From 107565dc04129eac0f4917b94740cc7a0c47725e Mon Sep 17 00:00:00 2001
From: Jordan Orelli <jordanorelli@gmail.com>
Date: Sat, 20 Oct 2012 20:09:42 -0400
Subject: [PATCH] added quote

---
 input.lisp | 42 ------------------------------------------
 input.scm  | 30 ++++++++++++++++++++++++++++++
 skeam.go   |  5 +++++
 special.go | 24 ++++++++++++++++++++++++
 4 files changed, 59 insertions(+), 42 deletions(-)
 delete mode 100644 input.lisp
 create mode 100644 input.scm
 create mode 100644 special.go

diff --git a/input.lisp b/input.lisp
deleted file mode 100644
index 5e3ae9f..0000000
--- a/input.lisp
+++ /dev/null
@@ -1,42 +0,0 @@
-(+ 1 (+ 1 1) (dave (sam 1)))
-
-; alright I have comments now!!!!
-; woooohooo!!!!
-; nice nice nice
-
-(+ 1
-   22.3
-   a
-   ;here comes a comment
-   3.
-   (one two three)
-   "this is a string"
-   4.0
-   ((one two) three)
-   abøne
-   (dave
-     1
-     "here's an escaped quote: \" how neat!!!"
-     2
-     "and here;'s an escaped \\, sweet!"
-     albert-camus
-     3
-     (sam 3 2 2)))
-
-
-
-(begin (set! x 1)
-       (set! x (+ x 1))
-       (* x 2))
-
-; ------------------------------------------------------------------------------
-; the following stuff comes directly from the norvig essay, instead of being
-; contrived lexer tests.
-; ------------------------------------------------------------------------------
-
-; define a function and then execute it
-(begin (define r 3) (* 3.141592653 (* r r)))
-
-; same thing, alternative form without "begin"
-(define area (lambda (r) (* 3.141592653 (* r r))))
-(area 3)
diff --git a/input.scm b/input.scm
new file mode 100644
index 0000000..fddaea4
--- /dev/null
+++ b/input.scm
@@ -0,0 +1,30 @@
+; ------------------------------------------------------------------------------
+; literals
+; ------------------------------------------------------------------------------
+
+; integer
+1
+
+; float
+3.14
+
+; string
+"jordan"
+
+; ------------------------------------------------------------------------------
+; basic math
+; ------------------------------------------------------------------------------
+
+(+ 1 1)
+(- 1 1)
+(* 1 1)
+(/ 1 1)
+
+; ------------------------------------------------------------------------------
+; grammar
+; ------------------------------------------------------------------------------
+
+(define x 5)
+x
+
+(quote 1 2 3)
diff --git a/skeam.go b/skeam.go
index dfcb65d..b3cc39a 100644
--- a/skeam.go
+++ b/skeam.go
@@ -14,6 +14,10 @@ var DEBUG = false
 
 type sexp []interface{}
 
+func (s sexp) String() string {
+	return "(" + fmt.Sprint(s...) + ")"
+}
+
 type symbol string
 
 var universe = &environment{
@@ -22,6 +26,7 @@ var universe = &environment{
 	"*":      proc(multiplication),
 	"/":      proc(division),
 	"define": special(define),
+	"quote":  special(quote),
 }
 
 // parses the string lexeme into a value that can be eval'd
diff --git a/special.go b/special.go
new file mode 100644
index 0000000..42e14fc
--- /dev/null
+++ b/special.go
@@ -0,0 +1,24 @@
+package main
+
+import (
+	"fmt"
+	"reflect"
+)
+
+type special func(*environment, ...interface{}) (interface{}, error)
+
+func define(env *environment, args ...interface{}) (interface{}, error) {
+	if len(args) != 2 {
+		return nil, fmt.Errorf(`received %d arguments in *define*, expected exactly 2`, len(args))
+	}
+	s, ok := args[0].(symbol)
+	if !ok {
+		return nil, fmt.Errorf(`first argument to *define* must be symbol, received %v`, reflect.TypeOf(args[0]))
+	}
+	env.set(s, args[1])
+	return nil, nil
+}
+
+func quote(_ *environment, args ...interface{}) (interface{}, error) {
+	return sexp(args), nil
+}