[Home] Namespace Microsoft.FSharp.Text


Modules (as contributed by assembly 'FSharp.Core')

ModuleDescription
Microsoft.FSharp.Text.Printf Extensible printf-style formatting for numbers and other datatypes

Format specifications are strings with "%" markers indicating format placeholders. Format placeholders consist of:

    %[flags][width][.precision][type]
  

where the type is interpreted as follows:

     %b:         bool, formatted as "true" or "false"
     %s:         string, formatted as its unescaped contents
     %d, %i:     any basic integer type formatted as a decimal integer, signed if the basic integer type is signed.
     %u:         any basic integer type formatted as an unsigned decimal integer
     %x, %X, %o: any basic integer type formatted as an unsigned hexadecimal 
                 (a-f)/Hexadecimal (A-F)/Octal integer
 
     %e, %E, %f, %F, %g, %G: 
                 any basic floating point type (float,float32) formatted
                 using a C-style floating point format specifications, i.e
 
     %e, %E: Signed value having the form [-]d.dddde[sign]ddd where 
                 d is a single decimal digit, dddd is one or more decimal
                 digits, ddd is exactly three decimal digits, and sign 
                 is + or -
 
     %f:     Signed value having the form [-]dddd.dddd, where dddd is one
                 or more decimal digits. The number of digits before the 
                 decimal point depends on the magnitude of the number, and 
                 the number of digits after the decimal point depends on 
                 the requested precision.
 
     %g, %G: Signed value printed in f or e format, whichever is 
                 more compact for the given value and precision.
 
 
    %M:      System.Decimal value
 
    %O:      Any value, printed by boxing the object and using it's ToString method(s)
 
    %A:      Any value, printed by using Microsoft.FSharp.Text.StructuredFormat.Display.any_to_string with the default layout settings 
 
    %a:      A general format specifier, requires two arguments:
                 (1) a function which accepts two arguments:
                     (a) a context parameter of the appropriate type for the
                         given formatting function (e.g. an #System.IO.TextWriter)
                     (b) a value to print
                         and which either outputs or returns appropriate text.
 
                 (2) the particular value to print
 
 
    %t:      A general format specifier, requires one argument:
                 (1) a function which accepts a context parameter of the
                     appropriate type for the given formatting function (e.g. 
                     an #System.IO.TextWriter)and which either outputs or returns 
                     appropriate text.

  Basic integer types are:
     byte,sbyte,int16,uint16,int32,uint32,int64,uint64,nativeint,unativeint
  Basic floating point types are:
     float, float32

 
 The following format patterns are accepted but a warning is printed:

     %h(d|u|x|X|o)
     %l(d|u|x|X|o)

  The following format patterns are now deprecated:

     %Ld, %Li, %Lu, %Lx, %LX, %Lo: same, but an int64
     %nd, %ni, %nu, %nx, %nX, %no: same, but a nativeint
     %Ud, %Ui, %Uu, %Ux, %UX, %Uo: same, but an unsigned int32 (uint32)
     %ULd, %ULi, %ULu, %ULx, %ULX, %ULo: same, but an unsigned int64 (uint64)
     %Und, %Uni, %Unu, %Unx, %UnX, %Uno: same, but an unsigned nativeint (unativeint)
 

Valid flags are:

     0: add zeros instead of spaces to make up the required width
     '-': left justify the result within the width specified
     '+': add a '+' character if the number is positive (to match a '-' sign 
          for negatives)
     ' ': add an extra space if the number is positive (to match a '-' 
              sign for negatives)
 

The printf '#' flag is invalid and a compile-time error will be reported if it is used.

   Printf.printf "Hello %s, %d = %d * %d" "World" 6 2 3;
   Printf.sprintf "Hello %s" "World";
   Printf.printf "Hello %a" output_string "World";
 
Microsoft.FSharp.Text.PrintfImpl

Type Definitions

TypeDescription
type Format Type of a formatting expression 'a : function type generated by printf 'b: type argument passed to %a formatters 'c: value generated by the overall printf action (e.g. sprint generates a string) 'd: value generated after post processing (e.g. failwithf generates a string internally then raises an exception) 'e: tuple of values generated by scan or match
type Format

Deprecated/Unsafe Type Definitions

TypeDescription
type format4

Note: Consider using Printf.Format<_,_,_,_> instead

Internal type of a formatting expression Note: an abbreviation for Format<'a,'b,'c,'d>

See Also

Namespaces


Documentation for assembly FSharp.Core, version 1.9.4.19, generated using F# version 1.9.4.19