Document import type

Closes https://github.com/gleam-lang/language-tour/issues/61

2 files changed, 31 insertions, 0 deletions

diff --git a/src/content/chapter0_basics/lesson18_constants/code.gleam b/src/content/chapter0_basics/lesson18_constants/code.gleam
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+++ b/src/content/chapter0_basics/lesson18_constants/code.gleam
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+import gleam/io
+
+const ints: List(Int) = [1, 2, 3]
+
+const floats = [1.0, 2.0, 3.0]
+
+pub fn main() {
+  io.debug(ints)
+  io.debug(ints == [1, 2, 3])
+
+  io.debug(floats)
+  io.debug(floats == [1.0, 2.0, 3.0])
+}
diff --git a/src/content/chapter0_basics/lesson18_constants/en.html b/src/content/chapter0_basics/lesson18_constants/en.html
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+<p>
+  As well as let assignments Gleam also has constants, which are defined at the
+  top level of a module.
+</p>
+<p>
+  Constants must be literal values, functions cannot be used in their
+  definitions.
+</p>
+<p>
+  Constants may be useful for values that are used throughout your program,
+  permitting them to be named and to ensure there are no differences in the
+  definition between each use.
+</p>
+<p>
+  Using a constant may be more efficient than creating the same value in
+  multiple functions, though the exact performance characteristics will depend
+  on the runtime and whether compiling to Erlang or JavaScript.
+</p>