Lesson 01 · A literal name match - Build a Glob and Gitignore Matcher

A literal name match

Every glob is a pattern with special characters sprinkled into an ordinary name, so the honest place to start is a pattern with no special characters at all - a plain string that must match exactly. Today you build the one function the whole library grows out of.

The goal

Match a pattern against a name by exact equality.

Start here - the target

TO DO

Scenario: A pattern with no wildcards matches only the identical name

Giventhe pattern 'foo'

WhenMatch is called against various names

ThenMatch("foo", "foo") is true, and Match("foo", "bar") is false

AndMatch("foo", "food") is false and Match("foo", "fo") is false - a literal pattern matches the whole name, not a prefix or a substring

Background

A glob is a small pattern language for matching filenames: *.txt, src/**, [abc]. Before any of the special characters mean anything, the base case has to be right - a pattern that is just an ordinary name matches only that exact name. Not a prefix, not a substring, the whole thing.

Today’s Match is deliberately trivial: string equality. Every later lesson keeps the same signature - Match(pattern, name) returning a boolean - and teaches one more character (?, *, [, \, /) how to behave. Getting the literal case and the signature pinned now means each new feature is a small, local change to one function.

Make it work

// the whole library grows from this one function
func Match(pattern, name string) bool {
  return pattern == name
}

CheckpointDONE

Match compares a wildcard-free pattern to a name by exact equality. Commit and stop here.