Copyright (C) 1994, Digital Equipment Corp.
The Scan interface provides procedures for reading strings,
booleans, integers, and floating-point numbers from a text string.
Similar functionality on readers is availble from the Lex
interface.
INTERFACE Scan;
IMPORT Word, Lex, FloatMode;
Each of these procedures parses a string of characters and converts
it to a binary value. Leading and trailing blanks (ie. characters
in Lex.Blanks) are ignored. Lex.Error is raised if the first
non-blank substring is not generated by the corresponding Lex
grammar or if there are zero or more than one non-blank substrings.
FloatMode.Trap is raised as per Lex.
PROCEDURE Bool(txt: TEXT): BOOLEAN
RAISES {Lex.Error};
PROCEDURE Int(txt: TEXT; defaultBase: [2..16] := 10): INTEGER
RAISES {Lex.Error, FloatMode.Trap};
PROCEDURE Unsigned(txt: TEXT; defaultBase: [2..16] := 16): Word.T
RAISES {Lex.Error, FloatMode.Trap};
PROCEDURE Real(txt: TEXT): REAL
RAISES {Lex.Error, FloatMode.Trap};
PROCEDURE LongReal(txt: TEXT): LONGREAL
RAISES {Lex.Error, FloatMode.Trap};
PROCEDURE Extended(txt: TEXT): EXTENDED
RAISES {Lex.Error, FloatMode.Trap};
END Scan.