Hacked #lang algol60 into place

(Patch from Danny Yoo, touched up a little.)

collects/algol60/examples/euler.a60

@@ -1,3 +1,5 @@
+#lang algol60
+
 begin
 
 procedure euler (fct,sum,eps,tim); value eps,tim; integer tim;

collects/algol60/examples/jensen.a60

@@ -1,3 +1,5 @@
+#lang algol60
+
 begin
   integer procedure SIGMA(x, i, n);
     value n;

collects/algol60/examples/nqueen.a60

@@ -1,3 +1,5 @@
+#lang algol60
+
 begin
         comment
           -- From the NASE A60 distribution --
@@ -57,7 +59,7 @@ tryNextN:
         integer x;
         begin
                 integer y;
-        
+
                 for y := 1 step 1 until N do
                 begin
                         if empcol [ y ] & empup [ x-y ] 
@@ -120,5 +122,3 @@ contN:
 
         end
 end
-
-

collects/algol60/examples/primes.a60

@@ -1,3 +1,5 @@
+#lang algol60
+
 begin
         comment
           -- From the NASE A60 distribution --
@@ -57,11 +59,11 @@ begin
                 for i := 2 step 1 until NN div 2 do
                         for j := 2 * i step i until NN do
                                 arr [j] := false;
-                
+
                 for i := 2 step 1 until NN do
                         if arr [i] then
                                 printnln (i);
                 printsln (`done.')
 
         end
-end             
+end

collects/algol60/lang/algol60.rkt

@@ -0,0 +1,8 @@
+#lang racket/base
+
+(require "../runtime.rkt"
+         "../prims.rkt")
+
+(provide (all-from-out racket/base)
+         (all-from-out "../prims.rkt")
+         (all-from-out "../runtime.rkt"))

collects/algol60/lang/reader.rkt

@@ -0,0 +1,48 @@
+#lang s-exp syntax/module-reader
+algol60/lang/algol60
+
+#:read algol60-read
+#:read-syntax algol60-read-syntax
+#:info algol60-get-info
+#:whole-body-readers? #t
+
+
+(require "../parse.rkt"
+         ;; Parses to generate an AST. Identifiers in the AST
+         ;; are represented as syntax objects with source location.
+
+         "../simplify.rkt"
+         ;; Desugars the AST, transforming `for' to `if'+`goto',
+         ;; and flattening `if' statements so they are always
+         ;; of the for `if <exp> then goto <label> else goto <label>'
+
+         "../compile.rkt"
+         ;; Compiles a simplified AST to Scheme.
+
+         mzlib/file
+         syntax/strip-context)
+
+
+(define (algol60-read in)
+  (map syntax->datum (algol60-read-syntax #f in)))
+
+
+(define (algol60-read-syntax src in)
+  (define parsed (parse-a60-port in src))
+  (define simplified (simplify parsed #'here))
+  (define compiled (compile-simplified simplified #'here))
+  (define stripped (strip-context compiled))
+
+  (list stripped))
+
+
+
+;; Extension: cooperate with DrRacket and tell it to use the default,
+;; textual lexer and color scheme when editing algol programs.
+(define (algol60-get-info key default default-filter)
+  (case key
+    [(color-lexer)
+     (dynamic-require 'syntax-color/default-lexer
+                      'default-lexer)]
+    [else
+     (default-filter key default)]))