1 files changed, 217 insertions, 0 deletions
diff --git a/src/luarocks/queries.lua b/src/luarocks/queries.lua
new file mode 100644
index 0000000..0c8790f
--- /dev/null
+++ b/src/luarocks/queries.lua
@@ -0,0 +1,217 @@
+
+local queries = {}
+
+local vers = require("luarocks.core.vers")
+local util = require("luarocks.util")
+local cfg = require("luarocks.core.cfg")
+
+local query_mt = {}
+
+query_mt.__index = query_mt
+
+function query_mt.type()
+   return "query"
+end
+
+-- Fallback default value for the `arch` field, if not explicitly set.
+query_mt.arch = {
+   src = true,
+   all = true,
+   rockspec = true,
+   installed = true,
+   -- [cfg.arch] = true, -- this is set later
+}
+
+-- Fallback default value for the `substring` field, if not explicitly set.
+query_mt.substring = false
+
+--- Convert the arch field of a query table to table format.
+-- @param input string, table or nil
+local function arch_to_table(input)
+   if type(input) == "table" then
+      return input
+   elseif type(input) == "string" then
+      local arch = {}
+      for a in input:gmatch("[%w_-]+") do
+         arch[a] = true
+      end
+      return arch
+   end
+end
+
+--- Prepare a query in dependency table format.
+-- @param name string: the package name.
+-- @param namespace string?: the package namespace.
+-- @param version string?: the package version.
+-- @param substring boolean?: match substrings of the name
+-- (default is false, match full name)
+-- @param arch string?: a string with pipe-separated accepted arch values
+-- @param operator string?: operator for version matching (default is "==")
+-- @return table: A query in table format
+function queries.new(name, namespace, version, substring, arch, operator)
+   assert(type(name) == "string")
+   assert(type(namespace) == "string" or not namespace)
+   assert(type(version) == "string" or not version)
+   assert(type(substring) == "boolean" or not substring)
+   assert(type(arch) == "string" or not arch)
+   assert(type(operator) == "string" or not operator)
+
+   operator = operator or "=="
+
+   local self = {
+      name = name,
+      namespace = namespace,
+      constraints = {},
+      substring = substring,
+      arch = arch_to_table(arch),
+   }
+   if version then
+      table.insert(self.constraints, { op = operator, version = vers.parse_version(version)})
+   end
+
+   query_mt.arch[cfg.arch] = true
+   return setmetatable(self, query_mt)
+end
+
+-- Query for all packages
+-- @param arch string (optional)
+function queries.all(arch)
+   assert(type(arch) == "string" or not arch)
+
+   return queries.new("", nil, nil, true, arch)
+end
+
+do
+   local parse_constraints
+   do
+      local parse_constraint
+      do
+         local operators = {
+            ["=="] = "==",
+            ["~="] = "~=",
+            [">"] = ">",
+            ["<"] = "<",
+            [">="] = ">=",
+            ["<="] = "<=",
+            ["~>"] = "~>",
+            -- plus some convenience translations
+            [""] = "==",
+            ["="] = "==",
+            ["!="] = "~="
+         }
+
+         --- Consumes a constraint from a string, converting it to table format.
+         -- For example, a string ">= 1.0, > 2.0" is converted to a table in the
+         -- format {op = ">=", version={1,0}} and the rest, "> 2.0", is returned
+         -- back to the caller.
+         -- @param input string: A list of constraints in string format.
+         -- @return (table, string) or nil: A table representing the same
+         -- constraints and the string with the unused input, or nil if the
+         -- input string is invalid.
+         parse_constraint = function(input)
+            assert(type(input) == "string")
+
+            local no_upgrade, op, version, rest = input:match("^(@?)([<>=~!]*)%s*([%w%.%_%-]+)[%s,]*(.*)")
+            local _op = operators[op]
+            version = vers.parse_version(version)
+            if not _op then
+               return nil, "Encountered bad constraint operator: '"..tostring(op).."' in '"..input.."'"
+            end
+            if not version then
+               return nil, "Could not parse version from constraint: '"..input.."'"
+            end
+            return { op = _op, version = version, no_upgrade = no_upgrade=="@" and true or nil }, rest
+         end
+      end
+
+      --- Convert a list of constraints from string to table format.
+      -- For example, a string ">= 1.0, < 2.0" is converted to a table in the format
+      -- {{op = ">=", version={1,0}}, {op = "<", version={2,0}}}.
+      -- Version tables use a metatable allowing later comparison through
+      -- relational operators.
+      -- @param input string: A list of constraints in string format.
+      -- @return table or nil: A table representing the same constraints,
+      -- or nil if the input string is invalid.
+      parse_constraints = function(input)
+         assert(type(input) == "string")
+
+         local constraints, oinput, constraint = {}, input
+         while #input > 0 do
+            constraint, input = parse_constraint(input)
+            if constraint then
+               table.insert(constraints, constraint)
+            else
+               return nil, "Failed to parse constraint '"..tostring(oinput).."' with error: ".. input
+            end
+         end
+         return constraints
+      end
+   end
+
+   --- Prepare a query in dependency table format.
+   -- @param depstr string: A dependency in string format
+   -- as entered in rockspec files.
+   -- @return table: A query in table format, or nil and an error message in case of errors.
+   function queries.from_dep_string(depstr)
+      assert(type(depstr) == "string")
+
+      local ns_name, rest = depstr:match("^%s*([a-zA-Z0-9%.%-%_]*/?[a-zA-Z0-9][a-zA-Z0-9%.%-%_]*)%s*([^/]*)")
+      if not ns_name then
+         return nil, "failed to extract dependency name from '"..depstr.."'"
+      end
+
+      ns_name = ns_name:lower()
+
+      local constraints, err = parse_constraints(rest)
+      if not constraints then
+         return nil, err
+      end
+
+      local name, namespace = util.split_namespace(ns_name)
+
+      local self = {
+         name = name,
+         namespace = namespace,
+         constraints = constraints,
+      }
+
+      query_mt.arch[cfg.arch] = true
+      return setmetatable(self, query_mt)
+   end
+end
+
+function queries.from_persisted_table(tbl)
+   query_mt.arch[cfg.arch] = true
+   return setmetatable(tbl, query_mt)
+end
+
+--- Build a string representation of a query package name.
+-- Includes namespace, name and version, but not arch or constraints.
+-- @param query table: a query table
+-- @return string: a result such as `my_user/my_rock 1.0` or `my_rock`.
+function query_mt:__tostring()
+   local out = {}
+   if self.namespace then
+      table.insert(out, self.namespace)
+      table.insert(out, "/")
+   end
+   table.insert(out, self.name)
+
+   if #self.constraints > 0 then
+      local pretty = {}
+      for _, c in ipairs(self.constraints) do
+         local v = c.version.string
+         if c.op == "==" then
+            table.insert(pretty, v)
+         else
+            table.insert(pretty, c.op .. " " .. v)
+         end
+      end
+      table.insert(out, " ")
+      table.insert(out, table.concat(pretty, ", "))
+   end
+
+   return table.concat(out)
+end
+
+return queries