Function Repository Resource:

SpliceAt

Source Notebook

Splice expressions at certain positions

Contributed by: Nikolay Murzin

ResourceFunction["SpliceAt"][expr,{e₁,e₂,…},pos]

splices expressions e_i at position pos of expr.

ResourceFunction["SpliceAt"][expr,{p₁→{e₁₁,e₁₂,…},p₂→{e₂₁,e₂₂,…},…}]

splices expressions e_ij at corresponding positions p_i.

ResourceFunction["SpliceAt"][{e₁,e₂,…}, pos]

represents an operator form that can be applied to an expression.

ResourceFunction["SpliceAt"][{p₁→{e₁₁,e₁₂,…},p₂→{e₂₁,e₂₂,…},…}]

represents an operator form with rules.

Examples

Basic Examples (3)

Splice a list of expressions inside another expression:

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Splice at multiple positions:

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Splice with rules:

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Scope (3)

Use Unevaluated to prevent premature evaluation:

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Use RuleDelayed to delay evaluation for rules:

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Use operator forms:

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Properties and Relations (4)

In most cases, SpliceAt is just equivalent to Insert with Sequence:

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But Insert will not work at deeper than first level inside held arguments:

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While SpliceAt works as expected:

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Also Insert does not support multiple insertions, while SpliceAt does:

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Possible Issues (2)

Root position is invalid:

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Subhead position is invalid:

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Version History

1.0.0 – 19 April 2022

Related Resources

Author Notes

Main motivation was to splice inside held arguments

License Information

This work is licensed under a Creative Commons Attribution 4.0 International License