Scope of Haloform reaction We know that methyl ketones and secondary alcohols oxidizable to methyl ketones, such as isopropanol. The only primary alcohol and aldehyde to undergo this reaction are ethanol and acetaldehyde, respectively. 1,3-Diketones such as acetylacetone also give the haloform reaction.
Do Terminal Alkynes give Haloform Reaction if Yes then how the mechanism will follow?
Terminal alkynes, including phenyl acetylene, react with iodine (in MeOH) to give 1,2-diiodoalkenes according to this JOC paper  here. Presence or absence of base will not alter the outcome. Presence of AgNO3 gives some di-iodo ketone which can then give rise to the iodoform reaction.