move array ops into library, implement concat and size

1 files changed, 243 insertions, 0 deletions

diff --git a/alv-lib/array.moon b/alv-lib/array.moon
new file mode 100644
index 0000000..94499bc
--- /dev/null
+++ b/alv-lib/array.moon
@@ -0,0 +1,243 @@
+import Array, Op, PureOp, Constant, Error, const, sig, evt from require 'alv.base'
+
+get = Constant.meta
+  meta:
+    name: 'get'
+    summary: "Index into Arrays."
+    examples: { '(get array i)' }
+    description: "Get the value at index `i` (starting at 0).
+
+`i` has to be a constant expression."
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + const.num
+    type: (inputs) =>
+      { array, i } = inputs
+      array\type!\get i.result!
+
+    tick: =>
+      { array, i } = @unwrap_all!
+      @out\set array[i + 1]
+
+set = Constant.meta
+  meta:
+    name: 'set'
+    summary: "Update values in Arrays."
+    examples: { '(set array i val)' }
+    description: "Set the value for `i` to `val`.
+
+`i` has to be a constant expression. This is a pure op, so at most one of
+`array` and `val` may be a !-stream."
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + const.num + (sig! / evt!)
+    type: (inputs) =>
+      { array, i, val } = inputs
+      type = array\type!
+      expected = type\get i.result!
+
+      if expected ~= val\type!
+        msg = string.format "expected value of type %s, not %s",
+                            expected, val\type!
+        error Error 'argument', msg
+
+      type
+
+    tick: =>
+      { array, key, val } = @unwrap_all!
+
+      array = [v for v in *array]
+      array[key + 1] = val
+
+      @out\set array
+
+head = Constant.meta
+  meta:
+    name: 'head'
+    summary: "Get the first element from an array."
+    examples: { '(head array)' }
+
+  value: class extends PureOp
+    pattern: (sig! / evt!)*1
+    type: (inputs) =>
+      type = inputs[1]\type!
+
+      assert type.__class == Array, Error 'argument', "expected an Array"
+      assert type.size > 0, Error 'argument', "cannot get head of empty Array"
+
+      type.type
+
+    tick: =>
+      { array } = @unwrap_all!
+      @out\set array[1]
+
+tail = Constant.meta
+  meta:
+    name: 'tail'
+    summary: "Get everything except the first element from an array."
+    examples: { '(tail array)' }
+
+  value: class extends PureOp
+    pattern: (sig! / evt!)*1
+    type: (inputs) =>
+      type = inputs[1]\type!
+
+      assert type.__class == Array, Error 'argument', "expected an Array"
+      assert type.size > 0, Error 'argument', "cannot get tail of empty Array"
+
+      Array type.size - 1, type.type
+
+    tick: =>
+      { array } = @unwrap_all!
+      @out\set [v for v in *array[2,]]
+
+prepend = Constant.meta
+  meta:
+    name: 'prepend'
+    summary: "Prepend a new value at the start of an Array."
+    examples: { '(prepend array val)' }
+    description: "Prepend `val` to `array` at index `0`, moving other values back.
+
+This is a pure op, so at most one of `array` and `val` may be a !-stream."
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + (sig! / evt!)
+    type: (inputs) =>
+      { array, val } = inputs
+      type = array\type!
+
+      if val\type! ~= type.type
+        msg = string.format "expected value of type %s, not %s",
+                            type.type, val\type!
+        error Error 'argument', msg
+
+      Array type.size + 1, type.type
+
+    tick: =>
+      { array, val } = @unwrap_all!
+
+      array = [v for v in *array]
+      table.insert array, 1, val
+
+      @out\set array
+
+insert = Constant.meta
+  meta:
+    name: 'insert'
+    summary: "Insert new values into Arrays."
+    examples: { '(insert array i val)' }
+    description: "Insert `val` into `array` at `i`, moving other values back if
+necessary.
+
+`i` has to be a constant expression. This is a pure op, so at most one of
+`array` and `val` may be a !-stream."
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + const.num + (sig! / evt!)
+    type: (inputs) =>
+      { array, i, val } = inputs
+      type = array\type!
+      i = i.result!
+
+      if i > type.size or i < 0
+        error Error 'argument', "index '#{i}' out of range!"
+      if val\type! ~= type.type
+        msg = string.format "expected value of type %s, not %s",
+                            type.type, val\type!
+        error Error 'argument', msg
+
+      Array type.size + 1, type.type
+
+    tick: =>
+      { array, i, val } = @unwrap_all!
+
+      array = [v for v in *array]
+      table.insert array, i + 1, val
+
+      @out\set array
+
+remove = Constant.meta
+  meta:
+    name: 'remove'
+    summary: "Remove values from Arrays."
+    examples: { '(remove array i)' }
+    description: "Removes the value at index `i` from `array`.
+
+`i` has to be a constant expression."
+
+  value: class extends PureOp
+    pattern: (sig! / evt!) + const.num
+    type: (inputs) =>
+      { array, i } = inputs
+      type = array\type!
+
+      -- check index range
+      type\get i.result!
+
+      Array type.size - 1, type.type
+
+    tick: =>
+      { array, i, val } = @unwrap_all!
+
+      array = [v for v in *array]
+      table.remove array, i + 1
+
+      @out\set array
+
+size = Constant.meta
+  meta:
+    name: 'size'
+    summary: "Get Array size"
+    examples: { '(size array)' }
+
+  value: class extends Op
+    setup: (inputs) =>
+      super {}
+
+      assert #inputs == 1, Error 'argument', "expected exactly one argument"
+      type = inputs[1]\type!
+      assert type.__class == Array, Error 'argument', "expected an Array"
+
+      @out = Constant.num type.size
+
+concat = Constant.meta
+  meta:
+    name: 'concat'
+    summary: "Concatenate Arrays"
+    examples: { '(concat arr1 arr2 [arr3…])' }
+
+  value: class extends PureOp
+    pattern: (sig! / evt!)\rep 2
+    type: (inputs) =>
+      size = 0
+      type = inputs[1]\type!.type
+
+      for input in *inputs
+        array = input\type!
+
+        if array.type ~= type
+          msg = string.format "Cannot concatenate different arrays %s, %s",
+                inputs[1]\type!, array
+          error Error 'argument', msg
+
+        size += array.size
+
+      Array size, type
+
+    tick: =>
+      arrays = @unwrap_all!
+      out = {}
+
+      for array in *arrays
+        for val in *array
+          table.insert out, val
+
+      @out\set out
+
+{
+  :get, :set
+  :head, :tail, :prepend
+  :insert, :remove
+
+  :size, :concat
+}