implement (set) as per spec

4 files changed, 45 insertions, 11 deletions

diff --git a/alv/builtins.moon b/alv/builtins.moon
index b1c8593..9610b5f 100644
--- a/alv/builtins.moon
+++ b/alv/builtins.moon
@@ -532,6 +532,39 @@ get = Constant.meta
         val = val[key]
       @out\set val
 
+set = Constant.meta
+  meta:
+    name: 'set'
+    summary: "Update Arrays and Structs."
+    examples: { '(set val key new-val)' }
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + (const.str / const.sym / const.num) + (sig! / evt!)
+    type: (inputs) => inputs[1]\type!
+
+    setup: (...) =>
+      super ...
+
+      { val, key, new_val } = @inputs
+
+      expected_val_typ = val\type!\get key!
+      got_val_typ = new_val\type!
+      if expected_val_typ ~= got_val_typ
+        msg = string.format "expected value for key '%s' to be %s, not %s",
+                            key!, expected_val_typ, got_val_typ
+        error Error 'argument', msg
+
+    tick: =>
+      { val, key, new_val } = @unwrap_all!
+
+      if type(key) == 'number'
+        key = key + 1
+
+      val = {k,v for k,v in pairs val}
+      val[key] = new_val
+
+      @out\set val
+
 loop = Constant.meta
   meta:
     name: 'loop'
@@ -629,7 +662,8 @@ Scope.from_table {
   '~': to_sig
   '!': to_evt
 
-  :array, :struct, :get
+  :array, :struct
+  :get, :set
 
   :loop, :recur
 
diff --git a/alv/result/const.moon b/alv/result/const.moon
index 9e24ab1..ecd386d 100644
--- a/alv/result/const.moon
+++ b/alv/result/const.moon
@@ -45,7 +45,7 @@ class Constant extends Result
   --- compare two values.
   --
   -- Compares two `SigStream`s by comparing their types and their Lua values.
-  __eq: (other) => other.type == @type and other.value == @value
+  __eq: (other) => other.type == @type and @type\eq other.value, @value
 
   --- Result metatype.
   -- @tfield string metatype (`=`)
diff --git a/spec/lang/array_spec.moon b/spec/lang/array_spec.moon
index 97632e3..25c0167 100644
--- a/spec/lang/array_spec.moon
+++ b/spec/lang/array_spec.moon
@@ -33,11 +33,11 @@ describe "array", ->
 
     it "checks value type", ->
       err = assert.has.error -> COPILOT\eval_once '(set (array 1) 0 "a")'
-      assert.matches "argument error: TBD", err
+      assert.matches "expected value for key '0' to be num, not str", err
 
     it "checks index range", ->
       err = assert.has.error -> COPILOT\eval_once '(set (array 1 2) -1 0)'
-      assert.matches "index '-1' out of range!", err
+      assert.matches "index '%-1' out of range!", err
 
       COPILOT\eval_once '(set (array 1 2) 0 0)'
 
@@ -75,21 +75,21 @@ describe "array", ->
       assert.is.equal svec3\mk_const({ 'a', 'b', 'c' }), rt.result
 
     it "can insert a value", ->
-      rt = COPILOT\eval_once '(set (array "b" "c") 0 "a")'
+      rt = COPILOT\eval_once '(insert (array "b" "c") 0 "a")'
       assert.is.true rt\is_const!
       assert.is.equal svec3\mk_const({ 'a', 'b', 'c' }), rt.result
 
-      rt = COPILOT\eval_once '(set (array "a" "c") 1 "b")'
+      rt = COPILOT\eval_once '(insert (array "a" "c") 1 "b")'
       assert.is.true rt\is_const!
       assert.is.equal svec3\mk_const({ 'a', 'b', 'c' }), rt.result
 
-      rt = COPILOT\eval_once '(set (array "a" "b") 1 "c")'
+      rt = COPILOT\eval_once '(insert (array "a" "b") 1 "c")'
       assert.is.true rt\is_const!
       assert.is.equal svec3\mk_const({ 'a', 'b', 'c' }), rt.result
 
     it "checks index range", ->
       err = assert.has.error -> COPILOT\eval_once '(insert (array 1 2) -1 0)'
-      assert.matches "index '-1' out of range!", err
+      assert.matches "index '%-1' out of range!", err
 
       COPILOT\eval_once '(insert (array 1 2) 0 0)'
 
@@ -117,7 +117,7 @@ describe "array", ->
 
     it "checks index range", ->
       err = assert.has.error -> COPILOT\eval_once '(remove (array 1 2 3) -1)'
-      assert.matches "index '-1' out of range!", err
+      assert.matches "index '%-1' out of range!", err
 
       err = assert.has.error -> COPILOT\eval_once '(remove (array 1 2 3) 3)'
       assert.matches "index '3' out of range!", err
diff --git a/spec/lang/struct_spec.moon b/spec/lang/struct_spec.moon
index 57c7e79..aa7b689 100644
--- a/spec/lang/struct_spec.moon
+++ b/spec/lang/struct_spec.moon
@@ -14,11 +14,11 @@ describe "struct", ->
 
     it "cannot add members", ->
       err = assert.has.error -> COPILOT\eval_once '(set (struct "a" 1) "b" 2)'
-      assert.matches "argument error: TBD", err
+      assert.matches "{a: num} has no 'b' key", err
 
     it "checks value type", ->
       err = assert.has.error -> COPILOT\eval_once '(set (struct "a" 1) "a" "str")'
-      assert.matches "argument error: TBD", err
+      assert.matches "expected value for key 'a' to be num, not str", err
 
   describe "(get)", ->
     it "can get values", ->