A VSCode extension that displays AST node counts for Go functions via CodeLens, helping you identify functions suitable for inline optimization.

• Real-time AST counting: Shows the number of AST nodes in each function as you type
• Inline optimization hints: Highlights functions under the 80-node threshold that may be inlined by the Go compiler
• Function call detection: Marks functions with calls using ~ prefix, indicating potential inlining uncertainty
• Noinline directive support: Detects //go:noinline comments and optionally hides those functions
• Configurable filtering: Customize which functions to display based on node count and call count

This extension is for reference only. The AST node count shown is an approximation and may not perfectly match the compiler's internal cost model. To verify whether a function will actually be inlined, always check the output of:

go build -gcflags="-m -m"

This extension contributes the following settings:

• goAstCodeLens.debounceDelay (default: 1000): Delay in milliseconds before recalculating AST nodes after typing stops
• goAstCodeLens.showOnlyInlineable (default: true): Only show CodeLens for functions with less than 80 AST nodes
• goAstCodeLens.maxFuncCalls (default: 1): Maximum number of function calls allowed to show CodeLens (0 = no function calls allowed)
• goAstCodeLens.showNoinline (default: false): Show CodeLens for functions with //go:noinline directive

• Go AST CodeLens: Delete AST Counter Binary: Delete the compiled AST counter binary
• Go AST CodeLens: Rebuild AST Counter Binary: Rebuild the AST counter binary

The extension uses a Go helper program to parse your code and count AST nodes. The counting logic:

• Counts all statements and expressions
• Skips structural nodes (BlockStmt, FieldList, Field)
• For KeyValueExpr, only counts the value part
• Excludes built-in functions (append, len, make, etc.) from function call count

Functions with any function calls (including built-ins) are marked with ~ to indicate the actual node count may be higher if those calls get inlined.

• Go must be installed on your system
• The extension will automatically compile the AST counter on first use

MIT