1 files changed, 48 insertions, 0 deletions
diff --git a/docs/eval.rst b/docs/eval.rst
new file mode 100644
index 0000000..1e66698
--- /dev/null
+++ b/docs/eval.rst
@@ -0,0 +1,48 @@
+Evaluation
+==========
+
+Because Lisp code is represented with data structures, each data structure
+can be used as interpreter instruction. Evaluation of data, when used as
+interpreter expression, is defined according to data type:
+
+    * number, string, builtin function, builtin syntax, function, syntax
+
+        Data of this type evaluate to itself (expression consisting of
+        single instance of data evaluates to provided data instance).
+
+    * symbol
+
+        Symbols evaluate to data associated to provided symbol in
+        current evaluation context. If context entry associated with the symbol
+        is not available, evaluation error is signaled.
+
+    * pair/list
+
+        Lists evaluate to function/syntax application. As first step,
+        first element of list is evaluated. If first element evaluates
+        to function or builtin function, all remaining elements are also
+        evaluated and used as provided arguments. If first element evaluates
+        to syntax or builtin syntax, remaining list elements are not evaluated
+        and are used as provided arguments. After evaluation of first element
+        and possible argument evaluation (in case of functions), evaluation
+        is delegated to function/syntax application (described in following
+        chapters). If first list element doesn't evaluate to function/syntax,
+        evaluation error is signaled. Exception to this rule is empty
+        list which evaluates to itself.
+
+
+Source code
+-----------
+
+eval.h
+''''''
+
+.. literalinclude:: ../src_c/eval.h
+    :language: c
+
+
+eval.c
+''''''
+
+.. literalinclude:: ../src_c/eval.c
+    :language: c