add and use PureOp

5 files changed, 128 insertions, 106 deletions

diff --git a/alv-lib/logic.moon b/alv-lib/logic.moon
index aaf255e..5ca4e68 100644
--- a/alv-lib/logic.moon
+++ b/alv-lib/logic.moon
@@ -1,4 +1,4 @@
-import Op, SigStream, Constant, Input, Error, T, val from require 'alv.base'
+import PureOp, Constant, T, val, evt from require 'alv.base'
 
 all_same = (first, list) ->
   for v in *list
@@ -14,19 +14,16 @@ tobool = (val) ->
     else
       true
 
-class ReduceOp extends Op
-  pattern = val! + val! * 0
-  setup: (inputs) =>
-    @out or= SigStream T.bool
-    { first, rest } = pattern\match inputs
-    super
-      first: Input.hot first
-      rest: [Input.hot v for v in *rest]
+any = val! / evt!
+
+class ReduceOp extends PureOp
+  pattern: any\rep 2, nil
+  type: T.bool
 
   tick: =>
-    { :first, :rest } = @unwrap_all!
-    accum = tobool first
-    for val in *rest
+    args = @unwrap_all!
+    accum = tobool args[1]
+    for val in *args[2,]
       accum = @.fn accum, tobool val
 
     @out\set accum
@@ -38,32 +35,22 @@ eq = Constant.meta
     examples: { '(== a b [c]…)', '(eq a b [c]…)' }
     description: "`true` if the types and values of all arguments are equal."
 
-  value: class extends Op
-    pattern = val! + val! * 0
+  value: class extends ReduceOp
     setup: (inputs) =>
-      @out or= SigStream T.bool, false
-      { first, rest } = pattern\match inputs
-      same = all_same first\type!, [i\type! for i in *rest]
-
-      super if same
-        {
-          first: Input.hot first
-          rest: [Input.hot v for v in *rest]
-        }
-      else
-        {}
+      @state or= {}
+      @state.same_type = all_same inputs[1]\type!, [i\type! for i in *inputs[2,]]
+      super inputs
 
     tick: =>
-      if not @inputs.first
+      if not @state.same_type
         @out\set false
         return
 
-      { :first, :rest } = @unwrap_all!
-      type = @inputs.first\type!
-
-      equal = true
-      for other in *rest
-        if not type\eq first, other
+      typ = @inputs[1]\type!
+      args = @unwrap_all!
+      equal, first = true, args[1]
+      for other in *args[2,]
+        if not typ\eq first, other
           equal = false
           break
 
@@ -76,25 +63,24 @@ not_eq = Constant.meta
     examples: { '(!= a b [c]…)', '(not-eq a b [c]…)' }
     description: "`true` if types or values of any two arguments are different."
 
-  value: class extends Op
+  value: class extends ReduceOp
     setup: (inputs) =>
-      @out or= SigStream T.bool, false
-      assert #inputs > 1, Error 'argument', "need at least two values"
-      super [Input.hot v for v in *inputs]
+      @state or= {}
+      @state.same_type = all_same inputs[1]\type!, [i\type! for i in *inputs[2,]]
+      super inputs
 
     tick: =>
-      if not @inputs[1]
+      if not @state.same_type
         @out\set true
         return
 
-      diff = true
-      for a=1, #@inputs-1
-        for b=a+1, #@inputs
-          if @inputs[a].result == @inputs[b].result
-            diff = false
-            break
-
-        break unless diff
+      typ = @inputs[1]\type!
+      args = @unwrap_all!
+      diff, first = true, args[1]
+      for other in *args[2,]
+        if typ\eq first, other
+          diff = false
+          break
 
       @out\set diff
 
@@ -120,14 +106,10 @@ not_ = Constant.meta
     summary: "Logical NOT."
     examples: { '(not a)' }
 
-  value: class extends Op
-    setup: (inputs) =>
-      @out or= SigStream T.bool, false
-      value = val!\match inputs
-      super value: Input.hot value
-
-    tick: =>
-      @out\set not tobool @inputs.value!
+  value: class extends PureOp
+    pattern: any\rep 1, 1
+    type: T.bool
+    tick: => @out\set not tobool @inputs[1]!
 
 bool = Constant.meta
   meta:
@@ -136,14 +118,10 @@ bool = Constant.meta
     examples: { '(bool a)' }
     description: "`false` if a is `false`, `nil` or `0`, `true` otherwise."
 
-  value: class extends Op
-    setup: (inputs) =>
-      @out or= SigStream T.bool
-      value = val!\match inputs
-      super value: Input.hot value
-
-    tick: =>
-      @out\set tobool @inputs.value!
+  value: class extends PureOp
+    pattern: any\rep 1, 1
+    type: T.bool
+    tick: => @out\set tobool @inputs[1]!
 
 {
   :eq, '==': eq
diff --git a/alv-lib/math.moon b/alv-lib/math.moon
index 8037e8a..b51718a 100644
--- a/alv-lib/math.moon
+++ b/alv-lib/math.moon
@@ -1,31 +1,23 @@
-import Op, Constant, SigStream, Error, Input, T, val from require 'alv.base'
+import PureOp, Constant, T, val, evt from require 'alv.base'
 unpack or= table.unpack
 
-class ReduceOp extends Op
-  pattern = val.num + val.num*0
-  setup: (inputs) =>
-    @out or= SigStream T.num
-    { first, rest } = pattern\match inputs
-    super
-      first: Input.hot first
-      rest: [Input.hot v for v in *rest]
+num = val.num / evt.num
+
+class ReduceOp extends PureOp
+  pattern: num\rep 2, nil
+  type: T.num
 
   tick: =>
-    { :first, :rest } = @unwrap_all!
-    accum = first
-    for val in *rest
+    args = @unwrap_all!
+    accum = args[1]
+    for val in *args[2,]
       accum = @.fn accum, val
     @out\set accum
 
 func_op = (func, pattern) ->
-  class extends Op
-
-    setup: (inputs) =>
-      @out or= SigStream T.num
-
-      params = pattern\match inputs
-      super [Input.hot p for p in *params]
-
+  class extends PureOp
+    pattern: pattern
+    type: T.num
 
     tick: => @out\set func unpack @unwrap_all!
 
@@ -35,20 +27,15 @@ func_def = (name, args, func, summary, pattern) ->
        :name
        :summary
        examples: { "(#{name} #{args})" }
-     value: func_op func, pattern or val.num\rep 1, 1
+     value: func_op func, pattern or num\rep 1, 1
 
 evenodd_op = (remainder) ->
-  class extends Op
-    pattern = val.num + -val.num
-    setup: (inputs) =>
-      @out or= SigStream T.bool
-      { val, div } = pattern\match inputs
-      super
-        val: Input.hot val
-        div: Input.hot div or SigStream.num 2
+  class extends PureOp
+    pattern: num + -num
+    type: T.bool
 
     tick: =>
-      { :val, :div } = @unwrap_all!
+      { val, div } = @unwrap_all!
       @out\set (val % div) == remainder
 
 add = Constant.meta
@@ -101,7 +88,7 @@ mod = Constant.meta
     summary: 'Modulo operator.'
     examples: { '(% num div)', '(mod num div)' }
     description: "Calculate remainder of division by `div`."
-  value: func_op ((a, b) -> a % b), val.num + val.num
+  value: func_op ((a, b) -> a % b), num + num
 
 even = Constant.meta
   meta:
@@ -127,7 +114,7 @@ mix = Constant.meta
     summary: 'Linearly interpolate.'
     examples: { '(mix a b i)' }
     description: "Interpolate between `a` and `b` using `i` in range 0-1."
-  value: func_op ((a, b, i) -> i*b + (1-i)*a), val.num + val.num + val.num
+  value: func_op ((a, b, i) -> i*b + (1-i)*a), num + num + num
 
 min = Constant.meta
   meta:
@@ -135,7 +122,7 @@ min = Constant.meta
     summary: "Find the minimum."
     examples: { '(min a b [c…])' }
     description: "Return the lowest of arguments."
-  value: func_op math.min, val.num*0
+  value: func_op math.min, num*0
 
 max = Constant.meta
   meta:
@@ -143,7 +130,7 @@ max = Constant.meta
     summary: "Find the maximum."
     examples: { '(max a b [c…])' }
     description: "Return the highest of arguments."
-  value: func_op math.max, val.num*0
+  value: func_op math.max, num*0
 
 cos = func_def 'cos', 'alpha', math.cos, "Cosine function (radians)."
 sin = func_def 'sin', 'alpha', math.sin, "Sine function (radians)."
@@ -151,7 +138,7 @@ tan = func_def 'tan', 'alpha', math.tan, "Tangent function (radians)."
 acos = func_def 'acos', 'cos', math.acos, "Inverse cosine function (radians)."
 asin = func_def 'asin', 'sin', math.asin, "Inverse sine function (radians)."
 atan = func_def 'atan', 'tan', math.atan, "Inverse tangent function (radians)."
-atan2 = func_def 'atan2', 'y x', math.atan2, "Inverse tangent function (two argument version).", val.num + val.num
+atan2 = func_def 'atan2', 'y x', math.atan2, "Inverse tangent function (two argument version).", num + num
 cosh = func_def 'cosh', 'alpha', math.cosh, "Hyperbolic cosine function (radians)."
 sinh = func_def 'sinh', 'alpha', math.sinh, "Hyperbolic sine function (radians)."
 tanh = func_def 'tanh', 'alpha', math.tanh, "Hyperbolic tangent function (radians)."
@@ -161,7 +148,7 @@ ceil = func_def 'ceil', 'val', math.ceil, "Round towards positive infinity."
 abs = func_def 'abs', 'val', math.abs, "Get the absolute value."
 
 exp = func_def 'exp', 'exp', math.floor, "*e* number raised to a power."
-log = func_def 'log', 'val [base]', math.log, "Logarithm with given base.", val.num + -val.num
+log = func_def 'log', 'val [base]', math.log, "Logarithm with optional base.", num + -num
 log10 = func_def 'log10', 'val', math.log10, "Logarithm with base 10."
 sqrt = func_def 'sqrt', 'val', math.sqrt, "Square root function."
 
diff --git a/alv-lib/string.moon b/alv-lib/string.moon
index 9f09f10..24a2a1b 100644
--- a/alv-lib/string.moon
+++ b/alv-lib/string.moon
@@ -1,17 +1,16 @@
-import Op, Constant, SigStream, Input, T from require 'alv.base'
+import PureOp, Constant, Input, T, val, evt from require 'alv.base'
+
+any = val! / evt!
 
 str = Constant.meta
   meta:
     name: 'str'
     summary: "Concatenate/stringify values."
     examples: { '(.. v1 [v2…])', '(str v1 [v2…])' }
-  value: class extends Op
-    setup: (inputs) =>
-      @out or= SigStream T.str
-      super [Input.hot v for v in *inputs]
-
-    tick: =>
-      @out\set table.concat [tostring v! for v in *@inputs]
+  value: class extends PureOp
+    pattern: any\rep 1, nil
+    type: T.str
+    tick: => @out\set table.concat [tostring i! for i in *@inputs]
 
 {
   :str, '..': str
diff --git a/alv/base/init.moon b/alv/base/init.moon
index 0cab7e3..65730a3 100644
--- a/alv/base/init.moon
+++ b/alv/base/init.moon
@@ -6,6 +6,7 @@
 --
 -- @module base
 -- @see Op
+-- @see PureOp
 -- @see Builtin
 -- @see FnDef
 -- @see Input
@@ -24,6 +25,7 @@
 -- @see Error
 
 import Op from require 'alv.base.op'
+import PureOp from require 'alv.base.pureop'
 import Builtin from require 'alv.base.builtin'
 import FnDef from require 'alv.base.fndef'
 import Input from require 'alv.base.input'
@@ -34,7 +36,7 @@ import RTNode from require 'alv.rtnode'
 import Error from require 'alv.error'
 
 {
-  :Op
+  :Op, :PureOp
   :Builtin
   :FnDef
   :Input
diff --git a/alv/base/pureop.moon b/alv/base/pureop.moon
new file mode 100644
index 0000000..ea3b810
--- /dev/null
+++ b/alv/base/pureop.moon
@@ -0,0 +1,56 @@
+----
+-- Stateless Operator base for pure functions.
+--
+-- All arguments can be evt- and val-capable. If one of the arguments is an
+-- !-stream, it will be the only `Input.hot`. If there are no !-streams,
+-- all inputs are hot. Passing more than one !-stream is an argument error.
+--
+-- To use `PureOp`, extend the class and set/implement only `pattern`, `type`
+-- and `tick`.
+-- @classmod PureOp
+import Op from require 'alv.base.op'
+import Input from require 'alv.base.input'
+import SigStream, EvtStream from require 'alv.result'
+import Error from require 'alv.error'
+
+unpack or= table.unpack
+
+class PureOp extends Op
+--- members.
+-- @section members
+
+  --- the argument pattern.
+  --
+  -- Must resolve to a simple sequence-table (depth 1).
+  --
+  -- @tfield match.Pattern pattern
+  @pattern: nil
+
+  --- the result type.
+  -- @tfield type.Type type
+  @type: nil
+
+  --- set up inputs for a range of things.
+  setup: (inputs) =>
+    args = @@pattern\match inputs
+
+    local trigger
+    for arg in *args
+      if arg.result.metatype == '!'
+        assert not trigger, Error 'argument', "pure op can take at most one !-stream."
+        trigger = arg
+
+    if trigger
+      super for a in *args
+        if a == trigger
+          Input.hot trigger
+        else
+          Input.cold a
+      @out = EvtStream @@type
+    else
+      super [Input.hot a for a in *args]
+      @out or= SigStream @@type
+
+{
+  :PureOp
+}