gudusoft.gsqlparser.pp2.render

Class ConservativeTokenRenderer

Object

gudusoft.gsqlparser.pp2.render.ConservativeTokenRenderer

All Implemented Interfaces:

RegionRenderer

public final class ConservativeTokenRenderer
extends Object
implements RegionRenderer

The MVP fallback renderer (plan §7.3/S14): walks the region's slice of a Pp2TokenStream and emits each token's text with light spacing. No clause-level layout, no recognition pipeline — pure token passthrough.

Why it exists

GuardedAstDelegate (S13) only fires on regions whose source actually parses. Everything else — invalid SQL, partial scripts, vendor fragments the parser doesn't yet support — needs a renderer that guarantees every solid input token appears in the output, in order without throwing or losing bytes. Until the lexical island pipeline (S31) ships, the conservative renderer is the only safety net the engine has. Even after S31 lands it stays as the last-resort renderer for cases where the island pipeline itself throws.

Output shape

Two operating modes, selected by Pp2FormatOptions.commentPolicy:

• CommentPolicy.PRESERVE (default): emit each token's original preceding whitespace verbatim — the renderer is a byte-exact passthrough modulo the inter-region leading trivia, which is handed off to the region assembler (S15).
• CommentPolicy.REANCHOR / CommentPolicy.REFLOW: a single space between consecutive tokens, with a "\n" inserted after every ";". No other layout choices are made — the renderer never reorders, never drops, never merges.

Regardless of policy, tokens carrying the TokenRole.NO_FORMAT_ZONE role are emitted with their original preceding whitespace, so --BEGIN_NO_FORMAT/--END_NO_FORMAT blocks survive byte-exact through any policy.

Leading-trivia ownership

The renderer never emits leading whitespace for the first token of the range — that whitespace belongs to the inter-region gap handled by the assembler (S15). The renderer's output starts with the first token's text and ends with the last token's text. Trailing trivia after the last token is similarly the assembler's responsibility.

Content-preservation guarantee

Every Pp2Token in the range contributes its text to the output exactly once, in source order; nothing is dropped, reordered, or collapsed. This guarantee is verified by TokenEquivalence in ConservativeTokenRendererTest.

Plan reference: §5.2, §7.3/S14, §7.4/S14.

Constructor Summary

Constructors

Constructor and Description
ConservativeTokenRenderer()

Method Summary

Modifier and Type	Method and Description
long	getEmittedTokenCount() Number of tokens emitted across all rendered regions.
long	getRenderedRegionCount() Number of regions render(...) has produced output for.
RendererId	id() Identifier mirrored on RendererId so Pp2FormatResult.Region.getRendererId() reflects which strategy actually produced the text for the region.
String	render(RegionParseOutcome outcome, Pp2TokenStream stream, Pp2FormatOptions opts) Render the outcome's region to its final text.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConservativeTokenRenderer

public ConservativeTokenRenderer()

Method Detail

getRenderedRegionCount

public long getRenderedRegionCount()

Number of regions render(...) has produced output for.

getEmittedTokenCount

public long getEmittedTokenCount()

Number of tokens emitted across all rendered regions.

id

public RendererId id()

Description copied from interface: RegionRenderer

Identifier mirrored on RendererId so Pp2FormatResult.Region.getRendererId() reflects which strategy actually produced the text for the region.

Specified by:

id in interface RegionRenderer

render

public String render(RegionParseOutcome outcome,
                     Pp2TokenStream stream,
                     Pp2FormatOptions opts)

Description copied from interface: RegionRenderer

Render the outcome's region to its final text.

Specified by:

render in interface RegionRenderer

Parameters:

outcome - non-null parse outcome for the region. Implementations may assume RegionParseOutcome.getRange() and RegionParseOutcome.getParsedSql() are non-null. RegionParseOutcome.getParser() is non-null only for AST_OK outcomes.

stream - the engine's full Pp2TokenStream for the whole input script (token-based renderers slice into it via the outcome's range token indices)

opts - non-null pp2 options

Returns:

the formatted text for this region, or null (the only sentinel) to signal fall-through to the next renderer in the chain. An empty string is a valid rendering, not a fall-through.