This document explains how to work with local variables in Codegen.

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Overview

Through the CodeBlock class, Graph-sitter exposes APIs for analyzing and manipulating local variables within code blocks.

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Basic Usage

Every code block (function body, loop body, etc.) provides access to its local variables:

# Get all local variables in a function
function = codebase.get_function("process_data")
local_vars = function.code_block.local_var_assignments
for var in local_vars:
    print(var.name)

# Find a specific variable
config_var = function.code_block.get_local_var_assignment("config")
config_var.rename("settings")  # Updates all references safely

# Rename a variable used in this scope (but not necessarily declared here)
function.rename_local_variable("foo", "bar")

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Fuzzy Matching

Graph-sitter supports fuzzy matching when searching for local variables. This allows you to find variables whose names contain a substring, rather than requiring exact matches:

# Get all local variables containing "config"
function = codebase.get_function("process_data")

# Exact match - only finds variables named exactly "config"
exact_matches = function.code_block.get_local_var_assignments("config")
# Returns: config = {...}

# Fuzzy match - finds any variable containing "config"
fuzzy_matches = function.code_block.get_local_var_assignments("config", fuzzy_match=True)
# Returns: config = {...}, app_config = {...}, config_settings = {...}

# Fuzzy matching also works for variable usages
usages = function.code_block.get_variable_usages("config", fuzzy_match=True)

# And for renaming variables
function.code_block.rename_variable_usages("config", "settings", fuzzy_match=True)
# Renames: config -> settings, app_config -> app_settings, config_settings -> settings_settings

Be careful with fuzzy matching when renaming variables, as it will replace the matched substring in all variable names. This might lead to unintended renames like config_settings becoming settings_settings.