41 lines
1.1 KiB
Plaintext
41 lines
1.1 KiB
Plaintext
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DEFINITION MODULE RealInOut;
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(*
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Terminal input/output of REAL values
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From the book 'Programming in Modula-2' by Prof. N. Wirth.
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*)
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EXPORT QUALIFIED ReadReal, WriteReal, WriteRealOct, Done;
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VAR Done: BOOLEAN;
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PROCEDURE ReadReal(VAR x: REAL);
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(*- Read a REAL from the terminal.
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out: x the number read.
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The syntax accepted is:
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["+"|"-"] digit {digit} ["." digit {digit}] ["E"["+"|"-"] digit [digit]]
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If a number is found, Done is set to TRUE (otherwise FALSE).
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At most 7 digits are significant, leading zeros not
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counting. Maximum exponent is 38. Input terminates
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with a blank or any control character. DEL may be used
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for backspacing.
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*)
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PROCEDURE WriteReal(x: REAL; n: CARDINAL);
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(*- Write a REAL to the terminal, right-justified.
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in: x number to write,
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n minimum field width.
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If fewer than n characters are needed to represent x, leading
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blanks are output.
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*)
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PROCEDURE WriteRealOct(x: REAL);
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(*- Write a REAL to terminal, in octal form with exponent and mantissa.
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*)
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END RealInOut.
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