Glyphs and Latin

Glyphs and operators#

Faber uses glyphs where the symbol is structural. Below is the full inventory of source glyphs recognised by the lexer.

Value flow#

Type shape#

Comparison#

Logical and bitwise#

Assignment updates#

Both are assignment. They differ in when the value is decided.

← stores a value at execution time: bindings, reassignment, mutation. = attaches a value the compiler already knows — field shape inside a literal, declaration metadata, annotation fields. Most languages spell both with = and leave the reader to infer which is meant; Faber splits them, so the glyph itself tells you whether anything happens at runtime.

class Punctum {
    int x
    int y
}

main {
    const Punctum p ← Punctum {x = 10, y = 20}
    var int count ← 0
    count ← count + 1
    print p.x, count
}

p ← … runs. x = 10 does not — it is the shape of the value being built, settled before the program starts.

Worked through in full under The binding convention matters.

Optional chaining and non-null assertion#

Ranges#

Literal delimiters#

Punctuation#

Latin vocabulary and structural glyphs#

Three signal choices that make Faber source recognisable at a glance.

Faber makes three deliberate signal choices that work together to produce source with stable grammatical shape. A reader can see the semantic role of every construct before knowing which target backend the code will be compiled to.

The three signals#

These three are designed to be mutually reinforcing. A reader who knows Faber in one locale can read it in any locale because the glyphs and structure never change. A reader who knows the Rust backend can still recognise the Faber source because the Latin keywords and type-first order produce a distinct visual register.

Type-first declarations#

Faber puts the type before the name in every declaration. This is the opposite of mainstream C-family syntax, and it is deliberate:

Type-first declarations mean the shape of data is the first thing the reader sees. This aligns naturally with languages that read left-to-right for semantic breadth — Chinese, Hindi, and Arabic declarations follow the same order.

fn divide(int a, int b) → int ∪ null {
    if b ≡ 0 then return null
    return a / b
}

Latin behavioural vocabulary#

Faber uses Latin words for every construct that has behavioural or grammatical shape. The vocabulary is small and regular, drawn from a single classical source rather than the mixed etymologies of most programming languages.

Declarations#

Bindings and transfer#

Control flow#

The Latin vocabulary is bindable — it ships with the canonical pack but can be remapped through reader locale. A Thai programmer sees ถ้า instead of si; a Chinese programmer sees 函数 instead of functio. The vocabulary is not privileged; only the grammar is.

Keywords are contextual: since Radix v0.79.0 there is no global reserved keyword table. The lexer emits identifiers for all words and the parser recognizes a keyword by spelling in its grammar position. A word is only a keyword in the slot where it is expected; everywhere else it is an ordinary identifier — you can name a variable si, a function functio, or a parameter vel. A small residual set (cape, custodi, itera, sic, iace, mori, adfirma, cede, incipit, incipiet, importa, ex) is still globally reserved.

Structural glyphs#

Where behavioural vocabulary uses Latin words, structural meaning uses universal glyphs. These never localise and never change their meaning across renderings. They are the visual anchor that makes Faber source recognisable regardless of which human language the keywords are rendered in.

Value flow#

Type shape#

Comparison and logic#

The binding convention matters#

One glyph choice deserves special attention because it is the most common point of confusion for new readers:

Most languages overload = for both "define this field in a type" and "put a runtime value in this variable." Faber splits those jobs. Every ← is live data flow; every = inside Type { … } is genus field layout.

# Runtime binding: ← attaches a value to a name
fixum numerus count ← 0
varia textus label ← "ready"
count ← count + 1

# Structural shape: = defines field values inside a literal
fixum _ p ← Point {
    x = 10,
    y = 20
}

Compared to mainstream languages#

The table below shows how common programming language patterns map to Faber's three-signal system. The Faber column uses a different glyph or keyword for each distinct semantic job — no overloading.

References#

1. EBNF grammar — full glyph and keyword inventory
2. radix/corpus/ — language corpus with 304 exemplar files across all keywords
3. radix/corpus/operatores/ — operator and glyph exemplars
4. Commandments — the nine design laws that preserve these signals

Canonical vs sugar surfaces#

Multiple parseable surfaces, one semantic shape.

A recurring pattern in Faber's design: the language defines one canonical spelling for each construct, but accepts multiple sugar spellings that are semantically identical. The compiler does not prefer one over the other — both parse to the same AST node. The formatter decides which spelling to emit based on context and mode.

The rule: Sugar spellings are semantically identical to long form. Multiple surfaces parse to the same HirAnnotation or type node. faber format --locale la re-emits canonical spellings; author mode preserves the sugar the author wrote.

Numeric type sugar#

Numeric types have long-form canonical spellings and compact sugar forms. The choice is per-module, not per-repository — a CLI package may use long form everywhere, while a tensor kernel module uses sugar:

General Faber (prefer long form):

const list<f32> values ← vacua

const tensor<f32, [2, 3]> grid ← vacua

const int<i32> narrow ← 7

Numeric modules (prefer sugar):

const list<f32> values ← vacua

const tensor<f32, [2, 3]> grid ← vacua

const int<i32> narrow ← 7

Sugar is type-position only. Value identifiers named f32, tf32, or mf32 are unchanged — the compiler only interprets these as sugar when they appear in type positions. A file that consistently uses sugar should say so once at the top:

# STYLE: numeric sugar (tf32, mf32, sf32, lf32, lu32)

Annotation sugar#

Faber annotations follow the same dual-surface model as numeric types. Annotations are compiler-owned metadata attached to declarations — like @ optio for CLI option definitions or @ futura for async functions (legacy — prefer the fiet posture word in the signature slot).

Canonical form: a braced record with explicit field names:

@ optio {
    binding = verbose,
    brevis = "v",
    longum = "verbose",
    typus = bivalens,
    ubique = verum,
    descriptio = "Enable verbose output"
}

Sugar form: positional arguments and named aliases:

@ optio verbose brevis "v" longum "verbose" typus bivalens ubique descriptio "Enable verbose output"

Both forms produce the same HirAnnotation record. The canonical form is explicit and self-documenting; the sugar form is concise for frequently-used annotations where the field order is well-known. faber format --locale la re-emits canonical braced records; author mode preserves the author's chosen form.

Author vs canonical formatting#

The faber format command operates in two modes that mirror the canonical-vs-sugar principle:

Both modes run through the compiler's full front half (lex, parse, analyse for canonical). Invalid source produces compiler diagnostics — the formatter does not silently format broken input.

Key rules for both modes:

• Four-space indentation
• Stroustrup braces: opening { on the same line as the controlling header
• Author mode preserves the presence of blank lines but collapses runs of more than one
• Author mode does not insert blank lines the source did not contain
• Canonical mode normalises type spellings to long form, tensor sugar to canonical, annotations to braced records
• Canonical mode emits T ∪ nihil for nullable unions, sponte for optional parameters

Design principle#

The canonical-vs-sugar pattern appears in multiple places because it is a deliberate design principle, not a collection of one-off conveniences:

The pattern serves two goals. First, it lowers the barrier to entry — new users can write tf32[4] without typing tensor<fractus<f32>, [4]>. Second, it keeps the canonical language unambiguous — when precision matters, the long form says exactly what it means. The formatter bridges the two: authors write sugar, reviewers can request canonical, and CI can enforce either.

References#

1. radix/docs/design/numeric-type-sugar.md — full sugar families, spelling preferences
2. radix/docs/design/annotation-sugar.md — dual-surface annotation model
3. radix/docs/design/faber-canonical-surface.md — author vs canonical format policy
4. faber/docs/EBNF.md — grammar tables for sugar forms