diff options
Diffstat (limited to 'spew/config.go')
| -rw-r--r-- | spew/config.go | 188 |
1 files changed, 177 insertions, 11 deletions
diff --git a/spew/config.go b/spew/config.go index 5e619d9..076a503 100644 --- a/spew/config.go +++ b/spew/config.go @@ -16,12 +16,30 @@ package spew -// ConfigState is used to describe 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. In addition, each -// SpewState instance provides access to a unique ConfigState which can be used -// to control the configuration of that particular instance. +import ( + "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. // @@ -30,11 +48,6 @@ type ConfigState struct { // nested data structures. MaxDepth int - // Indent specifies the string to use for each indentation level. It is - // 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 - // DisableMethods specifies whether or not error and Stringer interfaces are // invoked for types that implement them. DisableMethods bool @@ -55,4 +68,157 @@ type ConfigState struct { // The configuration can be changed by modifying the contents of spew.Config. var Config ConfigState = ConfigState{Indent: " "} -var defaultConfig = 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)...) +} + +/* +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 + +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. +*/ +func (c *ConfigState) Dump(a ...interface{}) { + fdump(c, os.Stdout, a...) +} + +// 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 +func NewDefaultConfig() *ConfigState { + return &ConfigState{Indent: " "} +} |