began work on implementing those weird variable string op things

This commit is contained in:
2025-05-12 01:04:53 -04:00
parent cc8d384704
commit 2666670939
2 changed files with 289 additions and 25 deletions

View File

@@ -1,6 +1,9 @@
use std::collections::HashSet;
use std::str::FromStr;
use crate::state::{read_vars, write_meta, LogTab};
use glob::Pattern;
use crate::state::{read_vars, write_meta, write_vars, LogTab};
use crate::procio::{IoBuf, IoFrame, IoMode};
use crate::prelude::*;
use crate::parse::{Redir, RedirType};
@@ -122,7 +125,7 @@ impl Expander {
}
'{' if var_name.is_empty() => in_brace = true,
'}' if in_brace => {
let var_val = read_vars(|v| v.get_var(&var_name));
let var_val = perform_param_expansion(&var_name)?;
result.push_str(&var_val);
var_name.clear();
break
@@ -321,6 +324,256 @@ pub fn unescape_str(raw: &str) -> String {
result
}
pub enum ParamExp {
Len, // #var_name
DefaultUnsetOrNull(String), // :-
DefaultUnset(String), // -
SetDefaultUnsetOrNull(String), // :=
SetDefaultUnset(String), // =
AltSetNotNull(String), // :+
AltNotNull(String), // +
ErrUnsetOrNull(String), // :?
ErrUnset(String), // ?
Substr(usize), // :pos
SubstrLen(usize,usize), // :pos:len
RemShortestPrefix(String), // #pattern
RemLongestPrefix(String), // ##pattern
RemShortestSuffix(String), // %pattern
RemLongestSuffix(String), // %%pattern
ReplaceFirstMatch(String,String), // /search/replace
ReplaceAllMatches(String,String), // //search/replace
ReplacePrefix(String,String), // #search/replace
ReplaceSuffix(String,String), // %search/replace
VarNamesWithSuffix(String), // !prefix@ || !prefix*
ExpandInnerVar(String), // !var
}
impl FromStr for ParamExp {
type Err = ShErr;
fn from_str(s: &str) -> Result<Self, Self::Err> {
use ParamExp::*;
let parse_err = || Err(ShErr::Simple {
kind: ShErrKind::SyntaxErr,
msg: "Invalid parameter expansion".into(),
notes: vec![],
});
// Handle indirect var expansion: ${!var}
if let Some(var) = s.strip_prefix('!') {
if var.ends_with('*') || var.ends_with('@') {
return Ok(VarNamesWithSuffix(var.to_string()));
}
return Ok(ExpandInnerVar(var.to_string()));
}
// Pattern removals
if let Some(rest) = s.strip_prefix("##") {
return Ok(RemLongestPrefix(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('#') {
return Ok(RemShortestPrefix(rest.to_string()));
}
if let Some(rest) = s.strip_prefix("%%") {
return Ok(RemLongestSuffix(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('%') {
return Ok(RemShortestSuffix(rest.to_string()));
}
// Replacements
if let Some(rest) = s.strip_prefix("//") {
let mut parts = rest.splitn(2, '/');
let pattern = parts.next().unwrap_or("");
let repl = parts.next().unwrap_or("");
return Ok(ReplaceAllMatches(pattern.to_string(), repl.to_string()));
}
if let Some(rest) = s.strip_prefix('/') {
let mut parts = rest.splitn(2, '/');
let pattern = parts.next().unwrap_or("");
let repl = parts.next().unwrap_or("");
return Ok(ReplaceFirstMatch(pattern.to_string(), repl.to_string()));
}
// Fallback / assignment / alt
if let Some(rest) = s.strip_prefix(":-") {
return Ok(DefaultUnsetOrNull(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('-') {
return Ok(DefaultUnset(rest.to_string()));
} else if let Some(rest) = s.strip_prefix(":+") {
return Ok(AltSetNotNull(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('+') {
return Ok(AltNotNull(rest.to_string()));
} else if let Some(rest) = s.strip_prefix(":=") {
return Ok(SetDefaultUnsetOrNull(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('=') {
return Ok(SetDefaultUnset(rest.to_string()));
} else if let Some(rest) = s.strip_prefix(":?") {
return Ok(ErrUnsetOrNull(rest.to_string()));
} else if let Some(rest) = s.strip_prefix('?') {
return Ok(ErrUnset(rest.to_string()));
}
// Substring
if let Some((pos, len)) = parse_pos_len(s) {
return Ok(match len {
Some(l) => SubstrLen(pos, l),
None => Substr(pos),
});
}
parse_err()
}
}
pub fn parse_pos_len(s: &str) -> Option<(usize, Option<usize>)> {
let raw = s.strip_prefix(':')?;
if let Some((start,len)) = raw.split_once(':') {
Some((
start.parse::<usize>().ok()?,
len.parse::<usize>().ok(),
))
} else {
Some((
raw.parse::<usize>().ok()?,
None,
))
}
}
pub fn perform_param_expansion(raw: &str) -> ShResult<String> {
let vars = read_vars(|v| v.clone());
let mut chars = raw.chars();
let mut var_name = String::new();
let mut rest = String::new();
if raw.starts_with('#') {
return Ok(vars.get_var(raw.strip_prefix('#').unwrap()).len().to_string())
}
while let Some(ch) = chars.next() {
match ch {
'!' |
'#' |
'%' |
':' |
'-' |
'+' |
'=' |
'?' => {
rest = chars.collect();
break
}
_ => var_name.push(ch)
}
}
if let Ok(expansion) = rest.parse::<ParamExp>() {
match expansion {
ParamExp::Len => unreachable!(),
ParamExp::DefaultUnsetOrNull(default) => {
if !vars.var_exists(&var_name) || vars.get_var(&var_name).is_empty() {
Ok(default)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::DefaultUnset(default) => {
if !vars.var_exists(&var_name) {
Ok(default)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::SetDefaultUnsetOrNull(default) => {
if !vars.var_exists(&var_name) || vars.get_var(&var_name).is_empty() {
write_vars(|v| v.set_var(&var_name, &default, false));
Ok(default)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::SetDefaultUnset(default) => {
if !vars.var_exists(&var_name) {
write_vars(|v| v.set_var(&var_name, &default, false));
Ok(default)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::AltSetNotNull(alt) => {
if vars.var_exists(&var_name) && !vars.get_var(&var_name).is_empty() {
Ok(alt)
} else {
Ok("".into())
}
}
ParamExp::AltNotNull(alt) => {
if vars.var_exists(&var_name) {
Ok(alt)
} else {
Ok("".into())
}
}
ParamExp::ErrUnsetOrNull(err) => {
if !vars.var_exists(&var_name) || vars.get_var(&var_name).is_empty() {
Err(
ShErr::Simple { kind: ShErrKind::ExecFail, msg: err, notes: vec![] }
)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::ErrUnset(err) => {
if !vars.var_exists(&var_name) {
Err(
ShErr::Simple { kind: ShErrKind::ExecFail, msg: err, notes: vec![] }
)
} else {
Ok(vars.get_var(&var_name))
}
}
ParamExp::Substr(pos) => {
let value = vars.get_var(&var_name);
if let Some(substr) = value.get(pos..) {
Ok(substr.to_string())
} else {
Ok(value)
}
}
ParamExp::SubstrLen(pos, len) => {
let value = vars.get_var(&var_name);
let end = pos.saturating_add(len);
if let Some(substr) = value.get(pos..end) {
Ok(substr.to_string())
} else {
Ok(value)
}
}
ParamExp::RemShortestPrefix(prefix) => {
let value = vars.get_var(&var_name);
let pattern = Pattern::new(&prefix).unwrap();
for i in 0..=value.len() {
let sliced = &value[..i];
if pattern.matches(sliced) {
return Ok(value[i..].to_string())
}
}
Ok(value)
}
ParamExp::RemLongestPrefix(prefix) => todo!(),
ParamExp::RemShortestSuffix(suffix) => todo!(),
ParamExp::RemLongestSuffix(suffix) => todo!(),
ParamExp::ReplaceFirstMatch(search, replace) => todo!(),
ParamExp::ReplaceAllMatches(search, replace) => todo!(),
ParamExp::ReplacePrefix(search, replace) => todo!(),
ParamExp::ReplaceSuffix(search, replace) => todo!(),
ParamExp::VarNamesWithSuffix(suffix) => todo!(),
ParamExp::ExpandInnerVar(var_name) => todo!(),
}
} else {
Ok(vars.get_var(&var_name))
}
}
#[derive(Debug)]
pub enum PromptTk {
AsciiOct(i32),