klisp

commit 4d1f83db67b92f2e444b26a9b7412160764e90b2
parent ef72093ba723f1d9592e0b21399d774b00ebd939
Author: Andres Navarro <canavarro82@gmail.com>
Date:   Tue, 22 Mar 2011 23:56:57 -0300

Added string-ref to the ground environment.

Diffstat:
M
src/kground.c
 | 
2
+-
M
src/kgstrings.c
 | 
19
++++++++++++++++++-
M
src/kgstrings.h
 | 
2
+-

3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/src/kground.c b/src/kground.c
@@ -589,7 +589,7 @@ void kinit_ground_env(klisp_State *K)
     add_applicative(K, ground_env, "string-length", kgstring_length, 0);
 
     /* 13.1.4? string-ref */
-    /* TODO */
+    add_applicative(K, ground_env, "string-ref", kstring_ref, 0);
 
     /* 13.1.5? string-set! */
     /* TODO */
diff --git a/src/kgstrings.c b/src/kgstrings.c
@@ -60,7 +60,24 @@ void kgstring_length(klisp_State *K, TValue *xparams, TValue ptree,
 }
 
 /* 13.1.4? string-ref */
-/* TODO */
+void kstring_ref(klisp_State *K, TValue *xparams, TValue ptree, TValue denv)
+{
+    UNUSED(xparams);
+    UNUSED(denv);
+    bind_2tp(K, "string-ref", ptree, "string", ttisstring, str,
+	     "finite integer", ttisfixint, tv_i);
+
+    int32_t i = ivalue(tv_i);
+    
+    if (i < 0 || i >= kstring_size(str)) {
+	/* TODO show index */
+	klispE_throw(K, "string-ref: index out of bounds");
+	return;
+    }
+
+    TValue res = ch2tv(kstring_buf(str)[i]);
+    kapply_cc(K, res);
+}
 
 /* 13.1.5? string-set! */
 /* TODO */
diff --git a/src/kgstrings.h b/src/kgstrings.h
@@ -29,7 +29,7 @@ void kgstring_length(klisp_State *K, TValue *xparams, TValue ptree,
 		     TValue denv);
 
 /* 13.1.4? string-ref */
-/* TODO */
+void kstring_ref (klisp_State *K, TValue *xparams, TValue ptree, TValue denv);
 
 /* 13.1.5? string-set! */
 /* TODO */