doc λ in HtDP Intm+Lam and Adv

svn: r14540

collects/scribblings/htdp-langs/advanced.scrbl

@@ -4,18 +4,24 @@
           "prim-ops.ss"
           (for-label lang/htdp-advanced))
 
-@(define-syntax-rule (bd intm-define intm-define-struct intm-lambda intm-local intm-letrec intm-let intm-let* intm-time)
+@(define-syntax-rule (bdl intm-define intm-lambda)
+   (begin
+    (require (for-label lang/htdp-intermediate-lambda))
+    (define intm-define (scheme define))
+    (define intm-lambda (scheme lambda))))
+@(bdl intm-define intm-lambda)
+
+@(define-syntax-rule (bd intm-define-struct intm-local intm-letrec intm-let intm-let* intm-time)
    (begin
     (require (for-label lang/htdp-intermediate))
     (define intm-define (scheme define))
     (define intm-define-struct (scheme define-struct))
-    (define intm-lambda (scheme lambda))
     (define intm-local (scheme local))
     (define intm-letrec (scheme letrec))
     (define intm-let (scheme let))
     (define intm-let* (scheme let*))
     (define intm-time (scheme time))))
-@(bd intm-define intm-define-struct intm-lambda intm-local intm-letrec intm-let intm-let* intm-time)
+@(bd intm-define-struct intm-local intm-letrec intm-let intm-let* intm-time)
 
 @(define-syntax-rule (bbd beg-define beg-define-struct beg-cond beg-if beg-and beg-or beg-check-expect beg-require)
    (begin
@@ -36,7 +42,7 @@
 @declare-exporting[lang/htdp-advanced]
 
 @schemegrammar*+qq[
-#:literals (define define-struct lambda cond else if and or empty true false require lib planet
+#:literals (define define-struct lambda λ cond else if and or empty true false require lib planet
             local let let* letrec time begin begin0 set! delay shared recur when case unless
             check-expect check-within check-error)
 (check-expect check-within check-error require)
@@ -53,6 +59,7 @@
       (set! id expr)
       (delay expr)
       (lambda (id ...) expr)
+      (λ (id ...) expr)
       (local [definition ...] expr)
       (letrec ([id expr] ...) expr)
       (shared ([id expr] ...) expr)
@@ -126,7 +133,10 @@ additional set of operations:
 
 @section[#:tag "advanced-lambda"]{@scheme[lambda]}
 
-@defform[(lambda (id ...) expr)]{
+@deftogether[(
+@defform[(lambda (id ...) expr)]
+@defform[(λ (id ...) expr)]
+)]{
 
 The same as Intermediate with Lambda's @|intm-lambda|, except that a
 function is allowed to accept zero arguments.}

collects/scribblings/htdp-langs/intermediate-lambda.scrbl

@@ -35,7 +35,7 @@
 @declare-exporting[lang/htdp-intermediate-lambda]
 
 @schemegrammar*+qq[
-#:literals (define define-struct lambda cond else if and or empty true false require lib planet
+#:literals (define define-struct lambda λ cond else if and or empty true false require lib planet
             local let let* letrec time check-expect check-within check-error)
 (check-expect check-within check-error require)
 [program (code:line def-or-expr ...)]
@@ -47,6 +47,7 @@
             (define id expr)
             (define-struct id (id ...))]
 [expr (lambda (id id ...) expr)
+      (λ (id id ...) expr)
       (local [definition ...] expr)
       (letrec ([id expr] ...) expr)
       (let ([id expr] ...) expr)
@@ -97,6 +98,10 @@ for @scheme[lambda], since a @scheme[lambda] form is an expression.}
 Creates a function that takes as many arguments as given @scheme[id]s,
 and whose body is @scheme[expr].}
 
+@defform[(λ (id id ...) expr)]{
+
+The Greek letter @scheme[λ] is a synonym for @scheme[lambda].}
+
 @; ----------------------------------------------------------------------
 
 @section[#:tag "intermediate-lambda-call"]{Function Calls}