1 (** Shared string utility functions. 2 3 Centralizes whitespace handling to avoid duplication across prescan, lexer, 4 and normalization modules. *) 5 6 (** Strip leading whitespace (spaces and tabs). *) 7 let lstrip s = 8 let len = String.length s in 9 let i = ref 0 in 10 while !i < len && (s.[!i] = ' ' || s.[!i] = '\t') do 11 incr i 12 done; 13 if !i = 0 then s else String.sub s !i (len - !i) 14 15 (** Strip trailing whitespace (spaces, tabs, and carriage returns). *) 16 let rstrip s = 17 let len = String.length s in 18 let i = ref (len - 1) in 19 while !i >= 0 && (s.[!i] = ' ' || s.[!i] = '\t' || s.[!i] = '\r') do 20 decr i 21 done; 22 if !i = len - 1 then s else String.sub s 0 (!i + 1) 23 24 (** Strip both leading and trailing whitespace. *) 25 let strip s = lstrip (rstrip s) 26