use debruijn indexing

[lambda.git] / lambda.y

diff --git a/lambda.y b/lambda.y
index 388693d..b0fe73a 100644 (file)
--- a/lambda.y
+++ b/lambda.y
@@ -41,18 +41,35 @@ struct lambda *make_ident(char *i)
        struct lambda *r = make_lambda();
        r->which = lambda_ident;
        r->data.identifier.ident = strdup(i);
-       r->data.identifier.revision = 0;
+       r->data.identifier.binding = NULL;
        return r;
 }
 
+void lambda_bind(struct lambda *tob, struct lambda *binding, char *ident)
+{
+       switch(tob->which){
+       case lambda_ident:
+               if(strcmp(ident, tob->data.identifier.ident) == 0 && tob->data.identifier.binding == NULL)
+                       tob->data.identifier.binding = binding;
+               break;
+       case lambda_abs:
+               lambda_bind(tob->data.abstraction.expr, binding, ident);
+               break;
+       case lambda_app:
+               lambda_bind(tob->data.application.expr1, binding, ident);
+               lambda_bind(tob->data.application.expr2, binding, ident);
+               break;
+       }
+}
+
 struct lambda *make_abstraction(char *i, bool strict, struct lambda *t)
 {
        struct lambda *r = make_lambda();
        r->which = lambda_abs;
        r->data.abstraction.ident = strdup(i);
-       r->data.abstraction.revision = 0;
        r->data.abstraction.strict = strict;
        r->data.abstraction.expr = t;
+       lambda_bind(t, r, i);
        return r;
 }
 
@@ -102,6 +119,7 @@ struct lambda *decls_lookup(char *ident)
 
 int main()
 {
+       setbuf(stdout, NULL);
        int r = yyparse();
        yylex_destroy();
        return r;
@@ -117,21 +135,25 @@ program
        :
        | lambda SEMICOLON program
 lambda
-       : term
-               {
-                       int maxdepth = 1000;
-                       printf("     ");
-                       lambda_reduce(&$1, &$1, &maxdepth);
-                       lambda_print($1, NULL);
-                       lambda_free($1);
-               }
-       | FUNC func
+       : FUNC func
                {
                        decls_prepend($1->data.identifier.ident, $2);
                        printf("%s = ", $1->data.identifier.ident);
                        lambda_print($2, NULL);
+                       putchar('\n');
                        lambda_free($1);
                }
+       | term
+               {
+                       struct lambda *t = $1;
+                       printf("     ");
+                       for(unsigned int i = 0; i<999; i++)
+                               if(!lambda_reduce(&t, &t, true))
+                                       break;
+                       lambda_print(t, NULL);
+                       putchar('\n');
+                       lambda_free(t);
+               }
 func
        : ASSIGN term
                { $$ = $2; }