[oil-language] Examples of rewriting to use arrays.

oil_lang/testdata/array-rewrite-1.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+#
+# Example of Oil arrays.
+#
+# Adapted from ./linux-4.8.7/scripts/tags.sh
+
+# Show args to a command
+argv() { spec/bin/argv.py "$@"; }
+
+#
+# OLD, BASH-COMPATIBLE WAY
+#
+
+regex=('one' 'two')
+flags=()
+
+for r in "${regex[@]}"; do
+  flags[${#flags[@]}]="--regex=$r"
+done
+
+argv "${flags[@]}"
+
+
+#
+# NEW OIL WAY
+#
+# Things fixed:
+# - verbose "${a[@]}" becomes @a
+# - a=() is weird because it doesn't allow spaces around =
+# - builtin 'push' for appending
+#
+
+shopt -s static-word-eval oil-parse-at
+
+var regex2 = @(two three)
+var flags2 = @()
+
+for r in @regex2; do
+  push flags2 _ "--regex=$r"
+done
+
+argv @flags2

oil_lang/testdata/array-rewrite-2.sh

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+#!/bin/bash
+#
+# Example of rewriting string-based argv processing to use arrays.
+#
+# Adapted from ./linux-4.8.7/scripts/link-vmlinux.sh
+
+# Show args to a command
+argv() { spec/bin/argv.py "$@"; }
+
+#
+# OLD, BASH-COMPATIBLE WAY
+#
+# This style can't handle paths with spaces
+
+path='/etc/path with spaces'
+
+CONFIG_HAVE_FOO=yes
+
+flags=''
+
+if [ -n "${CONFIG_HAVE_FOO}" ]; then
+  flags="${flags} --foo=$path"
+fi
+
+if [ -n "${CONFIG_HAVE_BAR}" ]; then
+  flags="${flags} --bar"
+fi
+
+argv ${flags}  # unquoted splitting
+
+
+#
+# NEW OIL WAY
+#
+# - no quoting is necessary because of static-word-eval
+# - splice arrays with @
+# - builtin 'push' for appending
+#   - I might want to change the ignored delimiter character _ to something like
+#     : or :: or \\ .  Opinions?
+
+shopt -s oil-parse-at static-word-eval
+
+CONFIG_HAVE_FOO=yes
+
+var flags = @()
+
+if test -n $CONFIG_HAVE_FOO; then
+  push flags _ --foo=$path
+fi
+
+if test -n $CONFIG_KALLSYMS_BASE_RELATIVE; then
+  push flags _ --bar
+fi
+
+argv @flags