fn expand_vars(source: &str) -> Result<String, ArgumentError> {
    let mut expanded = String::new();
    let mut chars = source.chars().enumerate().peekable();
    let mut last = 0;

    while let Some((i, c)) = chars.next() {
        match c {
            '$' => {
                if i != 0 {
                    expanded.push_str(&source[last..i]);
                }

                let (name, next) = match chars.peek() {
                    None => return Err(ArgumentError::UnterminatedSequence('$')),
                    Some((_, '{')) => {
                        if let Some(n) = source[i + 1..].find('}') {
                            (&source[i + 2..i + n + 1], i + n + 2)
                        } else {
                            return Err(ArgumentError::UnterminatedSequence('{'));
                        }
                    }
                    Some((_, _)) => {
                        if let Some(n) =
                            source[i + 1..].find(|c: char| !c.is_alphanumeric() && c != '_')
                        {
                            (&source[i + 1..i + n + 1], i + n + 1)
                        } else {
                            (&source[i + 1..], source.len())
                        }
                    }
                };
                let value = env::var(name).unwrap_or_else(|_| String::new());

                expanded.push_str(value.as_str());

                last = next;
            }
            '\'' => {
                chars.find(|(_, c)| *c == '\'');
            }
            _ => { /* do nothing */ }
        }
    }

    if last < source.len() {
        expanded.push_str(&source[last..]);
    }

    Ok(expanded)
}
/// Expand all found parameter expansions, bot in and outside of double quotes.
Expand all found parameter expansions, bot in and outside of double quotes.
Expand all found parameter expansions bot in and outside of double quotes .
fn expand_vars(source: &str) -> Result<String, ArgumentError> {
    let mut expanded = String::new();
    let mut chars = source.chars().enumerate().peekable();
    let mut last = 0;
    while let Some((i, c)) = chars.next() {
        match c {
            '$' => {
                if i != 0 {
                    expanded.push_str(&source[last..i]);
                }
                let (name, next) = match chars.peek() {
                    None => return Err(ArgumentError::UnterminatedSequence('$')),
                    Some((_, '{')) => {
                        if let Some(n) = source[i + 1..].find('}') {
                            (&source[i + 2..i + n + 1], i + n + 2)
                        } else {
                            return Err(ArgumentError::UnterminatedSequence('{'));
                        }
                    }
                    Some((_, _)) => {
                        if let Some(n) =
                            source[i + 1..].find(|c: char| !c.is_alphanumeric() && c != '_')
                        {
                            (&source[i + 1..i + n + 1], i + n + 1)
                        } else {
                            (&source[i + 1..], source.len())
                        }
                    }
                };
                let value = env::var(name).unwrap_or_else(|_| String::new());
                expanded.push_str(value.as_str());
                last = next;
            }
            '\'' => {
                chars.find(|(_, c)| *c == '\'');
            }
            _ => { /* do nothing */ }
        }
    }
    if last < source.len() {
        expanded.push_str(&source[last..]);
    }
    Ok(expanded)
}
fn expand_vars ( source : & str ) -> Result < String , ArgumentError > { let mut expanded = String :: new ( ) ; let mut chars = source . chars ( ) . enumerate ( ) . peekable ( ) ; let mut last = 0 ; while let Some ( ( i , c ) ) = chars . next ( ) { match c { '$' => { if i != 0 { expanded . push_str ( & source [ last .. i ] ) ; } let ( name , next ) = match chars . peek ( ) { None => return Err ( ArgumentError :: UnterminatedSequence ( '$' ) ) , Some ( ( _ , '{' ) ) => { if let Some ( n ) = source [ i + 1 .. ] . find ( '}' ) { ( & source [ i + 2 .. i + n + 1 ] , i + n + 2 ) } else { return Err ( ArgumentError :: UnterminatedSequence ( '{' ) ) ; } } Some ( ( _ , _ ) ) => { if let Some ( n ) = source [ i + 1 .. ] . find ( | c : char | ! c . is_alphanumeric ( ) && c != '_' ) { ( & source [ i + 1 .. i + n + 1 ] , i + n + 1 ) } else { ( & source [ i + 1 .. ] , source . len ( ) ) } } } ; let value = env :: var ( name ) . unwrap_or_else ( | _ | String :: new ( ) ) ; expanded . push_str ( value . as_str ( ) ) ; last = next ; } '\'' => { chars . find ( | ( _ , c ) | * c == '\'' ) ; } _ => { /* do nothing */ } } } if last < source . len ( ) { expanded . push_str ( & source [ last .. ] ) ; } Ok ( expanded ) }
Expand all found parameter expansions, bot in and outside of double quotes.
Expand all found parameter expansions bot in and outside of double quotes .
source
&str