tcl: Phase 4 env-as-value — current-env/eval-in-env/env-lookup/env-extend (+5 tests, 342/342 total)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/tcl/tests/idioms.sx

@@ -29,161 +29,164 @@
     (define
       ok
       (fn (label actual expected) (tcl-idiom-assert label expected actual)))
-
-    ; 1. lmap idiom: accumulate mapped values with foreach+lappend
-    (ok "idiom-lmap"
+    (ok
+      "idiom-lmap"
       (get
-        (run "set result {}\nforeach x {1 2 3} { lappend result [expr {$x * $x}] }\nset result")
+        (run
+          "set result {}\nforeach x {1 2 3} { lappend result [expr {$x * $x}] }\nset result")
         :result)
       "1 4 9")
-
-    ; 2. Recursive list flatten
-    (ok "idiom-flatten"
+    (ok
+      "idiom-flatten"
       (get
         (run
           "proc flatten {lst} { set out {}\n  foreach item $lst {\n    if {[llength $item] > 1} {\n      foreach sub [flatten $item] { lappend out $sub }\n    } else {\n      lappend out $item\n    }\n  }\n  return $out\n}\nflatten {1 {2 3} {4 {5 6}}}")
         :result)
       "1 2 3 4 5 6")
-
-    ; 3. String builder accumulator
-    (ok "idiom-string-builder"
+    (ok
+      "idiom-string-builder"
       (get
-        (run "set buf \"\"\nforeach w {Hello World Tcl} { append buf $w \" \" }\nstring trimright $buf")
+        (run
+          "set buf \"\"\nforeach w {Hello World Tcl} { append buf $w \" \" }\nstring trimright $buf")
         :result)
       "Hello World Tcl")
-
-    ; 4. Default parameter via info exists
-    (ok "idiom-default-param"
-      (get
-        (run "if {![info exists x]} { set x 42 }\nset x")
-        :result)
+    (ok
+      "idiom-default-param"
+      (get (run "if {![info exists x]} { set x 42 }\nset x") :result)
       "42")
-
-    ; 5. Association list lookup (parallel key/value lists)
-    (ok "idiom-alist-lookup"
+    (ok
+      "idiom-alist-lookup"
       (get
         (run
           "set keys {a b c}\nset vals {10 20 30}\nset idx [lsearch $keys b]\nlindex $vals $idx")
         :result)
       "20")
-
-    ; 6. Proc with optional args via args
-    (ok "idiom-optional-args"
+    (ok
+      "idiom-optional-args"
       (get
         (run
           "proc greet {name args} {\n  set greeting \"Hello\"\n  if {[llength $args] > 0} { set greeting [lindex $args 0] }\n  return \"$greeting $name\"\n}\ngreet World Hi")
         :result)
       "Hi World")
-
-    ; 7. Builder pattern: dict create from args
-    (ok "idiom-dict-builder"
+    (ok
+      "idiom-dict-builder"
       (get
         (run
           "proc build-dict {args} { dict create {*}$args }\ndict get [build-dict name Alice age 30] name")
         :result)
       "Alice")
-
-    ; 8. Loop with index using array
-    (ok "idiom-loop-with-index"
+    (ok
+      "idiom-loop-with-index"
       (get
-        (run
-          "set i 0\nforeach x {a b c} { set arr($i) $x; incr i }\nset arr(1)")
+        (run "set i 0\nforeach x {a b c} { set arr($i) $x; incr i }\nset arr(1)")
         :result)
       "b")
-
-    ; 9. String reverse via split+lreverse+join
-    (ok "idiom-string-reverse"
+    (ok
+      "idiom-string-reverse"
       (get
         (run
           "set s hello\nset chars [split $s \"\"]\nset rev [lreverse $chars]\njoin $rev \"\"")
         :result)
       "olleh")
-
-    ; 10. Number to padded string
-    (ok "idiom-number-format"
-      (get (run "format \"%05d\" 42") :result)
-      "00042")
-
-    ; 11. Dict comprehension pattern
-    (ok "idiom-dict-comprehension"
+    (ok "idiom-number-format" (get (run "format \"%05d\" 42") :result) "00042")
+    (ok
+      "idiom-dict-comprehension"
       (get
         (run
           "set squares {}\nforeach n {1 2 3 4} { dict set squares $n [expr {$n * $n}] }\ndict get $squares 3")
         :result)
       "9")
-
-    ; 12. Stack ADT using list: push/pop
-    (ok "idiom-stack"
+    (ok
+      "idiom-stack"
       (get
         (run
           "proc stack-push {stackvar val} { upvar $stackvar s; lappend s $val }\nproc stack-pop {stackvar} { upvar $stackvar s; set val [lindex $s end]; set s [lrange $s 0 end-1]; return $val }\nset stk {}\nstack-push stk 10\nstack-push stk 20\nstack-push stk 30\nstack-pop stk")
         :result)
       "30")
-
-    ; 13. Queue ADT using list: enqueue/dequeue
-    (ok "idiom-queue"
+    (ok
+      "idiom-queue"
       (get
         (run
           "proc q-enq {qvar val} { upvar $qvar q; lappend q $val }\nproc q-deq {qvar} { upvar $qvar q; set val [lindex $q 0]; set q [lrange $q 1 end]; return $val }\nset q {}\nq-enq q alpha\nq-enq q beta\nq-enq q gamma\nq-deq q")
         :result)
       "alpha")
-
-    ; 14. Pipeline via proc chaining
-    (ok "idiom-pipeline"
+    (ok
+      "idiom-pipeline"
       (get
         (run
           "proc double {x} { expr {$x * 2} }\nproc add1 {x} { expr {$x + 1} }\nproc pipeline {val procs} { foreach p $procs { set val [$p $val] }; return $val }\npipeline 5 {double add1 double}")
         :result)
       "22")
-
-    ; 15. Memoize pattern using dict (simple cache, not recursive)
-    (ok "idiom-memoize"
+    (ok
+      "idiom-memoize"
       (get
         (run
           "set cache {}\nproc cached-square {n} { global cache\n  if {[dict exists $cache $n]} { return [dict get $cache $n] }\n  set r [expr {$n * $n}]\n  dict set cache $n $r\n  return $r\n}\nset a [cached-square 7]\nset b [cached-square 7]\nset c [cached-square 8]\nexpr {$a == $b && $c == 64}")
         :result)
       "1")
-
-    ; 16. Simple expression evaluator in Tcl (recursive descent)
-    (ok "idiom-recursive-eval"
+    (ok
+      "idiom-recursive-eval"
       (get
         (run
           "proc calc {expr} { return [::tcl::mathop::+ 0 [expr $expr]] }\nexpr {3 + 4 * 2}")
         :result)
       "11")
-
-    ; 17. Apply proc to each pair in a dict
-    (ok "idiom-dict-for"
+    (ok
+      "idiom-dict-for"
       (get
         (run
           "set d [dict create a 1 b 2 c 3]\nset total 0\ndict for {k v} $d { incr total $v }\nset total")
         :result)
       "6")
-
-    ; 18. Find max in list
-    (ok "idiom-find-max"
+    (ok
+      "idiom-find-max"
       (get
         (run
           "proc list-max {lst} {\n  set m [lindex $lst 0]\n  foreach x $lst { if {$x > $m} { set m $x } }\n  return $m\n}\nlist-max {3 1 4 1 5 9 2 6}")
         :result)
       "9")
-
-    ; 19. Filter list by predicate
-    (ok "idiom-filter-list"
+    (ok
+      "idiom-filter-list"
       (get
         (run
           "proc list-filter {lst pred} {\n  set out {}\n  foreach x $lst { if {[$pred $x]} { lappend out $x } }\n  return $out\n}\nproc is-even {n} { expr {$n % 2 == 0} }\nlist-filter {1 2 3 4 5 6} is-even")
         :result)
       "2 4 6")
-
-    ; 20. Zip two lists
-    (ok "idiom-zip"
+    (ok
+      "idiom-zip"
       (get
         (run
           "proc zip {a b} {\n  set out {}\n  set n [llength $a]\n  for {set i 0} {$i < $n} {incr i} {\n    lappend out [lindex $a $i]\n    lappend out [lindex $b $i]\n  }\n  return $out\n}\nzip {1 2 3} {a b c}")
         :result)
       "1 a 2 b 3 c")
-
+    (ok
+      "env-lookup-basic"
+      (env-lookup (let ((x 42)) (current-env)) "x")
+      42)
+    (ok
+      "env-lookup-missing"
+      (env-lookup (let ((x 42)) (current-env)) "z")
+      nil)
+    (ok
+      "env-extend-lookup"
+      (let
+        ((e (let ((x 5)) (current-env))))
+        (env-lookup (env-extend e "y" 10) "y"))
+      10)
+    (ok
+      "eval-in-env-parent"
+      (let
+        ((x 5))
+        (eval-in-env (env-extend (current-env) "y" 10) (quote (+ x y))))
+      15)
+    (ok
+      "eval-in-env-multi"
+      (let
+        ((base (current-env)))
+        (eval-in-env
+          (env-extend (env-extend base "a" 3) "b" 7)
+          (quote (* a b))))
+      21)
     (dict
       "passed"
       tcl-idiom-pass