commit ff71edc2c9ee44b580990f0303e769ef619c6ee0
parent 591a0d20ab6d174a655969b8d04f9f0d6c05617b
Author: Drew DeVault <sir@cmpwn.com>
Date: Tue, 20 Apr 2021 12:31:58 -0400
fmt: move module docs into README
Diffstat:
| A | fmt/README | | | 42 | ++++++++++++++++++++++++++++++++++++++++++ |
| M | fmt/fmt.ha | | | 38 | -------------------------------------- |
2 files changed, 42 insertions(+), 38 deletions(-)
diff --git a/fmt/README b/fmt/README
@@ -0,0 +1,42 @@
+A format string consists of a string of literal characters, to be printed
+verbatim, and format sequences, which describe how to format arguments from a
+set of variadic parameters for printing.
+
+A format sequence is enclosed in curly braces "{}". An empty sequence takes the
+next argument from the parameter list, in order. A specific parameter may be
+selected by indexing it from zero: "{0}", "{1}", and so on. To print "{", use
+"{{", and for "}", use "}}".
+
+You may use a colon to add format modifiers; for example, "{:x}" will format an
+argument in hexadecimal, and "{3:-10}" will left-align the 3rd argument to at
+least 10 characters.
+
+The format modifiers takes the form of an optional flag character:
+
+- "0": Numeric values are zero-padded up to the required width.
+- "-": The value shall be left-aligned, and spaces inserted on the right to meet the required width. "-" takes precedence over "0" if both are used.
+- " ": (a space) insert a space before positive numbers, where "-" would be if it were negative.
+- "+": insert a "+" before positive numbers, where "-" would be if it were negative. "+" takes precedence over " " if both are used.
+
+Following the flag, an optional decimal number shall specify the minimum width
+of this field. If "0" or "-" were not given, the default behavior shall be to
+pad with spaces to achieve the necessary width.
+
+Following the width, an optional precision may be given as a decimal number
+following a "." character. For integer types, this gives the minimum number of
+digits to include. For floating types, this gives the number of digits following
+the radix to include.
+
+Following the precision, an optional character controls the output format:
+
+- x, X: print in lowercase or uppercase hexadecimal
+- o, b: print in octal or binary
+
+Some examples:
+
+ fmt::printf("hello {}", "world"); // "hello world"
+ fmt::printf("{1} {0}", "hello", "world"); // "world hello"
+ fmt::printf("{:x} {:X}", 51966, 61453); // "CAFE F00D"
+ fmt::printf("{:-5}", 42); // "42 "
+ fmt::printf("{:5}", 42); // " 42"
+ fmt::printf("{:05}", 42); // "00042"
diff --git a/fmt/fmt.ha b/fmt/fmt.ha
@@ -1,41 +1,3 @@
-// A format string consists of a string of literal characters, to be printed
-// verbatim, and format sequences, which describe how to format arguments from
-// a set of variadic parameters for printing.
-//
-// A format sequence is enclosed in curly braces '{}'. An empty sequence takes
-// the next argument from the parameter list, in order. A specific parameter may
-// be selected by indexing it from zero: '{0}', '{1}', and so on. To print '{',
-// use '{{', and for '}', use '}}'.
-//
-// You may use a colon to add format modifiers; for example, '{:x}' will format
-// an argument in hexadecimal, and '{3:-10}' will left-align the 3rd argument to
-// at least 10 characters.
-//
-// The format modifiers takes the form of an optional flag character:
-//
-// 0: Numeric values are zero-padded up to the required width.
-// -: The value shall be left-aligned, and spaces inserted on the right to meet
-// the required width. '-' takes precedence over '0' if both are used.
-// : (a space) insert a space before positive numbers, where '-' would be if it
-// were negative.
-// +: insert a '+' before positive numbers, where '-' would be if it were
-// negative. '+' takes precedence over ' ' if both are used.
-//
-// Following the flag, an optional decimal number shall specify the minimum
-// width of this field. If '0' or '-' were not given, the default behavior shall
-// be to pad with spaces to achieve the necessary width.
-//
-// Following the width, an optional precision may be given as a decimal number
-// following a '.' character. For integer types, this gives the minimum number
-// of digits to include. For floating types, this gives the number of digits
-// following the radix to include.
-//
-// Following the precision, an optional character controls the output format:
-//
-// x, X: print in lowercase or uppercase hexadecimal
-// o, b: print in octal or binary
-//
-// TODO: Expand this with more format modifiers
use ascii;
use bufio;
use encoding::utf8;
