map ';' MACRO (';' LIST)*

Summary

The map macro applies a transformation function (specified as a macro name) to each element of one or more lists, collecting the results into a new comma-separated list. This is similar to the functional programming map operation.

Syntax

${map;<macro-name>[;<list>...]}

Parameters

• macro-name - Name of a macro to invoke for each element (without the ${} wrapper)
• list - One or more semicolon-separated lists to process

Behavior

• Combines all provided lists into a single list
• For each element, invokes: ${<macro-name>;<element>}
• Collects all transformation results
• Returns results as a comma-separated string

Examples

Transform list elements:

# Define transformation macro
upper;${toupper;$1}

# Map to uppercase
${map;upper;apple,banana,cherry}

Add prefix to each element:

# Define prefix macro
add-prefix;modified-$1

${map;add-prefix;file1,file2,file3}
# Returns: "modified-file1,modified-file2,modified-file3"

Process file list:

# Define file processor
process;${basename;$1}

${map;process;/path/to/file1.jar;/path/to/file2.jar}
# Returns basenames of files

Calculate transformations:

# Define calculation macro
double;${multiply;$1;2}

${map;double;1,2,3,4,5}
# Returns: "2,4,6,8,10"

Use Cases

• Transforming lists with complex logic
• Applying consistent transformations to all elements
• Building derived lists from source data
• Functional-style list processing
• Batch operations on list elements
• Data transformation pipelines

Notes

• The invoked macro receives one argument: the element value
• Unlike ${foreach}, no index is passed to the macro
• The macro must be defined before use (either as a property or built-in)
• Results are joined with commas
• Empty lists produce empty results
• See also: ${foreach} for transformations that need the element index
• See also: ${apply} for passing entire lists to a macro

See test cases in MacroTestsForDocsExamples.java