1 files changed, 92 insertions, 0 deletions
diff --git a/src_c/eval.c b/src_c/eval.c
new file mode 100644
index 0000000..e04537e
--- /dev/null
+++ b/src_c/eval.c
@@ -0,0 +1,92 @@
+#include "eval.h"
+#include "ctx.h"
+#include "apply.h"
+
+
+static lsp_status_t eval_args(lsp_env_t *e, lsp_addr_t ctx, lsp_addr_t args,
+                              lsp_addr_t *result) {
+    lsp_addr_t last = e->m->nil;
+    *result = e->m->nil;
+    lsp_status_t status;
+
+    while (args != e->m->nil) {
+        lsp_addr_t arg = lsp_mem_get_pair_first(e->m, args);
+        status = lsp_env_resolve(e, ctx, arg, &arg);
+        if (status != LSP_SUCCESS)
+            goto error;
+
+        lsp_addr_t new_last;
+        status = lsp_mem_create_pair(e->m, arg, e->m->nil, &new_last);
+        lsp_mem_dec_ref(e->m, arg);
+        if (status != LSP_SUCCESS)
+            goto error;
+
+        if (*result == e->m->nil) {
+            *result = new_last;
+
+        } else {
+            lsp_mem_set_pair_second(e->m, last, new_last);
+            lsp_mem_dec_ref(e->m, new_last);
+        }
+
+        last = new_last;
+        args = lsp_mem_get_pair_second(e->m, args);
+    }
+
+    return LSP_SUCCESS;
+
+error:
+    lsp_mem_dec_ref(e->m, *result);
+    return status;
+}
+
+
+lsp_status_t lsp_eval(lsp_env_t *e, lsp_addr_t ctx, lsp_addr_t value) {
+    lsp_status_t status = LSP_SUCCESS;
+
+    if (lsp_mem_is_number(e->m, value) || lsp_mem_is_string(e->m, value) ||
+        lsp_mem_is_builtin(e->m, value) ||
+        lsp_mem_is_function_or_syntax(e->m, value))
+        return lsp_env_set_result_value(e, value);
+
+    if (lsp_mem_is_symbol(e->m, value)) {
+        lsp_addr_t result;
+        status = lsp_ctx_get(e->m, ctx, value, &result);
+        if (status != LSP_SUCCESS)
+            return status;
+
+        status = lsp_env_set_result_value(e, result);
+        lsp_mem_dec_ref(e->m, result);
+        return status;
+    }
+
+    if (lsp_mem_is_pair(e->m, value)) {
+        if (value == e->m->nil)
+            return lsp_env_set_result_value(e, e->m->nil);
+
+        lsp_addr_t callable = lsp_mem_get_pair_first(e->m, value);
+        lsp_addr_t args = lsp_mem_get_pair_second(e->m, value);
+
+        status = lsp_env_resolve(e, ctx, callable, &callable);
+        if (status != LSP_SUCCESS)
+            return status;
+
+        if (lsp_mem_is_builtin_function(e->m, callable) ||
+            lsp_mem_is_function(e->m, callable)) {
+            status = eval_args(e, ctx, args, &args);
+        } else {
+            status = lsp_mem_inc_ref(e->m, args);
+        }
+        if (status != LSP_SUCCESS) {
+            lsp_mem_dec_ref(e->m, callable);
+            return status;
+        }
+
+        status = lsp_apply(e, ctx, callable, args);
+        lsp_mem_dec_ref(e->m, callable);
+        lsp_mem_dec_ref(e->m, args);
+        return status;
+    }
+
+    return LSP_ERR_EVAL;
+}