more fold

1 files changed, 32 insertions, 6 deletions

diff --git a/bootstrap/fold.c b/bootstrap/fold.c
index 8f080a0..6a62359 100644
--- a/bootstrap/fold.c
+++ b/bootstrap/fold.c
@@ -58,7 +58,7 @@ numcast(struct expr *ex, const struct type *to) {
 }
 
 static void
-unary(struct expr *ex) {
+funary(struct expr *ex) {
    struct expr *r = ex->unop.child;
    const struct type *ty = ex->ty;
 
@@ -96,7 +96,7 @@ unary(struct expr *ex) {
 }
 
 static void
-binop(struct expr *ex) {
+fbinop(struct expr *ex) {
    struct expr *l = ex->binop.lhs;
    struct expr *r = ex->binop.rhs;
    const struct type *ty = ex->ty,
@@ -159,7 +159,7 @@ binop(struct expr *ex) {
 }
 
 static void
-cond(struct expr *ex) {
+fcond(struct expr *ex) {
    struct expr *test = ex->cond.test,
                *t = ex->cond.t,
                *f = ex->cond.f;
@@ -180,6 +180,28 @@ cond(struct expr *ex) {
    free(f);
 }
 
+static void
+findex(struct expr *ex) {
+   struct expr *ty = ex->ty,
+               *l = ex->index.lhs,
+               *r = ex->index.rhs;
+   
+   if (!fold(l) || !fold(r))
+      return;
+
+   if (l->t == Estrlit) {
+      if (r->u > l->strlit.n)
+         return;
+      ex->t = Eintlit;
+      ex->i = l->strlit.d[r->u];
+   } else {
+      assert(0);
+   }
+   
+   free(l);
+   free(r);
+}
+
 int
 fold(struct expr *ex) {
    switch (ex->t) {
@@ -189,13 +211,17 @@ fold(struct expr *ex) {
    case Estrlit:case Enullit:
       return 1;
    case Eprefix:
-      unary(ex);
+      funary(ex);
       break;
    case Ebinop:
-      binop(ex);
+      fbinop(ex);
       break;
    case Econd:
-      cond(ex);
+      fcond(ex);
+      break;
+   case Eindex:
+      findex(ex);
+      break;
    default:
       break;
    }