compat(require, have, rules);

 
                return require == have;
        }
 
                return require == have;
        }


@@ -1151,7 +1157,7 @@ A separate function encoding these cases will simplify some code later.
        {
                int cmp;
                if (tl != tr)
        {
                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;
                switch (tl->vtype) {
                case Vlabel: cmp = left->label == right->label ? 0 : 1; break;
                case Vnum: cmp = mpq_cmp(left->num, right->num); break;


@@ -1268,13 +1274,13 @@ executable.
                $0->val.bool = 0;
        }$
        | NUMBER ${ {
                $0->val.bool = 0;
        }$
        | NUMBER ${ {

-               char tail[3];
+               char tail[3] = "";

                $0 = new_val(Tnum, $1);
                $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 ${ {
                char tail[3];
        } }$
        | STRING ${ {
                char tail[3];


@@ -1313,6 +1319,7 @@ executable.
                if (!type_compat(type, val->vtype, rules))
                        type_err(c, "error: expected %1 found %2",
                                   prog, type, rules, val->vtype);
                if (!type_compat(type, val->vtype, rules))
                        type_err(c, "error: expected %1 found %2",
                                   prog, type, rules, val->vtype);

+               *perr |= Erval;

                return val->vtype;
        }
 
                return val->vtype;
        }
 


@@ -1435,6 +1442,7 @@ match "case".
                if (!type_compat(type, Tlabel, rules))
                        type_err(c, "error: expected %1 found %2",
                                 prog, type, rules, Tlabel);
                if (!type_compat(type, Tlabel, rules))
                        type_err(c, "error: expected %1 found %2",
                                 prog, type, rules, Tlabel);

+               *perr |= Erval;

                return Tlabel;
        }
 ###### interp exec cases
                return Tlabel;
        }
 ###### interp exec cases


@@ -2015,7 +2023,7 @@ tell if it was set or not later.
        {
                if (!v->global) {
                        if (!c->local || !v->type)
        {
                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
                        if (v->frame_pos + v->type->size > c->local_size) {
                                printf("INVALID frame_pos\n");  // NOTEST
                                exit(2);                        // NOTEST


@@ -2041,7 +2049,7 @@ tell if it was set or not later.
                        t->prepare_type(c, t, 1);       // NOTEST
 
                if (c->global_size & (t->align - 1))
                        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;
                if (!v) {
                        v = &scratch;
                        v->type = t;


@@ -2088,7 +2096,7 @@ stack.
                        if (v->merged != v)
                                continue;
                        if (!t)
                        if (v->merged != v)
                                continue;
                        if (!t)

-                               continue;
+                               continue;       // NOTEST

                        if (v->frame_pos >= 0)
                                continue;
                        while (done && done->scope_end < v->scope_start)
                        if (v->frame_pos >= 0)
                                continue;
                        while (done && done->scope_end < v->scope_start)


@@ -2266,13 +2274,6 @@ correctly.
                        return Tnone;                                   // NOTEST
                }
                v = v->merged;
                        return Tnone;                                   // NOTEST
                }
                v = v->merged;

-               if (v->constant && (rules & Rnoconstant)) {
-                       type_err(c, "error: Cannot assign to a constant: %v",
-                                prog, NULL, 0, NULL);
-                       type_err(c, "info: name was defined as a constant here",
-                                v->where_decl, NULL, 0, NULL);
-                       return v->type;
-               }

                if (v->type == Tnone && v->where_decl == prog)
                        type_err(c, "error: variable used but not declared: %v",
                                 prog, NULL, 0, NULL);
                if (v->type == Tnone && v->where_decl == prog)
                        type_err(c, "error: variable used but not declared: %v",
                                 prog, NULL, 0, NULL);


@@ -2290,9 +2291,9 @@ correctly.
                }
                if (!v->global || v->frame_pos < 0)
                        *perr |= Eruntime;
                }
                if (!v->global || v->frame_pos < 0)
                        *perr |= Eruntime;

-               if (!type)
-                       return v->type;
-               return type;
+               if (v->constant)
+                       *perr |= Econst;
+               return v->type;

        }
 
 ###### interp exec cases
        }
 
 ###### interp exec cases


@@ -2397,16 +2398,16 @@ 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)
                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)
                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)
                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)
 
                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);
                        mpz_init(q);
                        mpz_tdiv_q(q, mpq_numref(vsize->num), mpq_denref(vsize->num));
                        type->array.size = mpz_get_si(q);


@@ -2415,7 +2416,7 @@ 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)
                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;
 
                type->array.static_size = 1;
                type->size = type->array.size * type->array.member->size;


@@ -2459,26 +2460,23 @@ with a const size by whether they are prepared at parse time or not.
                        free(ptr);
        }
 
                        free(ptr);
        }
 

-       static int array_compat(struct type *require, struct type *have)
+       static int array_compat(struct type *require, struct type *have,
+                               enum val_rules rules)

        {
                if (have->compat != require->compat)
                        return 0;
                /* Both are arrays, so we can look at details */
                if (!type_compat(require->array.member, have->array.member, 0))
                        return 0;
        {
                if (have->compat != require->compat)
                        return 0;
                /* 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)
                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;
 
                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)
        }
 
        static void array_print_type(struct type *type, FILE *f)


@@ -2552,29 +2550,18 @@ with a const size by whether they are prepared at parse time or not.
                $0->array.vsize = v;
        } }$
 
                $0->array.vsize = v;
        } }$
 

-###### Grammar
-       $*type
-       OptType -> Type ${ $0 = $<1; }$
-               | ${ $0 = NULL; }$
-

 ###### formal type grammar
 
 ###### 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.size = 0;
                $0->array.unspec = 1;

-               $0->array.vsize = v;
+               $0->array.vsize = NULL;

        } }$
 
 ###### Binode types
        } }$
 
 ###### Binode types

-       Index,
+       Index, Length,

 
 ###### term grammar
 
 
 ###### term grammar
 


@@ -2586,6 +2573,13 @@ with a const size by whether they are prepared at parse time or not.
                $0 = b;
        } }$
 
                $0 = b;
        } }$
 

+       | 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);
 ###### print binode cases
        case Index:
                print_exec(b->left, -1, bracket);


@@ -2594,13 +2588,18 @@ with a const size by whether they are prepared at parse time or not.
                printf("]");
                break;
 
                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,
                 * result is the member type of the array
                 */
 ###### propagate binode cases
        case Index:
                /* left must be an array, right must be a number,
                 * result is the member type of the array
                 */

-               propagate_types(b->right, c, perr, Tnum, 0);
-               t = propagate_types(b->left, c, perr, NULL, rules & Rnoconstant);
+               propagate_types(b->right, c, perr_local, Tnum, 0);
+               t = propagate_types(b->left, c, perr, NULL, 0);

                if (!t || t->compat != array_compat) {
                        type_err(c, "error: %1 cannot be indexed", prog, t, 0, NULL);
                        return NULL;
                if (!t || t->compat != array_compat) {
                        type_err(c, "error: %1 cannot be indexed", prog, t, 0, NULL);
                        return NULL;


@@ -2613,6 +2612,20 @@ with a const size by whether they are prepared at parse time or not.
                }
                break;
 
                }
                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;
 ###### interp binode cases
        case Index: {
                mpz_t q;


@@ -2638,6 +2651,13 @@ with a const size by whether they are prepared at parse time or not.
                ltype = NULL;
                break;
        }
                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
 
 
 #### Structs
 


@@ -2915,24 +2935,31 @@ function will be needed.
        }
 
 ###### top level grammar
        }
 
 ###### top level grammar

-       DeclareStruct -> struct IDENTIFIER FieldBlock Newlines ${ {
-               struct type *t;
-               t = find_type(c, $ID.txt);
-               if (!t)
-                       t = add_type(c, $ID.txt, &structure_prototype);
-               else if (t->size >= 0) {
+       $*type
+       StructName -> IDENTIFIER ${ {
+               struct type *t = find_type(c, $ID.txt);
+
+               if (t && t->size >= 0) {

                        tok_err(c, "error: type already declared", &$ID);
                        tok_err(c, "info: this is location of declartion", &t->first_use);
                        tok_err(c, "error: type already declared", &$ID);
                        tok_err(c, "info: this is location of declartion", &t->first_use);

-                       /* Create a new one - duplicate */
-                       t = add_type(c, $ID.txt, &structure_prototype);
-               } else {
-                       struct type tmp = *t;
-                       *t = structure_prototype;
-                       t->name = tmp.name;
-                       t->next = tmp.next;
+                       t = NULL;

                }
                }

-               t->structure.field_list = $<FB;
+               if (!t)
+                       t = add_type(c, $ID.txt, NULL);

                t->first_use = $ID;
                t->first_use = $ID;

+               $0 = t;
+       } }$
+       $void
+       DeclareStruct -> struct StructName FieldBlock Newlines ${ {
+               struct type *t = $<SN;
+               struct type tmp = *t;
+
+               *t = structure_prototype;
+               t->name = tmp.name;
+               t->next = tmp.next;
+               t->first_use = tmp.first_use;
+
+               t->structure.field_list = $<FB;

        } }$
 
        $*fieldlist
        } }$
 
        $*fieldlist


@@ -2942,10 +2969,17 @@ function will be needed.
        | SimpleFieldList EOL ${ $0 = $<SFL; }$
 
        FieldLines -> SimpleFieldList Newlines ${ $0 = $<SFL; }$
        | 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 ${
 
        SimpleFieldList -> Field ${ $0 = $<F; }$
        | SimpleFieldList ; Field ${


@@ -2987,10 +3021,10 @@ function will be needed.
                        if (fl->type->print && fl->init) {
                                fprintf(f, " = ");
                                if (fl->type == Tstr)
                        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)
                                print_value(fl->type, fl->init, f);
                                if (fl->type == Tstr)

-                                       fprintf(f, "\"");       // UNTESTED
+                                       fprintf(f, "\"");

                        }
                        fprintf(f, "\n");
                }
                        }
                        fprintf(f, "\n");
                }


@@ -3116,8 +3150,12 @@ anything in the heap or on the stack.  A reference can be assigned
                /* Nothing to do here */
        }
 
                /* Nothing to do here */
        }
 

-       static int reference_compat(struct type *require, struct type *have)
+       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)
                if (have->compat != require->compat)
                        return 0;
                if (have->reference.referent != require->reference.referent)


@@ -3145,7 +3183,6 @@ anything in the heap or on the stack.  A reference can be assigned
                return Tnone;
        }
 
                return Tnone;
        }
 

-

        static struct type reference_prototype = {
                .print_type = reference_print_type,
                .cmp_eq = reference_cmp,
        static struct type reference_prototype = {
                .print_type = reference_print_type,
                .cmp_eq = reference_cmp,


@@ -3257,6 +3294,7 @@ anything in the heap or on the stack.  A reference can be assigned
                                r->reftype = type;
                                *perr |= Eretry;
                        }
                                r->reftype = type;
                                *perr |= Eretry;
                        }

+                       *perr |= Erval;

                        return type;
                case RefNil:
                        if (type && type->free != reference_free)
                        return type;
                case RefNil:
                        if (type && type->free != reference_free)


@@ -3266,9 +3304,10 @@ anything in the heap or on the stack.  A reference can be assigned
                                r->reftype = type;
                                *perr |= Eretry;
                        }
                                r->reftype = type;
                                *perr |= Eretry;
                        }

+                       *perr |= Erval;

                        return type;
                case RefFree:
                        return type;
                case RefFree:

-                       t = propagate_types(r->right, c, perr, NULL, 0);
+                       t = propagate_types(r->right, c, perr_local, NULL, 0);

                        if (t && t->free != reference_free)
                                type_err(c, "error: @free can only be assigned a reference, not %1",
                                         prog, t, 0, NULL);
                        if (t && t->free != reference_free)
                                type_err(c, "error: @free can only be assigned a reference, not %1",
                                         prog, t, 0, NULL);


@@ -3313,7 +3352,7 @@ anything in the heap or on the stack.  A reference can be assigned
 ###### Expressions: dereference
 
 ###### Binode types
 ###### Expressions: dereference
 
 ###### Binode types

-       Deref,
+       Deref, AddressOf,

 
 ###### term grammar
 
 
 ###### term grammar
 


@@ -3329,25 +3368,46 @@ anything in the heap or on the stack.  A reference can be assigned
                print_exec(b->left, -1, bracket);
                printf("@");
                break;
                print_exec(b->left, -1, bracket);
                printf("@");
                break;

+       case AddressOf:
+               print_exec(b->left, -1, bracket);
+               break;

 
 ###### propagate binode cases
        case Deref:
                /* left must be a reference, and we return what it refers to */
                /* FIXME how can I pass the expected type down? */
                t = propagate_types(b->left, c, perr, NULL, 0);
 
 ###### propagate binode cases
        case Deref:
                /* left must be a reference, and we return what it refers to */
                /* FIXME how can I pass the expected type down? */
                t = propagate_types(b->left, c, perr, NULL, 0);

+               *perr &= ~Erval;

                if (!t || t->free != reference_free)
                        type_err(c, "error: Cannot dereference %1", b, t, 0, NULL);
                else
                        return t->reference.referent;
                break;
 
                if (!t || t->free != reference_free)
                        type_err(c, "error: Cannot dereference %1", b, t, 0, NULL);
                else
                        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
 ###### interp binode cases

-       case Deref: {
+       case Deref:

                left = interp_exec(c, b->left, &ltype);
                lrv = left.ref;
                rvtype = ltype->reference.referent;
                break;
                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
 
 
 #### Functions


@@ -3440,12 +3500,21 @@ further detailed when Expression Lists are introduced.
                val->function = NULL;
        }
 
                val->function = NULL;
        }
 

-       static int function_compat(struct type *require, struct type *have)
+       static int function_compat(struct type *require, struct type *have,
+                                  enum val_rules rules)

        {
                // FIXME can I do anything here yet?
                return 0;
        }
 
        {
                // FIXME can I do anything here yet?
                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)
        {
        static void function_check_args(struct parse_context *c, enum prop_err *perr,
                                        struct type *require, struct exec *args)
        {


@@ -3457,13 +3526,22 @@ further detailed when Expression Lists are introduced.
 
                while (param) {
                        struct var *pv = cast(var, param->left);
 
                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;
                        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);
                }
                        param = cast(binode, param->right);
                        arg = cast(binode, arg->right);
                }


@@ -3474,6 +3552,7 @@ further detailed when Expression Lists are introduced.
 
        static void function_print(struct type *type, struct value *val, FILE *f)
        {
 
        static void function_print(struct type *type, struct value *val, FILE *f)
        {

+               fprintf(f, "\n");

                print_exec(val->function, 1, 0);
        }
 
                print_exec(val->function, 1, 0);
        }
 


@@ -3507,7 +3586,6 @@ further detailed when Expression Lists are introduced.
                        } else
                                type_print(type->function.return_type, f);
                }
                        } else
                                type_print(type->function.return_type, f);
                }

-               fprintf(f, "\n");

        }
 
        static void function_free_type(struct type *t)
        }
 
        static void function_free_type(struct type *t)


@@ -3666,9 +3744,10 @@ it in the "SimpleStatement Grammar" which will be described later.
                        return NULL;
                }
                *perr |= Eruntime;
                        return NULL;
                }
                *perr |= Eruntime;

-               v->var->type->check_args(c, perr, v->var->type, args);
+               v->var->type->check_args(c, perr_local, v->var->type, args);

                if (v->var->type->function.inline_result)
                        *perr |= Emaycopy;
                if (v->var->type->function.inline_result)
                        *perr |= Emaycopy;

+               *perr |= Erval;

                return v->var->type->function.return_type;
        }
 
                return v->var->type->function.return_type;
        }
 


@@ -3781,7 +3860,7 @@ there.
                struct binode *b2 = cast(binode, b->right);
                struct type *t2;
 
                struct binode *b2 = cast(binode, b->right);
                struct type *t2;
 

-               propagate_types(b->left, c, perr, Tbool, 0);
+               propagate_types(b->left, c, perr_local, Tbool, 0);

                t = propagate_types(b2->left, c, perr, type, 0);
                t2 = propagate_types(b2->right, c, perr, type ?: t, 0);
                return t ?: t2;
                t = propagate_types(b2->left, c, perr, type, 0);
                t2 = propagate_types(b2->right, c, perr, type ?: t, 0);
                return t ?: t2;


@@ -3793,7 +3872,7 @@ there.
                struct binode *b2 = cast(binode, b->right);
                left = interp_exec(c, b->left, &ltype);
                if (left.bool)
                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);
                }
                else
                        rv = interp_exec(c, b2->right, &rvtype);
                }


@@ -3853,15 +3932,12 @@ lists.  In that case a separate function is used to print them.
 ### Expressions: Boolean
 
 The next class of expressions to use the `binode` will be Boolean
 ### 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,
 evaluate the second expression if not necessary.
 
 ###### Binode types
        And,

-       AndThen,

        Or,
        Or,

-       OrElse,

        Not,
 
 ###### declare terminals
        Not,
 
 ###### declare terminals


@@ -3877,14 +3953,6 @@ evaluate the second expression if not necessary.
                b->right = $<3;
                $0 = b;
        } }$
                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;
        | Expression and Expression ${ {
                struct binode *b = new(binode);
                b->op = And;


@@ -3892,14 +3960,6 @@ evaluate the second expression if not necessary.
                b->right = $<3;
                $0 = b;
        } }$
                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;
        | not Expression ${ {
                struct binode *b = new(binode);
                b->op = Not;


@@ -3915,13 +3975,6 @@ evaluate the second expression if not necessary.
                print_exec(b->right, -1, bracket);
                if (bracket) printf(")");
                break;
                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);
        case Or:
                if (bracket) printf("(");
                print_exec(b->left, -1, bracket);


@@ -3929,13 +3982,6 @@ evaluate the second expression if not necessary.
                print_exec(b->right, -1, bracket);
                if (bracket) printf(")");
                break;
                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 ");
        case Not:
                if (bracket) printf("(");
                printf("not ");


@@ -3945,9 +3991,7 @@ evaluate the second expression if not necessary.
 
 ###### propagate binode cases
        case And:
 
 ###### propagate binode cases
        case And:

-       case AndThen:

        case Or:
        case Or:

-       case OrElse:

        case Not:
                /* both must be Tbool, result is Tbool */
                propagate_types(b->left, c, perr, Tbool, 0);
        case Not:
                /* both must be Tbool, result is Tbool */
                propagate_types(b->left, c, perr, Tbool, 0);


@@ -3955,25 +3999,16 @@ evaluate the second expression if not necessary.
                if (type && type != Tbool)
                        type_err(c, "error: %1 operation found where %2 expected", prog,
                                   Tbool, 0, type);
                if (type && type != Tbool)
                        type_err(c, "error: %1 operation found where %2 expected", prog,
                                   Tbool, 0, type);

+               *perr |= Erval;

                return Tbool;
 
 ###### interp binode cases
        case And:
                return Tbool;
 
 ###### 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);
                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);
                rv = interp_exec(c, b->left, &rvtype);
                if (!rv.bool)
                        rv = interp_exec(c, b->right, NULL);


@@ -4069,13 +4104,14 @@ expression operator, and the `CMPop` non-terminal will match one of them.
                if (t)
                        propagate_types(b->right, c, perr, t, 0);
                else {
                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,
                                    Tbool, rules, type);
                }
                if (!type_compat(type, Tbool, 0))
                        type_err(c, "error: Comparison returns %1 but %2 expected", prog,
                                    Tbool, rules, type);

+               *perr |= Erval;

                return Tbool;
 
 ###### interp binode cases
                return Tbool;
 
 ###### interp binode cases


@@ -4232,9 +4268,10 @@ parentheses around an expression converts it into a Term,
                if (bracket) printf(")");
                break;
        case Bracket:
                if (bracket) printf(")");
                break;
        case Bracket:

-               printf("(");
+               /* Avoid double brackets... */
+               if (!bracket) printf("(");

                print_exec(b->right, indent, bracket);
                print_exec(b->right, indent, bracket);

-               printf(")");
+               if (!bracket) printf(")");

                break;
 
 ###### propagate binode cases
                break;
 
 ###### propagate binode cases


@@ -4253,6 +4290,7 @@ parentheses around an expression converts it into a Term,
                if (!type_compat(type, Tnum, 0))
                        type_err(c, "error: Arithmetic returns %1 but %2 expected", prog,
                                   Tnum, rules, type);
                if (!type_compat(type, Tnum, 0))
                        type_err(c, "error: Arithmetic returns %1 but %2 expected", prog,
                                   Tnum, rules, type);

+               *perr |= Erval;

                return Tnum;
 
        case Concat:
                return Tnum;
 
        case Concat:


@@ -4262,15 +4300,17 @@ parentheses around an expression converts it into a Term,
                if (!type_compat(type, Tstr, 0))
                        type_err(c, "error: Concat returns %1 but %2 expected", prog,
                                   Tstr, rules, type);
                if (!type_compat(type, Tstr, 0))
                        type_err(c, "error: Concat returns %1 but %2 expected", prog,
                                   Tstr, rules, type);

+               *perr |= Erval;

                return Tstr;
 
        case StringConv:
                /* op must be string, result is number */
                propagate_types(b->left, c, perr, Tstr, 0);
                if (!type_compat(type, Tnum, 0))
                return Tstr;
 
        case StringConv:
                /* 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);
                          "error: Can only convert string to number, not %1",
                                prog, type, 0, NULL);

+               *perr |= Erval;

                return Tnum;
 
        case Test:
                return Tnum;
 
        case Test:


@@ -4279,6 +4319,7 @@ parentheses around an expression converts it into a Term,
                if (!t || !t->test)
                        type_err(c, "error: '?' requires a testable value, not %1",
                                 prog, t, 0, NULL);
                if (!t || !t->test)
                        type_err(c, "error: '?' requires a testable value, not %1",
                                 prog, t, 0, NULL);

+               *perr |= Erval;

                return Tbool;
 
        case Choose:
                return Tbool;
 
        case Choose:


@@ -4290,10 +4331,11 @@ parentheses around an expression converts it into a Term,
                if (t && t->test == NULL)
                        type_err(c, "error: \"??\" requires a testable value, not %1",
                                 prog, t, 0, NULL);
                if (t && t->test == NULL)
                        type_err(c, "error: \"??\" requires a testable value, not %1",
                                 prog, t, 0, NULL);

+               *perr |= Erval;

                return t;
 
        case Bracket:
                return t;
 
        case Bracket:

-               return propagate_types(b->right, c, perr, type, 0);
+               return propagate_types(b->right, c, perr, type, rules);

 
 ###### interp binode cases
 
 
 ###### interp binode cases
 


@@ -4355,19 +4397,19 @@ parentheses around an expression converts it into a Term,
                rvtype = Tnum;
 
                struct text tx = right.str;
                rvtype = Tnum;
 
                struct text tx = right.str;

-               char tail[3];
+               char tail[3] = "";

                int neg = 0;
                if (tx.txt[0] == '-') {
                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)
                }
                if (number_parse(rv.num, tail, tx) == 0)

-                       mpq_init(rv.num);       // UNTESTED
+                       mpq_init(rv.num);

                else if (neg)
                else if (neg)

-                       mpq_neg(rv.num, rv.num);        // UNTESTED
+                       mpq_neg(rv.num, rv.num);

                if (tail[0])
                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:
 
                break;
        case Test:


@@ -4467,7 +4509,8 @@ 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); }$
        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 = $<Sl; }$
        |        IN OptNL Statementlist OUT ${ $0 = $<Sl; }$
 
        OpenBlock -> OpenScope { IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$


@@ -4476,7 +4519,7 @@ the common header for all reductions to use.
        |        OpenScope SimpleStatements EOL ${ $0 = reorder_bilist($<SS); }$
        |        IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
 
        |        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 = $<Sl; }$
 
        |        { OpenScope SimpleStatements } ${ $0 = reorder_bilist($<SS); }$
        |        IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
 


@@ -4490,7 +4533,7 @@ the common header for all reductions to use.
 
        ComplexStatements -> ComplexStatements ComplexStatement ${
                if ($2 == NULL) {
 
        ComplexStatements -> ComplexStatements ComplexStatement ${
                if ($2 == NULL) {

-                       $0 = $<1;
+                       $0 = $<1;       // NOTEST - impossible

                } else {
                        $0 = new(binode);
                        $0->op = Block;
                } else {
                        $0 = new(binode);
                        $0->op = Block;


@@ -4500,7 +4543,7 @@ the common header for all reductions to use.
        }$
        | ComplexStatement ${
                if ($1 == NULL) {
        }$
        | ComplexStatement ${
                if ($1 == NULL) {

-                       $0 = NULL;
+                       $0 = NULL;      // NOTEST - impossible

                } else {
                        $0 = new(binode);
                        $0->op = Block;
                } else {
                        $0 = new(binode);
                        $0->op = Block;


@@ -4540,25 +4583,13 @@ the common header for all reductions to use.
 
 ###### print binode cases
        case Block:
 
 ###### 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
                break;
 
 ###### propagate binode cases


@@ -4574,7 +4605,9 @@ the common header for all reductions to use.
                struct binode *e;
 
                for (e = b; e; e = cast(binode, e->right)) {
                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)
                        if ((rules & Rboolok) && (t == Tbool || t == Tnone))
                                t = NULL;
                        if (t == Tnone && e->right)


@@ -4663,7 +4696,7 @@ printed.
                else
                        b = cast(binode, b->right);
                while (b) {
                else
                        b = cast(binode, b->right);
                while (b) {

-                       propagate_types(b->left, c, perr, NULL, 0);
+                       propagate_types(b->left, c, perr_local, NULL, 0);

                        b = cast(binode, b->right);
                }
                break;
                        b = cast(binode, b->right);
                }
                break;


@@ -4775,29 +4808,53 @@ be declared at any time.
 
        case Assign:
        case Declare:
 
        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
                 */
                 * Type must support 'dup',
                 * For Assign, left must not be constant.
                 * result is Tnone
                 */

-               t = propagate_types(b->left, c, perr, NULL,
-                                   (b->op == Assign ? Rnoconstant : 0));
+               *perr &= ~(Erval | Econst);
+               t = propagate_types(b->left, c, perr, NULL, 0);

                if (!b->right)
                        return Tnone;
 
                if (t) {
                if (!b->right)
                        return Tnone;
 
                if (t) {

-                       if (propagate_types(b->right, c, perr, t, 0) != t)
-                               if (b->left->type == Xvar)
-                                       type_err(c, "info: variable '%v' was set as %1 here.",
-                                                cast(var, b->left)->var->where_set, t, rules, NULL);
+                       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 {
                } else {

-                       t = propagate_types(b->right, c, perr, NULL, 0);
+                       t = propagate_types(b->right, c, perr_local, NULL, 0);

                        if (t)
                        if (t)

-                               propagate_types(b->left, c, perr, t,
-                                               (b->op == Assign ? Rnoconstant : 0));
+                               propagate_types(b->left, c, perr, t, 0);
+               }
+               if (*perr & Erval)
+                       type_err(c, "error: cannot assign to an rval", b,
+                                NULL, 0, NULL);
+               else if (b->op == Assign && (*perr & Econst)) {
+                       type_err(c, "error: Cannot assign to a constant: %v",
+                                b->left, NULL, 0, NULL);
+                       if (b->left->type == Xvar) {
+                               struct var *var = cast(var, b->left);
+                               struct variable *v = var->var;
+                               type_err(c, "info: name was defined as a constant here",
+                                        v->where_decl, NULL, 0, NULL);
+                       }

                }
                }

-               if (t && t->dup == NULL && !(*perr & Emaycopy))
+               if (t && t->dup == NULL && !(*perr_local & Emaycopy))

                        type_err(c, "error: cannot assign value of type %1", b, t, 0, NULL);
                        type_err(c, "error: cannot assign value of type %1", b, t, 0, NULL);

+               if (b->left->type == Xvar && (*perr_local & Efail))
+                       type_err(c, "info: variable '%v' was set as %1 here.",
+                                cast(var, b->left)->var->where_set, t, rules, NULL);

                return Tnone;
 
                break;
                return Tnone;
 
                break;


@@ -4819,10 +4876,10 @@ be declared at any time.
                val = var_value(c, v);
                if (v->type->prepare_type)
                        v->type->prepare_type(c, v->type, 0);
                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);
                        val_init(v->type, val);

+               else
+                       dinterp_exec(c, b->right, val, v->type, 0);

                break;
        }
 
                break;
        }
 


@@ -5246,9 +5303,7 @@ casepart` to track a list of case parts.
 
 ###### propagate binode cases
        case Loop:
 
 ###### propagate binode cases
        case Loop:

-               t = propagate_types(b->right, c, perr, 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
                return propagate_types(b->left, c, perr, type, rules);
 
 ###### propagate exec cases


@@ -5268,13 +5323,9 @@ casepart` to track a list of case parts.
                struct casepart *cp;
 
                t = propagate_types(cs->forpart, c, perr, Tnone, 0);
                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 (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);
                }
                if (cs->casepart == NULL) {
                        propagate_types(cs->condpart, c, perr, Tbool, 0);


@@ -5286,9 +5337,9 @@ 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)
                             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)
                        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)
                        // Now we have a type (I hope) push it down
                        if (t) {
                                for (cp = cs->casepart; cp; cp = cp->next)


@@ -5304,8 +5355,8 @@ casepart` to track a list of case parts.
                        type = propagate_types(cs->elsepart, c, perr, NULL, rules);
                for (cp = cs->casepart;
                     cp && !type;
                        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);
                if (type) {
                        if (!cs->looppart)
                                propagate_types(cs->thenpart, c, perr, type, rules);


@@ -5403,7 +5454,7 @@ various declarations in the parse context.
        | DeclarationList Declaration
 
        Declaration -> ERROR Newlines ${
        | DeclarationList Declaration
 
        Declaration -> ERROR Newlines ${

-               tok_err(c,      // UNTESTED
+               tok_err(c,      // NOTEST

                        "error: unhandled parse error", &$1);
        }$
        | DeclareConstant
                        "error: unhandled parse error", &$1);
        }$
        | DeclareConstant


@@ -5632,8 +5683,8 @@ is a bit more interesting at this level.
                        struct value fn = {.function = code};
                        struct type *t;
                        var_block_close(c, CloseFunction, code);
                        struct value fn = {.function = code};
                        struct type *t;
                        var_block_close(c, CloseFunction, code);

-                       t = add_anon_type(c, &function_prototype, 
-                                         "func %.*s", name->name->name.len, 
+                       t = add_anon_type(c, &function_prototype,
+                                         "func %.*s", name->name->name.len,

                                          name->name->name.txt);
                        name->type = t;
                        t->function.params = reorder_bilist(args);
                                          name->name->name.txt);
                        name->type = t;
                        t->function.params = reorder_bilist(args);


@@ -5709,10 +5760,13 @@ 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);
                                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);
                                        print_value(v->type, val, stdout);

+                               }

                                printf("/* frame size %d */\n", v->type->function.local_size);
                                target -= 1;
                        }
                                printf("/* frame size %d */\n", v->type->function.local_size);
                                target -= 1;
                        }


@@ -5745,7 +5799,7 @@ is a bit more interesting at this level.
                                all_ok = 0;
                        if (!v->type->function.inline_result &&
                            !v->type->function.return_type->dup) {
                                all_ok = 0;
                        if (!v->type->function.inline_result &&
                            !v->type->function.return_type->dup) {

-                               type_err(c, "error: function cannot return value of type %1", 
+                               type_err(c, "error: function cannot return value of type %1",

                                         v->where_decl, v->type->function.return_type, 0, NULL);
                        }
 
                                         v->where_decl, v->type->function.return_type, 0, NULL);
                        }
 


@@ -5814,15 +5868,12 @@ is a bit more interesting at this level.
                        struct value *vl = var_value(c, v->var);
                        struct value arg;
                        struct type *t;
                        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;
                        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++) {
                                t->prepare_type(c, t, 0);
                                array_init(v->var->type, vl);
                                for (i = 0; i < argc; i++) {


@@ -5876,7 +5927,7 @@ things which will likely grow as the languages grows.
                name:string
                alive:Boolean
 
                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
                print "Hello World, what lovely oceans you have!"
                print "Are there", five, "?"
                print pi, pie, "but", cake


@@ -5904,7 +5955,7 @@ things which will likely grow as the languages grows.
                a : number
                a = A;
                b:number = B
                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
                        while a != b:
                                if a < b:
                                        b = b - a