ref: 0644aa11c120a581eec1d47c66208e08b946ec08
dir: /man/2/string/
.TH STRING 2 .SH NAME string: append, drop, in, prefix, quoted, splitl, splitr, splitstrl, splitstrr, take, tobig, toint, toreal, tolower, toupper, unquoted \- string operations .SH SYNOPSIS .EX include "string.m"; str := load String String->PATH; append: fn(s: string, l: list of string): list of string; drop: fn(s, cl: string): string; in: fn(c: int, cl: string): int; prefix: fn(pre, s: string): int; splitl: fn(s, cl: string): (string, string); splitr: fn(s, cl: string): (string, string); splitstrl: fn(s, t: string): (string, string); splitstrr: fn(s, t: string): (string, string); take: fn(s, cl: string): string; tobig: fn(s: string, base: int): (big, string); toint: fn(s: string, base: int): (int, string); toreal: fn(s: string, base: int): (real, string); tolower: fn(s: string): string; toupper: fn(s: string): string; quoted: fn(args: list of string): string; unquoted: fn(s: string): list of string; .EE .SH DESCRIPTION The .I cl argument to some of these functions is a character class in which a .B - between any two characters indicates a range and a .B ^ in the first position means .I not in the class. Example of classes are .B \&"a-zA-Z" and .B \&"^acg-mr"\c \&. .PP .B Append appends string .I s to the end of string list .IR l . .PP .B Drop removes the maximal prefix of string .I s that is in class .IR cl . .PP .B In returns 1 if character .I c is in class .I cl and 0 if it is not. .PP .B Prefix returns 1 if string .I pre is a prefix of string .I s and 0 if it is not. .PP .B Splitl splits string .I s just before the first character in class .IR cl . .PP .B Splitr splits string .I s just after the last character in class .IR cl . .PP .B Splitstrl splits string .I s just before the leftmost segment of string .I s that consists entirely of string .IR t , and returns a tuple with the resulting pair of strings. If .I t does not occur in .IR s , the result is .RI ( s , nil ). .PP .B Splitstrr splits string .I s just after the rightmost segment of string .I s that consists entirely of string .IR t , and returns a tuple with the resulting pair of strings. If .I t does not occur in .IR s , the result is .RI ( nil, s ). .PP .B Take returns the maximal prefix of string .I s that is in class .IR cl . .PP .B Toint returns as an integer the value represented by the string .IR s . The string is scanned up to the first character inconsistent with .IR base . The first inconsistent character marks the beginning of the returned string. Leading white-space characters are ignored. The .I base can be any integer in the range 2 to 36, inclusive; or 0 in which case the base can be specified as part of the string, in Limbo style (e.g. 16rffff). .PP .B Tobig has the same specification as .B toint except that converts to 64-bit .BR big . .PP .B Toreal is similar to .BR toint , except that it expects a floating-point number after optional leading white space: an optional sign, then a string of digits containing a decimal point, then an optional .RB ` e ' or .RB ` E ' followed by an optionally signed decimal integer exponent. The string of digits can optionally be preceded by a base (radix) specifier of the form .IB B r , as for integers. Any exponent is then interpreted as a power of that base. Alternatively, following any leading white space and an optional sign, either .B nan or .B infinity can appear, in any case, and .B toreal will return the appropriate value for IEEE floating-point. .PP .B Tolower converts all upper case letters in the string .I s to lower case letters. .PP .B Toupper converts all lower case letters in the string .I s to upper case letters. .PP .B Quoted takes a list of strings, .IR args , and returns a single string with the value of each element of .I args separated from the next by a single space. When forming the string, the text of any element that contains white space or single quotes is first quoted by surrounding it by single quotes .RB ( ' ... ' ) within which each existing single quote is doubled .RB ( '' ), following the conventions of .IR sh (1). .PP .B Unquoted takes a string .IR s , quoted according to the conventions of .BR quoted , and splits it into separate strings. It splits the string at each maximal sequence of unquoted white space (blank, newline or tab), stripping single quotes except where paired, to form the corresponding list of strings, which it returns. .SH SOURCE .B /appl/lib/string.b