--- /dev/null
+/*
+ * Copyright (c) 2013 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "os"
+)
+
+// ConfigState houses the configuration options used by spew to format and
+// display values. There is a global instance, Config, that is used to control
+// all top-level Formatter and Dump functionality. Each ConfigState instance
+// provides methods equivalent to the top-level functions.
+//
+// The zero value for ConfigState provides no indentation. You would typically
+// want to set it to a space or a tab.
+//
+// Alternatively, you can use NewDefaultConfig to get a ConfigState instance
+// with default settings. See the documentation of NewDefaultConfig for default
+// values.
+type ConfigState struct {
+ // Indent specifies the string to use for each indentation level. The
+ // global config instance that all top-level functions use set this to a
+ // single space by default. If you would like more indentation, you might
+ // set this to a tab with "\t" or perhaps two spaces with " ".
+ Indent string
+
+ // MaxDepth controls the maximum number of levels to descend into nested
+ // data structures. The default, 0, means there is no limit.
+ //
+ // NOTE: Circular data structures are properly detected, so it is not
+ // necessary to set this value unless you specifically want to limit deeply
+ // nested data structures.
+ MaxDepth int
+
+ // DisableMethods specifies whether or not error and Stringer interfaces are
+ // invoked for types that implement them.
+ DisableMethods bool
+
+ // DisablePointerMethods specifies whether or not to check for and invoke
+ // error and Stringer interfaces on types which only accept a pointer
+ // receiver when the current type is not a pointer.
+ //
+ // NOTE: This might be an unsafe action since calling one of these methods
+ // with a pointer receiver could technically mutate the value, however,
+ // in practice, types which choose to satisify an error or Stringer
+ // interface with a pointer receiver should not be mutating their state
+ // inside these interface methods. As a result, this option relies on
+ // access to the unsafe package, so it will not have any effect when
+ // running in environments without access to the unsafe package such as
+ // Google App Engine or with the "safe" build tag specified.
+ DisablePointerMethods bool
+
+ // DisablePointerAddresses specifies whether to disable the printing of
+ // pointer addresses. This is useful when diffing data structures in tests.
+ DisablePointerAddresses bool
+
+ // DisableCapacities specifies whether to disable the printing of capacities
+ // for arrays, slices, maps and channels. This is useful when diffing
+ // data structures in tests.
+ DisableCapacities bool
+
+ // ContinueOnMethod specifies whether or not recursion should continue once
+ // a custom error or Stringer interface is invoked. The default, false,
+ // means it will print the results of invoking the custom error or Stringer
+ // interface and return immediately instead of continuing to recurse into
+ // the internals of the data type.
+ //
+ // NOTE: This flag does not have any effect if method invocation is disabled
+ // via the DisableMethods or DisablePointerMethods options.
+ ContinueOnMethod bool
+
+ // SortKeys specifies map keys should be sorted before being printed. Use
+ // this to have a more deterministic, diffable output. Note that only
+ // native types (bool, int, uint, floats, uintptr and string) and types
+ // that support the error or Stringer interfaces (if methods are
+ // enabled) are supported, with other types sorted according to the
+ // reflect.Value.String() output which guarantees display stability.
+ SortKeys bool
+
+ // SpewKeys specifies that, as a last resort attempt, map keys should
+ // be spewed to strings and sorted by those strings. This is only
+ // considered if SortKeys is true.
+ SpewKeys bool
+}
+
+// Config is the active configuration of the top-level functions.
+// The configuration can be changed by modifying the contents of spew.Config.
+var Config = ConfigState{Indent: " "}
+
+// Errorf is a wrapper for fmt.Errorf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the formatted string as a value that satisfies error. See NewFormatter
+// for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Errorf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Errorf(format string, a ...interface{}) (err error) {
+ return fmt.Errorf(format, c.convertArgs(a)...)
+}
+
+// Fprint is a wrapper for fmt.Fprint that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the number of bytes written and any write error encountered. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Fprint(w, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+ return fmt.Fprint(w, c.convertArgs(a)...)
+}
+
+// Fprintf is a wrapper for fmt.Fprintf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the number of bytes written and any write error encountered. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Fprintf(w, format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+ return fmt.Fprintf(w, format, c.convertArgs(a)...)
+}
+
+// Fprintln is a wrapper for fmt.Fprintln that treats each argument as if it
+// passed with a Formatter interface returned by c.NewFormatter. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Fprintln(w, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+ return fmt.Fprintln(w, c.convertArgs(a)...)
+}
+
+// Print is a wrapper for fmt.Print that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the number of bytes written and any write error encountered. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Print(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Print(a ...interface{}) (n int, err error) {
+ return fmt.Print(c.convertArgs(a)...)
+}
+
+// Printf is a wrapper for fmt.Printf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the number of bytes written and any write error encountered. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Printf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Printf(format string, a ...interface{}) (n int, err error) {
+ return fmt.Printf(format, c.convertArgs(a)...)
+}
+
+// Println is a wrapper for fmt.Println that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the number of bytes written and any write error encountered. See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Println(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Println(a ...interface{}) (n int, err error) {
+ return fmt.Println(c.convertArgs(a)...)
+}
+
+// Sprint is a wrapper for fmt.Sprint that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the resulting string. See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Sprint(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprint(a ...interface{}) string {
+ return fmt.Sprint(c.convertArgs(a)...)
+}
+
+// Sprintf is a wrapper for fmt.Sprintf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter. It returns
+// the resulting string. See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Sprintf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprintf(format string, a ...interface{}) string {
+ return fmt.Sprintf(format, c.convertArgs(a)...)
+}
+
+// Sprintln is a wrapper for fmt.Sprintln that treats each argument as if it
+// were passed with a Formatter interface returned by c.NewFormatter. It
+// returns the resulting string. See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+// fmt.Sprintln(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprintln(a ...interface{}) string {
+ return fmt.Sprintln(c.convertArgs(a)...)
+}
+
+/*
+NewFormatter returns a custom formatter that satisfies the fmt.Formatter
+interface. As a result, it integrates cleanly with standard fmt package
+printing functions. The formatter is useful for inline printing of smaller data
+types similar to the standard %v format specifier.
+
+The custom formatter only responds to the %v (most compact), %+v (adds pointer
+addresses), %#v (adds types), and %#+v (adds types and pointer addresses) verb
+combinations. Any other verbs such as %x and %q will be sent to the the
+standard fmt package for formatting. In addition, the custom formatter ignores
+the width and precision arguments (however they will still work on the format
+specifiers not handled by the custom formatter).
+
+Typically this function shouldn't be called directly. It is much easier to make
+use of the custom formatter by calling one of the convenience functions such as
+c.Printf, c.Println, or c.Printf.
+*/
+func (c *ConfigState) NewFormatter(v interface{}) fmt.Formatter {
+ return newFormatter(c, v)
+}
+
+// Fdump formats and displays the passed arguments to io.Writer w. It formats
+// exactly the same as Dump.
+func (c *ConfigState) Fdump(w io.Writer, a ...interface{}) {
+ fdump(c, w, a...)
+}
+
+/*
+Dump displays the passed parameters to standard out with newlines, customizable
+indentation, and additional debug information such as complete types and all
+pointer addresses used to indirect to the final value. It provides the
+following features over the built-in printing facilities provided by the fmt
+package:
+
+ * Pointers are dereferenced and followed
+ * Circular data structures are detected and handled properly
+ * Custom Stringer/error interfaces are optionally invoked, including
+ on unexported types
+ * Custom types which only implement the Stringer/error interfaces via
+ a pointer receiver are optionally invoked when passing non-pointer
+ variables
+ * Byte arrays and slices are dumped like the hexdump -C command which
+ includes offsets, byte values in hex, and ASCII output
+
+The configuration options are controlled by modifying the public members
+of c. See ConfigState for options documentation.
+
+See Fdump if you would prefer dumping to an arbitrary io.Writer or Sdump to
+get the formatted result as a string.
+*/
+func (c *ConfigState) Dump(a ...interface{}) {
+ fdump(c, os.Stdout, a...)
+}
+
+// Sdump returns a string with the passed arguments formatted exactly the same
+// as Dump.
+func (c *ConfigState) Sdump(a ...interface{}) string {
+ var buf bytes.Buffer
+ fdump(c, &buf, a...)
+ return buf.String()
+}
+
+// convertArgs accepts a slice of arguments and returns a slice of the same
+// length with each argument converted to a spew Formatter interface using
+// the ConfigState associated with s.
+func (c *ConfigState) convertArgs(args []interface{}) (formatters []interface{}) {
+ formatters = make([]interface{}, len(args))
+ for index, arg := range args {
+ formatters[index] = newFormatter(c, arg)
+ }
+ return formatters
+}
+
+// NewDefaultConfig returns a ConfigState with the following default settings.
+//
+// Indent: " "
+// MaxDepth: 0
+// DisableMethods: false
+// DisablePointerMethods: false
+// ContinueOnMethod: false
+// SortKeys: false
+func NewDefaultConfig() *ConfigState {
+ return &ConfigState{Indent: " "}
+}
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