All: split types into types, env, printer, core.

- types: low-level mapping to the implementation language.
- core: functions on types that are exposed directly to mal.
- printer: implementation called by pr-str, str, prn, println.
- env: the environment implementation

- Also, unindent all TCO while loops so that the diff of step4 and
  step5 are minimized.

1 files changed, 50 insertions, 0 deletions

diff --git a/make/env.mk b/make/env.mk
new file mode 100644
index 0000000..d508283
--- /dev/null
+++ b/make/env.mk
@@ -0,0 +1,50 @@
+#
+# mal (Make Lisp) Object Types and Functions
+#
+
+ifndef __mal_env_included
+__mal_env_included := true
+
+_TOP_DIR := $(dir $(lastword $(MAKEFILE_LIST)))
+include $(_TOP_DIR)types.mk
+
+#
+# ENV
+#
+
+# An ENV environment is a hash-map with an __outer__ reference to an
+# outer environment
+define BIND_ARGS
+$(strip \
+  $(word 1,$(1) \
+    $(foreach fparam,$(call _nth,$(2),0),\
+      $(if $(call _EQ,&,$($(fparam)_value)),
+        $(call ENV_SET,$(1),$($(call _nth,$(2),1)_value),$(strip \
+          $(foreach new_list,$(call _list),
+            $(word 1,$(new_list) \
+              $(foreach val,$(3),$(call _conj!,$(new_list),$(val))))))),\
+        $(foreach val,$(word 1,$(3)),\
+          $(call ENV_SET,$(1),$($(fparam)_value),$(val))\
+          $(foreach left,$(call srest,$(2)),\
+            $(if $(call _EQ,0,$(call _count,$(left))),\
+              ,\
+              $(call BIND_ARGS,$(1),$(left),$(wordlist 2,$(words $(3)),$(3))))))))))
+endef
+
+# Create a new ENV and optional bind values in it
+#   $(1): outer environment (set as a key named __outer__)
+#   $(2): list/vector object of bind forms
+#   $(3): space separated list of expressions to bind
+ENV = $(strip $(foreach new_env,$(call _assoc!,$(call _hash_map),__outer__,$(if $(1),$(1),$(__nil))),$(if $(2),$(call BIND_ARGS,$(new_env),$(2),$(3)),$(new_env))))
+ENV_FIND = $(strip \
+             $(if $(call _contains?,$(1),$(subst =,$(__equal),$(2))),\
+               $(1),\
+               $(if $(call _EQ,$(__nil),$(call _get,$(1),__outer__)),\
+                 ,\
+                 $(call ENV_FIND,$(call _get,$(1),__outer__),$(2)))))
+
+ENV_GET = $(foreach env,|$(call ENV_FIND,$(1),$(2))|,$(if $(call _EQ,||,$(env)),$(call _error,'$(2)' not found),$(call _get,$(strip $(subst |,,$(env))),$(subst =,$(__equal),$(2)))))
+
+ENV_SET = $(if $(call _assoc!,$(1),$(subst =,$(__equal),$(2)),$(3)),$(1),)
+
+endif