user=> (format "%5d" 3)
" 3"
user=> (format "Pad with leading zeros %07d" 5432)
"Pad with leading zeros 0005432"
user=> (format "Left justified :%-7d:" 5432)
"Left justified :5432 :"
user=> (format "Locale-specific group separators %,12d" 1234567)
"Locale-specific group separators 1,234,567"
user=> (format "decimal %d octal %o hex %x upper-case hex %X" 63 63 63 63)
"decimal 63 octal 77 hex 3f upper-case hex 3F"
;; ====== Clojure format/printf and large integers =====
;; This big number doesn't fit in a Long. It is a
;; clojure.lang.BigInt, which format cannot handle directly.
user=> (format "%5d" 12345678901234567890)
IllegalFormatConversionException d != clojure.lang.BigInt java.util.Formatter$FormatSpecifier.failConversion (Formatter.java:3999)
;; You can convert it to a java.math.BigInteger, which format does handle.
user=> (format "%5d" (biginteger 12345678901234567890))
"12345678901234567890"
;; If you do this very often, you might want to use something like
;; format-plus to avoid sprinkling your code with calls to biginteger.
(defn coerce-unformattable-types [args]
(map (fn [x]
(cond (instance? clojure.lang.BigInt x) (biginteger x)
(instance? clojure.lang.Ratio x) (double x)
:else x))
args))
(defn format-plus [fmt & args]
(apply format fmt (coerce-unformattable-types args)))
;; Now this works:
user=> (format-plus "%5d" 12345678901234567890)
"12345678901234567890"
user=> (format "%5d" 3)
" 3"
user=> (format "Pad with leading zeros %07d" 5432)
"Pad with leading zeros 0005432"
user=> (format "Left justified :%-7d:" 5432)
"Left justified :5432 :"
user=> (format "Locale-specific group separators %,12d" 1234567)
"Locale-specific group separators 1,234,567"
user=> (format "decimal %d octal %o hex %x upper-case hex %X" 63 63 63 63)
"decimal 63 octal 77 hex 3f upper-case hex 3F"
;; ====== Clojure format/printf and large integers =====
;; This big number doesn't fit in a Long. It is a
;; clojure.lang.BigInt, which format cannot handle directly.
user=> (format "%5d" 12345678901234567890)
IllegalFormatConversionException d != clojure.lang.BigInt java.util.Formatter$FormatSpecifier.failConversion (Formatter.java:3999)
;; You can convert it to a java.math.BigInteger, which format does handle.
user=> (format "%5d" (biginteger 12345678901234567890))
"12345678901234567890"
;; If you do this very often, you might want to use something like
;; format-plus to avoid sprinkling your code with calls to biginteger.
(defn coerce-unformattable-types [args]
(map (fn [x]
(cond (instance? clojure.lang.BigInt x) (biginteger x)
(instance? clojure.lang.Ratio x) (double x)
:else x))
args))
(defn format-plus [fmt & args]
(apply format fmt (coerce-unformattable-types args)))
;; Now this works:
user=> (format-plus "%5d" 12345678901234567890)
"12345678901234567890"
