From 1c4975067d51ed69fdc9723255f8c4d4e92208b5 Mon Sep 17 00:00:00 2001
From: Ken Elf Mathieu Sternberg <elf@pendorwright.com>
Date: Fri, 3 Jul 2015 15:47:04 -0700
Subject: [PATCH] TEST: Add tests for the reader (!), which I had forgotten.

This also adds a number of accesory functions necessary for rationalizing
the record structure of an object in the lex/parse phase into something
more lisp-like.  There's a metadata issue here that I'm not quite wrapping
my head around.
---
 chapter1/astAccessors.coffee | 10 +++++++
 chapter1/astToList.coffee    | 51 ++++++++++++++++++++++++++++++++++++
 test/test_reader.coffee      | 34 ++++++++++++++++++++++++
 3 files changed, 95 insertions(+)
 create mode 100644 chapter1/astAccessors.coffee
 create mode 100644 chapter1/astToList.coffee
 create mode 100644 test/test_reader.coffee

diff --git a/chapter1/astAccessors.coffee b/chapter1/astAccessors.coffee
new file mode 100644
index 0000000..413461c
--- /dev/null
+++ b/chapter1/astAccessors.coffee
@@ -0,0 +1,10 @@
+{car, cdr} = require 'cons-lists/lists'
+
+symbol = (form) -> (car form)
+
+module.exports =
+  aSymbol: symbol
+  aValue:  (form) -> (car cdr form)
+  isAList: (form) -> (symbol form) == 'list'
+  isARecord: (form) -> (symbol form) == 'record'
+  isAVector: (form) -> (symbol form) == 'vector'
diff --git a/chapter1/astToList.coffee b/chapter1/astToList.coffee
new file mode 100644
index 0000000..2a0010e
--- /dev/null
+++ b/chapter1/astToList.coffee
@@ -0,0 +1,51 @@
+{car, cdr, cons, listp, nilp, nil, list, listToString} = require 'cons-lists/lists'
+{aSymbol, aValue} = require './astAccessors'
+
+# RICH_AST -> LISP_AST
+normalizeForm = (form) ->
+
+  listToRecord1 = (l) ->
+    o = Object.create(null)
+    while(l != nil)
+      o[normalizeForm(car l)] = normalizeForm(car cdr l)
+      l = cdr cdr l
+      null
+    o
+    
+  listToVector1 = (l) ->
+    while(l != nil) then p = normalizeForm(car l); l = cdr l; p
+
+  id = (a) -> a
+
+  methods = 
+    'list': normalizeForms
+    'vector': (atom) -> listToVector1(atom)
+    'record': (atom) -> listToRecord1(atom)
+
+    # Basic native types.  Meh.
+    'symbol': id
+    'number': id
+    'string': (atom) -> atom
+    'nil': (atom) -> nil
+  
+    # Values inherited from the VM.
+    'true': (atom) -> true
+    'false': (atom) -> false
+    'null': (atom) -> null
+    'undefined': (atom) -> undefined
+
+  methods[(car form)](car cdr form)
+
+
+normalizeForms = (forms) ->
+  # Yes, this reifies the expectation than an empty list and 'nil' are
+  # the same.
+  return nil if nilp forms
+  cons(normalizeForm(car forms), normalizeForms(cdr forms))
+  
+module.exports =
+  normalizeForm: normalizeForm
+  normalizeForms: normalizeForms
+
+
+  
diff --git a/test/test_reader.coffee b/test/test_reader.coffee
new file mode 100644
index 0000000..43dabe9
--- /dev/null
+++ b/test/test_reader.coffee
@@ -0,0 +1,34 @@
+chai = require 'chai'
+chai.should()
+expect = chai.expect 
+
+{cons, nil, nilp} = require "cons-lists/lists"
+{read, readForms} = require '../chapter1/reader'
+{normalizeForm} = require '../chapter1/astToList'
+
+describe "Core reader functions", ->
+  samples = [
+    ['nil', nil]
+    ['0', 0]
+    ['1', 1]
+    ['500', 500]
+    ['0xdeadbeef', 3735928559]
+    ['"Foo"', 'Foo']
+    ['(1)', cons(1)]
+    ['(1 2)', cons(1, (cons 2))]
+    ['(1 2 )', cons(1, (cons 2))]
+    ['( 1 2 )', cons(1, (cons 2))]
+    ['(   1   2   )', cons(1, (cons 2))]
+    ['("a" "b")', cons("a", (cons "b"))]
+    ['("a" . "b")', cons("a", "b")]
+    ['[]', []]
+    ['{}', {}]
+    ['[1 2 3]', [1, 2, 3]]
+    ['{foo "bar"}', {foo: "bar"}]
+  ]
+
+  for [t, v] in samples
+    do (t, v) ->
+      it "should interpret #{t} as #{v}", ->
+        res = normalizeForm read t
+        expect(res).to.deep.equal(v)