Add support for a casting mode option

kgryte · kgryte · commit 253e7a1edf71 · 2018-07-25T01:18:58.000-07:00
diff --git a/lib/node_modules/@stdlib/ndarray/array/README.md b/lib/node_modules/@stdlib/ndarray/array/README.md
@@ -80,21 +80,47 @@ arr = array( array( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ] ) );
 The function accepts the following `options`:
 
 -   `buffer`: data source. If provided along with a `buffer` argument, the argument takes precedence.
+
 -   `dtype`: underlying storage [data type][@stdlib/ndarray/dtypes]. If not specified and a data source is provided, the data type is inferred from the provided data source. If an input data source is not of the same type, this option specifies the data type to which to cast the input data. For non-[`ndarray`][@stdlib/ndarray/ctor] generic array data sources, the function casts generic array data elements to the default data type. In order to prevent this cast, the `dtype` option **must** be explicitly set to `'generic'`. Any time a cast is required, the `copy` option is set to `true`, as memory must be copied from the data source to an output data buffer. Default: `'float64'`.
--   `order`: specifies the memory layout of the data source as either row-major (C-style) or column-major (Fortran-style). If set to `'any'`, if a data source is column-major and not row-major, the order of the returned array is column-major; otherwise, the order of the returned array is always row-major. If set to `'same'`, the order of the returned array matches the order of an input data source. If set to either `'row-major'` or `'column-major'`, the order of the returned array is set to the option value. Note that specifying an order which differs from the order of a provided data source does **not** entail a conversion from one memory layout to another. In short, this option is descriptive, not prescriptive. Default: `'row-major'`.
--   `shape`: array shape (dimensions). If a shape is not specified, the function attempts to infer a shape based on a provided data source. For example, if provided a nested array, the function resolves nested array dimensions. If provided a multidimensional array data source, the function uses the array's associated shape. For most use cases, such inference suffices. In the remaining use cases, specifying a shape is necessary. For example, provide a shape to create a multidimensional array view over a linear data buffer, ignoring any existing shape meta data associated with a provided data source.
+
+-   `order`: specifies the memory layout of the data source as either row-major (C-style) or column-major (Fortran-style). The option may be one of the following values:
+
+    -   `row-major`: the order of the returned array is row-major.
+    -   `column-major`: the order of the returned array is column-major.
+    -   `any`: if a data source is column-major and not row-major, the order of the returned array is column-major; otherwise, the order of the returned array is row-major.
+    -   `same`: the order of the returned array matches the order of an input data source.
+
+    Note that specifying an order which differs from the order of a provided data source does **not** entail a conversion from one memory layout to another. In short, this option is descriptive, not prescriptive. Default: `'row-major'`.
+
+-   `shape`: array shape (dimensions). If a shape is not specified, the function attempts to infer a shape based on a provided data source. For example, if provided a nested array, the function resolves nested array dimensions. If provided a multidimensional array data source, the function uses the array's associated shape. For most use cases, such inference suffices. For the remaining use cases, specifying a shape is necessary. For example, provide a shape to create a multidimensional array view over a linear data buffer, ignoring any existing shape meta data associated with a provided data source.
+
 -   `flatten`: `boolean` indicating whether to automatically flatten generic array data sources. If an array shape is not specified, the shape is inferred from the dimensions of nested arrays prior to flattening. If a use case requires partial flattening, partially flatten **prior** to invoking this function and set the option value to `false` to prevent further flattening during invocation. Default: `true`.
+
 -   `copy`: `boolean` indicating whether to (shallow) copy source data to a new data buffer. The function does **not** perform a deep copy. To prevent undesired shared changes in state for generic arrays containing objects, perform a deep copy **prior** to invoking this function. Default: `false`.
+
 -   `ndmin`: specifies the minimum number of dimensions. If an array shape has fewer dimensions than required by `ndmin`, the function **prepends** singleton dimensions to the array shape in order to satisfy the dimensions requirement. Default: `0`.
+
+-   `casting`: specifies the casting rule used to determine acceptable casts. The option may be one of the following values:
+
+    -   `none`: only allow casting between identical types.
+    -   `equiv`: allow casting between identical and byte swapped types.
+    -   `safe`: only allow "safe" casts.
+    -   `same-kind`: allow "safe" casts and casts within the same kind (e.g., between signed integers or between floats).
+    -   `unsafe`: allow casting between all types (including between integers and floats).
+
+    Default: `'safe'`.
+
 -   `codegen`: `boolean` indicating whether to use code generation. Default: `true`.
--   `mode`: specifies how to handle indices which exceed array dimensions. Default: `'throw'`.
--   `submode`: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions. If provided fewer modes than dimensions, the function recycles modes using modulo arithmetic. Default: `[ options.mode ]`.
 
-The function supports the following `modes`:
+-   `mode`: specifies how to handle indices which exceed array dimensions.
+
+    -   `throw`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should throw an error when an index exceeds array dimensions.
+    -   `wrap`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should wrap around an index exceeding array dimensions using modulo arithmetic.
+    -   `clamp`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should set an index exceeding array dimensions to either `0` (minimum index) or the maximum index.
+   
+    Default: `'throw'`.
 
--   `throw`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should throw an error when an index exceeds array dimensions.
--   `wrap`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should wrap around an index exceeding array dimensions using modulo arithmetic.
--   `clamp`: specifies that an [`ndarray`][@stdlib/ndarray/ctor] instance should set an index exceeding array dimensions to either `0` (minimum index) or the maximum index.
+-   `submode`: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions. If provided fewer modes than dimensions, the function recycles modes using modulo arithmetic. Default: `[ options.mode ]`.
 
 By default, the function returns [`ndarray`][@stdlib/ndarray/ctor] instances which use code generation for fast element lookup. To disable code generation, set the `codegen` option to `false`.
 
diff --git a/lib/node_modules/@stdlib/ndarray/array/docs/repl.txt b/lib/node_modules/@stdlib/ndarray/array/docs/repl.txt
@@ -27,13 +27,18 @@
 
     options.order: string (optional)
         Specifies the memory layout of the data source as either row-major (C-
-        style) or column-major (Fortran-style). If set to 'any', if a data
-        source is column-major and not row-major, the order of the returned
-        array is column-major; otherwise, the order of the returned array is
-        always row-major. If set to 'same', the order of the returned array
-        matches the order of an input data source. If set to either 'row-major'
-        or 'column-major', the order of the returned array is set to the option
-        value. Note that specifying an order which differs from the order of a
+        style) or column-major (Fortran-style). The option may be one of the
+        following values:
+
+        - 'row-major': the order of the returned array is row-major.
+        - 'column-major': the order of the returned array is column-major.
+        - 'any': if a data source is column-major and not row-major, the order
+          of the returned array is column-major; otherwise, the order of the
+          returned array is row-major.
+        - 'same': the order of the returned array matches the order of an input
+          data source.
+
+        Note that specifying an order which differs from the order of a
         provided data source does *not* entail a conversion from one memory
         layout to another. In short, this option is descriptive, not
         prescriptive. Default: 'row-major'.
@@ -44,7 +49,7 @@
         if provided a nested array, the function resolves nested array
         dimensions. If provided a multidimensional array data source, the
         function uses the array's associated shape. For most use cases, such
-        inference suffices. In the remaining use cases, specifying a shape is
+        inference suffices. For the remaining use cases, specifying a shape is
         necessary. For example, provide a shape to create a multidimensional
         array view over a linear data buffer, ignoring any existing shape meta
         data associated with a provided data source.
@@ -69,29 +74,53 @@
         dimensions to the array shape in order to satisfy the dimensions
         requirement. Default: 0.
 
+    options.casting: string ( optional)
+        Specifies the casting rule used to determine acceptable casts. The
+        option may be one of the following values:
+
+        - 'none': only allow casting between identical types.
+        - 'equiv': allow casting between identical and byte swapped types.
+        - 'safe': only allow "safe" casts.
+        - 'same-kind': allow "safe" casts and casts within the same kind (e.g.,
+          between signed integers or between floats).
+        - 'unsafe': allow casting between all types (including between integers
+          and floats).
+
+        Default: 'safe'.
+
     options.codegen: boolean (optional)
         Boolean indicating whether to use code generation. Code generation can
         boost performance, but may be problematic in browser contexts enforcing
         a strict content security policy (CSP). Default: true.
 
     options.mode: string (optional)
-        Specifies how to handle indices which exceed array dimensions. If equal
-        to 'throw', an ndarray instance throws an error when an index exceeds
-        array dimensions. If equal to 'wrap', an ndarray instance wraps around
-        indices exceeding array dimensions using modulo arithmetic. If equal to
-        'clamp', an ndarray instance sets an index exceeding array dimensions to
-        either `0` (minimum index) or the maximum index. Default: 'throw'.
+        Specifies how to handle indices which exceed array dimensions. The
+        option may be one of the following values:
+
+        - 'throw': an ndarray instance throws an error when an index exceeds
+          array dimensions.
+        - 'wrap': an ndarray instance wraps around indices exceeding array
+          dimensions using modulo arithmetic.
+        - 'clamp', an ndarray instance sets an index exceeding array dimensions
+          to either `0` (minimum index) or the maximum index.
+
+        Default: 'throw'.
 
     options.submode: Array<string> (optional)
         Specifies how to handle subscripts which exceed array dimensions. If a
-        mode for a corresponding dimension is equal to 'throw', an ndarray
-        instance throws an error when a subscript exceeds array dimensions. If
-        equal to 'wrap', an ndarray instance wraps around subscripts exceeding
-        array dimensions using modulo arithmetic. If equal to 'clamp', an
-        ndarray instance sets a subscript exceeding array dimensions to either
-        `0` (minimum index) or the maximum index. If the number of modes is
-        fewer than the number of dimensions, the function recycles modes using
-        modulo arithmetic. Default: [ options.mode ].
+        mode for a corresponding dimension is equal to
+
+        - 'throw': an ndarray instance throws an error when a subscript exceeds
+          array dimensions.
+        - 'wrap': an ndarray instance wraps around subscripts exceeding array
+          dimensions using modulo arithmetic.
+        - 'clamp': an ndarray instance sets a subscript exceeding array
+          dimensions to either `0` (minimum index) or the maximum index.
+
+        If the number of modes is fewer than the number of dimensions, the
+        function recycles modes using modulo arithmetic.
+
+        Default: [ options.mode ].
 
     Returns
     -------
diff --git a/lib/node_modules/@stdlib/ndarray/array/lib/defaults.json b/lib/node_modules/@stdlib/ndarray/array/lib/defaults.json
@@ -1,9 +1,10 @@
 {
-	"dtype": "float64",
-	"order": "row-major",
+	"casting": "safe",
 	"codegen": true,
-	"mode": "throw",
 	"copy": false,
+	"dtype": "float64",
 	"flatten": true,
-	"ndmin": 0
+	"mode": "throw",
+	"ndmin": 0,
+	"order": "row-major"
 }
diff --git a/lib/node_modules/@stdlib/ndarray/array/lib/main.js b/lib/node_modules/@stdlib/ndarray/array/lib/main.js
@@ -34,6 +34,7 @@ var ctor = require( '@stdlib/ndarray/ctor' );
 var mctor = require( '@stdlib/ndarray/memoized-ctor' );
 var isDataType = require( '@stdlib/ndarray/base/assert/is-data-type' );
 var isOrder = require( '@stdlib/ndarray/base/assert/is-order' );
+var isCastingMode = require( '@stdlib/ndarray/base/assert/is-casting-mode' );
 var createBuffer = require( '@stdlib/ndarray/base/buffer' );
 var getType = require( '@stdlib/ndarray/base/buffer-dtype' );
 var arrayShape = require( '@stdlib/array/shape' );
@@ -63,6 +64,7 @@ var expandStrides = require( './expand_strides.js' );
 * @param {boolean} [options.copy=false] - boolean indicating whether to copy source data to a new data buffer
 * @param {boolean} [options.flatten=true] - boolean indicating whether to automatically flatten generic array data sources
 * @param {NonNegativeInteger} [options.ndmin=0] - minimum number of dimensions
+* @param {string} [options.casting="safe"] - casting rule used to determine what constitutes an acceptable cast
 * @throws {TypeError} options argument must be an object
 * @throws {TypeError} must provide valid options
 * @throws {Error} must provide either an array shape, data source, or both
@@ -243,6 +245,14 @@ function array() {
 	} else {
 		opts.copy = defaults.copy;
 	}
+	if ( hasOwnProp( options, 'casting' ) ) {
+		opts.casting = options.casting;
+		if ( !isCastingMode( opts.casting ) ) {
+			throw new TypeError( 'invalid option. `casting` option must be a recognized casting mode. Option: `' + opts.casting + '`.' );
+		}
+	} else {
+		opts.casting = defaults.casting;
+	}
 	// If not provided a shape, infer from a provided data source...
 	if ( hasOwnProp( options, 'shape' ) ) {
 		shape = options.shape;
