colorama

flax/chains.py

@@ -178,7 +178,7 @@ def dyadic_link(link, w, x, flat=False):
             if call == None:
                 call = overloads.get("any-any")
             if call == None:
-                raise ValueError
+                error("call: overload not defined")
             return call(x)
     elif not flat_w and link.dw > dw:
         return dyadic_link(link, [w], x)
@@ -369,7 +369,7 @@ def monadic_link(link, x, flat=False):
             if call == None:
                 call = overloads.get("any")
             if call == None:
-                raise ValueError
+                error("call: overload not defined")
             return call(x)
     elif link.dx > dx:
         return monadic_link(link, [x])

flax/error.py

@@ -1,15 +1,16 @@
 # error: holds the error handling things
 import sys
 import flax.common
+from colorama import Fore, Style
 
 
-def error(msg, exit_status=1, prefix="\n'"):
+def error(msg, exit_status=1, prefix="'"):
     """error: errors with msg and optional exit_status"""
-    print(prefix + str(msg), file=sys.stderr)
+    print(Fore.RED + prefix + str(msg) + Style.RESET_ALL, file=sys.stderr)
     exit(exit_status)
 
 
-def debug(msg, prefix='\n"'):
+def debug(msg, prefix='"'):
     """debug: log a debug message to stderr"""
     if flax.common.DEBUG:
-        print(prefix + str(msg), file=sys.stderr)
+        print(Fore.YELLOW + prefix + str(msg) + Style.RESET_ALL, file=sys.stderr)

flax/lexer.py

@@ -3,6 +3,7 @@
 import re
 
 from flax.builtins import *
+from flax.error import error
 from flax.common import TOKEN_TYPE
 
 __all__ = ["TOKEN_TYPE", "tokenise"]
@@ -74,7 +75,7 @@ def tokenise(program):
             elif digraph in quicks:
                 tokens.append([TOKEN_TYPE.QUICK, digraph])
             else:
-                raise NameError("Digraph not defined.")
+                error(f'syn: non-existent diagraph "{diagraph}"')
         elif head == LIST_DELIMETER_L:
             contents = ""
             k = 1

flax/parser.py

@@ -118,7 +118,7 @@ def parse(tokens):
                         if stack == [] and chains == []:
                             if token[1] in "ⁿ":
                                 break
-                            error(f'not enough links to pop for "{token[1]}"')
+                            error(f'syn: not enough links for "{token[1]}"')
                         popped.insert(0, (stack or chains).pop())
                     stack += quicks[token[1]].qlink(popped, trains, index)
             chains.append(create_chain(stack, arity, is_forward))

pyproject.toml

@@ -12,6 +12,7 @@ flax = "flax.main:main"
 python = ">=3.9"
 mpmath = "*"
 more_itertools = "*"
+colorama = "*"
 
 [tool.poetry.dev-dependencies]
 pytest = "*"