rsspice 0.1.0

Pure Rust port of the SPICE Toolkit for space geometry
Documentation
//
// GENERATED FILE
//

use super::*;
use crate::SpiceContext;
use f2rust_std::*;

/// Position of substring
///
/// Find the first occurrence in a string of a substring, starting at
/// a specified location, searching forward.
///
/// # Required Reading
///
/// * [SCANNING](crate::required_reading::scanning)
///
/// # Brief I/O
///
/// ```text
///  VARIABLE  I/O  DESCRIPTION
///  --------  ---  --------------------------------------------------
///  STR        I   A character string
///  SUBSTR     I   Substring to locate in the character string.
///  START      I   Where to start looking for SUBSTR in STR.
///
///  The function returns the index of SUBSTR in STR following START
/// ```
///
/// # Detailed Input
///
/// ```text
///  STR      is any character string.
///
///  SUBSTR   is a substring to look for in STR. Spaces in
///           SUBSTR are significant.
///
///  START    is the position in STR to begin looking for SUBSTR.
/// ```
///
/// # Detailed Output
///
/// ```text
///  The function returns the index of the beginning of the first
///  substring of STR that begins on or after index START and is equal
///  to SUBSTR. If the substring cannot be found after START, the
///  function is returns 0.
/// ```
///
/// # Exceptions
///
/// ```text
///  Error free.
///
///  1)  If START is less than 1, the search begins at the first
///      character of the string.
///
///  2)  If START is greater than the length of the string, POS
///      returns zero.
/// ```
///
/// # Particulars
///
/// ```text
///  POS is case sensitive.
///
///  An entire family of related SPICELIB routines (POS, CPOS, NCPOS,
///  POSR, CPOSR, NCPOSR) is described in the Required Reading.
///
///  Those familiar with the .TRUE. BASIC language should note that
///  these functions are equivalent to the .TRUE. BASIC intrinsic
///  functions with the same names.
/// ```
///
/// # Examples
///
/// ```text
///  Let STRING = 'AN ANT AND AN ELEPHANT        '
///                123456789012345678901234567890
///
///   Normal (Sequential) Searching:
///   ------------------------------
///
///         POS ( STRING, 'AN',  1 ) =  1
///         POS ( STRING, 'AN',  3 ) =  4
///         POS ( STRING, 'AN',  6 ) =  8
///         POS ( STRING, 'AN', 10 ) = 12
///         POS ( STRING, 'AN', 14 ) = 20
///         POS ( STRING, 'AN', 22 ) =  0
///
///   START out of bounds:
///   --------------------
///
///         POS ( STRING, 'AN', -5 ) =  1
///         POS ( STRING, 'AN',  0 ) =  1
///         POS ( STRING, 'AN', 31 ) =  0
///         POS ( STRING, 'AN', 44 ) =  0
///
///   Significance of Spaces:
///   -----------------------
///
///         POS ( STRING, 'AN',    1 ) =  1
///         POS ( STRING, ' AN',   1 ) =  3
///         POS ( STRING, ' AN ',  1 ) = 11
///         POS ( STRING, ' AN  ', 1 ) =  0
/// ```
///
/// # Author and Institution
///
/// ```text
///  J. Diaz del Rio    (ODC Space)
///  H.A. Neilan        (JPL)
///  B.V. Semenov       (JPL)
///  W.L. Taber         (JPL)
/// ```
///
/// # Version
///
/// ```text
/// -    SPICELIB Version 1.1.0, 04-JUL-2021 (JDR)
///
///         Added IMPLICIT NONE statement.
///
///         Edited the header to comply with NAIF standard.
///
/// -    SPICELIB Version 1.0.3, 31-JAN-2008 (BVS)
///
///         Removed non-standard end-of-declarations marker
///         'C%&END_DECLARATIONS' from comments.
///
/// -    SPICELIB Version 1.0.2, 10-MAR-1992 (WLT)
///
///         Comment section for permuted index source lines was added
///         following the header.
///
/// -    SPICELIB Version 1.0.1, 26-MAR-1991 (HAN)
///
///         The Required Reading file POSITION was renamed to SCANNING.
///         This header was updated to reflect the change.
///
/// -    SPICELIB Version 1.0.0, 31-JAN-1990 (WLT)
/// ```
pub fn pos(str: &str, substr: &str, start: i32) -> i32 {
    let ret = POS(str.as_bytes(), substr.as_bytes(), start);
    ret
}

//$Procedure POS ( Position of substring )
pub fn POS(STR: &[u8], SUBSTR: &[u8], START: i32) -> i32 {
    let mut POS: i32 = 0;
    let mut FOUND: bool = false;
    let mut LENSTR: i32 = 0;
    let mut OFFSET: i32 = 0;
    let mut LCHNCE: i32 = 0;
    let mut B: i32 = 0;

    //
    // Local variables
    //

    //
    // Let's find out how big every body is.
    //
    LENSTR = intrinsics::LEN(STR);
    OFFSET = intrinsics::MAX0(&[0, (intrinsics::LEN(SUBSTR) - 1)]);
    LCHNCE = (LENSTR - OFFSET);

    B = intrinsics::MAX0(&[1, START]);

    //
    // Look for the string until we run find it or run out of room to
    // look.
    //
    FOUND = false;
    POS = 0;

    while !FOUND {
        if (B > LCHNCE) {
            return POS;
        } else if fstr::eq(fstr::substr(STR, B..=(B + OFFSET)), SUBSTR) {
            POS = B;
            return POS;
        } else {
            B = (B + 1);
        }
    }

    POS
}