base/small-spacer-merge-to-enspace

Level

AuthoringFaithfulCorpusEquivEvery profile applies this rule; its output remains suitable for authoring.

Fidelity

renderPreserves rendering under the reference renderer.

Package

base

Source

base/authoring/spacing_merge/small_spacer_merge_to_enspace.rs (opens in new tab)

Triggers

\,, \:, \; commands

Produces

\enspace command

Touches

\,, \:, \; commands

Rewrite patterns#

1. thin-triple\,\,\,\enspace
2. colon-semicolon\:\;\enspace
3. semicolon-colon\;\:\enspace

Examples#

Each example shows this rule applied in isolation. A complete normalization profile may make additional changes.

A\,\,\,B

A\enspace B

A\:\;B

A\enspace B

A\;\:B

A\enspace B

A\,\,\,\,\,\,\,B

A\enspace\enspace\,B

A\:\;\;\:B

A\enspace\enspace B

\text{A\,\,\,B}

\text{A\,\,\,B}

Related rules#

Upstream rules#

• ams/impliedby-to-Longleftarrow Collapse impliedby to the explicit AMS long-left-arrow spelling with source-backed spacing.
• ams/implies-to-Longrightarrow Collapse implies to the explicit AMS long-right-arrow spelling with source-backed spacing.
• ams/idotsint-expand Expand idotsint to explicit repeated integral surfaces.
• base/gt-space-to-colon-space Collapse \> to the canonical medium math space command \:
• base/thinspace-to-comma-space Collapse thinspace to the explicit thin math space command.

Downstream rules#

• base/double-enspace-to-quad Rewrite two adjacent enspaces to one exact-width quad.
• base/enspace-drop Drop enspace in math mode and collapse each text-mode enspace run to one ordinary space.

Same family#

• ams/nobreakspace-to-tilde Collapse nobreakspace to the canonical nonbreaking space token.
• base/break-to-linebreak Collapse break to the explicit linebreak command.
• base/newline-to-linebreak Collapse newline to the explicit linebreak command.
• base/control-space-to-tilde Rewrite math-mode control space to the canonical active space token.
• base/gt-space-to-colon-space Collapse \> to the canonical medium math space command \:
• base/hfil-to-hfill Collapse hfil to the canonical hfill command under MathJax spacing semantics.
• base/hfilll-to-hfill Collapse hfilll to the canonical hfill command.
• base/hskip-to-hspace Collapse hskip to the explicit hspace command.
• base/negthinspace-to-neg-comma-space Collapse negthinspace to the explicit negative thin math space command.
• base/space-to-tilde Collapse space to the explicit nonbreaking space token.
• base/thinspace-to-comma-space Collapse thinspace to the explicit thin math space command.
• base/double-enspace-to-quad Rewrite two adjacent enspaces to one exact-width quad.
• base/double-quad-to-qquad Merge two adjacent quads into one qquad for authoring normalization.
• base/allowbreak-drop Drop allowbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/badbreak-drop Drop badbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/goodbreak-drop Drop goodbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/mathstrut-drop Drop the invisible mathstrut layout helper in cleanup-oriented normalization.
• base/nobreak-drop Drop nobreak as a pure linebreak hint during cleanup-oriented normalization.
• base/strut-drop Drop the fixed empty strut node in cleanup-oriented normalization.
• base/enspace-drop Drop enspace in math mode and collapse each text-mode enspace run to one ordinary space.
• base/qquad-drop Drop qquad in math mode and collapse each text-mode qquad run to one ordinary space.
• base/quad-drop Drop quad in math mode and collapse each text-mode quad run to one ordinary space.
• base/mkern-to-mspace Collapse mkern to the explicit mspace command.
• base/mskip-to-mspace Collapse mskip to the explicit mspace command.

Notes#

Authoring-level exact-width canonicalization for math-mode sibling runs. Starting at the first matching Spacer in a maximal run, scan left to right and replace every non-overlapping declared chunk in one rule application: each three consecutive \, commands become one \enspace, and each \:\; or \;\: pair becomes one \enspace. Process all available multiples at once instead of relying on later fixed-point iterations; for example, seven consecutive \, commands become \enspace\enspace\,, and \:\;\;\: becomes \enspace\enspace. Preserve unmatched remainder commands in their original order. MathJax defines \, as exactly 3/18 em and \enspace as exactly 0.5 em, so the declared width algebra is exact. The reviewed inline mismatch for repeated thin-space chunks is an accepted browser layout quantization exception: separately positioned mspace elements can accumulate to a one-pixel raster size difference even though their MathJax lengths are equal. Do not generalize this exception beyond these declared chunks or relax the global rendering threshold. Do not generalize this rule into arbitrary width decomposition or reorder other equal-width runs. Text-mode records, groups, scripts, cells, other slots, negative spacing, ActiveSpace, control space, hspace, and mspace remain unchanged. Every Applied result consumes at least one complete source chunk and produces no touched small-spacer target, so the total count of touched source spacer nodes strictly decreases.

Disable this rule#

TransformEngine(profile="corpus", disable_rules=["base/small-spacer-merge-to-enspace"])

new TransformEngine({ profile: 'corpus', disableRules: ['base/small-spacer-merge-to-enspace'] })

Open in Playground