Implementation:Ggml org Llama cpp Regex Partial Header

Knowledge Sources	Ggml_org_Llama_cpp
Domains	Parsing, Regex
Last Updated	2026-02-15 00:00 GMT

Overview

Declares the interface for regex matching with partial match support.

Description

Defines the `common_regex_match_type` enum (none, partial, full), `common_string_range` for match group positions with begin/end offsets, and `common_regex_match` for match results containing the type and a vector of groups. The `common_regex` class wraps a pattern string, a compiled `std::regex`, and a precomputed reversed partial regex. Exposes `search()` for full/partial matching and `regex_to_reversed_partial_regex()` as a public test helper.

Usage

Include this header to use the partial regex matching API in constrained generation systems. It provides the type definitions and class interface needed to detect both full and partial regex matches on streaming model output.

Code Reference

Source Location

• Repository: Ggml_org_Llama_cpp
• File: common/regex-partial.h
• Lines: 1-56

Signature

enum common_regex_match_type {
    COMMON_REGEX_MATCH_TYPE_NONE,
    COMMON_REGEX_MATCH_TYPE_PARTIAL,
    COMMON_REGEX_MATCH_TYPE_FULL,
};

struct common_string_range {
    size_t begin;
    size_t end;
    common_string_range(size_t begin, size_t end);
    bool empty() const;
    bool operator==(const common_string_range & other) const;
};

struct common_regex_match {
    common_regex_match_type type = COMMON_REGEX_MATCH_TYPE_NONE;
    std::vector<common_string_range> groups;
    bool operator==(const common_regex_match & other) const;
    bool operator!=(const common_regex_match & other) const;
};

class common_regex {
public:
    explicit common_regex(const std::string & pattern);
    common_regex_match search(const std::string & input, size_t pos, bool as_match = false) const;
    const std::string & str() const;
};

std::string regex_to_reversed_partial_regex(const std::string & pattern);

Import

#include "regex-partial.h"

I/O Contract

Inputs

Name	Type	Required	Description
pattern	const std::string &	Yes	Regex pattern to compile and use for matching
input	const std::string &	Yes	String to search for full or partial matches
pos	size_t	Yes	Starting position in the input string
as_match	bool	No	If true, requires the full remaining string to match (defaults to false)

Outputs

Name	Type	Description
match	common_regex_match	Result containing match type (NONE/PARTIAL/FULL) and group positions
str()	const std::string &	The original pattern string

Usage Examples

#include "regex-partial.h"

// Construct a regex with partial match support
common_regex rx("\\d{3}-\\d{4}");

// Search for a match
common_regex_match result = rx.search("555-1234 extra", 0);
if (result.type == COMMON_REGEX_MATCH_TYPE_FULL) {
    // result.groups[0] contains the full match range
    auto range = result.groups[0];
    // range.begin == 0, range.end == 8
}

// Check for partial match at end of streaming input
common_regex_match partial = rx.search("555-12", 0, true);
// partial.type == COMMON_REGEX_MATCH_TYPE_PARTIAL

Related Pages

• Principle:Ggml_org_Llama_cpp_Constrained_Decoding