WIP: overhaul the gdt expression implementation - gsl-shell.git - gsl-shell

diff --git a/expr-print.lua b/expr-print.lua
index ca837d57..5d106296 100644
--- a/expr-print.lua
+++ b/expr-print.lua

@@ -1,6 +1,7 @@

local format, concat = string.format, table.concat

-local oper_table = {['+'] = 0, ['-'] = 0, ['*'] = 1, ['/'] = 1, ['^'] = 2, ['%'] = -1}

+-- TODO: this information is duplicated from expr-parser => remove the duplication

+local oper_table = {['+'] = 0, ['-'] = 0, ['*'] = 1, ['/'] = 1, ['^'] = 2, ['='] = 3, ['>'] = 3, ['<'] = 3, ['%'] = -1}

local ex_print

@@ -32,8 +33,8 @@ end

ex_print = function(e)

if type(e) == 'number' then

return e, 3

- elseif e.name then

- local s = e.name

+ elseif type(e) == 'string' then

+ local s = e

if not is_ident_simple(s) then s = format('[%s]', s) end

return s, 3

elseif e.func then

@@ -49,7 +50,8 @@ end

local function schema_print(e)

local ys = exlist_print(e.y)

local xs = exlist_print(e.x)

- return format("%s ~ %s", ys, xs)

+ local cs = exlist_print(e.conds)

+ return format("%s ~ %s : %s", ys, xs, cs)

end

local function eval_operator(op, a, b)

@@ -58,28 +60,31 @@ local function eval_operator(op, a, b)

elseif op == '*' then return a * b

elseif op == '/' then return a / b

elseif op == '^' then return a ^ b

+ elseif op == '=' then return (a == b and 1 or 0)

+ elseif op == '>' then return (a > b and 1 or 0)

+ elseif op == '<' then return (a < b and 1 or 0)

else error('unkown operation: ' .. op) end

end

-local function eval(expr, scope)

+local function eval(expr, scope, scope_state)

if type(expr) == 'number' then

return expr

- elseif expr.name then

- return scope.ident(expr)

+ elseif type(expr) == 'string' then

+ return scope.ident(expr, scope_state)

elseif expr.func then

- local arg_value = eval(expr.arg, scope)

+ local arg_value = eval(expr.arg, scope, scope_state)

if arg_value then

local f = scope.func(expr)

- if not f then error('unknown function: '..expr.func) end

+ if not f then error('unknown function: ' .. expr.func) end

return f(arg_value)

end

else

if #expr == 1 then

- local v = eval(expr[1], scope)

+ local v = eval(expr[1], scope, scope_state)

if v then return -v end

else

- local a = eval(expr[1], scope)

- local b = eval(expr[2], scope)

+ local a = eval(expr[1], scope, scope_state)

+ local b = eval(expr[2], scope, scope_state)

if a and b then

return eval_operator(expr.operator, a, b)

end

@@ -91,8 +96,8 @@ end

local function ref_list_rec(expr, list)

if type(expr) == 'number' then

return

- elseif expr.name then

- list[expr.name] = true

+ elseif type(expr) == 'string' then

+ list[expr] = true

elseif expr.func then

ref_list_rec(expr.arg, list)

else