expandMacrosWith:

In Pharo, there's a very useful method String>expandMacrosWith:, virtually without documentation. It's much like printf in C. I guess it's easily understood from a few examples, so here go:

"<1s> is replaced by the first argument, a string.
 <n> is a newline, <t> is a tab. 
 % escapes brackets."
'<1s><n><t>%<inject><n><t>^<1s>' expandMacrosWith: 'player'
➔
'player
 <inject>
 ^player'


"p calls printString":
'<1p>' expandMacrosWith: #(1 2 3)
➔
'#(1 2 3)'


"? prints one string or another, depending on a Boolean"
'Dear <1?Mr:Mrs> <2s>, your contract has expired.' 
  expandMacrosWith: false   with: 'Smith'
➔
'Dear Mrs Smith, your contract has expired.'