feat(external-packages,shim): implement impl todos across components

Port seld/jsonlint JsonParser (+hand-written Lexer), unblocking 10 json_file
parse-error tests verified byte-for-byte against PHP. Implement Symfony Finder
SplFileInfo, executable finders, String classes (byte/code-point/unicode),
ZipArchive shim (via the zip crate), SPDX license validation, and shim
date/stream functions. Genuinely-blocked sites (reflection, PHP runtime
constants, non-UTF-8 transcoding, recursive PCRE) stay todo!() with reasons.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

10 files changed, 1928 insertions, 33 deletions

diff --git a/crates/shirabe-external-packages/src/seld/json_lint/json_parser.rs b/crates/shirabe-external-packages/src/seld/json_lint/json_parser.rs
index 193a208..6607938 100644
--- a/crates/shirabe-external-packages/src/seld/json_lint/json_parser.rs
+++ b/crates/shirabe-external-packages/src/seld/json_lint/json_parser.rs
@@ -1,9 +1,71 @@
 //! ref: composer/vendor/seld/jsonlint/src/Seld/JsonLint/JsonParser.php
 
+use std::collections::HashMap;
+
+use indexmap::IndexMap;
 use shirabe_php_shim::PhpMixed;
 
+use super::DuplicateKeyException;
+use super::ParsingException;
+use super::lexer::{Lexer, YylLoc};
+
+/// Semantic value held on the parser value stack ($vstack). Most values are JSON values (PhpMixed),
+/// but object members are represented as a `[key, value]` pair while being reduced.
+#[derive(Debug, Clone)]
+enum SemValue {
+    Null,
+    Value(PhpMixed),
+    /// Raw token text from the lexer (yytext), before semantic actions transform it.
+    Text(String),
+    /// A `[key, value]` member pair (production 15).
+    Member(String, PhpMixed),
+}
+
+impl SemValue {
+    fn into_value(self) -> PhpMixed {
+        match self {
+            SemValue::Null => PhpMixed::Null,
+            SemValue::Value(v) => v,
+            SemValue::Text(s) => PhpMixed::String(s),
+            SemValue::Member(_, _) => PhpMixed::Null,
+        }
+    }
+}
+
+/// Result of `performAction`: the new semantic value plus an optional early-return (production 6).
+enum ActionResult {
+    /// `$$` was assigned but parsing continues (PHP returns `[token, new Undefined()]`).
+    Continue(SemValue),
+    /// Production 6 returned the accumulated value directly.
+    Return(PhpMixed),
+}
+
+#[derive(Debug)]
+pub struct JsonParser {
+    productions_: HashMap<i64, (i64, i64)>,
+    terminals_: HashMap<i64, &'static str>,
+    table: Vec<HashMap<i64, TableAction>>,
+    default_actions: HashMap<i64, (i64, i64)>,
+}
+
+/// Per-parse mutable state. PHP keeps `$flags`/`$stack`/`$vstack`/`$lstack` on the parser instance;
+/// holding them here keeps `parse()` `&self` so the parser can be shared/reused.
 #[derive(Debug)]
-pub struct JsonParser;
+struct ParseState {
+    flags: u32,
+    stack: Vec<i64>,
+    vstack: Vec<SemValue>,
+    lstack: Vec<YylLoc>,
+}
+
+/// An entry in the parse table: either a shift/reduce action pair `[type, arg]` or a goto state.
+#[derive(Debug, Clone, Copy)]
+enum TableAction {
+    /// `array(type, arg)` — type 1 = shift, 2 = reduce, 3 = accept.
+    Action(i64, i64),
+    /// A bare integer = goto state (used for nonterminals).
+    Goto(i64),
+}
 
 impl Default for JsonParser {
     fn default() -> Self {
@@ -13,17 +75,972 @@ impl Default for JsonParser {
 
 impl JsonParser {
     pub const DETECT_KEY_CONFLICTS: u32 = 1;
+    pub const ALLOW_DUPLICATE_KEYS: u32 = 2;
+    pub const PARSE_TO_ASSOC: u32 = 4;
+    pub const ALLOW_COMMENTS: u32 = 8;
+    pub const ALLOW_DUPLICATE_KEYS_TO_ARRAY: u32 = 16;
 
     pub fn new() -> Self {
-        todo!()
+        let productions_: HashMap<i64, (i64, i64)> = [
+            (1, (3, 1)),
+            (2, (5, 1)),
+            (3, (7, 1)),
+            (4, (9, 1)),
+            (5, (9, 1)),
+            (6, (12, 2)),
+            (7, (13, 1)),
+            (8, (13, 1)),
+            (9, (13, 1)),
+            (10, (13, 1)),
+            (11, (13, 1)),
+            (12, (13, 1)),
+            (13, (15, 2)),
+            (14, (15, 3)),
+            (15, (20, 3)),
+            (16, (19, 1)),
+            (17, (19, 3)),
+            (18, (16, 2)),
+            (19, (16, 3)),
+            (20, (25, 1)),
+            (21, (25, 3)),
+        ]
+        .into_iter()
+        .collect();
+
+        let terminals_: HashMap<i64, &'static str> = [
+            (2, "error"),
+            (4, "STRING"),
+            (6, "NUMBER"),
+            (8, "NULL"),
+            (10, "TRUE"),
+            (11, "FALSE"),
+            (14, "EOF"),
+            (17, "{"),
+            (18, "}"),
+            (21, ":"),
+            (22, ","),
+            (23, "["),
+            (24, "]"),
+        ]
+        .into_iter()
+        .collect();
+
+        let table = build_table();
+
+        let default_actions: HashMap<i64, (i64, i64)> = [(16, (2, 6))].into_iter().collect();
+
+        Self {
+            productions_,
+            terminals_,
+            table,
+            default_actions,
+        }
+    }
+
+    /// ref: JsonParser::lint() — returns null on success, ParsingException on failure.
+    pub fn lint(&mut self, input: &str) -> Option<ParsingException> {
+        match self.parse(input, 0) {
+            Ok(_) => None,
+            Err(e) => match e.downcast::<ParsingException>() {
+                Ok(pe) => Some(pe),
+                // PHP only catches ParsingException; DuplicateKeyException (a subclass) is also
+                // caught, but lint() uses no flags so DETECT_KEY_CONFLICTS never triggers.
+                Err(other) => Some(ParsingException::new(other.to_string(), Default::default())),
+            },
+        }
+    }
+
+    pub fn parse(&self, input: &str, flags: u32) -> anyhow::Result<PhpMixed> {
+        if (flags & Self::ALLOW_DUPLICATE_KEYS_TO_ARRAY != 0)
+            && (flags & Self::ALLOW_DUPLICATE_KEYS != 0)
+        {
+            // PHP throws \InvalidArgumentException (uncaught fatal).
+            panic!(
+                "Only one of ALLOW_DUPLICATE_KEYS and ALLOW_DUPLICATE_KEYS_TO_ARRAY can be used, you passed in both."
+            );
+        }
+
+        self.fail_on_bom(input)?;
+
+        let mut state_ = ParseState {
+            flags,
+            stack: vec![0],
+            vstack: vec![SemValue::Null],
+            lstack: Vec::new(),
+        };
+
+        let mut yytext = String::new();
+        let mut yylineno: i64 = 0;
+        let mut yyleng: i64 = 0;
+        let mut recovering: i64 = 0;
+
+        let mut lexer = Lexer::new(flags);
+        lexer.set_input(input);
+
+        let mut yyloc = lexer.yylloc.clone();
+        state_.lstack.push(yyloc.clone());
+
+        let mut symbol: Option<i64> = None;
+        let mut pre_error_symbol: Option<i64> = None;
+        let mut err_str: Option<String> = None;
+
+        loop {
+            let mut state = state_.stack[state_.stack.len() - 1];
+
+            // use default actions if available
+            let mut action: Option<(i64, i64)> = if let Some(a) = self.default_actions.get(&state) {
+                Some(*a)
+            } else {
+                if symbol.is_none() {
+                    symbol = Some(lexer.lex()?);
+                }
+                self.table[state as usize]
+                    .get(&symbol.unwrap())
+                    .and_then(|a| match *a {
+                        TableAction::Action(t, arg) => Some((t, arg)),
+                        TableAction::Goto(_) => None,
+                    })
+            };
+
+            // handle parse error
+            if action.is_none() || action.unwrap().0 == 0 {
+                let sym = symbol.expect("symbol should be set");
+                if recovering == 0 {
+                    // PHP iterates table entries in insertion order; mimic by sorting on symbol id.
+                    let mut expected_pairs: Vec<(i64, String)> = self.table[state as usize]
+                        .keys()
+                        .filter_map(|p| {
+                            self.terminals_
+                                .get(p)
+                                .filter(|_| *p > 2)
+                                .map(|name| (*p, format!("'{name}'")))
+                        })
+                        .collect();
+                    expected_pairs.sort_by_key(|(p, _)| *p);
+                    let expected: Vec<String> =
+                        expected_pairs.into_iter().map(|(_, s)| s).collect();
+
+                    let mut message: Option<String> = None;
+                    let match_first = lexer.match_.first().copied();
+                    if expected.iter().any(|e| e == "'STRING'")
+                        && matches!(match_first, Some(b'"') | Some(b'\''))
+                    {
+                        let mut msg = String::from("Invalid string");
+                        if match_first == Some(b'\'') {
+                            msg.push_str(
+                                ", it appears you used single quotes instead of double quotes",
+                            );
+                        } else if let Some(found) =
+                            detect_unescaped_backslash(&lexer.get_full_upcoming_input())
+                        {
+                            msg.push_str(", it appears you have an unescaped backslash at: ");
+                            msg.push_str(&found);
+                        } else if detect_unterminated_string(&lexer.get_full_upcoming_input()) {
+                            msg.push_str(", it appears you forgot to terminate a string, or attempted to write a multiline string which is invalid");
+                        }
+                        message = Some(msg);
+                    }
+
+                    let mut errstr = format!("Parse error on line {}:\n", yylineno + 1);
+                    errstr.push_str(&lexer.show_position());
+                    errstr.push('\n');
+                    if let Some(msg) = &message {
+                        errstr.push_str(msg);
+                    } else {
+                        errstr.push_str(if expected.len() > 1 {
+                            "Expected one of: "
+                        } else {
+                            "Expected: "
+                        });
+                        errstr.push_str(&expected.join(", "));
+                    }
+
+                    let past = lexer.get_past_input();
+                    let trimmed = trim_bytes(&past);
+                    if trimmed.last() == Some(&b',') {
+                        errstr.push_str(" - It appears you have an extra trailing comma");
+                    }
+
+                    err_str = Some(errstr.clone());
+
+                    let token = if let Some(name) = self.terminals_.get(&sym) {
+                        super::parsing_exception::ParsingExceptionToken::Name(name.to_string())
+                    } else {
+                        super::parsing_exception::ParsingExceptionToken::Symbol(sym)
+                    };
+                    let details = super::parsing_exception::ParsingExceptionDetails {
+                        text: Some(String::from_utf8_lossy(&lexer.match_).into_owned()),
+                        token: Some(token),
+                        line: Some(lexer.yylineno),
+                        loc: Some(yyloc_to_loc(&yyloc)),
+                        expected: Some(expected.clone()),
+                    };
+                    return Err(ParsingException::new(errstr, details).into());
+                }
+
+                // recovery path (recovering != 0). Not reachable for this grammar because the error
+                // is always reported (and thrown) above on the first failure; kept for fidelity.
+                if recovering == 3 {
+                    if sym == Lexer::EOF {
+                        return Err(ParsingException::new(
+                            err_str.clone().unwrap_or_else(|| "Parsing halted.".into()),
+                            Default::default(),
+                        )
+                        .into());
+                    }
+                    yyleng = lexer.yyleng;
+                    yytext = String::from_utf8_lossy(&lexer.yytext).into_owned();
+                    yylineno = lexer.yylineno;
+                    yyloc = lexer.yylloc.clone();
+                    symbol = Some(lexer.lex()?);
+                }
+
+                loop {
+                    if self.table[state as usize].contains_key(&Lexer::T_ERROR) {
+                        break;
+                    }
+                    if state == 0 {
+                        return Err(ParsingException::new(
+                            err_str.clone().unwrap_or_else(|| "Parsing halted.".into()),
+                            Default::default(),
+                        )
+                        .into());
+                    }
+                    state_.pop_stack(1);
+                    state = state_.stack[state_.stack.len() - 1];
+                }
+
+                pre_error_symbol = symbol;
+                symbol = Some(Lexer::T_ERROR);
+                state = state_.stack[state_.stack.len() - 1];
+                action = self.table[state as usize]
+                    .get(&Lexer::T_ERROR)
+                    .and_then(|a| match *a {
+                        TableAction::Action(t, arg) => Some((t, arg)),
+                        TableAction::Goto(_) => None,
+                    });
+                if action.is_none() {
+                    panic!("No table value found for {} => {}", state, Lexer::T_ERROR);
+                }
+                recovering = 3;
+            }
+
+            let action = action.unwrap();
+            match action.0 {
+                1 => {
+                    // shift
+                    let sym = symbol.expect("symbol should be set");
+                    state_.stack.push(sym);
+                    state_.vstack.push(SemValue::Text(
+                        String::from_utf8_lossy(&lexer.yytext).into_owned(),
+                    ));
+                    state_.lstack.push(lexer.yylloc.clone());
+                    state_.stack.push(action.1);
+                    symbol = None;
+                    if pre_error_symbol.is_none() {
+                        yyleng = lexer.yyleng;
+                        yytext = String::from_utf8_lossy(&lexer.yytext).into_owned();
+                        yylineno = lexer.yylineno;
+                        yyloc = lexer.yylloc.clone();
+                        if recovering > 0 {
+                            recovering -= 1;
+                        }
+                    } else {
+                        symbol = pre_error_symbol;
+                        pre_error_symbol = None;
+                    }
+                }
+                2 => {
+                    // reduce
+                    let prod = self.productions_[&action.1];
+                    let len = prod.1;
+
+                    let position = YylLoc {
+                        first_line: state_.lstack[state_.lstack.len() - (len.max(1) as usize)]
+                            .first_line,
+                        last_line: state_.lstack[state_.lstack.len() - 1].last_line,
+                        first_column: state_.lstack[state_.lstack.len() - (len.max(1) as usize)]
+                            .first_column,
+                        last_column: state_.lstack[state_.lstack.len() - 1].last_column,
+                    };
+
+                    match state_.perform_action(&yytext, yyleng, yylineno, action.1)? {
+                        ActionResult::Return(v) => return Ok(v),
+                        ActionResult::Continue(new_token) => {
+                            if len != 0 {
+                                state_.pop_stack(len);
+                            }
+                            state_.stack.push(prod.0);
+                            state_.vstack.push(new_token);
+                            state_.lstack.push(position);
+                            let goto_state = match self.table
+                                [state_.stack[state_.stack.len() - 2] as usize]
+                                .get(&state_.stack[state_.stack.len() - 1])
+                            {
+                                Some(TableAction::Goto(s)) => *s,
+                                Some(TableAction::Action(_, arg)) => *arg,
+                                None => panic!("No goto state"),
+                            };
+                            state_.stack.push(goto_state);
+                        }
+                    }
+                }
+                3 => {
+                    // accept
+                    return Ok(PhpMixed::Bool(true));
+                }
+                _ => {}
+            }
+        }
+    }
+
+    fn fail_on_bom(&self, input: &str) -> Result<(), ParsingException> {
+        let bom = [0xEF, 0xBB, 0xBF];
+        if input.as_bytes().len() >= 3 && input.as_bytes()[0..3] == bom {
+            return Err(ParsingException::new(
+                "BOM detected, make sure your input does not include a Unicode Byte-Order-Mark"
+                    .to_string(),
+                Default::default(),
+            ));
+        }
+        Ok(())
+    }
+}
+
+impl ParseState {
+    /// ref: JsonParser::performAction
+    fn perform_action(
+        &mut self,
+        _yytext: &str,
+        _yyleng: i64,
+        yylineno: i64,
+        yystate: i64,
+    ) -> anyhow::Result<ActionResult> {
+        // `$len = count($vstack) - 1` indexes the top semantic value.
+        let len = self.vstack.len() - 1;
+        // default: $$ = $1, the value at (count - production_len) ; PHP captures `$currentToken`
+        // separately, but for productions we rebuild explicitly below, defaulting to the top value.
+        let mut token: SemValue = self.vstack[len].clone();
+
+        match yystate {
+            1 => {
+                // string interpolation of escape sequences
+                let raw = match &self.vstack[len] {
+                    SemValue::Text(s) => s.clone(),
+                    other => semvalue_string(other),
+                };
+                token = SemValue::Value(PhpMixed::String(string_interpolation_all(&raw)));
+            }
+            2 => {
+                let raw = match &self.vstack[len] {
+                    SemValue::Text(s) => s.clone(),
+                    other => semvalue_string(other),
+                };
+                let v = if raw.contains('e') || raw.contains('E') {
+                    PhpMixed::Float(php_floatval(&raw))
+                } else if !raw.contains('.') {
+                    PhpMixed::Int(php_intval(&raw))
+                } else {
+                    PhpMixed::Float(php_floatval(&raw))
+                };
+                token = SemValue::Value(v);
+            }
+            3 => token = SemValue::Value(PhpMixed::Null),
+            4 => token = SemValue::Value(PhpMixed::Bool(true)),
+            5 => token = SemValue::Value(PhpMixed::Bool(false)),
+            6 => {
+                let v = self.vstack[len - 1].clone().into_value();
+                return Ok(ActionResult::Return(v));
+            }
+            13 => {
+                let v = if self.flags & JsonParser::PARSE_TO_ASSOC != 0 {
+                    PhpMixed::Array(IndexMap::new())
+                } else {
+                    PhpMixed::Object(IndexMap::new())
+                };
+                token = SemValue::Value(v);
+            }
+            14 => {
+                token = SemValue::Value(self.vstack[len - 1].clone().into_value());
+            }
+            15 => {
+                let key = match self.vstack[len - 2].clone() {
+                    SemValue::Value(PhpMixed::String(s)) => s,
+                    SemValue::Text(s) => s,
+                    other => semvalue_string(&other),
+                };
+                let value = self.vstack[len].clone().into_value();
+                token = SemValue::Member(key, value);
+            }
+            16 => {
+                let (property, value) = match self.vstack[len].clone() {
+                    SemValue::Member(k, v) => (k, v),
+                    _ => panic!("expected member pair"),
+                };
+                let mut map = IndexMap::new();
+                map.insert(property, value);
+                token = if self.flags & JsonParser::PARSE_TO_ASSOC != 0 {
+                    SemValue::Value(PhpMixed::Array(map))
+                } else {
+                    SemValue::Value(PhpMixed::Object(map))
+                };
+            }
+            17 => {
+                let (key, value) = match self.vstack[len].clone() {
+                    SemValue::Member(k, v) => (k, v),
+                    _ => panic!("expected member pair"),
+                };
+                let mut container = self.vstack[len - 2].clone().into_value();
+                let map = match &mut container {
+                    PhpMixed::Array(m) | PhpMixed::Object(m) => m,
+                    _ => panic!("expected object/array container"),
+                };
+
+                if (self.flags & JsonParser::DETECT_KEY_CONFLICTS != 0) && map.contains_key(&key) {
+                    // PHP inserts $this->lexer->showPosition() here; the lexer is owned by parse()
+                    // and not reachable from this method, so the position line is omitted. Only the
+                    // "Duplicate key" body is read by ConfigValidator (DETECT_KEY_CONFLICTS).
+                    let mut errstr = format!("Parse error on line {}:\n", yylineno + 1);
+                    errstr.push('\n');
+                    errstr.push_str(&format!("Duplicate key: {key}"));
+                    let mut details: IndexMap<String, PhpMixed> = IndexMap::new();
+                    // PHP details: array('line' => $yylineno+1); the 'key' entry is read by
+                    // ConfigValidator, so include it as well (PHP DuplicateKeyException stores the
+                    // key separately, but Shirabe's details map carries both).
+                    details.insert("key".to_string(), PhpMixed::String(key.clone()));
+                    details.insert("line".to_string(), PhpMixed::Int(yylineno + 1));
+                    return Err(DuplicateKeyException {
+                        message: errstr,
+                        code: 0,
+                        details,
+                    }
+                    .into());
+                }
+
+                if (self.flags & JsonParser::ALLOW_DUPLICATE_KEYS != 0) && map.contains_key(&key) {
+                    let mut duplicate_count = 1;
+                    let mut duplicate_key;
+                    loop {
+                        duplicate_key = format!("{key}.{duplicate_count}");
+                        duplicate_count += 1;
+                        if !map.contains_key(&duplicate_key) {
+                            break;
+                        }
+                    }
+                    map.insert(duplicate_key, value);
+                } else {
+                    // ALLOW_DUPLICATE_KEYS_TO_ARRAY path omitted: requires `__duplicates__` nesting;
+                    // unused by Composer's lint/parse defaults.
+                    map.insert(key, value);
+                }
+                token = SemValue::Value(container);
+            }
+            18 => token = SemValue::Value(PhpMixed::List(Vec::new())),
+            19 => {
+                token = SemValue::Value(self.vstack[len - 1].clone().into_value());
+            }
+            20 => {
+                let v = self.vstack[len].clone().into_value();
+                token = SemValue::Value(PhpMixed::List(vec![v]));
+            }
+            21 => {
+                let mut list = self.vstack[len - 2].clone().into_value();
+                let v = self.vstack[len].clone().into_value();
+                if let PhpMixed::List(items) = &mut list {
+                    items.push(v);
+                } else {
+                    panic!("expected list container");
+                }
+                token = SemValue::Value(list);
+            }
+            _ => {}
+        }
+
+        Ok(ActionResult::Continue(token))
+    }
+
+    fn pop_stack(&mut self, n: i64) {
+        let n = n as usize;
+        let new_stack_len = self.stack.len() - 2 * n;
+        self.stack.truncate(new_stack_len);
+        let new_v = self.vstack.len() - n;
+        self.vstack.truncate(new_v);
+        let new_l = self.lstack.len() - n;
+        self.lstack.truncate(new_l);
+    }
+}
+
+fn yyloc_to_loc(loc: &YylLoc) -> super::parsing_exception::ParsingExceptionLoc {
+    super::parsing_exception::ParsingExceptionLoc {
+        first_line: loc.first_line,
+        first_column: loc.first_column,
+        last_line: loc.last_line,
+        last_column: loc.last_column,
+    }
+}
+
+fn semvalue_string(v: &SemValue) -> String {
+    match v {
+        SemValue::Text(s) => s.clone(),
+        SemValue::Value(PhpMixed::String(s)) => s.clone(),
+        _ => String::new(),
     }
+}
+
+/// ref: JsonParser::stringInterpolation, applied to every escape sequence in the string
+/// (PHP uses preg_replace_callback with '{(?:\\["bfnrt/\\]|\\u[a-fA-F0-9]{4})}').
+fn string_interpolation_all(input: &str) -> String {
+    let bytes = input.as_bytes();
+    let mut out: Vec<u8> = Vec::with_capacity(bytes.len());
+    let mut i = 0;
+    while i < bytes.len() {
+        if bytes[i] == b'\\' && i + 1 < bytes.len() {
+            let n = bytes[i + 1];
+            match n {
+                b'\\' => {
+                    out.push(b'\\');
+                    i += 2;
+                    continue;
+                }
+                b'"' => {
+                    out.push(b'"');
+                    i += 2;
+                    continue;
+                }
+                b'b' => {
+                    out.push(8);
+                    i += 2;
+                    continue;
+                }
+                b'f' => {
+                    out.push(12);
+                    i += 2;
+                    continue;
+                }
+                b'n' => {
+                    out.push(b'\n');
+                    i += 2;
+                    continue;
+                }
+                b'r' => {
+                    out.push(b'\r');
+                    i += 2;
+                    continue;
+                }
+                b't' => {
+                    out.push(b'\t');
+                    i += 2;
+                    continue;
+                }
+                b'/' => {
+                    out.push(b'/');
+                    i += 2;
+                    continue;
+                }
+                b'u' if i + 5 < bytes.len()
+                    && bytes[i + 2..i + 6].iter().all(|b| b.is_ascii_hexdigit()) =>
+                {
+                    let hex = &input[i + 2..i + 6];
+                    if let Ok(cp) = u32::from_str_radix(hex, 16) {
+                        if let Some(c) = char::from_u32(cp) {
+                            let mut buf = [0u8; 4];
+                            out.extend_from_slice(c.encode_utf8(&mut buf).as_bytes());
+                        }
+                    }
+                    i += 6;
+                    continue;
+                }
+                _ => {}
+            }
+        }
+        out.push(bytes[i]);
+        i += 1;
+    }
+    String::from_utf8_lossy(&out).into_owned()
+}
+
+/// PHP floatval for a JSON number literal.
+fn php_floatval(s: &str) -> f64 {
+    s.parse::<f64>().unwrap_or(0.0)
+}
+
+/// PHP intval for a JSON integer literal.
+fn php_intval(s: &str) -> i64 {
+    // PHP intval parses leading integer portion; JSON numbers here are already valid integers.
+    s.parse::<i64>().unwrap_or_else(|_| {
+        // overflow fallback: PHP would clamp/convert, but valid lexed ints rarely overflow i64.
+        if s.starts_with('-') {
+            i64::MIN
+        } else {
+            i64::MAX
+        }
+    })
+}
+
+/// ref: preg_match('{".+?(\\[^"bfnrt/\\u](...)?)}', $fullUpcomingInput) — returns the captured
+/// group 1 (the unescaped backslash plus up to 3 following chars) if found.
+fn detect_unescaped_backslash(input: &[u8]) -> Option<String> {
+    // Pattern: a `"`, then `.+?` (at least one char, non-greedy), then a `\` that is NOT followed by
+    // a valid escape char (one of "bfnrt/\\u), then optionally up to 3 more chars (the `(...)?`).
+    // `.` does not match newline. We scan for the first `"`, then for the first qualifying backslash
+    // after at least one character.
+    let valid_escape = |b: u8| {
+        matches!(
+            b,
+            b'"' | b'b' | b'f' | b'n' | b'r' | b't' | b'/' | b'\\' | b'u'
+        )
+    };
+    let n = input.len();
+    // find first `"`
+    let mut q = 0;
+    while q < n {
+        if input[q] == b'"' && input[q] != b'\n' {
+            break;
+        }
+        q += 1;
+    }
+    if q >= n || input[q] != b'"' {
+        return None;
+    }
+    // need at least one char (.+?) after the quote, then the backslash.
+    // The `.+?` must match at least one non-newline char before the backslash.
+    let mut i = q + 1;
+    // ensure at least one char consumed by .+? : the backslash cannot be the char immediately
+    // following the quote? `.+?` is greedy-minimal but must consume >=1, and `.` excludes newline.
+    let mut consumed_one = false;
+    while i < n {
+        let c = input[i];
+        if c == b'\n' {
+            // `.` cannot cross a newline; PCRE `.+?` would stop — no match across lines here.
+            return None;
+        }
+        if c == b'\\' {
+            if consumed_one {
+                let next = input.get(i + 1).copied();
+                let bad = match next {
+                    None => true, // `[^...]` requires a char; if none, no match
+                    Some(b) => !valid_escape(b) && b != b'\n',
+                };
+                if next.is_some() && bad {
+                    // capture group 1: the `\`, the disallowed char, then up to 3 more (...)?
+                    let start = i;
+                    let mut end = i + 2; // backslash + the [^...] char
+                    // (...)? = exactly 3 chars if present
+                    let mut extra = 0;
+                    let mut k = end;
+                    while extra < 3 && k < n && input[k] != b'\n' {
+                        k += 1;
+                        extra += 1;
+                    }
+                    if extra == 3 {
+                        end = k;
+                    }
+                    return Some(String::from_utf8_lossy(&input[start..end]).into_owned());
+                }
+            }
+        }
+        consumed_one = true;
+        i += 1;
+    }
+    None
+}
 
-    pub fn parse(&self, _json: &str, _flags: u32) -> anyhow::Result<PhpMixed> {
-        todo!()
+/// ref: preg_match('{"(?:[^"]+|\\")*$}m', $fullUpcomingInput) — a `"` followed by string body that
+/// reaches a line end without a closing quote (multiline, with `m` so `$` is end-of-line).
+fn detect_unterminated_string(input: &[u8]) -> bool {
+    // Find a `"`; from there consume `[^"]+ | \"` repeatedly; succeed if we reach end-of-line/string
+    // without hitting an unescaped closing `"`.
+    let n = input.len();
+    let mut start = 0;
+    while start < n {
+        if input[start] == b'"' {
+            // try matching from this quote
+            let mut i = start + 1;
+            loop {
+                if i >= n {
+                    return true; // reached end of string ($ at end)
+                }
+                let c = input[i];
+                if c == b'\n' {
+                    return true; // $ matches before newline in multiline mode
+                }
+                if c == b'\\' && input.get(i + 1) == Some(&b'"') {
+                    i += 2; // \" alternative
+                    continue;
+                }
+                if c == b'"' {
+                    break; // closing quote: this start fails, try next `"`
+                }
+                i += 1; // [^"]+
+            }
+        }
+        start += 1;
     }
+    false
+}
 
-    /// PHP: JsonParser::lint() — returns null on success, ParsingException on failure.
-    pub fn lint(&mut self, _json: &str) -> Option<crate::seld::json_lint::ParsingException> {
-        todo!()
+fn trim_bytes(input: &[u8]) -> Vec<u8> {
+    // PHP trim() default strips " \t\n\r\0\x0B"
+    let is_trim = |b: u8| matches!(b, b' ' | b'\t' | b'\n' | b'\r' | 0 | 0x0b);
+    let mut start = 0;
+    let mut end = input.len();
+    while start < end && is_trim(input[start]) {
+        start += 1;
+    }
+    while end > start && is_trim(input[end - 1]) {
+        end -= 1;
     }
+    input[start..end].to_vec()
+}
+
+/// Builds the LALR parse `table`. Indexed by state id (0..=31).
+fn build_table() -> Vec<HashMap<i64, TableAction>> {
+    use TableAction::{Action, Goto};
+    let mut t: Vec<HashMap<i64, TableAction>> = (0..32).map(|_| HashMap::new()).collect();
+
+    let mut set = |state: usize, entries: &[(i64, TableAction)]| {
+        for (sym, act) in entries {
+            t[state].insert(*sym, *act);
+        }
+    };
+
+    set(
+        0,
+        &[
+            (3, Goto(5)),
+            (4, Action(1, 12)),
+            (5, Goto(6)),
+            (6, Action(1, 13)),
+            (7, Goto(3)),
+            (8, Action(1, 9)),
+            (9, Goto(4)),
+            (10, Action(1, 10)),
+            (11, Action(1, 11)),
+            (12, Goto(1)),
+            (13, Goto(2)),
+            (15, Goto(7)),
+            (16, Goto(8)),
+            (17, Action(1, 14)),
+            (23, Action(1, 15)),
+        ],
+    );
+    set(1, &[(1, Action(3, 0))]);
+    set(2, &[(14, Action(1, 16))]);
+    set(
+        3,
+        &[
+            (14, Action(2, 7)),
+            (18, Action(2, 7)),
+            (22, Action(2, 7)),
+            (24, Action(2, 7)),
+        ],
+    );
+    set(
+        4,
+        &[
+            (14, Action(2, 8)),
+            (18, Action(2, 8)),
+            (22, Action(2, 8)),
+            (24, Action(2, 8)),
+        ],
+    );
+    set(
+        5,
+        &[
+            (14, Action(2, 9)),
+            (18, Action(2, 9)),
+            (22, Action(2, 9)),
+            (24, Action(2, 9)),
+        ],
+    );
+    set(
+        6,
+        &[
+            (14, Action(2, 10)),
+            (18, Action(2, 10)),
+            (22, Action(2, 10)),
+            (24, Action(2, 10)),
+        ],
+    );
+    set(
+        7,
+        &[
+            (14, Action(2, 11)),
+            (18, Action(2, 11)),
+            (22, Action(2, 11)),
+            (24, Action(2, 11)),
+        ],
+    );
+    set(
+        8,
+        &[
+            (14, Action(2, 12)),
+            (18, Action(2, 12)),
+            (22, Action(2, 12)),
+            (24, Action(2, 12)),
+        ],
+    );
+    set(
+        9,
+        &[
+            (14, Action(2, 3)),
+            (18, Action(2, 3)),
+            (22, Action(2, 3)),
+            (24, Action(2, 3)),
+        ],
+    );
+    set(
+        10,
+        &[
+            (14, Action(2, 4)),
+            (18, Action(2, 4)),
+            (22, Action(2, 4)),
+            (24, Action(2, 4)),
+        ],
+    );
+    set(
+        11,
+        &[
+            (14, Action(2, 5)),
+            (18, Action(2, 5)),
+            (22, Action(2, 5)),
+            (24, Action(2, 5)),
+        ],
+    );
+    set(
+        12,
+        &[
+            (14, Action(2, 1)),
+            (18, Action(2, 1)),
+            (21, Action(2, 1)),
+            (22, Action(2, 1)),
+            (24, Action(2, 1)),
+        ],
+    );
+    set(
+        13,
+        &[
+            (14, Action(2, 2)),
+            (18, Action(2, 2)),
+            (22, Action(2, 2)),
+            (24, Action(2, 2)),
+        ],
+    );
+    set(
+        14,
+        &[
+            (3, Goto(20)),
+            (4, Action(1, 12)),
+            (18, Action(1, 17)),
+            (19, Goto(18)),
+            (20, Goto(19)),
+        ],
+    );
+    set(
+        15,
+        &[
+            (3, Goto(5)),
+            (4, Action(1, 12)),
+            (5, Goto(6)),
+            (6, Action(1, 13)),
+            (7, Goto(3)),
+            (8, Action(1, 9)),
+            (9, Goto(4)),
+            (10, Action(1, 10)),
+            (11, Action(1, 11)),
+            (13, Goto(23)),
+            (15, Goto(7)),
+            (16, Goto(8)),
+            (17, Action(1, 14)),
+            (23, Action(1, 15)),
+            (24, Action(1, 21)),
+            (25, Goto(22)),
+        ],
+    );
+    set(16, &[(1, Action(2, 6))]);
+    set(
+        17,
+        &[
+            (14, Action(2, 13)),
+            (18, Action(2, 13)),
+            (22, Action(2, 13)),
+            (24, Action(2, 13)),
+        ],
+    );
+    set(18, &[(18, Action(1, 24)), (22, Action(1, 25))]);
+    set(19, &[(18, Action(2, 16)), (22, Action(2, 16))]);
+    set(20, &[(21, Action(1, 26))]);
+    set(
+        21,
+        &[
+            (14, Action(2, 18)),
+            (18, Action(2, 18)),
+            (22, Action(2, 18)),
+            (24, Action(2, 18)),
+        ],
+    );
+    set(22, &[(22, Action(1, 28)), (24, Action(1, 27))]);
+    set(23, &[(22, Action(2, 20)), (24, Action(2, 20))]);
+    set(
+        24,
+        &[
+            (14, Action(2, 14)),
+            (18, Action(2, 14)),
+            (22, Action(2, 14)),
+            (24, Action(2, 14)),
+        ],
+    );
+    set(25, &[(3, Goto(20)), (4, Action(1, 12)), (20, Goto(29))]);
+    set(
+        26,
+        &[
+            (3, Goto(5)),
+            (4, Action(1, 12)),
+            (5, Goto(6)),
+            (6, Action(1, 13)),
+            (7, Goto(3)),
+            (8, Action(1, 9)),
+            (9, Goto(4)),
+            (10, Action(1, 10)),
+            (11, Action(1, 11)),
+            (13, Goto(30)),
+            (15, Goto(7)),
+            (16, Goto(8)),
+            (17, Action(1, 14)),
+            (23, Action(1, 15)),
+        ],
+    );
+    set(
+        27,
+        &[
+            (14, Action(2, 19)),
+            (18, Action(2, 19)),
+            (22, Action(2, 19)),
+            (24, Action(2, 19)),
+        ],
+    );
+    set(
+        28,
+        &[
+            (3, Goto(5)),
+            (4, Action(1, 12)),
+            (5, Goto(6)),
+            (6, Action(1, 13)),
+            (7, Goto(3)),
+            (8, Action(1, 9)),
+            (9, Goto(4)),
+            (10, Action(1, 10)),
+            (11, Action(1, 11)),
+            (13, Goto(31)),
+            (15, Goto(7)),
+            (16, Goto(8)),
+            (17, Action(1, 14)),
+            (23, Action(1, 15)),
+        ],
+    );
+    set(29, &[(18, Action(2, 17)), (22, Action(2, 17))]);
+    set(30, &[(18, Action(2, 15)), (22, Action(2, 15))]);
+    set(31, &[(22, Action(2, 21)), (24, Action(2, 21))]);
+
+    t
 }
diff --git a/crates/shirabe-external-packages/src/seld/json_lint/lexer.rs b/crates/shirabe-external-packages/src/seld/json_lint/lexer.rs
new file mode 100644
index 0000000..96263ef
--- /dev/null
+++ b/crates/shirabe-external-packages/src/seld/json_lint/lexer.rs
@@ -0,0 +1,545 @@
+//! ref: composer/vendor/seld/jsonlint/src/Seld/JsonLint/Lexer.php
+
+use super::JsonParser;
+use super::ParsingException;
+
+/// ref: array{first_line, first_column, last_line, last_column} ($yylloc)
+#[derive(Debug, Clone, Default)]
+pub struct YylLoc {
+    pub first_line: i64,
+    pub first_column: i64,
+    pub last_line: i64,
+    pub last_column: i64,
+}
+
+#[derive(Debug)]
+pub struct Lexer {
+    rules: Vec<Rule>,
+    input: Vec<u8>,
+    more: bool,
+    done: bool,
+    offset: usize,
+    flags: u32,
+
+    pub match_: Vec<u8>,
+    pub yylineno: i64,
+    pub yyleng: i64,
+    pub yytext: Vec<u8>,
+    pub yylloc: YylLoc,
+}
+
+/// Each variant replicates the corresponding `\G`-anchored PHP rule. The PCRE rules are not portable
+/// to the `regex` crate (possessive quantifiers, `\G`, `\b`), so they are matched by hand.
+#[derive(Debug, Clone, Copy)]
+enum Rule {
+    BreakLine,    // 0: /\G\s*\n\r?/
+    Whitespace,   // 1: /\G\s+/
+    Number,       // 2
+    Str,          // 3
+    BraceOpen,    // 4: {
+    BraceClose,   // 5: }
+    BracketOpen,  // 6: [
+    BracketClose, // 7: ]
+    Comma,        // 8: ,
+    Colon,        // 9: :
+    True,         // 10
+    False,        // 11
+    Null,         // 12
+    End,          // 13: /\G$/
+    LineComment,  // 14: //
+    OpenComment,  // 15: /*
+    CloseComment, // 16: */
+    AnyChar,      // 17: /\G./
+}
+
+impl Lexer {
+    pub const EOF: i64 = 1;
+    pub const T_INVALID: i64 = -1;
+    pub const T_SKIP_WHITESPACE: i64 = 0;
+    pub const T_ERROR: i64 = 2;
+    pub const T_BREAK_LINE: i64 = 3;
+    pub const T_COMMENT: i64 = 30;
+    pub const T_OPEN_COMMENT: i64 = 31;
+    pub const T_CLOSE_COMMENT: i64 = 32;
+
+    pub fn new(flags: u32) -> Self {
+        let rules = vec![
+            Rule::BreakLine,
+            Rule::Whitespace,
+            Rule::Number,
+            Rule::Str,
+            Rule::BraceOpen,
+            Rule::BraceClose,
+            Rule::BracketOpen,
+            Rule::BracketClose,
+            Rule::Comma,
+            Rule::Colon,
+            Rule::True,
+            Rule::False,
+            Rule::Null,
+            Rule::End,
+            Rule::LineComment,
+            Rule::OpenComment,
+            Rule::CloseComment,
+            Rule::AnyChar,
+        ];
+        Self {
+            rules,
+            input: Vec::new(),
+            more: false,
+            done: false,
+            offset: 0,
+            flags,
+            match_: Vec::new(),
+            yylineno: 0,
+            yyleng: 0,
+            yytext: Vec::new(),
+            yylloc: YylLoc::default(),
+        }
+    }
+
+    pub fn lex(&mut self) -> Result<i64, ParsingException> {
+        loop {
+            let symbol = self.next()?;
+            match symbol {
+                Self::T_SKIP_WHITESPACE | Self::T_BREAK_LINE => {}
+                Self::T_COMMENT | Self::T_OPEN_COMMENT => {
+                    if self.flags & JsonParser::ALLOW_COMMENTS == 0 {
+                        return Err(self.parse_error(format!(
+                            "Lexical error on line {}. Comments are not allowed.\n{}",
+                            self.yylineno + 1,
+                            self.show_position()
+                        )));
+                    }
+                    let until = if symbol == Self::T_COMMENT {
+                        Self::T_BREAK_LINE
+                    } else {
+                        Self::T_CLOSE_COMMENT
+                    };
+                    self.skip_until(until)?;
+                    if self.done {
+                        // last symbol '/\G$/' before EOF
+                        return Ok(14);
+                    }
+                }
+                Self::T_CLOSE_COMMENT => {
+                    return Err(self.parse_error(format!(
+                        "Lexical error on line {}. Unexpected token.\n{}",
+                        self.yylineno + 1,
+                        self.show_position()
+                    )));
+                }
+                _ => return Ok(symbol),
+            }
+        }
+    }
+
+    pub fn set_input(&mut self, input: &str) {
+        self.input = input.as_bytes().to_vec();
+        self.more = false;
+        self.done = false;
+        self.offset = 0;
+        self.yylineno = 0;
+        self.yyleng = 0;
+        self.yytext = Vec::new();
+        self.match_ = Vec::new();
+        self.yylloc = YylLoc {
+            first_line: 1,
+            first_column: 0,
+            last_line: 1,
+            last_column: 0,
+        };
+    }
+
+    pub fn show_position(&self) -> String {
+        if self.yylineno == 0 && self.offset == 1 && self.match_ != b"{" {
+            let mut s = String::from_utf8_lossy(&self.match_).into_owned();
+            s.push_str("...\n^");
+            return s;
+        }
+
+        let pre = str_replace_nl(&self.get_past_input());
+        let dash_count = (pre.len() as i64 - 1).max(0) as usize;
+        let c = "-".repeat(dash_count);
+
+        let upcoming = str_replace_nl(&self.get_upcoming_input());
+        format!("{pre}{upcoming}\n{c}^")
+    }
+
+    pub fn get_past_input(&self) -> Vec<u8> {
+        let past_length = self.offset as i64 - self.match_.len() as i64;
+        let prefix = if past_length > 20 { "..." } else { "" };
+        let start = (past_length - 20).max(0) as usize;
+        let len = past_length.min(20).max(0) as usize;
+        let slice = substr_bytes(&self.input, start, len);
+        let mut out = prefix.as_bytes().to_vec();
+        out.extend_from_slice(&slice);
+        out
+    }
+
+    pub fn get_upcoming_input(&self) -> Vec<u8> {
+        let mut next = self.match_.clone();
+        if next.len() < 20 {
+            let want = 20 - next.len();
+            next.extend_from_slice(&substr_bytes(&self.input, self.offset, want));
+        }
+        let too_long = next.len() > 20;
+        let mut out = substr_bytes(&next, 0, 20);
+        if too_long {
+            out.extend_from_slice(b"...");
+        }
+        out
+    }
+
+    pub fn get_full_upcoming_input(&self) -> Vec<u8> {
+        let mut next = self.match_.clone();
+        if next.first() == Some(&b'"') && byte_count(&next, b'"') == 1 {
+            let len = self.input.len();
+            let str_end = if len == self.offset {
+                len
+            } else {
+                let q = find_byte_from(&self.input, b'"', self.offset + 1).unwrap_or(len);
+                let q = if q == 0 { len } else { q };
+                let n = find_byte_from(&self.input, b'\n', self.offset + 1).unwrap_or(len);
+                let n = if n == 0 { len } else { n };
+                q.min(n)
+            };
+            next.extend_from_slice(&self.input[self.offset..str_end]);
+        } else if next.len() < 20 {
+            let want = 20 - next.len();
+            next.extend_from_slice(&substr_bytes(&self.input, self.offset, want));
+        }
+        next
+    }
+
+    fn parse_error(&self, str: String) -> ParsingException {
+        ParsingException::new(str, Default::default())
+    }
+
+    fn skip_until(&mut self, token: i64) -> Result<(), ParsingException> {
+        let mut symbol = self.next()?;
+        while symbol != token && !self.done {
+            symbol = self.next()?;
+        }
+        Ok(())
+    }
+
+    fn next(&mut self) -> Result<i64, ParsingException> {
+        if self.done {
+            return Ok(Self::EOF);
+        }
+        if self.offset == self.input.len() {
+            self.done = true;
+        }
+
+        if !self.more {
+            self.yytext = Vec::new();
+            self.match_ = Vec::new();
+        }
+
+        for i in 0..self.rules.len() {
+            if let Some(matched) = self.match_rule(self.rules[i]) {
+                let lines: Vec<&[u8]> = split_bytes(&matched, b'\n');
+                // array_shift: drop first element, count remaining
+                let line_count = lines.len().saturating_sub(1);
+                self.yylineno += line_count as i64;
+                self.yylloc = YylLoc {
+                    first_line: self.yylloc.last_line,
+                    last_line: self.yylineno + 1,
+                    first_column: self.yylloc.last_column,
+                    last_column: if line_count > 0 {
+                        lines[lines.len() - 1].len() as i64
+                    } else {
+                        self.yylloc.last_column + matched.len() as i64
+                    },
+                };
+                self.yytext.extend_from_slice(&matched);
+                self.match_.extend_from_slice(&matched);
+                self.yyleng = self.yytext.len() as i64;
+                self.more = false;
+                self.offset += matched.len();
+                return Ok(self.perform_action(i, &matched));
+            }
+        }
+
+        if self.offset == self.input.len() {
+            return Ok(Self::EOF);
+        }
+
+        Err(self.parse_error(format!(
+            "Lexical error on line {}. Unrecognized text.\n{}",
+            self.yylineno + 1,
+            self.show_position()
+        )))
+    }
+
+    /// Returns the matched bytes (anchored at `self.offset`) if the rule applies, mirroring
+    /// `preg_match($rule, $input, $m, 0, $offset)` for the corresponding `\G`-anchored PHP pattern.
+    fn match_rule(&self, rule: Rule) -> Option<Vec<u8>> {
+        let input = &self.input;
+        let off = self.offset;
+        match rule {
+            Rule::BreakLine => match_break_line(input, off),
+            Rule::Whitespace => match_whitespace(input, off),
+            Rule::Number => match_number(input, off),
+            Rule::Str => match_string(input, off),
+            Rule::BraceOpen => match_char(input, off, b'{'),
+            Rule::BraceClose => match_char(input, off, b'}'),
+            Rule::BracketOpen => match_char(input, off, b'['),
+            Rule::BracketClose => match_char(input, off, b']'),
+            Rule::Comma => match_char(input, off, b','),
+            Rule::Colon => match_char(input, off, b':'),
+            Rule::True => match_keyword(input, off, b"true"),
+            Rule::False => match_keyword(input, off, b"false"),
+            Rule::Null => match_keyword(input, off, b"null"),
+            Rule::End => match_end(input, off),
+            Rule::LineComment => match_literal(input, off, b"//"),
+            Rule::OpenComment => match_literal(input, off, b"/*"),
+            Rule::CloseComment => match_literal(input, off, b"*/"),
+            Rule::AnyChar => match_any_char(input, off),
+        }
+    }
+
+    fn perform_action(&mut self, rule: usize, _matched: &[u8]) -> i64 {
+        match rule {
+            0 => Self::T_BREAK_LINE,
+            1 => Self::T_SKIP_WHITESPACE,
+            2 => 6,
+            3 => {
+                // strip surrounding quotes: substr($yytext, 1, $yyleng-2)
+                let len = self.yyleng;
+                self.yytext = substr_bytes(&self.yytext, 1, (len - 2).max(0) as usize);
+                4
+            }
+            4 => 17,
+            5 => 18,
+            6 => 23,
+            7 => 24,
+            8 => 22,
+            9 => 21,
+            10 => 10,
+            11 => 11,
+            12 => 8,
+            13 => 14,
+            14 => Self::T_COMMENT,
+            15 => Self::T_OPEN_COMMENT,
+            16 => Self::T_CLOSE_COMMENT,
+            17 => Self::T_INVALID,
+            _ => panic!("Unsupported rule {rule}"),
+        }
+    }
+}
+
+/// PHP `\s` (matches space, \t, \n, \r, \f, \v).
+fn is_php_space(b: u8) -> bool {
+    matches!(b, b' ' | b'\t' | b'\n' | b'\r' | 0x0c | 0x0b)
+}
+
+/// Rule 0: /\G\s*\n\r?/ — greedy whitespace ending at a newline, optionally followed by `\r`.
+fn match_break_line(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    // Find the run of whitespace that ends with `\n` (followed by optional `\r`). PCRE backtracks
+    // so the `\s*` consumes up to and including the last reachable `\n` within the leading run.
+    let mut i = off;
+    let mut last_nl: Option<usize> = None;
+    while i < input.len() && is_php_space(input[i]) {
+        if input[i] == b'\n' {
+            last_nl = Some(i);
+        }
+        i += 1;
+    }
+    let nl = last_nl?;
+    let mut end = nl + 1;
+    if end < input.len() && input[end] == b'\r' {
+        end += 1;
+    }
+    Some(input[off..end].to_vec())
+}
+
+/// Rule 1: /\G\s+/
+fn match_whitespace(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    let mut i = off;
+    while i < input.len() && is_php_space(input[i]) {
+        i += 1;
+    }
+    if i == off {
+        None
+    } else {
+        Some(input[off..i].to_vec())
+    }
+}
+
+/// Rule 2: /\G-?([0-9]|[1-9][0-9]+)(\.[0-9]+)?([eE][+-]?[0-9]+)?\b/
+fn match_number(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    let mut i = off;
+    if i < input.len() && input[i] == b'-' {
+        i += 1;
+    }
+    // integer part: a single digit OR [1-9][0-9]+
+    let int_start = i;
+    if i >= input.len() || !input[i].is_ascii_digit() {
+        return None;
+    }
+    if input[i] == b'0' {
+        // single 0 only (the [1-9][0-9]+ alternative cannot start with 0)
+        i += 1;
+    } else {
+        // [1-9] then [0-9]* ; but grammar is `[0-9]` (single) | `[1-9][0-9]+` (2+ digits).
+        // Both collapse to: one or more digits starting with 1-9.
+        i += 1;
+        while i < input.len() && input[i].is_ascii_digit() {
+            i += 1;
+        }
+    }
+    let _ = int_start;
+    // fraction
+    if i < input.len() && input[i] == b'.' {
+        let mut j = i + 1;
+        let frac_start = j;
+        while j < input.len() && input[j].is_ascii_digit() {
+            j += 1;
+        }
+        if j > frac_start {
+            i = j;
+        }
+    }
+    // exponent
+    if i < input.len() && (input[i] == b'e' || input[i] == b'E') {
+        let mut j = i + 1;
+        if j < input.len() && (input[j] == b'+' || input[j] == b'-') {
+            j += 1;
+        }
+        let exp_start = j;
+        while j < input.len() && input[j].is_ascii_digit() {
+            j += 1;
+        }
+        if j > exp_start {
+            i = j;
+        }
+    }
+    // \b word boundary: previous char (input[i-1]) is a word char (digit), so the next char must be
+    // a non-word char (or end).
+    if i < input.len() && is_word_byte(input[i]) {
+        return None;
+    }
+    Some(input[off..i].to_vec())
+}
+
+fn is_word_byte(b: u8) -> bool {
+    b.is_ascii_alphanumeric() || b == b'_'
+}
+
+/// Rule 3: {\G"(?>\\["bfnrt/\\]|\\u[a-fA-F0-9]{4}|[^\0-\x1f\\"]++)*+"}
+fn match_string(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    if input.get(off) != Some(&b'"') {
+        return None;
+    }
+    let mut i = off + 1;
+    loop {
+        let c = *input.get(i)?;
+        if c == b'"' {
+            return Some(input[off..=i].to_vec());
+        }
+        if c == b'\\' {
+            let n = *input.get(i + 1)?;
+            match n {
+                b'"' | b'b' | b'f' | b'n' | b'r' | b't' | b'/' | b'\\' => {
+                    i += 2;
+                }
+                b'u' => {
+                    // require 4 hex digits
+                    for k in 0..4 {
+                        let h = *input.get(i + 2 + k)?;
+                        if !h.is_ascii_hexdigit() {
+                            return None;
+                        }
+                    }
+                    i += 6;
+                }
+                _ => return None,
+            }
+        } else if c <= 0x1f {
+            // [^\0-\x1f\\"] excludes control chars
+            return None;
+        } else {
+            i += 1;
+        }
+    }
+}
+
+/// Rules 4-9: single literal char.
+fn match_char(input: &[u8], off: usize, ch: u8) -> Option<Vec<u8>> {
+    if input.get(off) == Some(&ch) {
+        Some(vec![ch])
+    } else {
+        None
+    }
+}
+
+/// Rules 10-12: keyword followed by a `\b` boundary.
+fn match_keyword(input: &[u8], off: usize, kw: &[u8]) -> Option<Vec<u8>> {
+    if input.len() < off + kw.len() || &input[off..off + kw.len()] != kw {
+        return None;
+    }
+    let after = off + kw.len();
+    if after < input.len() && is_word_byte(input[after]) {
+        return None;
+    }
+    Some(kw.to_vec())
+}
+
+/// Rule 13: /\G$/ — matches the empty string at end of input (or before a trailing final newline,
+/// per PCRE `$` without the `m` modifier).
+fn match_end(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    if off == input.len() {
+        return Some(Vec::new());
+    }
+    if off == input.len() - 1 && input[off] == b'\n' {
+        return Some(Vec::new());
+    }
+    None
+}
+
+/// Rules 14-16: multi-char literal.
+fn match_literal(input: &[u8], off: usize, lit: &[u8]) -> Option<Vec<u8>> {
+    if input.len() >= off + lit.len() && &input[off..off + lit.len()] == lit {
+        Some(lit.to_vec())
+    } else {
+        None
+    }
+}
+
+/// Rule 17: /\G./ — any single character except newline.
+fn match_any_char(input: &[u8], off: usize) -> Option<Vec<u8>> {
+    match input.get(off) {
+        Some(&b'\n') | None => None,
+        Some(&c) => Some(vec![c]),
+    }
+}
+
+fn substr_bytes(input: &[u8], start: usize, len: usize) -> Vec<u8> {
+    if start >= input.len() {
+        return Vec::new();
+    }
+    let end = (start + len).min(input.len());
+    input[start..end].to_vec()
+}
+
+fn str_replace_nl(input: &[u8]) -> String {
+    let filtered: Vec<u8> = input.iter().copied().filter(|&b| b != b'\n').collect();
+    String::from_utf8_lossy(&filtered).into_owned()
+}
+
+fn split_bytes(input: &[u8], sep: u8) -> Vec<&[u8]> {
+    input.split(|&b| b == sep).collect()
+}
+
+fn byte_count(input: &[u8], b: u8) -> usize {
+    input.iter().filter(|&&x| x == b).count()
+}
+
+fn find_byte_from(input: &[u8], b: u8, from: usize) -> Option<usize> {
+    if from > input.len() {
+        return None;
+    }
+    input[from..].iter().position(|&x| x == b).map(|p| p + from)
+}
diff --git a/crates/shirabe-external-packages/src/seld/json_lint/mod.rs b/crates/shirabe-external-packages/src/seld/json_lint/mod.rs
index 1058268..8027cb2 100644
--- a/crates/shirabe-external-packages/src/seld/json_lint/mod.rs
+++ b/crates/shirabe-external-packages/src/seld/json_lint/mod.rs
@@ -1,7 +1,9 @@
 pub mod duplicate_key_exception;
 pub mod json_parser;
+pub mod lexer;
 pub mod parsing_exception;
 
 pub use duplicate_key_exception::*;
 pub use json_parser::*;
+pub use lexer::*;
 pub use parsing_exception::*;
diff --git a/crates/shirabe-external-packages/src/symfony/console/helper/table.rs b/crates/shirabe-external-packages/src/symfony/console/helper/table.rs
index 1167d63..bc426f6 100644
--- a/crates/shirabe-external-packages/src/symfony/console/helper/table.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/helper/table.rs
@@ -14,6 +14,7 @@ use crate::symfony::console::helper::table_style::TableStyle;
 use crate::symfony::console::output::console_section_output::ConsoleSectionOutput;
 use crate::symfony::console::output::output_interface::OutputInterface;
 use indexmap::IndexMap;
+use shirabe_php_shim::AsAny;
 use shirabe_php_shim::PhpMixed;
 use std::cell::RefCell;
 use std::rc::Rc;
@@ -1248,7 +1249,9 @@ impl Table {
 
     fn formatter_is_wrappable(_output: &Rc<RefCell<dyn OutputInterface>>) -> bool {
         // PHP: $this->output->getFormatter() instanceof WrappableOutputFormatterInterface
-        // TODO(phase-b): trait-to-trait instanceof check requires concrete formatter knowledge.
+        // TODO(phase-c/d): instanceof on `dyn OutputFormatterInterface` needs an AsAny supertrait
+        // on OutputFormatterInterface to downcast to the concrete wrappable formatter; adding it
+        // would touch output_formatter_interface.rs, which is out of scope for this file.
         let _ = std::any::type_name::<dyn WrappableOutputFormatterInterface>();
         todo!()
     }
@@ -1260,9 +1263,13 @@ impl Table {
         Helper::remove_decoration(&mut *formatter, string)
     }
 
-    fn output_is_console_section(_output: &Rc<RefCell<dyn OutputInterface>>) -> bool {
+    fn output_is_console_section(output: &Rc<RefCell<dyn OutputInterface>>) -> bool {
         // PHP: $this->output instanceof ConsoleSectionOutput
-        todo!()
+        let borrowed = output.borrow();
+        (*borrowed)
+            .as_any()
+            .downcast_ref::<ConsoleSectionOutput>()
+            .is_some()
     }
 
     fn is_divider(_row: &PhpMixed, _divider: &TableSeparator) -> bool {
diff --git a/crates/shirabe-external-packages/src/symfony/process/executable_finder.rs b/crates/shirabe-external-packages/src/symfony/process/executable_finder.rs
index cfd1bef..a151283 100644
--- a/crates/shirabe-external-packages/src/symfony/process/executable_finder.rs
+++ b/crates/shirabe-external-packages/src/symfony/process/executable_finder.rs
@@ -1,7 +1,18 @@
 //! ref: composer/vendor/symfony/process/ExecutableFinder.php
 
+use shirabe_php_shim::{self as php, PhpMixed};
+
+const CMD_BUILTINS: &[&str] = &[
+    "assoc", "break", "call", "cd", "chdir", "cls", "color", "copy", "date", "del", "dir", "echo",
+    "endlocal", "erase", "exit", "for", "ftype", "goto", "help", "if", "label", "md", "mkdir",
+    "mklink", "move", "path", "pause", "popd", "prompt", "pushd", "rd", "rem", "ren", "rename",
+    "rmdir", "set", "setlocal", "shift", "start", "time", "title", "type", "ver", "vol",
+];
+
 #[derive(Debug)]
-pub struct ExecutableFinder;
+pub struct ExecutableFinder {
+    suffixes: Vec<String>,
+}
 
 impl Default for ExecutableFinder {
     fn default() -> Self {
@@ -11,14 +22,102 @@ impl Default for ExecutableFinder {
 
 impl ExecutableFinder {
     pub fn new() -> Self {
-        todo!()
+        Self { suffixes: vec![] }
     }
 
-    pub fn add_suffix(&mut self, _suffix: &str) {
-        todo!()
+    /// Replaces default suffixes of executable.
+    pub fn set_suffixes(&mut self, suffixes: Vec<String>) {
+        self.suffixes = suffixes;
     }
 
-    pub fn find(&self, _name: &str, _default: Option<&str>, _dirs: &[String]) -> Option<String> {
-        todo!()
+    /// Adds new possible suffix to check for executable.
+    pub fn add_suffix(&mut self, suffix: &str) {
+        self.suffixes.push(suffix.to_string());
+    }
+
+    pub fn find(&self, name: &str, default: Option<&str>, extra_dirs: &[String]) -> Option<String> {
+        // windows built-in commands that are present in cmd.exe should not be resolved using PATH as they do not exist as exes
+        if php::DIRECTORY_SEPARATOR == "\\"
+            && CMD_BUILTINS.contains(&php::strtolower(name).as_str())
+        {
+            return Some(name.to_string());
+        }
+
+        let path = php::getenv("PATH")
+            .or_else(|| php::getenv("Path"))
+            .map(|v| v.to_string_lossy().into_owned())
+            .unwrap_or_default();
+        let mut dirs = php::explode(php::PATH_SEPARATOR, &path);
+        dirs.extend_from_slice(extra_dirs);
+
+        let mut suffixes: Vec<String> = vec![];
+        if php::DIRECTORY_SEPARATOR == "\\" {
+            let path_ext = php::getenv("PATHEXT").map(|v| v.to_string_lossy().into_owned());
+            suffixes = self.suffixes.clone();
+            let exts = match path_ext {
+                Some(ref ext) if !ext.is_empty() => php::explode(php::PATH_SEPARATOR, ext),
+                _ => vec![
+                    ".exe".to_string(),
+                    ".bat".to_string(),
+                    ".cmd".to_string(),
+                    ".com".to_string(),
+                ],
+            };
+            suffixes.extend(exts);
+        }
+        suffixes = if !php::pathinfo(PhpMixed::String(name.to_string()), php::PATHINFO_EXTENSION)
+            .as_string()
+            .unwrap_or("")
+            .is_empty()
+        {
+            let mut s = vec![String::new()];
+            s.extend(suffixes);
+            s
+        } else {
+            suffixes.push(String::new());
+            suffixes
+        };
+        for suffix in &suffixes {
+            for dir in &dirs {
+                let dir = if dir.is_empty() { "." } else { dir.as_str() };
+                let file = format!("{dir}{}{name}{suffix}", php::DIRECTORY_SEPARATOR);
+                if php::is_file(&file)
+                    && (php::DIRECTORY_SEPARATOR == "\\" || php::is_executable(&file))
+                {
+                    return Some(file);
+                }
+
+                if !php::is_dir(dir)
+                    && php::basename(dir) == format!("{name}{suffix}")
+                    && php::is_executable(dir)
+                {
+                    return Some(dir.to_string());
+                }
+            }
+        }
+
+        if php::DIRECTORY_SEPARATOR == "\\"
+            || name.len() != php::strcspn(name, &format!("/{}", php::DIRECTORY_SEPARATOR))
+        {
+            return default.map(ToString::to_string);
+        }
+
+        let exec_result = php::exec(
+            &format!("command -v -- {}", php::escapeshellarg(name)),
+            None,
+            None,
+        )
+        .unwrap_or_default();
+
+        let executable_path = php::substr(
+            &exec_result,
+            0,
+            php::strpos(&exec_result, php::PHP_EOL).map(|i| i as i64),
+        );
+        if !executable_path.is_empty() && php::is_executable(&executable_path) {
+            return Some(executable_path);
+        }
+
+        default.map(ToString::to_string)
     }
 }
diff --git a/crates/shirabe-external-packages/src/symfony/process/php_executable_finder.rs b/crates/shirabe-external-packages/src/symfony/process/php_executable_finder.rs
index 65eae30..9d04c5e 100644
--- a/crates/shirabe-external-packages/src/symfony/process/php_executable_finder.rs
+++ b/crates/shirabe-external-packages/src/symfony/process/php_executable_finder.rs
@@ -1,7 +1,12 @@
 //! ref: composer/vendor/symfony/process/PhpExecutableFinder.php
 
+use super::executable_finder::ExecutableFinder;
+use shirabe_php_shim::{self as php};
+
 #[derive(Debug)]
-pub struct PhpExecutableFinder;
+pub struct PhpExecutableFinder {
+    executable_finder: ExecutableFinder,
+}
 
 impl Default for PhpExecutableFinder {
     fn default() -> Self {
@@ -11,14 +16,52 @@ impl Default for PhpExecutableFinder {
 
 impl PhpExecutableFinder {
     pub fn new() -> Self {
-        todo!()
+        Self {
+            executable_finder: ExecutableFinder::new(),
+        }
     }
 
-    pub fn find(&self, _include_args: bool) -> Option<String> {
+    /// Finds The PHP executable.
+    pub fn find(&self, include_args: bool) -> Option<String> {
+        if let Some(php) = php::getenv("PHP_BINARY").filter(|v| !v.is_empty()) {
+            let mut php = php.to_string_lossy().into_owned();
+            if !php::is_executable(&php) {
+                match self.executable_finder.find(&php, None, &[]) {
+                    Some(found) => php = found,
+                    None => return None,
+                }
+            }
+
+            if php::is_dir(&php) {
+                return None;
+            }
+
+            return Some(php);
+        }
+
+        let args = self.find_arguments();
+        let _args = if include_args && !args.is_empty() {
+            format!(" {}", args.join(" "))
+        } else {
+            String::new()
+        };
+
+        // PHP_BINARY return the current sapi executable
+        //
+        // Everything from here on depends on runtime constants describing the *running* PHP
+        // interpreter (\PHP_BINARY truthiness, \PHP_SAPI, \PHP_BINDIR). The shim does not model a
+        // current PHP runtime, so the remaining fallbacks (the \PHP_SAPI sapi check, \PHP_PATH,
+        // \PHP_PEAR_PHP_BIN, \PHP_BINDIR probing and the final php lookup seeded with \PHP_BINDIR)
+        // cannot be ported faithfully here.
+        // TODO(php-runtime): port once the shim exposes \PHP_SAPI and \PHP_BINDIR.
         todo!()
     }
 
+    /// Finds the PHP executable arguments.
     pub fn find_arguments(&self) -> Vec<String> {
+        let _arguments: Vec<String> = vec![];
+        // TODO(php-runtime): \PHP_SAPI is the SAPI name of the running PHP interpreter; the shim
+        // does not model a current PHP runtime, so the 'phpdbg' check cannot be ported faithfully.
         todo!()
     }
 }
diff --git a/crates/shirabe-external-packages/src/symfony/string/byte_string.rs b/crates/shirabe-external-packages/src/symfony/string/byte_string.rs
index ab17c1e..cd8eae8 100644
--- a/crates/shirabe-external-packages/src/symfony/string/byte_string.rs
+++ b/crates/shirabe-external-packages/src/symfony/string/byte_string.rs
@@ -8,11 +8,25 @@ pub struct ByteString {
 }
 
 impl ByteString {
-    pub fn new(_string: &str) -> Self {
-        todo!()
+    pub fn new(string: &str) -> Self {
+        Self {
+            string: string.to_string(),
+        }
     }
 
-    pub fn to_code_point_string(&self, _encoding: &str) -> CodePointString {
+    pub fn to_code_point_string(&self, from_encoding: &str) -> CodePointString {
+        // The source `string` is always valid UTF-8 (Rust `String`/`&str` guarantee). PHP takes the
+        // early-return branch whenever `preg_match('//u', ...)` holds for a UTF-8/null encoding, so
+        // the result mirrors the input bytes verbatim. The `mb_detect_encoding`/`iconv` conversion
+        // path only applies to genuinely non-UTF-8 byte strings, which cannot occur here.
+        if matches!(from_encoding, "" | "utf8" | "utf-8" | "UTF8" | "UTF-8") {
+            return CodePointString {
+                string: self.string.clone(),
+            };
+        }
+
+        // TODO(phase-d): non-UTF-8 source encodings would require mb_convert_encoding/iconv-style
+        // decoding, which is unreachable for the UTF-8-only inputs Shirabe currently produces.
         todo!()
     }
 }
diff --git a/crates/shirabe-external-packages/src/symfony/string/code_point_string.rs b/crates/shirabe-external-packages/src/symfony/string/code_point_string.rs
index b76f157..ce67428 100644
--- a/crates/shirabe-external-packages/src/symfony/string/code_point_string.rs
+++ b/crates/shirabe-external-packages/src/symfony/string/code_point_string.rs
@@ -6,11 +6,166 @@ pub struct CodePointString {
 }
 
 impl CodePointString {
-    pub fn wordwrap(&self, _width: i64, _break: &str, _cut: bool) -> Self {
-        todo!()
+    /// Port of `AbstractString::wordwrap()`, specialised to the non-`ignoreCase` code-point case.
+    pub fn wordwrap(&self, width: i64, r#break: &str, cut: bool) -> Self {
+        // `split($break)` with no flags reduces to `explode($break, $string)` here, then `chunk()`
+        // yields one entry per code point. `ignoreCase` is always false for freshly built instances.
+        let lines: Vec<&str> = if !r#break.is_empty() {
+            self.string.split(r#break).collect()
+        } else {
+            vec![&self.string]
+        };
+
+        let mut chars: Vec<String> = Vec::new();
+        let mut mask = String::new();
+
+        if lines.len() == 1 && lines[0].is_empty() {
+            return Self {
+                string: String::new(),
+            };
+        }
+
+        for (i, line) in lines.iter().enumerate() {
+            if i != 0 {
+                chars.push(r#break.to_string());
+                mask.push('#');
+            }
+
+            for ch in line.chars() {
+                let s = ch.to_string();
+                mask.push(if s == " " { ' ' } else { '?' });
+                chars.push(s);
+            }
+        }
+
+        let mut string = String::new();
+        let mut j: usize = 0;
+        // PHP seeds both `$b` and `$i` at -1; mirror with signed indices.
+        let mut i: i64 = -1;
+        let mask = php_wordwrap(&mask, width, "#", cut);
+        let mask_bytes = mask.as_bytes();
+
+        let mut b: i64 = -1;
+        loop {
+            // strpos($mask, '#', $b + 1)
+            let from = (b + 1) as usize;
+            let Some(rel) = mask_bytes[from..].iter().position(|&c| c == b'#') else {
+                break;
+            };
+            b = (from + rel) as i64;
+
+            i += 1;
+            while i < b {
+                string.push_str(&chars[j]);
+                j += 1;
+                i += 1;
+            }
+
+            if chars[j] == r#break || chars[j] == " " {
+                j += 1;
+            }
+
+            string.push_str(r#break);
+        }
+
+        for c in &chars[j..] {
+            string.push_str(c);
+        }
+
+        Self { string }
     }
 
-    pub fn to_byte_string(&self, _encoding: &str) -> String {
+    pub fn to_byte_string(&self, to_encoding: &str) -> String {
+        // The source is always valid UTF-8, so PHP's `toByteString` returns the string verbatim
+        // whenever the target is null/UTF-8 (the only encodings reached here). The
+        // mb_convert_encoding/iconv path applies only to non-UTF-8 targets, which do not occur.
+        if matches!(to_encoding, "" | "utf8" | "utf-8" | "UTF8" | "UTF-8") {
+            return self.string.clone();
+        }
+
+        // TODO(phase-d): converting to a non-UTF-8 target encoding needs mb_convert_encoding/iconv,
+        // unreachable for Shirabe's UTF-8-only output.
         todo!()
     }
 }
+
+/// Port of PHP's built-in `wordwrap()` (`PHP_FUNCTION(wordwrap)` in ext/standard/string.c).
+/// Byte-based, matching PHP's single-byte/multi-byte break and cut handling.
+fn php_wordwrap(text: &str, linelength: i64, breakchar: &str, docut: bool) -> String {
+    let text = text.as_bytes();
+    let breakchar = breakchar.as_bytes();
+    let textlen = text.len() as i64;
+    let breaklen = breakchar.len() as i64;
+
+    if textlen == 0 {
+        return String::new();
+    }
+
+    let mut laststart: i64 = 0;
+    let mut lastspace: i64 = 0;
+
+    // Special case for a single-character break that needs no extra storage.
+    if breaklen == 1 && !docut {
+        let mut out = text.to_vec();
+        let mut current = 0i64;
+        while current < textlen {
+            let c = out[current as usize];
+            if c == breakchar[0] {
+                laststart = current + 1;
+                lastspace = current + 1;
+            } else if c == b' ' {
+                if current - laststart >= linelength {
+                    out[current as usize] = breakchar[0];
+                    laststart = current + 1;
+                }
+                lastspace = current;
+            } else if current - laststart >= linelength && laststart != lastspace {
+                out[lastspace as usize] = breakchar[0];
+                laststart = lastspace + 1;
+            }
+            current += 1;
+        }
+        return String::from_utf8_lossy(&out).into_owned();
+    }
+
+    // Multiple character line break or forced cut.
+    let mut out: Vec<u8> = Vec::new();
+    let mut current = 0i64;
+    while current < textlen {
+        // When we hit an existing break, copy to the new buffer and fix up laststart/lastspace.
+        if text[current as usize] == breakchar[0]
+            && current + breaklen < textlen
+            && &text[current as usize..(current + breaklen) as usize] == breakchar
+        {
+            out.extend_from_slice(&text[laststart as usize..(current + breaklen) as usize]);
+            current += breaklen - 1;
+            laststart = current + 1;
+            lastspace = current + 1;
+        } else if text[current as usize] == b' ' {
+            if current - laststart >= linelength {
+                out.extend_from_slice(&text[laststart as usize..current as usize]);
+                out.extend_from_slice(breakchar);
+                laststart = current + 1;
+            }
+            lastspace = current;
+        } else if current - laststart >= linelength && docut && laststart >= lastspace {
+            out.extend_from_slice(&text[laststart as usize..current as usize]);
+            out.extend_from_slice(breakchar);
+            laststart = current;
+            lastspace = current;
+        } else if current - laststart >= linelength && laststart < lastspace {
+            out.extend_from_slice(&text[laststart as usize..lastspace as usize]);
+            out.extend_from_slice(breakchar);
+            laststart = lastspace + 1;
+            lastspace = lastspace + 1;
+        }
+        current += 1;
+    }
+
+    // Copy over any stragglers.
+    if laststart != current {
+        out.extend_from_slice(&text[laststart as usize..current as usize]);
+    }
+
+    String::from_utf8_lossy(&out).into_owned()
+}
diff --git a/crates/shirabe-external-packages/src/symfony/string/mod.rs b/crates/shirabe-external-packages/src/symfony/string/mod.rs
index 411a3f3..139d726 100644
--- a/crates/shirabe-external-packages/src/symfony/string/mod.rs
+++ b/crates/shirabe-external-packages/src/symfony/string/mod.rs
@@ -6,11 +6,12 @@ pub use byte_string::*;
 pub use code_point_string::*;
 pub use unicode_string::*;
 
-/// Mirror of Symfony's `u()` / `b()` helper functions.
-pub fn b(_string: &str) -> ByteString {
-    todo!()
+/// Mirror of Symfony's `b()` helper function.
+pub fn b(string: &str) -> ByteString {
+    ByteString::new(string)
 }
 
-pub fn s(_string: &str) -> UnicodeString {
-    todo!()
+/// Mirror of Symfony's `u()` helper function.
+pub fn s(string: &str) -> UnicodeString {
+    UnicodeString::new(string)
 }
diff --git a/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs b/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
index 8917f20..e415846 100644
--- a/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
+++ b/crates/shirabe-external-packages/src/symfony/string/unicode_string.rs
@@ -34,11 +34,23 @@ impl UnicodeString {
         width
     }
 
+    // TODO(phase-d): the faithful `length()` uses `grapheme_strlen` (extended grapheme clusters),
+    // which needs Unicode segmentation tables with no Rust std equivalent and no permitted crate.
+    // Approximated with the code-point count, exact only when no combining/multi-code-point
+    // clusters are present (e.g. ASCII).
     pub fn length(&self) -> i64 {
-        todo!()
+        shirabe_php_shim::mb_strlen(&self.string, "UTF-8")
     }
 
-    pub fn slice(&self, _start: i64, _length: Option<i64>) -> Self {
-        todo!()
+    // TODO(phase-d): the faithful `slice()` uses `grapheme_substr` (grapheme-cluster offsets), which
+    // needs Unicode segmentation tables with no std equivalent and no permitted crate. Approximated
+    // with code-point offsets via `mb_substr`, exact only without combining/multi-code-point clusters.
+    pub fn slice(&self, start: i64, length: Option<i64>) -> Self {
+        Self::new(&shirabe_php_shim::mb_substr(
+            &self.string,
+            start,
+            length,
+            Some("UTF-8"),
+        ))
     }
 }