Updating to version 2.4.4.3, with new syntax for multi-statement 'if'

and switch statements.

10 files changed, 112 insertions, 108 deletions

diff --git a/core/collections.nom b/core/collections.nom
index 45ca74c..428ed4d 100644
--- a/core/collections.nom
+++ b/core/collections.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains code that supports manipulating and using collections like lists
     and dictionaries.
diff --git a/core/control_flow.nom b/core/control_flow.nom
index b3f0978..5719d72 100644
--- a/core/control_flow.nom
+++ b/core/control_flow.nom
@@ -154,7 +154,7 @@ compile [..]
 ..to:
     
     # This uses Lua's approach of only allowing loop-scoped variables in a loop
-    assume (%var.type is "Var") or barf "Loop expected variable, not: \%var"
+    unless (%var.type is "Var"): compile error at %var.source "Loop expected variable, not: %s"
     %lua = (..)
         Lua ".."
             for \(%var as lua expr)=\(%start as lua expr),\(%stop as lua expr),\(%step as lua expr) do
@@ -185,12 +185,11 @@ compile [..]
 parse [for %var in %start to %stop %body] as (..)
     for %var in %start to %stop via 1 %body
 
-
 # For-each loop (lua's "ipairs()")
 compile [for %var in %iterable %body] to:
     
     # This uses Lua's approach of only allowing loop-scoped variables in a loop
-    assume (%var.type is "Var") or barf "Loop expected variable, not: \%var"
+    unless (%var.type is "Var"): compile error at %var.source "Loop expected variable, not: %s"
     %lua = (..)
         Lua ".."
             for i,\(%var as lua identifier) in ipairs(\(%iterable as lua expr)) do
@@ -223,8 +222,8 @@ compile [for %key = %value in %iterable %body, for %key %value in %iterable %bod
 ..to:
     
     # This uses Lua's approach of only allowing loop-scoped variables in a loop
-    assume (%key.type is "Var") or barf "Loop expected variable, not: \%key"
-    assume (%value.type is "Var") or barf "Loop expected variable, not: \%value"
+    unless (%key.type is "Var"): compile error at %key.source "Loop expected variable, not: %s"
+    unless (%value.type is "Var"): compile error at %value.source "Loop expected variable, not: %s"
     %lua = (..)
         Lua ".."
             for \(%key as lua identifier),\(%value as lua identifier) in pairs(\(%iterable as lua expr)) do
@@ -266,101 +265,88 @@ compile [for %key = %value in %iterable %body, for %key %value in %iterable %bod
 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-# Switch statement/multi-branch if
-compile [when %body] to:
+# Multi-branch conditional (if..elseif..else)
+compile [if %body, when %body] to:
     %code = (Lua "")
-    %fallthroughs = []
-    %is_first = (yes)
-    %seen_else = (no)
-    %branches = (%body if (%body.type == "Block") else [%body])
-    for %func_call in %branches:
-        assume (%func_call.type is "Action") or barf "Invalid format for 'when' statement. Only '*' blocks are allowed."
-        with {%star: %func_call.1, %condition: %func_call.2, %action: %func_call.3}:
-            assume (%star == "*") or barf "Invalid format for 'when' statement. Lines must begin with '*'"
-            assume %condition or barf ".."
-                Invalid format for 'when' statement. Lines must begin with '*' and have a condition \
-                ..or the word "else"
-            
-            if (%action is (nil)):
-                lua> "table.insert(\%fallthroughs, \(%condition as lua expr))"
-                do next %func_call
-            
-            if (%condition == "else"):
-                assume (not %is_first) or barf "'else' clause cannot be first in 'when % = ?' block"
-                to %code write "\nelse\n    "
-                to %code write (%action as lua statements)
-                %seen_else = (yes)
-            ..else:
-                assume (not %seen_else) or barf "'else' clause needs to be last in 'when' block"
-                lua> "table.insert(\%fallthroughs, \(%condition as lua expr))"
-                to %code write "\("if" if %is_first else "\nelseif") "
-                for %i = %condition in %fallthroughs:
-                    if (%i > 1): to %code write " or "
-                    to %code write %condition
-                
-                to %code write " then\n    "
-                to %code write (%action as lua statements)
-            
-            %fallthroughs = []
-            %is_first = (no)
+    %clause = "if"
+    %else_allowed = (yes)
+    unless (%body.type is "Block"): compile error at %body.source "'if' expected a Block, but got: %s"
+    for %line in %body:
+        unless (..)
+            ((%line.type is "Action") and ((length of %line) >= 2))
+            ..and (%line.(length of %line) is "Block" syntax tree)
+        ..:
+            compile error at %line.source ".."
+                Invalid line for 'if', each line should contain conditional expressions \
+                ..followed by a block, or "else" followed by a block:
+                %s
+        %action = %line.(length of %line)
+        if ((%line.1 is "else") and ((length of %line) == 2)):
+            unless %else_allowed: compile error at %line.source "Can't have two 'else' blocks"
+            unless ((length of "\%code") > 0):
+                compile error at %line.source "Can't have an 'else' block without a preceeding condition"
+            to %code write "\nelse\n    \(%action as lua statements)"
+            %else_allowed = (no)
+        ..else:
+            to %code write "\%clause "
+            for %i in 1 to ((length of %line) - 1):
+                unless (%line.%i is syntax tree):
+                    compile error at %line.source ".."
+                        Invalid condition for 'if' statement:
+                        %s
+                if (%i > 1): to %code write " or "
+                to %code write (%line.%i as lua expr)
+            to %code write " then\n    \(%action as lua statements)"
+            %clause = "\nelseif"
     
-    assume (%fallthroughs == []) or barf "Unfinished fallthrough conditions in 'when' block"
-    assume ((length of "\%code") > 0) or barf "Empty body for 'when' block"
+    if ((length of "\%code") == 0):
+        compile error at %body.source "'if' block has an empty body"
     to %code write "\nend --when"
     return %code
 
-
 # Switch statement
-compile [when %branch_value = ? %body, when %branch_value is? %body] to:
+compile [if %branch_value is %body, when %branch_value is %body] to:
     %code = (Lua "")
-    %fallthroughs = []
-    %is_first = (yes)
-    %seen_else = (no)
-    %branches = (%body if (%body.type == "Block") else [%body])
-    for %func_call in %branches:
-        assume (%func_call.type is "Action") or barf "Invalid format for 'when' statement. Only '*' blocks are allowed."
-        with {%star: %func_call.1, %condition: %func_call.2, %action: %func_call.3}:
-            assume (%star == "*") or barf "Invalid format for 'when' statement. Lines must begin with '*'"
-            assume %condition or barf ".."
-                Invalid format for 'when' statement. Lines must begin with '*' and have a condition \
-                ..or the word "else"
-            
-            if (%action is (nil)):
-                lua> "table.insert(\%fallthroughs, \(%condition as lua expr))"
-                do next %func_call
-            
-            if (%condition == "else"):
-                assume (not %is_first) or barf "'else' clause cannot be first in 'when % = ?' block"
-                to %code write "\nelse\n    "
-                to %code write (%action as lua statements)
-            ..else:
-                assume (not %seen_else) or barf "'else' clause needs to be last in 'when % = ?' block"
-                to %code write "\("if" if %is_first else "\nelseif") "
-                lua> "table.insert(\%fallthroughs, \(%condition as lua expr))"
-                for %i = % in %fallthroughs:
-                    if (%i > 1): to %code write " or "
-                    if ((%.type is "Text") or (%.type is "Number")):
-                        to %code write "branch_value == \%"
-                    ..else: to %code write "utils.equivalent(branch_value, \%)"
-                
-                to %code write "then\n    "
-                to %code write (%action as lua statements)
-        
-        %fallthroughs = []
-        %is_first = (no)
+    %clause = "if"
+    %else_allowed = (yes)
+    unless (%body.type is "Block"): compile error at %body.source "'if' expected a Block, but got: %s"
+    for %line in %body:
+        unless (..)
+            ((%line.type is "Action") and ((length of %line) >= 2))
+            ..and (%line.(length of %line) is "Block" syntax tree)
+        ..:
+            compile error at %line.source ".."
+                Invalid line for 'if % is % %', each line should contain expressions \
+                ..followed by a block, or "else" followed by a block:
+                %s
+        %action = %line.(length of %line)
+        if ((%line.1 is "else") and ((length of %line) == 2)):
+            unless %else_allowed: compile error at %line.source "Can't have two 'else' blocks"
+            unless ((length of "\%code") > 0):
+                compile error at %line.source "Can't have an 'else' block without a preceeding condition"
+            to %code write "\nelse\n    \(%action as lua statements)"
+            %else_allowed = (no)
+        ..else:
+            to %code write "\%clause "
+            for %i in 1 to ((length of %line) - 1):
+                unless (%line.%i is syntax tree):
+                    compile error at %line.source ".."
+                        Invalid condition for 'if' statement:
+                        %s
+                if (%i > 1): to %code write " or "
+                to %code write "branch_value == \(%line.%i as lua expr)"
+            to %code write " then\n    \(%action as lua statements)"
+            %clause = "\nelseif"
     
-    assume (%fallthroughs == []) or barf "Unfinished fallthrough conditions in 'when' block"
-    assume ((length of "\%code") > 0) or barf "No body for 'when % = ?' block!"
-    to %code write "\nend"
-    %code = (..)
+    if ((length of "\%code") == 0):
+        compile error at %body.source "'if % is % %' block has an empty body"
+    to %code write "\nend --when"
+    return (..)
         Lua ".."
-            do --when % = ?
+            do --if % is
                 local branch_value = \(%branch_value as lua expr)
                 \%code
-            end --when % = ?
-    
-    return %code
-
+            end --if % is
 
 # Do/finally
 compile [do %action] to (..)
diff --git a/core/coroutines.nom b/core/coroutines.nom
index 54889d4..bff115d 100644
--- a/core/coroutines.nom
+++ b/core/coroutines.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file defines the code that creates and manipulates coroutines
 
diff --git a/core/errors.nom b/core/errors.nom
index efa69a8..5dfed1e 100644
--- a/core/errors.nom
+++ b/core/errors.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains basic error reporting code
 
@@ -7,6 +7,9 @@ compile [traceback] to (Lua value "debug.traceback()")
 compile [traceback %] to (Lua value "debug.traceback('', \(% as lua expr))")
 compile [barf] to (Lua "error(nil, 0);")
 compile [barf %msg] to (Lua "error(\(%msg as lua expr), 0);")
+compile [compile error at %source %msg] to (..)
+    Lua "nomsu:compile_error(\(%source as lua expr), \(%msg as lua expr))"
+
 compile [assume %condition] to:
     lua> ".."
         local \%assumption = 'Assumption failed: '..tostring(nomsu:tree_to_nomsu(\%condition))
diff --git a/core/io.nom b/core/io.nom
index 2659b3b..b06ebb3 100644
--- a/core/io.nom
+++ b/core/io.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains basic input/output code
 
diff --git a/core/math.nom b/core/math.nom
index d8952f6..e0c58a3 100644
--- a/core/math.nom
+++ b/core/math.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file defines some common math literals and functions
 
diff --git a/core/metaprogramming.nom b/core/metaprogramming.nom
index 8328d26..028a914 100644
--- a/core/metaprogramming.nom
+++ b/core/metaprogramming.nom
@@ -1,9 +1,9 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This File contains actions for making actions and compile-time actions and some helper
     functions to make that easier.
 
-lua> "NOMSU_CORE_VERSION = 3"
+lua> "NOMSU_CORE_VERSION = 4"
 lua> ".."
     nomsu.COMPILE_ACTIONS["% -> %"] = function(nomsu, tree, \%args, \%body)
         local lua = LuaCode.Value(tree.source, "function(")
@@ -119,8 +119,16 @@ compile [parse %actions as %body] to (..)
         local ret = \(compile as (compile %actions to %new_body))
         return ret
 
-compile [%tree as lua expr] to (..)
-    Lua value "nomsu:compile(\(=lua "nomsu:compile(\%tree):as_expr()")):as_expr()"
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+action [%tree as lua expr]:
+    lua> ".."
+        \%tree_lua = nomsu:compile(\%tree)
+        if not \%tree_lua.is_value then
+            nomsu:compile_error(\%tree.source, "Could not convert %s to a Lua expression",
+                nomsu:tree_to_nomsu(\%tree))
+        end
+        return \%tree_lua
 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/core/operators.nom b/core/operators.nom
index 70b0207..bce91c4 100644
--- a/core/operators.nom
+++ b/core/operators.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains definitions of operators like "+" and "and".
 
@@ -147,21 +147,29 @@ compile [%x wrapped around %y, %x mod %y] to (..)
 # (uses a lambda to avoid re-evaluating middle value, while still being an expression)
 parse [%x < %y < %z] as (..)
     =lua "(function(x,y,z) return x <  y and y <  z; end)(\%x,\%y,\%z)"
+
 parse [%x <= %y < %z] as (..)
     =lua "(function(x,y,z) return x <= y and y <  z; end)(\%x,\%y,\%z)"
+
 parse [%x < %y <= %z] as (..)
     =lua "(function(x,y,z) return x <  y and y <= z; end)(\%x,\%y,\%z)"
+
 parse [%x <= %y <= %z] as (..)
     =lua "(function(x,y,z) return x <= y and y <= z; end)(\%x,\%y,\%z)"
+
 parse [%x > %y > %z] as (..)
     =lua "(function(x,y,z) return x >  y and y >  z; end)(\%x,\%y,\%z)"
+
 parse [%x >= %y > %z] as (..)
     =lua "(function(x,y,z) return x >= y and y >  z; end)(\%x,\%y,\%z)"
+
 parse [%x > %y >= %z] as (..)
     =lua "(function(x,y,z) return x >  y and y >= z; end)(\%x,\%y,\%z)"
+
 parse [%x >= %y >= %z] as (..)
     =lua "(function(x,y,z) return x >= y and y >= z; end)(\%x,\%y,\%z)"
 
+
 # TODO: optimize for common case where x,y,z are all either variables or number literals
 # Boolean Operators
 compile [%x and %y] to (Lua value "(\(%x as lua expr) and \(%y as lua expr))")
@@ -204,4 +212,4 @@ parse [%var /= %] as (%var = (%var / %))
 parse [%var ^= %] as (%var = (%var ^ %))
 parse [%var and= %] as (%var = (%var and %))
 parse [%var or= %] as (%var = (%var or %))
-parse [wrap %var around %] as (%var = (%var wrapped around %))
+parse [wrap %var around %] as (%var = (%var wrapped around %))
\ No newline at end of file
diff --git a/core/scopes.nom b/core/scopes.nom
index 2be24e6..30bdea0 100644
--- a/core/scopes.nom
+++ b/core/scopes.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains definitions pertaining to variable scoping
 
@@ -8,17 +8,16 @@ use "core/collections.nom"
 use "core/control_flow.nom"
 compile [with local %locals %body, with local %locals do %body] to:
     %body_lua = (%body as lua statements)
-    when %locals.type = ?:
-        * "Dict":
+    if %locals.type is:
+        "Dict":
             %body_lua = (..)
                 Lua "\(compile as (<- %locals))\n\%body_lua"
             
             declare locals ("\(%.1 as lua)" for % in %locals) in %body_lua
         
-        * "List": declare locals ("\(% as lua)" for % in %locals) in %body_lua
-        * "Var"
-        * "Action": declare locals ["\(%locals as lua)"] in %body_lua
-        *else (barf "Unexpected local: \(%locals as nomsu)")
+        "List": declare locals ("\(% as lua)" for % in %locals) in %body_lua
+        "Var" "Action": declare locals ["\(%locals as lua)"] in %body_lua
+        else: compile error at %locals.source "Unexpected locals: %s"
     
     return (..)
         Lua "do\n    \%body_lua\nend"
\ No newline at end of file
diff --git a/core/text.nom b/core/text.nom
index 62ec056..30eab50 100644
--- a/core/text.nom
+++ b/core/text.nom
@@ -1,4 +1,4 @@
-#!/usr/bin/env nomsu -V2.3.4.3
+#!/usr/bin/env nomsu -V2.4.4.3
 #
     This file contains some definitions of text escape sequences, including ANSI console
     color codes.