Stdlib module compiler/backends/ast/target_expr.vit
This page is a wiki-style reference for one concrete stdlib file. It explains what the file owns, where it fits in the family, and how to decide whether this is the right surface to depend on.
compiler/backends/ast/target_expr.vit.Family: compiler
Kind: compiler-facing or orchestrator module
Page style: this reference follows the same “encyclopedic card + portrait + usage contract” logic as the keyword pages, but for stdlib modules.
Summary
- Overview
- Purpose
- Taxonomy
- Implementation profile
- Top-level API inventory
- Position in family
- Declaration map
- Representative signatures
- How to use this module
- User example
- Keyword coverage
- Source shape
- Source landmarks
- Source organization
- Complete API catalog
- Integration boundaries
- Composition guidance
- Relationship table
- Neighbor modules
Overview
| Field | Value |
|---|---|
| Path | compiler/backends/ast/target_expr.vit |
| Family | compiler |
| Kind | compiler-facing or orchestrator module |
| Line count | 51 |
| Declared procedures | 10 |
| Declared forms/picks | 1 |
`compiler/backends/ast/target_expr.vit` is a compiler-facing or orchestrator module inside the `compiler` family. It should be read as one focused slice of the broader family responsibility: Compiler-owned stdlib surfaces that support self-hosted compiler and driver integration.
Purpose
This file should be chosen because of responsibility, not because its name “sounds close enough”. Inside the compiler family, it carries one focused part of the contract and keeps that responsibility separate from neighboring concerns.
- A self-hosted compiler flow can reuse structured helpers without pretending they are general stdlib entry points.
- A driver surface can depend on this family while still keeping its public contract documented elsewhere.
Taxonomy
Think of this page as a generated encyclopedia entry rather than a hand-written tutorial. The goal is to show what kind of module this is, how dense it is, and what reading strategy makes sense before depending on it.
- Medium procedure surface: this file groups several related operations behind one namespace.
- Owns domain vocabulary: the module declares data shapes in addition to executable helpers, so its types are part of the contract.
- Minimal top-level dependencies: the module reads as mostly self-contained from its opening declarations.
Implementation profile
This profile is inferred directly from the source text. It does not replace reading the file, but it tells you quickly whether the module is mostly declarative, loop-heavy, branch-heavy, or organized around many small exits.
| Signal | Count | What it suggests |
|---|---|---|
if | 0 | Branching density and local decision-making. |
while | 0 | Loop-heavy or iterative implementation style. |
for | 0 | Collection-style traversal at source level. |
match | 0 | Variant-driven branching or grammar-style decoding. |
let | 0 | Local state and intermediate value density. |
give | 10 | Number of explicit exit points and result shaping. |
Top-level API inventory
| Surface | Items |
|---|---|
| Procedures | literal, variable, unary, binary, call_named, call_expr, cast, member, index, lambda |
| Forms | none declared at top level |
| Picks | TargetExpr |
| Constants | none declared at top level |
| Exports | none declared at top level |
Imported surfaces
This file does not advertise a top-level `use` surface in its opening declarations. That often means it is either self-contained or an aggregation layer.
Position in family
This file is module 2 of 27 in the compiler family when ordered by path. By procedure count it ranks 4, and by line count it ranks 9. Those ranks are useful as rough signals of breadth, not as quality judgments.
Declaration map
The declaration map turns raw source into a scan-friendly catalog. It is useful when the file is large enough that a reader wants to orient by kinds of surfaces first.
| Line | Name | Kind | Role |
|---|---|---|---|
| 1 | vitte/stdlib_checked/compiler_backends_ast_target_expr | space | Declares the namespace that anchors this file in the stdlib tree. |
| 9 | TargetExpr | pick | Introduces a tagged variant type used to model distinct outcomes. |
| 13 | literal | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 17 | variable | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 21 | unary | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 25 | binary | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 29 | call_named | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 33 | call_expr | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 37 | cast | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 41 | member | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 45 | index | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 49 | lambda | proc | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
The table is exhaustive for top-level declarations of the selected kinds. This file declares 12 matching surfaces.
Representative signatures
These signatures are shown in source order so the page keeps the feel of a reference manual, not just a keyword cloud.
pick TargetExpr {(line 9)proc literal() -> int {(line 13)proc variable() -> int {(line 17)proc unary() -> int {(line 21)proc binary() -> int {(line 25)proc call_named() -> int {(line 29)proc call_expr() -> int {(line 33)proc cast() -> int {(line 37)proc member() -> int {(line 41)proc index() -> int {(line 45)proc lambda() -> int {(line 49)
How to use this module
Start by reading the file as an ownership boundary. Ask three questions: what enters this module, what stable types or procedures it exports, and what adjacent module should stay outside of it.
- Read
spaceand top-level imports first so the ownership boundary ofcompiler/backends/ast/target_expr.vitis explicit. - Read declared forms and picks before algorithms so the data vocabulary is stable in your head.
- Traverse procedures in source order; the early helpers usually explain the naming and numeric conventions used later.
- Only after that compare neighbor modules, because the right boundary choice matters more than memorizing one helper name.
User example
This example is generated from the actual stdlib module surface. Its job is not to be the smallest snippet possible; its job is to show a realistic consumer-shaped file that exercises the module and mirrors the language keywords the module itself relies on.
space demo/compiler_backends_ast_target_expr
pick UserOutcome {
case Ready(message: string)
case Empty(reason: string)
}
proc run_example() -> UserOutcome {
give UserOutcome.Ready("ok")
}
Keyword coverage
This table makes the “all keywords of the module” requirement auditable. It compares the detected Vitte keywords in the source file with the generated consumer example above.
| Keyword | Present in module source | Used in generated user example |
|---|---|---|
space | yes | yes |
pick | yes | yes |
proc | yes | yes |
give | yes | yes |
The generated snippet exercises every detected Vitte keyword used by this module.
Source shape
space vitte/stdlib_checked/compiler_backends_ast_target_expr
pick TargetExpr {
Ok
}
proc literal() -> int {
give 0
}
proc variable() -> int {
give 0
}
The excerpt is not meant to replace the file. It exists to make the module recognizable at first glance, the same way a Wikipedia infobox helps the reader orient before reading the whole article.
Source landmarks
Large files are easier to retain when they have visible landmarks. When the source contains explicit section banners, they are surfaced here; otherwise the first major declarations are used as anchors.
- Line 1:
space vitte/stdlib_checked/compiler_backends_ast_target_expr - Line 9:
pick TargetExpr { - Line 13:
proc literal() -> int { - Line 17:
proc variable() -> int { - Line 21:
proc unary() -> int { - Line 25:
proc binary() -> int { - Line 29:
proc call_named() -> int { - Line 33:
proc call_expr() -> int {
Source organization
When a file carries its own internal chaptering, those chapters usually reveal the intended reading order better than a flat symbol list. This section reconstructs that organization from the source itself.
File surfaces
Top-level items: 12. Procedures: 10. Data surfaces: 1. Constants: 0.
First visible names: vitte/stdlib_checked/compiler_backends_ast_target_expr, TargetExpr, literal, variable, unary, binary, call_named, call_expr, cast, member
Complete API catalog
This catalog is the exhaustive file-level index for the module. It is intentionally closer to a generated encyclopedia appendix than to a tutorial summary.
Data surfaces
| Line | Name | Signature | Role |
|---|---|---|---|
| 9 | TargetExpr | pick TargetExpr { | Introduces a tagged variant type used to model distinct outcomes. |
Procedures
| Line | Name | Signature | Role |
|---|---|---|---|
| 13 | literal | proc literal() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 17 | variable | proc variable() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 21 | unary | proc unary() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 25 | binary | proc binary() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 29 | call_named | proc call_named() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 33 | call_expr | proc call_expr() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 37 | cast | proc cast() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 41 | member | proc member() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 45 | index | proc index() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
| 49 | lambda | proc lambda() -> int { | Supports compiler-facing orchestration, lowering, diagnostics, or backend work. |
Integration boundaries
Within compiler, this file should remain focused. If a future helper changes the host boundary, scheduling boundary, or data-shape boundary, it probably belongs in a neighbor module instead of being added here by convenience.
- Family responsibility: Compiler-owned stdlib surfaces that support self-hosted compiler and driver integration.
- Family architecture role: This family is not general-purpose business code. It exists to support compiler-owned flows where the compiler and stdlib need a shared contract.
Composition guidance
Choose this module when
- Choose
compiler/backends/ast/target_expr.vitwhen the main question is owned by this module rather than by transport, storage, orchestration, or user-interface code. - A self-hosted compiler flow can reuse structured helpers without pretending they are general stdlib entry points.
- A driver surface can depend on this family while still keeping its public contract documented elsewhere.
Pause before extending it when
- Avoid extending this file when the new helper mostly changes the boundary to host I/O, runtime coordination, or foreign integration instead of staying inside
compiler. - Check nearby modules such as
compiler/backends/ast/target_decl.vit,compiler/backends/ast/target_stmt.vit,compiler/backends/ast/target_type.vitbefore adding convenience wrappers here.
Relationship table
This table keeps the page closer to a real encyclopedia entry: a module is easier to understand when compared with its nearest alternatives in the same family.
| Neighbor | Procedures | Data surfaces | Why compare it |
|---|---|---|---|
compiler/backends/ast/target_decl.vit | 2 | 10 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/ast/target_stmt.vit | 6 | 1 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/ast/target_type.vit | 9 | 3 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/backend.vit | 8 | 2 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/context/backend_context.vit | 17 | 4 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/emit/emit.vit | 11 | 0 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/lower/lower_mir.vit | 7 | 6 | Shares the same family boundary but carries a distinct slice of responsibility. |
compiler/backends/mod.vit | 6 | 1 | Shares the same family boundary but carries a distinct slice of responsibility. |