syntax_data: {"ast_node_type":"other","tokens":[{"end":49,"kind":"keyword","start":0,"text":"dx:"}]}
source_snippet:         dx: reg, reg_abcd = ["dx", "edx", "rdx"],
context_before:         cx: reg, reg_abcd = ["cx", "ecx", "rcx"],
context_after:         si: reg = ["si", "esi", "rsi"] % esi_reserved,