gsl-shell.git - gsl-shell

diff --git a/expr-actions.lua b/expr-actions.lua
index 8ba169a1..3e82cf1c 100644
--- a/expr-actions.lua
+++ b/expr-actions.lua

@@ -29,6 +29,10 @@ end

local function ident_action(id) return id end

+local function literal_action(name)

+ return {literal= name}

+end

+

-- return true iff expr is a variable (with enums or not).

-- if it is a variable returns, in addition, the var_name and the enumeration flag

local function is_variable(expr)

@@ -47,6 +51,7 @@ end

return {

infix = infix_action,

ident = ident_action,

+ literal = literal_action,

prefix = prefix_action,

enum = enum_action,

func_eval = func_eval_action,

diff --git a/expr-lexer.lua b/expr-lexer.lua
index c075d8a5..c13b1c38 100644
--- a/expr-lexer.lua
+++ b/expr-lexer.lua

@@ -52,6 +52,10 @@ function expr_lexer.next_token(lexer)

lexer:skip('%s*')

if lexer.n > len(lexer.src) then return {type= 'EOF'} end

local c = lexer:char()

+ if c == '\'' then

+ local str = lexer:consume("'[^']+'")

+ return {type= 'literal', value = str:sub(2, -2)}

+ end

if c == '[' then

local str = lexer:consume('%b[]')

return {type= 'ident', value= str:sub(2,-2)}

diff --git a/expr-parse.lua b/expr-parse.lua
index 85e770e9..a8e72481 100644
--- a/expr-parse.lua
+++ b/expr-parse.lua

@@ -28,6 +28,10 @@ local function factor(lexer, actions)

else

return actions.ident(id)

end

+ elseif token.type == 'literal' then

+ local x = token.value

+ lexer:next()

+ return actions.literal(x)

elseif token.type == 'number' then

local x = token.value

lexer:next()

diff --git a/expr-print.lua b/expr-print.lua
index ebbc6518..4c73f44d 100644
--- a/expr-print.lua
+++ b/expr-print.lua

@@ -38,6 +38,8 @@ ex_print = function(e)

local s = e

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

return s, 3

+ elseif e.literal then

+ return format('%q', e.literal)

elseif e.func then

local arg_str = ex_print(e.arg)

return format('%s(%s)', e.func, arg_str), 3

@@ -72,6 +74,8 @@ local function eval(expr, scope, ...)

return expr

elseif type(expr) == 'string' then

return scope.ident(expr, ...)

+ elseif expr.literal then

+ return expr.literal

elseif expr.func then

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

if arg_value then

@@ -99,6 +103,8 @@ local function ref_list_rec(expr, list)

return

elseif type(expr) == 'string' then

list[expr] = true

+ elseif expr.literal then

+ return

elseif expr.func then

ref_list_rec(expr.arg, list)

else