Reading numbers from an input stream without using the Lisp reader.
read-integer (&optional input-stream eof-error-p eof-value recursivep &key unsigned-number plus-sign minus-sign group-separator radix)
Read an integer from an input stream.
read-float (&optional input-stream eof-error-p eof-value recursivep &key unsigned-number plus-sign minus-sign group-separator decimal-point exponent-marker float-format significand-radix exponent-radix exponent-base)
Read a floating-point number from an input stream.
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Optional arguments input-stream, eof-error-p, eof-value, and recursivep behave similar to
read. -
Keyword argument unsigned-number controls the sign conventions; plus or minus sign, minus sign only (no explicit plus sign), or unsigned.
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Keyword arguments plus-sign, minus-sign, group-separator, decimal-point, and exponent-marker denote character sets.
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Keyword arguments significand-radix, exponent-radix, and exponent-base provide support for reading, for example, C99 hexadecimal floating-point literals.
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Leading and trailing whitespace is not ignored.
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Compatible with
with-input-from-string.
The read-integer and read-float functions are designed to read
external number representations. The read-number function (to be
defined) is reserved for reading any Lisp number representation.
The functions provided by read-number are different to parse-number and parse-float because they read characters sequentially from a stream instead of parsing a string directly.