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Annotation of researchv8dc/cmd/awk/NEW, revision 1.1

1.1     ! root        1: BUGS:
        !             2:        ARGC and ARGV include a - for stdin when there are no args.
        !             3: 
        !             4: WISH LIST:
        !             5: 
        !             6:        %c
        !             7:        re parsing function of some kind
        !             8:        save compiled state
        !             9:        lazy field evaluation
        !            10:        type decls
        !            11:        scanf
        !            12:        access to run-time fcns
        !            13:        c output, link to c
        !            14:        char fcns, left side fcns (e.g., lsubstr)
        !            15:        coercion of expr to condition and vice versa
        !            16:        begin & end in patterns
        !            17:        limits on arrays, etc., ought to be dynamic instead of static.
        !            18: 
        !            19: 
        !            20: CHANGES SO FAR (Jul 85):
        !            21: 
        !            22: added & in replacement of sub() and gsub();  use \& to quote it
        !            23: 
        !            24: mutiple BEGIN's and END's concatenated
        !            25: 
        !            26: replaced error reporting mechanism
        !            27: 
        !            28: "function" is a synonym for "func"
        !            29: 
        !            30: "delete array[elem]" removes elem from array
        !            31: 
        !            32: Fixed bug in field handling for ~ 25% speed up.
        !            33: 
        !            34: Augmented the getline function:
        !            35:        getline
        !            36:                sets $0, NR, NF, $1..., from next input record
        !            37:        getline x
        !            38:                sets x from next input record, sets NR,
        !            39:                but NOT $0, NF, etc.
        !            40:        getline < "foo"
        !            41:                sets $0 from file foo.  sets NF, $1...,
        !            42:                but NOT NR
        !            43:        getline x < "foo"
        !            44:                sets x from foo.  no effect on $0, NF, NR, etc.
        !            45: 
        !            46:        Files are as for print; they are matched by name,
        !            47:        and remain open until explicitly closed.
        !            48:        Input pipes work;  syntax is
        !            49:                "whatever" | getline
        !            50:                "something" | getline x
        !            51:        (This adds a reduce/reduce conflict
        !            52:        to the grammar, so it may be a bad idea.)
        !            53: 
        !            54:        getline returns 0 on EOF, -1 on error, >0 normally
        !            55: 
        !            56: Added close function:
        !            57:        close("foo") calls fclose for right file or pclose for pipe
        !            58: 
        !            59: Added sub(regexp, replacement, str) and gsub(...).
        !            60:        Substitutes replacement for leftmost occurrence
        !            61:        of regexpr in str, or in $0 if no str supplied.
        !            62:        Gsub substitutes for all.  Number of changes
        !            63:        is returned.
        !            64: 
        !            65: Regular expressions can be dynamic.  Any constant string
        !            66:        or variable can be used as a regular expression
        !            67:        in sub(), gsub, or after ~ and !~.
        !            68: 
        !            69: Field separators can be regular expressions, both in FS
        !            70:        and as the 3rd argument of split().
        !            71: 
        !            72: Added "i in arr" condition, for if (...) and patterns.
        !            73:        i in arr  is true if arr[i] has been defined.
        !            74:        Note that this is different from asking if
        !            75:        arr[n] == i for some i!  We are searching for
        !            76:        a subscript, not a value.
        !            77: 
        !            78: terminal i/o, eg stderr
        !            79:        at least for output, no change needed:
        !            80:        print | "cat -u 1>&2"
        !            81:        can only have one of these active at one time.
        !            82: 
        !            83: ARGC and ARGV[] exist, essentially as in C.
        !            84:        ARGC is the number of arguments including the program name.
        !            85:        ARGV[0]..ARGV[ARGC-1] are the arguments
        !            86:        These can be modified in any way at any time.
        !            87:        If an ARGV[i] for i>0 is not null, it is assumed to be
        !            88:        the name of a file and is opened in the normal sequence.
        !            89:        New members of ARGV can be added dynamically beyond the
        !            90:        ones currently processed.
        !            91:        The argument '-' is added when input is stdin.
        !            92: 
        !            93: 
        !            94: added system(), rand(), srand(), sin, cos, atan2
        !            95: 
        !            96: added variable FNR -- line number in current file
        !            97:        can test FNR == 1 to see if in new file
        !            98: 
        !            99: Fixed so that \f, \b, \r, \ddd work in strings as in C
        !           100: 
        !           101: Functions are in:
        !           102:        recursive
        !           103:        arguments are call by value for scalars, by ref for arrays
        !           104:        declaration is
        !           105:                func f(arg list) statement
        !           106:                        arguments by name
        !           107:        arguments are local;  all others global
        !           108:        return [expr]
        !           109: 
        !           110: Order rules relaxed:
        !           111:        BEGIN, END, func declarations can occur anywhere a pattern can.
        !           112: 
        !           113: Added awkcheck when syntax error encountered,
        !           114:        for better identification of some errors.
        !           115:        Other error messages better.  Line number in source
        !           116:        and input line line both given for dynamic errors.
        !           117:        Some previously uncaught things now flagged
        !           118:        e.g.    print <= "foo"
        !           119:                print > foo (where foo is null)
        !           120:        detects calls of undefined functions, like foo(bar)

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