Documento de molib

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CLASS

moExpr

NAME

Constructor - create an expression string

VERSION

Version: 1.2.0

SYNOPSIS

moExpr(void);
moExpr(const moWCString& string);
moExpr(const moExpr& expr);
moExpr(const char *string, long length = -1, mowc::encoding_t encoding = mowc::MO_ENCODING_UTF8);
moExpr(const mowc::mc_t *string, long length = -1, mowc::encoding_t encoding = mowc::MO_ENCODING_UCS2_INTERNAL);
moExpr(const mowc::wc_t *string, long length = -1, mowc::encoding_t encoding = mowc::MO_ENCODING_UCS4_INTERNAL);
moExpr(const wchar_t *string, long length = -1);

DESCRIPTION

These constructors are similar to the moWCString() constructors.

Please, refer to the moWCString class for more information.

SEE ALSO

Result()

BUGS

Before a call to the Result() function, the error number is not defined.

COPYRIGHTS

AUTHORS

Alexis Wilke, Doug Barbieri

CLASS

moExpr

NAME

Result - computes a C expression

VERSION

Version: 1.2.0

SYNOPSIS

moWCString Result(void) const;

DESCRIPTION

The Result() function transforms the C expression present in the moExpr string object into a string with the result of the C expression.

At this time, it supports the following types:

identifiers [a-zA-Z_][a-zA-Z_0-9]* integers [0-9]+ floats [0-9]+\.[0-9]+([eE][-+][0-9]+)? strings \"([^"]|\\\")\" character \'...\' C like 8 bit characters

Identifiers are used to: 1. set variables and read them later (a = 5; b = a * 9),

2. function names: sin(3.14159),

3. casts: (long) "134"

The following are all the expression in their priority order that are currently supported in this function:

Operator Name Types supported

<expr>++ postfix increment integer, float <expr>-- postfix decrement integer, float

++<expr> prefix increment integer, float --<expr> prefix increment integer, float

!<expr> logical not integer, float, string see String.Reverse() ~<expr> bitwise not integer, string see String.Switchcase() +<expr> identity integer, float, string see String.Uppercase() -<expr> negate integer, float, string see String.Lowercase() (<expr>) grouping any (<type>) <expr> cast any <type> = int, long float, double string <expr>(<expr>) function call see the list of supported functions below <expr>[<expr>] array string also accepts: <expr>[<expr>..<expr>] <expr>[<expr>..] <expr>[..<expr>] (negative values are indexes from the end)

<expr>**<expr> power integer, float

<expr>*<expr> multiply integer, float <expr>/<expr> divide integer, float <expr>%<expr> modulo integer, float

<expr>+<expr> add integer, float, string see String.operator + <expr>-<expr> substract integer, float

<expr> << <expr> shift left integer <expr> >> <expr> shift right integer

<expr> < <expr> less than integer, float, string <expr> <= <expr> less or equal integer, float, string <expr> > <expr> greater than integer, float, string <expr> >= <expr> greater or equal integer, float, string

<expr> == <expr> equal integer, float, string <expr> != <expr> not equal integer, float, string

<expr>&<expr> bitwise and integer

<expr>^<expr> bitwise xor integer

<expr>|<expr> bitwise or integer

<expr>&&<expr> bitwise and integer, float, string

<expr>^^<expr> bitwise xor integer, float, string

<expr>||<expr> bitwise or integer, float, string

<expr>?<expr>:<expr> conditional integer, float, string

<expr> <assign op> <expr> assign identifier = anything the assign operators are any of: **=, *=, /=, %=, +=, -=, <<=, >>=, &=, |=, ^=

<expr>,<expr> comma any

<expr>;<expr> end expression any

Notes:

The comma separator can be used within a list of parameter for a function call as in regular C/C++.

The following is a list of the functions supported by this object so far:

atol() accept a string as parameter; transforms it to an integer

basename() returns the base name of the first parameter; when a second parameter is specified, make sure the first doesn't end with it (that is, if it does, that part - extension - is also removed)

capitalize_words() force the first letter of each word to an uppercase and all the others to lowercase

capitalize() force the very first letter to an uppercase letter and all the others to lowercase

clip() returns the string without any spaces at the start and at the end (see trim() also)

included() accept 2 or more parameters; it returns true if the first parameter is equal to any of the following parameters

Note: at this time only integers are supported

lower() change all the letters to lowercase letters

regexpr() check whether parameter 2 matches the regular expression defined in parameter 1; if the regular expression does match then this function returns true, otherwise it returns false

the following parameters are strings giving variable names which are set to whatever parameter fits in as defined in the regular expression (see the \(...\)) (this last feature is not supported yet)

replace() the first parameter is a string which represents a list of pairs separated by semi-colons; each pair consists of a string element to replace and what to replace it with the string element and its replacement have to be separated by an equal sign; as many pairs as you need can be included; example:

"'=<single quote>;\"=<double quote>"

This replaces each instance of ' and " by the full name of the quote.

the second parameter to this function is the string on which these replacements are applied; the result is the string with the characters replaced

reverse() reverse the order; swap the first and last letters, the second and one before last, etc.

strf() format a list of parameters; the first parameter is the format (as in printf(3C) under Linux); the following parameters are used as specified in the format; the result is the formatted string

strlen() return the length of a string in characters

switch_case() change all the lowercase letters in uppercase and vice versa

trim() trim the specified string from space and newline characters from the beginning and the end of the string (like clip() but includes the new lines)

upper() change all the letters to uppercase letters

RETURN VALUE

a string with the result
or "ERROR" to indicate that some error occured