]> ocean-lang.org Git - ocean/blobdiff - csrc/oceani.mdc
ocean: change program to receive argc and argv
[ocean] / csrc / oceani.mdc
index c6163a679c2ff92c8afbf6b969e0c56854829d3d..65790ec985469c5268208cd68bb38a8fc116f1df 100644 (file)
@@ -105,6 +105,7 @@ structures can be used.
 
 ###### Parser: header
        ## macros
+       struct parse_context;
        ## ast
        struct parse_context {
                struct token_config config;
@@ -242,7 +243,7 @@ structures can be used.
                                fprintf(stderr, "oceani: type error in program - not running.\n");
                                exit(1);
                        }
-                       interp_prog(context.prog, argv+optind+1);
+                       interp_prog(&context, context.prog, argc - optind, argv+optind);
                }
                free_exec(context.prog);
 
@@ -429,6 +430,7 @@ Named type are stored in a simple linked list.  Objects of each type are
                struct type *next;
                int size, align;
                void (*init)(struct type *type, struct value *val);
+               void (*prepare_type)(struct parse_context *c, struct type *type, int parse_time);
                void (*print)(struct type *type, struct value *val);
                void (*print_type)(struct type *type, FILE *f);
                int (*cmp_order)(struct type *t1, struct type *t2,
@@ -532,20 +534,6 @@ Named type are stored in a simple linked list.  Objects of each type are
                        printf("*Unknown*");            // NOTEST
        }
 
-       static struct value *val_alloc(struct type *t, struct value *init)
-       {
-               struct value *ret;
-
-               if (!t->size)
-                       val_init(t, NULL);
-               ret = calloc(1, t->size);
-               if (init)
-                       memcpy(ret, init, t->size);
-               else
-                       val_init(t, ret);
-               return ret;
-       }
-
 ###### forward decls
 
        static void free_value(struct type *type, struct value *v);
@@ -588,11 +576,11 @@ later.  In some cases a Boolean can be accepted as well as some other
 primary type, and in others any type is acceptable except a label (`Vlabel`).
 A separate function encoding these cases will simplify some code later.
 
-## type functions
+###### type functions
 
        int (*compat)(struct type *this, struct type *other);
 
-## ast functions
+###### ast functions
 
        static int type_compat(struct type *require, struct type *have, int rules)
        {
@@ -817,7 +805,6 @@ cannot nest, so a declaration while a name is in-scope is an error.
        struct variable {
                struct variable *previous;
                struct type *type;
-               struct value *val;
                struct binding *name;
                struct exec *where_decl;// where name was declared
                struct exec *where_set; // where type was set
@@ -967,6 +954,11 @@ recent instance.  These variables don't really belong in the
 is found.  Instead, they are detected and ignored when considering the
 list of in_scope names.
 
+The storage of the value of a variable will be described later.  For now
+we just need to know that when a variable goes out of scope, it might
+need to be freed.  For this we need to be able to find it, so assume that 
+`var_value()` will provide that.
+
 ###### variable fields
        struct variable *merged;
 
@@ -989,6 +981,9 @@ list of in_scope names.
                        }
        }
 
+###### forward decls
+       static struct value *var_value(struct parse_context *c, struct variable *v);
+
 ###### free context vars
 
        while (context.varlist) {
@@ -1000,8 +995,7 @@ list of in_scope names.
                        struct variable *t = v;
 
                        v = t->previous;
-                       free_value(t->type, t->val);
-                       free(t->val);
+                       free_value(t->type, var_value(&context, t));
                        if (t->depth == 0)
                                // This is a global constant
                                free_exec(t->where_decl);
@@ -1081,7 +1075,6 @@ all pending-scope variables become conditionally scoped.
                v->scope = InScope;
                v->in_scope = c->in_scope;
                c->in_scope = v;
-               v->val = NULL;
                return v;
        }
 
@@ -1190,6 +1183,112 @@ all pending-scope variables become conditionally scoped.
                }
        }
 
+#### Storing Values
+
+The value of a variable is store separately from the variable, on an
+analogue of a stack frame.  There are (currently) two frames that can be
+active.  A global frame which currently only stores constants, and a
+stacked frame which stores local variables.  Each variable knows if it
+is global or not, and what its index into the frame is.
+
+Values in the global frame are known immediately they are relevant, so
+the frame needs to be reallocated as it grows so it can store those
+values.  The local frame doesn't get values until the interpreted phase
+is started, so there is no need to allocate until the size is known.
+
+###### variable fields
+               short frame_pos;
+               short global;
+
+###### parse context
+
+       short global_size, global_alloc;
+       short local_size;
+       void *global, *local;
+
+###### ast functions
+
+       static struct value *var_value(struct parse_context *c, struct variable *v)
+       {
+               if (!v->global) {
+                       if (!c->local || !v->type)
+                               return NULL;
+                       if (v->frame_pos + v->type->size > c->local_size) {
+                               printf("INVALID frame_pos\n"); // NOTEST
+                               exit(2);
+                       }
+                       return c->local + v->frame_pos;
+               }
+               if (c->global_size > c->global_alloc) {
+                       int old = c->global_alloc;
+                       c->global_alloc = (c->global_size | 1023) + 1024;
+                       c->global = realloc(c->global, c->global_alloc);
+                       memset(c->global + old, 0, c->global_alloc - old);
+               }
+               return c->global + v->frame_pos;
+       }
+
+       static struct value *global_alloc(struct parse_context *c, struct type *t,
+                                         struct variable *v, struct value *init)
+       {
+               struct value *ret;
+               struct variable scratch;
+
+               if (t->prepare_type)
+                       t->prepare_type(c, t, 1);
+
+               if (c->global_size & (t->align - 1))
+                       c->global_size = (c->global_size + t->align) & ~(t->align-1);
+               if (!v) {
+                       v = &scratch;
+                       v->type = t;
+               }
+               v->frame_pos = c->global_size;
+               v->global = 1;
+               c->global_size += v->type->size;
+               ret = var_value(c, v);
+               if (init)
+                       memcpy(ret, init, t->size);
+               else
+                       val_init(t, ret);
+               return ret;
+       }
+
+As global values are found -- struct field initializers, labels etc --
+`global_alloc()` is called to record the value in the global frame.
+
+When the program is fully parsed, we need to walk the list of variables
+to find any that weren't merged away and that aren't global, and to
+calculate the frame size and assign a frame position for each variable.
+For this we have `scope_finalize()`.
+
+###### ast functions
+
+       static void scope_finalize(struct parse_context *c)
+       {
+               struct binding *b;
+
+               for (b = c->varlist; b; b = b->next) {
+                       struct variable *v;
+                       for (v = b->var; v; v = v->previous) {
+                               struct type *t = v->type;
+                               if (v->merged && v->merged != v)
+                                       continue;
+                               if (v->global)
+                                       continue;
+                               if (c->local_size & (t->align - 1))
+                                       c->local_size = (c->local_size + t->align) & ~(t->align-1);
+                               v->frame_pos = c->local_size;
+                               c->local_size += v->type->size;
+                       }
+               }
+               c->local = calloc(1, c->local_size);
+       }
+
+###### free context vars
+       free(context.global);
+       free(context.local);
+
 ### Executables
 
 Executables can be lots of different things.  In many cases an
@@ -1419,11 +1518,12 @@ in `rval`.
                struct value rval, *lval;
        };
 
-       static struct lrval _interp_exec(struct exec *e);
+       static struct lrval _interp_exec(struct parse_context *c, struct exec *e);
 
-       static struct value interp_exec(struct exec *e, struct type **typeret)
+       static struct value interp_exec(struct parse_context *c, struct exec *e,
+                                       struct type **typeret)
        {
-               struct lrval ret = _interp_exec(e);
+               struct lrval ret = _interp_exec(c, e);
 
                if (!ret.type) abort();
                if (typeret)
@@ -1433,16 +1533,19 @@ in `rval`.
                return ret.rval;
        }
 
-       static struct value *linterp_exec(struct exec *e, struct type **typeret)
+       static struct value *linterp_exec(struct parse_context *c, struct exec *e,
+                                         struct type **typeret)
        {
-               struct lrval ret = _interp_exec(e);
+               struct lrval ret = _interp_exec(c, e);
 
-               if (typeret)
+               if (ret.lval)
                        *typeret = ret.type;
+               else
+                       free_value(ret.type, &ret.rval);
                return ret.lval;
        }
 
-       static struct lrval _interp_exec(struct exec *e)
+       static struct lrval _interp_exec(struct parse_context *c, struct exec *e)
        {
                struct lrval ret;
                struct value rv = {}, *lrv = NULL;
@@ -1485,10 +1588,6 @@ different phases of parse, analyse, print, interpret.
 
 Thus far we have arrays and structs.
 
-Some complex types need do not exist in a name table, so they are kept
-on a linked list in the context (`anon_typelist`).  This allows them to
-be freed when parsing is complete.
-
 #### Arrays
 
 Arrays can be declared by giving a size and a type, as `[size]type' so
@@ -1503,36 +1602,68 @@ ever be referenced by the name it is declared with.  It is likely that
 a "`copy`" primitive will eventually be define which can be used to
 make a copy of an array with controllable recursive depth.
 
+For now we have two sorts of array, those with fixed size either because
+it is given as a literal number or because it is a struct member (which
+cannot have a runtime-changing size), and those with a size that is
+determined at runtime - local variables with a const size.  The former
+have their size calculated at parse time, the latter at run time.
+
+For the latter type, the `size` field of the type is the size of a
+pointer, and the array is reallocated every time it comes into scope.
+
+We differentiate struct fields with a const size from local variables
+with a const size by whether they are prepared at parse time or not.
+
 ###### type union fields
 
        struct {
-               int size;
+               short size;
+               short static_size;
                struct variable *vsize;
                struct type *member;
        } array;
 
+###### value union fields
+       void *array;  // used if not static_size
+
 ###### value functions
 
-       static void array_init(struct type *type, struct value *val)
+       static void array_prepare_type(struct parse_context *c, struct type *type,
+                                      int parse_time)
        {
-               int i;
+               struct value *vsize;
+               mpz_t q;
+               if (!type->array.vsize || type->array.static_size)
+                       return;
 
-               if (type->array.vsize) {
-                       mpz_t q;
-                       mpz_init(q);
-                       mpz_tdiv_q(q, mpq_numref(type->array.vsize->val->num),
-                                  mpq_denref(type->array.vsize->val->num));
-                       type->array.size = mpz_get_si(q);
-                       mpz_clear(q);
+               vsize = var_value(c, type->array.vsize);
+               mpz_init(q);
+               mpz_tdiv_q(q, mpq_numref(vsize->num), mpq_denref(vsize->num));
+               type->array.size = mpz_get_si(q);
+               mpz_clear(q);
+
+               if (parse_time) {
+                       type->array.static_size = 1;
+                       type->size = type->array.size * type->array.member->size;
+                       type->align = type->array.member->align;
                }
-               type->size = type->array.size * type->array.member->size;
-               type->align = type->array.member->align;
+       }
+
+       static void array_init(struct type *type, struct value *val)
+       {
+               int i;
+               void *ptr = val->ptr;
 
                if (!val)
-                       return;         
+                       return;
+               if (!type->array.static_size) {
+                       val->array = calloc(type->array.size, 
+                                           type->array.member->size);
+                       ptr = val->array;
+               }
                for (i = 0; i < type->array.size; i++) {
                        struct value *v;
-                       v = (void*)val->ptr + i * type->array.member->size;
+                       v = (void*)ptr + i * type->array.member->size;
                        val_init(type->array.member, v);
                }
        }
@@ -1540,12 +1671,17 @@ make a copy of an array with controllable recursive depth.
        static void array_free(struct type *type, struct value *val)
        {
                int i;
+               void *ptr = val->ptr;
 
+               if (!type->array.static_size)
+                       ptr = val->array;
                for (i = 0; i < type->array.size; i++) {
                        struct value *v;
-                       v = (void*)val->ptr + i * type->array.member->size;
+                       v = (void*)ptr + i * type->array.member->size;
                        free_value(type->array.member, v);
                }
+               if (!type->array.static_size)
+                       free(ptr);
        }
 
        static int array_compat(struct type *require, struct type *have)
@@ -1574,9 +1710,12 @@ make a copy of an array with controllable recursive depth.
 
        static struct type array_prototype = {
                .init = array_init,
+               .prepare_type = array_prepare_type,
                .print_type = array_print_type,
                .compat = array_compat,
                .free = array_free,
+               .size = sizeof(void*),
+               .align = sizeof(void*),
        };
 
 ###### declare terminals
@@ -1584,20 +1723,21 @@ make a copy of an array with controllable recursive depth.
 
 ###### type grammar
 
-       | [ NUMBER ] Type ${
-               $0 = calloc(1, sizeof(struct type));
-               *($0) = array_prototype;
-               $0->array.member = $<4;
-               $0->array.vsize = NULL;
-               {
+       | [ NUMBER ] Type ${ {
                char tail[3];
                mpq_t num;
+               struct text noname = { "", 0 };
+               struct type *t;
+
+               $0 = t = add_type(c, noname, &array_prototype);
+               t->array.member = $<4;
+               t->array.vsize = NULL;
                if (number_parse(num, tail, $2.txt) == 0)
                        tok_err(c, "error: unrecognised number", &$2);
                else if (tail[0])
                        tok_err(c, "error: unsupported number suffix", &$2);
                else {
-                       $0->array.size = mpz_get_ui(mpq_numref(num));
+                       t->array.size = mpz_get_ui(mpq_numref(num));
                        if (mpz_cmp_ui(mpq_denref(num), 1) != 0) {
                                tok_err(c, "error: array size must be an integer",
                                        &$2);
@@ -1606,41 +1746,26 @@ make a copy of an array with controllable recursive depth.
                                        &$2);
                        mpq_clear(num);
                }
-               $0->next = c->anon_typelist;
-               c->anon_typelist = $0;
-               }
-       }$
+               t->array.static_size = 1;
+               t->size = t->array.size * t->array.member->size;
+               t->align = t->array.member->align;
+       } }$
 
        | [ IDENTIFIER ] Type ${ {
                struct variable *v = var_ref(c, $2.txt);
+               struct text noname = { "", 0 };
 
                if (!v)
                        tok_err(c, "error: name undeclared", &$2);
                else if (!v->constant)
                        tok_err(c, "error: array size must be a constant", &$2);
 
-               $0 = calloc(1, sizeof(struct type));
-               *($0) = array_prototype;
+               $0 = add_type(c, noname, &array_prototype);
                $0->array.member = $<4;
                $0->array.size = 0;
                $0->array.vsize = v;
-               $0->next = c->anon_typelist;
-               c->anon_typelist = $0;
        } }$
 
-###### parse context
-
-       struct type *anon_typelist;
-
-###### free context types
-
-       while (context.anon_typelist) {
-               struct type *t = context.anon_typelist;
-
-               context.anon_typelist = t->next;
-               free(t);
-       }
-
 ###### Binode types
        Index,
 
@@ -1685,17 +1810,22 @@ make a copy of an array with controllable recursive depth.
        case Index: {
                mpz_t q;
                long i;
+               void *ptr;
 
-               lleft = linterp_exec(b->left, &ltype);
-               right = interp_exec(b->right, &rtype);
+               lleft = linterp_exec(c, b->left, &ltype);
+               right = interp_exec(c, b->right, &rtype);
                mpz_init(q);
                mpz_tdiv_q(q, mpq_numref(right.num), mpq_denref(right.num));
                i = mpz_get_si(q);
                mpz_clear(q);
 
+               if (ltype->array.static_size)
+                       ptr = lleft;
+               else
+                       ptr = *(void**)lleft;
                rvtype = ltype->array.member;
                if (i >= 0 && i < ltype->array.size)
-                       lrv = (void*)lleft + i * rvtype->size;
+                       lrv = ptr + i * rvtype->size;
                else
                        val_init(ltype->array.member, &rv);
                ltype = NULL;
@@ -1767,7 +1897,12 @@ function will be needed.
                for (i = 0; i < type->structure.nfields; i++) {
                        struct value *v;
                        v = (void*) val->ptr + type->structure.fields[i].offset;
-                       val_init(type->structure.fields[i].type, v);
+                       if (type->structure.fields[i].init)
+                               dup_value(type->structure.fields[i].type, 
+                                         type->structure.fields[i].init,
+                                         v);
+                       else
+                               val_init(type->structure.fields[i].type, v);
                }
        }
 
@@ -1789,7 +1924,6 @@ function will be needed.
                        if (t->structure.fields[i].init) {
                                free_value(t->structure.fields[i].type,
                                           t->structure.fields[i].init);
-                               free(t->structure.fields[i].init);
                        }
                free(t->structure.fields);
        }
@@ -1885,7 +2019,7 @@ function will be needed.
        {
                struct fieldref *f = cast(fieldref, e);
                struct type *ltype;
-               struct value *lleft = linterp_exec(f->left, &ltype);
+               struct value *lleft = linterp_exec(c, f->left, &ltype);
                lrv = (void*)lleft->ptr + ltype->structure.fields[f->index].offset;
                rvtype = ltype->structure.fields[f->index].type;
                break;
@@ -1974,15 +2108,16 @@ function will be needed.
                        if (!ok)
                                c->parse_error = 1;
                        else {
-                               struct value vl = interp_exec($5, NULL);
-                               $0->f.init = val_alloc($0->f.type, &vl);
+                               struct value vl = interp_exec(c, $5, NULL);
+                               $0->f.init = global_alloc(c, $0->f.type, NULL, &vl);
                        }
                } }$
                | IDENTIFIER : Type ${
                        $0 = calloc(1, sizeof(struct fieldlist));
                        $0->f.name = $1.txt;
                        $0->f.type = $<3;
-                       $0->f.init = val_alloc($0->f.type, NULL);
+                       if ($0->f.type->prepare_type)
+                               $0->f.type->prepare_type(c, $0->f.type, 1);
                }$
 
 ###### forward decls
@@ -2232,7 +2367,6 @@ link to find the primary instance.
                        v->where_decl = $0;
                        v->where_set = $0;
                        v->type = $<Type;
-                       v->val = NULL;
                } else {
                        v = var_ref(c, $1.txt);
                        $0->var = v;
@@ -2250,7 +2384,6 @@ link to find the primary instance.
                        v->where_decl = $0;
                        v->where_set = $0;
                        v->type = $<Type;
-                       v->val = NULL;
                        v->constant = 1;
                } else {
                        v = var_ref(c, $1.txt);
@@ -2270,7 +2403,6 @@ link to find the primary instance.
                        /* This might be a label - allocate a var just in case */
                        v = var_decl(c, $1.txt);
                        if (v) {
-                               v->val = NULL;
                                v->type = Tnone;
                                v->where_decl = $0;
                                v->where_set = $0;
@@ -2341,7 +2473,6 @@ link to find the primary instance.
                if (v->type == NULL) {
                        if (type && *ok != 0) {
                                v->type = type;
-                               v->val = NULL;
                                v->where_set = prog;
                                *ok = 2;
                        }
@@ -2366,7 +2497,7 @@ link to find the primary instance.
 
                if (v->merged)
                        v = v->merged;
-               lrv = v->val;
+               lrv = var_value(c, v);
                rvtype = v->type;
                break;
        }
@@ -2448,11 +2579,11 @@ there.
 
        case CondExpr: {
                struct binode *b2 = cast(binode, b->right);
-               left = interp_exec(b->left, &ltype);
+               left = interp_exec(c, b->left, &ltype);
                if (left.bool)
-                       rv = interp_exec(b2->left, &rvtype);
+                       rv = interp_exec(c, b2->left, &rvtype);
                else
-                       rv = interp_exec(b2->right, &rvtype);
+                       rv = interp_exec(c, b2->right, &rvtype);
                }
                break;
 
@@ -2565,27 +2696,27 @@ evaluate the second expression if not necessary.
 
 ###### interp binode cases
        case And:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               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(b->left, &rvtype);
+               rv = interp_exec(c, b->left, &rvtype);
                if (rv.bool)
-                       rv = interp_exec(b->right, NULL);
+                       rv = interp_exec(c, b->right, NULL);
                break;
        case Or:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               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(b->left, &rvtype);
+               rv = interp_exec(c, b->left, &rvtype);
                if (!rv.bool)
-                       rv = interp_exec(b->right, NULL);
+                       rv = interp_exec(c, b->right, NULL);
                break;
        case Not:
-               rv = interp_exec(b->right, &rvtype);
+               rv = interp_exec(c, b->right, &rvtype);
                rv.bool = !rv.bool;
                break;
 
@@ -2693,8 +2824,8 @@ expression operator, and the `CMPop` non-terminal will match one of them.
        case NEql:
        {
                int cmp;
-               left = interp_exec(b->left, &ltype);
-               right = interp_exec(b->right, &rtype);
+               left = interp_exec(c, b->left, &ltype);
+               right = interp_exec(c, b->right, &rtype);
                cmp = value_cmp(ltype, rtype, &left, &right);
                rvtype = Tbool;
                switch (b->op) {
@@ -2868,30 +2999,30 @@ should only insert brackets were needed for precedence.
 ###### interp binode cases
 
        case Plus:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               rv = interp_exec(c, b->left, &rvtype);
+               right = interp_exec(c, b->right, &rtype);
                mpq_add(rv.num, rv.num, right.num);
                break;
        case Minus:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               rv = interp_exec(c, b->left, &rvtype);
+               right = interp_exec(c, b->right, &rtype);
                mpq_sub(rv.num, rv.num, right.num);
                break;
        case Times:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               rv = interp_exec(c, b->left, &rvtype);
+               right = interp_exec(c, b->right, &rtype);
                mpq_mul(rv.num, rv.num, right.num);
                break;
        case Divide:
-               rv = interp_exec(b->left, &rvtype);
-               right = interp_exec(b->right, &rtype);
+               rv = interp_exec(c, b->left, &rvtype);
+               right = interp_exec(c, b->right, &rtype);
                mpq_div(rv.num, rv.num, right.num);
                break;
        case Rem: {
                mpz_t l, r, rem;
 
-               left = interp_exec(b->left, &ltype);
-               right = interp_exec(b->right, &rtype);
+               left = interp_exec(c, b->left, &ltype);
+               right = interp_exec(c, b->right, &rtype);
                mpz_init(l); mpz_init(r); mpz_init(rem);
                mpz_tdiv_q(l, mpq_numref(left.num), mpq_denref(left.num));
                mpz_tdiv_q(r, mpq_numref(right.num), mpq_denref(right.num));
@@ -2903,24 +3034,24 @@ should only insert brackets were needed for precedence.
                break;
        }
        case Negate:
-               rv = interp_exec(b->right, &rvtype);
+               rv = interp_exec(c, b->right, &rvtype);
                mpq_neg(rv.num, rv.num);
                break;
        case Absolute:
-               rv = interp_exec(b->right, &rvtype);
+               rv = interp_exec(c, b->right, &rvtype);
                mpq_abs(rv.num, rv.num);
                break;
        case Bracket:
-               rv = interp_exec(b->right, &rvtype);
+               rv = interp_exec(c, b->right, &rvtype);
                break;
        case Concat:
-               left = interp_exec(b->left, &ltype);
-               right = interp_exec(b->right, &rtype);
+               left = interp_exec(c, b->left, &ltype);
+               right = interp_exec(c, b->right, &rtype);
                rvtype = Tstr;
                rv.str = text_join(left.str, right.str);
                break;
        case StringConv:
-               right = interp_exec(b->right, &rvtype);
+               right = interp_exec(c, b->right, &rvtype);
                rtype = Tstr;
                rvtype = Tnum;
 
@@ -3142,7 +3273,7 @@ is in-place.
                while (rvtype == Tnone &&
                       b) {
                        if (b->left)
-                               rv = interp_exec(b->left, &rvtype);
+                               rv = interp_exec(c, b->left, &rvtype);
                        b = cast(binode, b->right);
                }
                break;
@@ -3231,7 +3362,7 @@ same solution.
                        if (b->left) {
                                if (sep)
                                        putchar(sep);
-                               left = interp_exec(b->left, &ltype);
+                               left = interp_exec(c, b->left, &ltype);
                                print_value(ltype, &left);
                                free_value(ltype, &left);
                                if (b->right)
@@ -3362,8 +3493,8 @@ it is declared, and error will be raised as the name is created as
 ###### interp binode cases
 
        case Assign:
-               lleft = linterp_exec(b->left, &ltype);
-               right = interp_exec(b->right, &rtype);
+               lleft = linterp_exec(c, b->left, &ltype);
+               right = interp_exec(c, b->right, &rtype);
                if (lleft) {
                        free_value(ltype, lleft);
                        dup_value(ltype, &right, lleft);
@@ -3374,17 +3505,19 @@ it is declared, and error will be raised as the name is created as
        case Declare:
        {
                struct variable *v = cast(var, b->left)->var;
+               struct value *val;
                if (v->merged)
                        v = v->merged;
+               val = var_value(c, v);
+               free_value(v->type, val);
+               if (v->type->prepare_type)
+                       v->type->prepare_type(c, v->type, 0);
                if (b->right) {
-                       right = interp_exec(b->right, &rtype);
-                       free_value(v->type, v->val);
-                       free(v->val);
-                       v->val = val_alloc(v->type, &right);
+                       right = interp_exec(c, b->right, &rtype);
+                       memcpy(val, &right, rtype->size);
                        rtype = Tnone;
                } else {
-                       free_value(v->type, v->val);
-                       v->val = val_alloc(v->type, NULL);
+                       val_init(v->type, val);
                }
                break;
        }
@@ -3411,9 +3544,11 @@ function.
                        struct var *v = cast(var, $0->right);
                        if (v->var->type == Tnone) {
                                /* Convert this to a label */
+                               struct value *val;
+
                                v->var->type = Tlabel;
-                               v->var->val = val_alloc(Tlabel, NULL);
-                               v->var->val->label = v->var->val;
+                               val = global_alloc(c, Tlabel, v->var, NULL);
+                               val->label = val;
                        }
                }
        }$
@@ -3436,7 +3571,7 @@ function.
 ###### interp binode cases
 
        case Use:
-               rv = interp_exec(b->right, &rvtype);
+               rv = interp_exec(c, b->right, &rvtype);
                break;
 
 ### The Conditional Statement
@@ -3866,44 +4001,44 @@ defined.
                struct value v, cnd;
                struct type *vtype, *cndtype;
                struct casepart *cp;
-               struct cond_statement *c = cast(cond_statement, e);
+               struct cond_statement *cs = cast(cond_statement, e);
 
-               if (c->forpart)
-                       interp_exec(c->forpart, NULL);
+               if (cs->forpart)
+                       interp_exec(c, cs->forpart, NULL);
                do {
-                       if (c->condpart)
-                               cnd = interp_exec(c->condpart, &cndtype);
+                       if (cs->condpart)
+                               cnd = interp_exec(c, cs->condpart, &cndtype);
                        else
                                cndtype = Tnone;
                        if (!(cndtype == Tnone ||
                              (cndtype == Tbool && cnd.bool != 0)))
                                break;
                        // cnd is Tnone or Tbool, doesn't need to be freed
-                       if (c->dopart)
-                               interp_exec(c->dopart, NULL);
+                       if (cs->dopart)
+                               interp_exec(c, cs->dopart, NULL);
 
-                       if (c->thenpart) {
-                               rv = interp_exec(c->thenpart, &rvtype);
-                               if (rvtype != Tnone || !c->dopart)
+                       if (cs->thenpart) {
+                               rv = interp_exec(c, cs->thenpart, &rvtype);
+                               if (rvtype != Tnone || !cs->dopart)
                                        goto Xcond_done;
                                free_value(rvtype, &rv);
                                rvtype = Tnone;
                        }
-               } while (c->dopart);
+               } while (cs->dopart);
 
-               for (cp = c->casepart; cp; cp = cp->next) {
-                       v = interp_exec(cp->value, &vtype);
+               for (cp = cs->casepart; cp; cp = cp->next) {
+                       v = interp_exec(c, cp->value, &vtype);
                        if (value_cmp(cndtype, vtype, &v, &cnd) == 0) {
                                free_value(vtype, &v);
                                free_value(cndtype, &cnd);
-                               rv = interp_exec(cp->action, &rvtype);
+                               rv = interp_exec(c, cp->action, &rvtype);
                                goto Xcond_done;
                        }
                        free_value(vtype, &v);
                }
                free_value(cndtype, &cnd);
-               if (c->elsepart)
-                       rv = interp_exec(c->elsepart, &rvtype);
+               if (cs->elsepart)
+                       rv = interp_exec(c, cs->elsepart, &rvtype);
                else
                        rvtype = Tnone;
        Xcond_done:
@@ -4019,8 +4154,8 @@ searching through for the Nth constant for decreasing N.
                if (!ok)
                        c->parse_error = 1;
                else if (v) {
-                       struct value res = interp_exec($5, &v->type);
-                       v->val = val_alloc(v->type, &res);
+                       struct value res = interp_exec(c, $5, &v->type);
+                       global_alloc(c, v->type, v, &res);
                }
        } }$
 
@@ -4043,12 +4178,13 @@ searching through for the Nth constant for decreasing N.
                                        printf("const\n");
                                target = i;
                        } else {
+                               struct value *val = var_value(&context, v);
                                printf("    %.*s :: ", v->name->name.len, v->name->name.txt);
                                type_print(v->type, stdout);
                                printf(" = ");
                                if (v->type == Tstr)
                                        printf("\"");
-                               print_value(v->type, v->val);
+                               print_value(v->type, val);
                                if (v->type == Tstr)
                                        printf("\"");
                                printf("\n");
@@ -4136,43 +4272,57 @@ analysis is a bit more interesting at this level.
 
        static int analyse_prog(struct exec *prog, struct parse_context *c)
        {
-               struct binode *b = cast(binode, prog);
+               struct binode *bp = cast(binode, prog);
+               struct binode *b;
                int ok = 1;
+               int arg = 0;
+               struct type *argv_type;
+               struct text argv_type_name = { " argv", 5 };
 
-               if (!b)
+               if (!bp)
                        return 0;       // NOTEST
-               do {
-                       ok = 1;
-                       propagate_types(b->right, c, &ok, Tnone, 0);
-               } while (ok == 2);
-               if (!ok)
-                       return 0;
 
-               for (b = cast(binode, b->left); b; b = cast(binode, b->right)) {
-                       struct var *v = cast(var, b->left);
-                       if (!v->var->type) {
-                               v->var->where_set = b;
-                               v->var->type = Tstr;
-                               v->var->val = NULL;
+               argv_type = add_type(c, argv_type_name, &array_prototype);
+               argv_type->array.member = Tstr;
+
+               for (b = cast(binode, bp->left); b; b = cast(binode, b->right)) {
+                       struct var *v;
+                       ok = 1;
+                       switch (arg++) {
+                       case 0: /* argc */
+                               v = cast(var, b->left);
+                               argv_type->array.vsize = v->var;
+                               propagate_types(b->left, c, &ok, Tnum, 0);
+                               break;
+                       case 1: /* argv */
+                               propagate_types(b->left, c, &ok, argv_type, 0);
+                               break;
+                       default: /* invalid */
+                               propagate_types(b->left, c, &ok, Tnone, 0);
                        }
                }
-               b = cast(binode, prog);
+
                do {
                        ok = 1;
-                       propagate_types(b->right, c, &ok, Tnone, 0);
+                       propagate_types(bp->right, c, &ok, Tnone, 0);
                } while (ok == 2);
                if (!ok)
                        return 0;
 
                /* Make sure everything is still consistent */
-               propagate_types(b->right, c, &ok, Tnone, 0);
-               return !!ok;
+               propagate_types(bp->right, c, &ok, Tnone, 0);
+               if (!ok)
+                       return 0;
+               scope_finalize(c);
+               return 1;
        }
 
-       static void interp_prog(struct exec *prog, char **argv)
+       static void interp_prog(struct parse_context *c, struct exec *prog, 
+                               int argc, char **argv)
        {
                struct binode *p = cast(binode, prog);
                struct binode *al;
+               int anum = 0;
                struct value v;
                struct type *vtype;
 
@@ -4181,26 +4331,38 @@ analysis is a bit more interesting at this level.
                al = cast(binode, p->left);
                while (al) {
                        struct var *v = cast(var, al->left);
-                       struct value *vl = v->var->val;
-
-                       if (argv[0] == NULL) {
-                               printf("Not enough args\n");
-                               exit(1);
+                       struct value *vl = var_value(c, v->var);
+                       struct value arg;
+                       struct type *t;
+                       mpq_t argcq;
+                       int i;
+
+                       switch (anum++) {
+                       case 0: /* argc */
+                               if (v->var->type == Tnum) {
+                                       mpq_init(argcq);
+                                       mpq_set_ui(argcq, argc, 1);
+                                       memcpy(vl, &argcq, sizeof(argcq));
+                               }
+                               break;
+                       case 1: /* argv */
+                               t = v->var->type;
+                               t->prepare_type(c, t, 0);
+                               array_init(v->var->type, vl);
+                               for (i = 0; i < argc; i++) {
+                                       struct value *vl2 = vl->array + i * v->var->type->array.member->size;
+                                       
+
+                                       arg.str.txt = argv[i];
+                                       arg.str.len = strlen(argv[i]);
+                                       free_value(Tstr, vl2);
+                                       dup_value(Tstr, &arg, vl2);
+                               }
+                               break;
                        }
                        al = cast(binode, al->right);
-                       if (vl)
-                               free_value(v->var->type, vl);
-                       if (!vl) {
-                               vl = val_alloc(v->var->type, NULL);
-                               v->var->val = vl;
-                       }
-                       free_value(v->var->type, vl);
-                       vl->str.len = strlen(argv[0]);
-                       vl->str.txt = malloc(vl->str.len);
-                       memcpy(vl->str.txt, argv[0], vl->str.len);
-                       argv++;
                }
-               v = interp_exec(p->right, &vtype);
+               v = interp_exec(c, p->right, &vtype);
                free_value(vtype, &v);
        }
 
@@ -4235,12 +4397,12 @@ things which will likely grow as the languages grows.
                name:string
                alive:Boolean
 
-       program Astr Bstr:
+       program argc argv:
                print "Hello World, what lovely oceans you have!"
                print "Are there", five, "?"
                print pi, pie, "but", cake
 
-               A := $Astr; B := $Bstr
+               A := $argv[1]; B := $argv[2]
 
                /* When a variable is defined in both branches of an 'if',
                 * and used afterwards, the variables are merged.