luarocks.fun: a basic set of functional utilities

Move `array_contains` away from the `luarocks.util` kitchen sink,
and add a `luarocks.fun` module with some basic functional utilities.

I considered using luafun instead, but at this point the basic
functionality of LuaRocks has no mandatory external dependencies,
so I thought I'd just add these functions internally instead.

4 files changed, 47 insertions, 15 deletions

diff --git a/src/luarocks/build.lua b/src/luarocks/build.lua
index 860cbdc1..74135379 100644
--- a/src/luarocks/build.lua
+++ b/src/luarocks/build.lua
@@ -3,6 +3,7 @@ local build = {}
 
 local path = require("luarocks.path")
 local util = require("luarocks.util")
+local fun = require("luarocks.fun")
 local fetch = require("luarocks.fetch")
 local fs = require("luarocks.fs")
 local dir = require("luarocks.dir")
@@ -254,7 +255,7 @@ function build.build_rockspec(rockspec_file, need_to_fetch, minimal_mode, deps_m
          build_spec.type = "builtin"
       end
 
-      if cfg.accepted_build_types and util.array_contains(cfg.accepted_build_types, build_spec.type) then
+      if cfg.accepted_build_types and fun.contains(cfg.accepted_build_types, build_spec.type) then
          return nil, "This rockspec uses the '"..build_spec.type.."' build type, which is blocked by the 'accepted_build_types' setting in your LuaRocks configuration."
       end
 
diff --git a/src/luarocks/fun.lua b/src/luarocks/fun.lua
new file mode 100644
index 00000000..e8e0c6bb
--- /dev/null
+++ b/src/luarocks/fun.lua
@@ -0,0 +1,40 @@
+
+--- A set of basic functional utilities
+local fun = {}
+
+function fun.concat(xs, ys)
+   local rs = {}
+   local n = #xs
+   for i = 1, n do
+      rs[i] = xs[i]
+   end
+   for i = 1, #ys do
+      rs[i + n] = ys[i]
+   end
+   return rs
+end
+
+function fun.contains(xs, v)
+   for _, x in ipairs(xs) do
+      if v == x then
+         return true
+      end
+   end
+   return false
+end
+
+function fun.map(f, xs)
+   local rs = {}
+   for i = 1, #xs do
+      rs[i] = f(xs[i])
+   end
+   return rs
+end
+
+function fun.traverse(f, t)
+   return fun.map(function(x)
+      return type(x) == "table" and fun.traverse(f, x) or f(x)
+   end, t)
+end
+
+return fun
diff --git a/src/luarocks/tools/patch.lua b/src/luarocks/tools/patch.lua
index 30ed1419..2e95e879 100644
--- a/src/luarocks/tools/patch.lua
+++ b/src/luarocks/tools/patch.lua
@@ -11,7 +11,7 @@
 local patch = {}
 
 local fs = require("luarocks.fs")
-local util = require("luarocks.util")
+local fun = require("luarocks.fun")
 
 local io = io
 local os = os
@@ -284,7 +284,7 @@ function patch.read_patch(filename, data)
     local advance
     if state == 'filenames' then
       if startswith(line, "--- ") then
-        if util.array_contains(files.source, nextfileno) then
+        if fun.contains(files.source, nextfileno) then
           all_ok = false
           warning(format("skipping invalid patch for %s",
                          files.source[nextfileno+1]))
@@ -307,7 +307,7 @@ function patch.read_patch(filename, data)
           table.insert(files.source, match)
         end
       elseif not startswith(line, "+++ ") then
-        if util.array_contains(files.source, nextfileno) then
+        if fun.contains(files.source, nextfileno) then
           all_ok = false
           warning(format("skipping invalid patch with no target for %s",
                          files.source[nextfileno+1]))
@@ -318,7 +318,7 @@ function patch.read_patch(filename, data)
         end
         state = 'header'
       else
-        if util.array_contains(files.target, nextfileno) then
+        if fun.contains(files.target, nextfileno) then
           all_ok = false
           warning(format("skipping invalid patch - double target at line %d",
                          lineno+1))
@@ -360,7 +360,7 @@ function patch.read_patch(filename, data)
     if not advance and state == 'hunkhead' then
       local m1, m2, m3, m4 = match_linerange(line)
       if not m1 then
-        if not util.array_contains(files.hunks, nextfileno-1) then
+        if not fun.contains(files.hunks, nextfileno-1) then
           all_ok = false
           warning(format("skipping invalid patch with no hunks for file %s",
                          files.target[nextfileno]))
diff --git a/src/luarocks/util.lua b/src/luarocks/util.lua
index 2c4724f4..59173449 100644
--- a/src/luarocks/util.lua
+++ b/src/luarocks/util.lua
@@ -442,15 +442,6 @@ function util.get_default_rockspec()
    end
 end
 
-function util.array_contains(tbl, value)
-   for _, v in ipairs(tbl) do
-      if v == value then
-         return true
-      end
-   end
-   return false
-end
-
 -- Quote Lua string, analogous to fs.Q.
 -- @param s A string, such as "hello"
 -- @return string: A quoted string, such as '"hello"'